Bernd Weiss, Primetals Technologies Austria, Austria

Co-Author:
Hermann Völkl, Primetals Technologies Austria
Robert Millner, Primetals Technologies Austria

Abstract:
Steel industry is responsible for about 8% of worldwide CO2 emissions and faces significant challenges to meet defined climate targets for the upcoming years. Recently the evaluation of transition solutions for state-of-the-art steel making process routes and finally carbon neutral steel production are the focus of investigations of steel producers. Massive changes in production routes are required to achieve a carbon net-tero steel production. The metallurgical model library “m.simtop” developed by Primetals enables the implementation of digital twins for any production scenario and enhances all kind of evaluations. The digital twins are fully based on chemical and metallurgical first principle modelling and capable of precisely depicting all kinds of integrated and alternative steel production routes. Utilizing this powerful platform, Primetals implemented a study on numerous process routes covering different technologies. In this work a selection of a comparison of state-of-the-art direct reduction steel making routes including variations thereof and also for emerging technologies is provided. Production routes covered are Midrex natural gas and hydrogen based as well as new processes such as Hyfor and HyREX. A comparison of consumption figures, OPEX as well as CO2 emissions will be discussed.

Mo Ahmed, Schneider Electric USA, United States

Co-Author:
Ling Dou, Schneider Electric
Rajesh Sharma, Schneider Electric

Abstract:
The steel industry has embarked on a decarbonization journey to address significant carbon footprint, with hydrogen a key abatement lever for decarbonization, steelmakers are facing challenges to scale hydrogen production at attractive cost, including sourcing of sufficient renewable energy. Scaling green hydrogen production to giga-watt scale requires intense efforts in terms of analysis around electrical designs, electrolyser selection and optimization across the complete value chain. Technologies like digital twins which help in analysis of hybrid electrical networks and the process needs are helping engineering companies to design the green hydrogen production facilities which are fit for purpose and scalable. Similarly, automation with integrated architecture helps in managing the complete production cycle from choosing the cheapest energy source to management of intermittency of power generation and associated downstream continuous process. Digital twins developed during design phase support efficiency improvement during operate and maintain phase supporting energy optimization and reduced unscheduled downtime. We will discuss how during different phases of the project, such digital solutions help de-risk the projects, improve performance and reduce overall cost.

Elena Jipnang, SMS group, Germany

Co-Author:
Atsushi Sugiyama, Midrex Technologies, Inc.
Leander Reuter, SMS group
Tim Kleier, SMS group
Brett Belford, SMS group

Abstract:
In view of the global climate emergency, the iron and steel industry bears a special responsibility. Around 30% of global industrial CO2 emissions are generated in the steelmaking value chain. Since there are several alternative ways to reduce CO2 emissions, which perform differently depending on factors like energy infrastructure and raw material availability and prices, an individual transition roadmap to less carbon-intensive steelmaking must be analyzed for each steel mill. The overall process simulation and subsequent analysis help to make the right decision between different green steel production route options. This paper focuses on a steady-state flowsheet simulation in HSC, which was defined and performed using a case study to illustrate how the simulations can be effectively applied to design and optimize the steel value chain in a DRP-OBF-BOF-EAF configuration. This thermochemical process simulation enables process designers and plant operators to rapidly determine the impacts on CO2 footprint and OPEX due to variations in pellet quality, fuels, point of raw material addition and distribution of the products within the flowsheet. It is further demonstrated how scrap and waste circularity within the process can be optimized to balance OPEX and CO2 impacts.

Paul Uhl-Hädicke, Fesios GmbH, Austria

Co-Author:
Matthias Stöckl, Fesios GmbH
Andreas Schneider, AG der Dillinger Hüttenwerke

Abstract:
Like many other steel producers in Europe and around the world, Stahl-Holding-Saar (SHS) has developed a master plan to significantly reduce CO2 emissions within the next decades. For the production site in Dillingen, a transition to a DRI-EAF production route shows the most promising effects, which means turning away from the traditional BF-BOF production route. Within the melt shop, two potential locations for the EAFs were identified to undergo a detailed investigation and comparison. Since the two locations are at very different ends of the melt shop, the new transport routes and logistics of ladles will undergo a large change and be very different to the original routes and logistics. A 3D production and logistics simulation of the entire melt shop was developed to quantitatively compare these layout alternatives, to iteratively optimize these concepts, and to reduce logistical bottlenecks and deficiencies. The two final layout concepts have been compared and rated according to the terms of productivity and logistics. With the final simulation results, it was clear that one EAF position is logistically favorable, as it allows higher productivity and flexibility within the melt shop. Finally, the results of this study have been used to deliver quantitative answers to assist in a qualified decision-making process with the objective of de-risking and verifying the future production concept.

Behnaz Rahmatmand, University of Newcastle, Australia

Co-Author:
Nicholas Ong, University of Newcastle
Kim Hockings, BHP Group
Salman Khoshk Rish, University of Newcastle

Abstract:
The reduction of CO2 emissions from blast furnace operations has received much attention in recent years. The introduction of hydrogen into the furnace is considered a promising solution for reducing the carbon intensity of blast furnace ironmaking. Although the substitution of pulverized coal and coke with hydrogen reduces the overall fuel rate, this can alter the thermal and chemical state inside the furnace, which in turn influences the reaction rate and the degradation mechanism of coke. This study investigates the impact of hydrogen injection and coke quality on coke gasification reactivity and kinetics. A high temperature thermogravimetric analyzer was used to study the CO2 and H2O gasification behaviour of coke lumps with CSR of 43.11 and 68.32 in the temperature range of 900-1200 °C. Three kinetic models, i.e., volumetric, random pore, and shrinking core, were used to explain the gasification behaviour. The shrinking core model was found to better fit the experimental data and was thus applied to calculate the gasification rate and to determine the reaction controlling mechanism. Coke reaction rates with H2O were up to 8 and 5 times greater than CO2 for low and high CSR cokes, respectively. Coke reactivity with H2O in the entire temperature range was found to be controlled by the interfacial reaction, while the reactivity with CO2 was controlled by both interfacial and diffusion which depended on the reaction temperature. The activation energy of coke gasification with H2O was up to 65% lower than that of CO2. However, this decrease was less pronounced for the high CSR coke, suggesting that a higher quality coke is required to mitigate the fast degradation of coke during reaction with steam.

Konstantin Weißhaar, AG der Dillinger Hüttenwerke, Germany

Abstract:
Since the coal market is very volatile and fast-moving, not only since the beginning of the energy crisis, rapid testing of alternatives for the coal blend of the Zentralkokerei Saar (ZKS) is indispensable. In this context, the most important tasks of a coke oven pilot facility are to investigate the effect of a test coal on the coke quality and the resulting wall pressure during the carbonisation. The latter parameter is of particular importance for the ZKS, as it is a coking plant using stamp charging operation with correspondingly increased wall pressures. For these reasons, the new ZKS coke oven pilot plant was built nearby the coke oven batteries in 2019. The optimization of the operating parameters took more time as expected. Especially the adjustment of the required coal cake density with a good homogeneity and the wall pressure measurement caused problems. By systematic modifications of the stamping program and the stamping machine, a satisfying density of 1020 - 1030 kg/m3 (dry) and homogeneity could be achieved. The homogeneity of the coal cake was investigated and quantified by core drilling and measurement of the individual layers. During the adjustment of the wall pressure measurement, a strong dependence on the ambient temperature was noticed, which initially amounted to almost 1 kN per °C temperature change. Through structural and procedural adjustments (stiffening of the mounting of the load cell, heating of oven walls, insulation of the wall pressure measurement), the temperature dependence could be reduced to 0.2 - 0.3 kN/°C. Nevertheless, the wall pressure results of the coking tests have to be corrected by a temperature correction function to minimize the error due to the temperature dependence.

Marc Schulten, thyssenkrupp Steel Europe AG, Germany

Co-Author:
Viktor Stiskala, thyssenkrupp Steel Europe AG
Alexander Sury, HUTNI PROJEKT Frydek-Mistek a.s.

Abstract:
thyssenkrupp Steel Europe successfully commissioned their pilot oven laboratory employing both a 10-kg carbonization retort and a 60-kg movable wall oven between the years 2014 and 2016. The installed facilities produce and deliver important timely information to coke plant operators who can profit from captive analysis results of internal gas pressure, wall pressure, and coke qualities obtained from actual coal blends and individual coals. Sufficient shrinkage of the coal charge in coke ovens is one of the most essential process conditions to ensure smooth oven pushing performance. As indirect findings on coal shrinkage behavior could only be derived from the results of the two pilot ovens, other considerations were reviewed. In view of the constantly changing conditions in the coal market coupled with the gradual ageing of coke ovens facing an elevated risk of refractory wear due to insufficient coal charge contraction control, the company decided to take another step towards securing their operational safety, prolonging the lifetime of the assets, and saving substantial resources in the maintenance budget. thyssenkrupp Steel Europe launched another major project in 2018 aiming at installing the sole heated oven as the only standardized tool for assessing coal shrinkage behavior when employing an internationally recognized test method. The company Hutni Projekt Frydek-Mistek was selected as the main contractor utilizing their long term experience with similar test facility installations, thus extending their previous successful co-operation with thyssenkrupp Steel Europe in the designing and commissioning of the 60-kg movable wall oven. The sole heated oven was put into operation in 2019. The objective of this paper is to outline the steps taken towards the successful commissioning and the resulting technical support to thyssenkrupp Steel Europe’s coke plant in Schwelgern.

Lorenzo Engel Fornasari, Ternium, Brazil

Co-Author:
Roberto Gerardo Bruna, Ternium
Camila Gisele Lalli, Ternium
Maite Ochoa, Ternium
Bruno Pinheiro da Silva, Ternium
Andres Aused, Ternium

Abstract:
Being able to accurately predict metallurgical coke properties for different parent coal blends is an important part of optimizing an integrated steelmaking plant production costs and ensuring blast furnace process safety. However, it is challenging to balance the economic pressures to use different coals and different blend compositions, the need for minimal product quality and the complexities of the coke-making process. The present work aims to construct coke quality models based on traditional analyses of constituent coals and some process parameters to enable better prediction for a wide range of blend characteristics. To this end, historical production data for process parameters and qualities of coke, coal and petcoke documented in a by-product coking plant were collected and processed using data mining and machine learning techniques. Attempts were made to model coke strength after reaction (CSR), stability and hardness indices by combining domain knowledge with feature engineering, feature selection algorithms and proposing three different models for each quality index - multiple linear regression, gradient boosted decision trees with XGBoost and gradient boosted linear trees with Light GBM. Cold strength models, especially those created using gradient boosting techniques, attained reasonable predictive ability. It is concluded that despite the inaccuracies surrounding industrial data collection, data mining and machine learning techniques provide a viable and promising framework for coke quality modeling in mature and well-documented processes.

Edward Bissaker, University of Newcastle, Australia

Co-Author:
Arash Tamesabi, University of Newcastle
David Jenkins, University of Newcastle
Merrick Mahoney , University of Newcastle
Bishnu Lamichhane , University of Newcastle

Abstract:
Metallurgical coke microstructure is highly variable and consists of features at a wide range of length scales. Understanding coke microstructure using 3D micro-CT analysis is a valuable tool for producing coke that meets the requirements of future steel-making technologies. The two-point correlation and lineal path functions are microstructure descriptors that can be used to distinguish between microstructure formations. We present a scalable, histogram-free parallel method to efficiently compute the angularly resolved two-point correlation and lineal path functions for large 3D coke microstructure images. We compute coke feature length scales and representative volume elements for coke microstructure and provide a quantitative framework for investigating optimal microstructures corresponding to coke strength.

Rolf Lamm, Minteq International GmbH, Germany

Abstract:
Continuous changes in the economic environment and the increasing number of EAF plants accompanied by competitive pressure require steel producers to introduce innovative measures to reduce costs, CO2 emissions and improve safety. The paper introduces the latest development of an automatic and continuous refractory maintenance system for the electric arc furnace (EAF), tailored of the requirements of modern steel production at an American steelplant. The automatic system has eliminated the disadvantages and inherent in intermittent refractory maintenance and follows the “No Person on the floor”- Safety-Philosophy. The functionality of the SCANTROL™ 4.0 system (laserscanner driven measurement of refractory thickness, visual representation of scanned results and intelligent material application) has significant enhanced productivity, working conditions and decision-making capabilities of steel operators. The 5th generation Laserscanner technology with more than 10 million measuring points per Scan in a furnace enables wear to be determined with a very high degree of accuracy and, thanks to the high measuring point density, joints and cracks can also be detected. With the help of the measurement data, an intelligent program calculates exactly the critical areas that need to be repaired. Furthermore, the quality and the required quantity of the repair gunning material is proposed. The information thus obtained is used to automatically control a gunning robot for repair of the refractory lining. This machine applies the repair compounds exactly where they are needed in the furnace. The overall effect at the steelplant has included: • Reduction in total refractory consumption • Increased furnace availability by reducing “Power Off” delays. • The ability to effectively maintain all areas of the furnace • Extending the available production period between brick relines • Improved operational safety • Integration of the determined data into an “Industry 4.0” environment

Delphine Rèche, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Christina Minari, Dimasimma Srl
Matteo Chini, Pittini S.p.A.
Denis Azzano, Pittini S.p.A.
Loris Bianco, Pittini S.p.A.
Stephan Lindemann, Salzgitter Flachstahl GmbH
Christian Clees, Multikopter.de
Peter Lundin, Swerim AB
Roberto Piancaldini, Rina Consulting – Centro Sviluppo Materiali S.p.A
Alexander Dunayvitser, VDEh-Betriebsforschungsinstitut GmbH
Kevin Sze, Swerim AB
Antonella Angrisani, Rina Consulting – Centro Sviluppo Materiali S.p.A

Abstract:
Although the use of unmanned vehicles for industrial applications is discussed a lot lately, systems in operation can hardly be found in the steel industry and common knowledge in the plants about the specific capabilities of UVs is poor. The objective of ROBOINSPECT project is to introduce novel robotic inspection systems in the European steel industry. For this purpose, existing technologies based on unmanned vehicles (UVs) are assigned to inspection tasks and technological gaps are closed by further developments. The aims are to reduce downtimes and increase occupational safety. Unmanned aerial (UAV) and ground (UGV) vehicles are developed for semi-autonomous operation during running production in confined and hazardous areas, using custom indoor navigation concepts. Software is provided to accelerate damage analysis of facilities and processes as well as to detect online plant misalignments. In this project, different UV types are used and specifically designed for different types of inspection tasks to cover a wide range of inspection work in the European steel industry. A drone has been developed together with improved software to be able to carry out indoor inspections without using a GPS navigation system. Another use case which is studied in this project is the use of ground vehicle together with a robotic arm equipped with a specific camera system developed for automatic inspection purposes. In addition, for another use case, a video microscope has been developed to analyse dynamic displacements of plants during operation by subpixel amplification (for example during steel rolling application). Intelligent software for image analysis to handle large data streams of visual material generated by the UVs’ sensors are also examined and developed here. To conclude, the (UVs) will help in production to carry out inspection and maintenance tasks in order to ensure highest safety for personal as well as time and money savings.

Arno Haschke, Primetals Technologies Germany, Germany

Co-Author:
Andreas Maierhofer, Primetals Technologies Germany
Sebastian Kündinger, Primetals Technologies Germany

Abstract:
"Over the last few years, several promising products on the market have been offering artificial intelligence or predictive maintenance to overcome the difficulties of monitoring the condition of assets in a plant. The key to creating the methods and analysis, which allow for reliable monitoring, rests in an understanding and knowledge of the process and technology of a production line. Reliable monitoring is accomplished using state-of-the-art methods, e.g., data analytics, for analyzing and creating suitable responses to operating conditions and disturbances. Primetals Technologies has developed a digital assistant that uses the understandings mentioned above to monitor any assets in any plant. Additionally, it can integrate existing monitoring systems, adapt to various data sources, or combine different analysis results to solve more complex monitoring demands in one central system. Besides reliable and automatically monitoring 24/7/365, the new system delivers solution-oriented information, which helps operators make the right decision and act fast in case of an alert. It provides this additional information based on built-in know-how to make anticipating and overcoming potential malfunctions easier."

Florian Hollensteiner, Primetals Technologies Austria, Austria

Co-Author:
Anna Theresa Strasser, Primetals Technologies Austria
Inge Aasheim, Primetals Technologies Austria
Gabriel Lenna Do Nascimento, Primetals Technologies Austria
Klaus Stohl, Primetals Technologies Austria
Michael Weinzinger, Primetals Technologies Austria
Irina Tolkacheva, Primetals Technologies Austria
Moritz Ortner, Primetals Technologies Austria
Georgiy Pervushin, Primetals Technologies Austria
Josef Boehm, Primetals Technologies Austria
Horst Puchner, Primetals Technologies Austria

Abstract:
One of the goals of maintenance management is to maximize the return on investment in assets. This leads to an opportunity that transforms maintenance and repair service from a cost factor, into an activity which influences profitability and leads to a competitive advantage. Metallurgical companies worldwide are using condition monitoring, computerized maintenance management systems solutions or 24/7 remote services. But how to make your maintenance even smarter? Primetals Technologies integrates these processes and methods to add more value to them according to the synergy law: the whole is greater than the sum of the parts. More than that, these methods have been successfully implemented in current steel productions and brought numerous results including unplanned and planned downtime decrease, total cost of ownership reduction and equipment availability growth. An example including achievements of this smarter maintenance management solutions are presented in this paper.

Christian Mengel, SMS group, Germany

Co-Author:
Sebastian Richard, SMS group
Ivars Valdmanis, SMS group
Lars Gillgren, SSAB AB

Abstract:
Digitalization in metallurgical industry is a focus in current development enabling process engineers and maintenance staff to optimize their processes and help solving problems in their daily work. Condition monitoring systems collecting relevant data from the process is aiming at monitoring the health of the main components. SMS groups Genius CM program package is offering several monitoring functions in the field of vibration analysis and mechanical and hydraulic machine parts making use of field units for local data collection and analyzing process data to derive information on the condition of the equipment. Within the rolling equipment of hot strip mills the conditions of the mill stands is of major importance. Bad mechanical conditions can lead to rolling problems e.g. roll positioning issues, thickness errors, cambered strips, tailend cobbles, strip surface defects or unplanned roll changes. New monitoring functions have been developed and applied focusing on the integrity of the mill stand. These are analyzing - the parallelism of the rolls indicating unacceptable wear conditions in the stands - the hysteresis of the roll positioning equipment monitoring the conditions in the force transmission components - and the roll force measurement equipment. Model based calculations and helping functions are targeting at optimal user support to determine the most critical equipment conditions and focus on the relevant steps for maintenance and required service actions. The paper gives a short introduction on the modular Genius CM software package and describes the new developed monitoring functions. Application cases of different hot rolling mills will give an insight of the possibilities for trouble shooting and measures to detect and solve acute problems in daily mill operation.

Matthew Del Gobbo, Hatch Ltd. , Canada

Co-Author:
Tom Plikas, Hatch Ltd.
Claire Velikonya, McMaster University
Jayant Borana, CRB Canada
Iakov Gordon, Hatch Ltd.
Umesh Shah, Hatch Ltd.
Matthew Del Gobbo, Hatch Ltd.

Abstract:
This paper describes the use of first principles-based approaches to predict the performance of existing and developing assets in the ironmaking flowsheet such as, for example, indurating/pelletizing machines and sinter coolers where the interaction between the solids, gas, and heat flows occurs in a recycled, coupled manner. Quantifying this interaction empirically or through field trials can be challenging. Examples are provided where physics-based models have been developed to simulate the operation of an existing unit and have been validated against field data to ensure they are representative of real-world performance. These approaches are useful for assessing how an existing and developing piece of equipment would respond to a proposed change in the process and operation. These changes can include, for example: re-configuring machine and energy flows for increased solids throughput and/or final pellet quality, reducing fuel consumption per ton of production to improve energy efficiency and reduce carbon-footprint, evaluating the impact of alternative feed type on machine performance, identifying and minimizing air ingress or air leakages, evaluating the feasibility of alternative energy sources such as resistive heating, plasma torches or biomass on performance, and improving overall process control strategies. Outputs from such models include mass and energy balances, solid and gas temperature profiles along the bed height and machine length, extent of heterogeneous reactions in the solids (drying, magnetite oxidation, etc.), interzonal gas flow movements, gas pressure drop prediction and impact on mechanical equipment requirements, refractory & furnace temperatures, burner/combustion performance, air ingress/leakage rates, and other technical parameters associated with machine performance affected by the gas dynamics and solids energy flows. These models are particularly useful as a database generator to improve real-time process control of the equipment.

Kaye Tindale, Rio Tinto plc, United Kingdom

Co-Author:
Pedro Gutemberg, Rio Tinto

Abstract:
The prospect of mining the world class iron deposits on the Simandou Range in the SE of Guinea, is becoming a reality as negotiations on the infrastructure progress with the JV partners. Blocks 3 & 4 of the Simandou deposit held by Rio Tinto Simfer – a joint venture between Rio Tinto, China Iron Ore Holdings (a Chinalco-led consortium of Chinese SoEs) and the Government of Guinea – covers two major deposits named Pic de Fon and Ouéléba, striking roughly 7km each, in a north south direction along the Simandou Range. Work is being undertaken to develop a greater understanding of the geology, genesis and mineralisation of the project to assist in the realisation of the resource and maximisation of value. The increasing geological knowledge presented in this paper will provide an understanding of impacts on the chemistry and physical characteristics of the material mined, processed, agglomerated, and smelted. Teamwork involving geologists, miners, chemists and metallurgists has been conducted to help us understand the impact of the geology on downstream processing requirements to meet the diverse future needs of clients i.e. steelmakers. A comprehensive test programme of work has been developed in order to test and prove Simandou ores as suitable feed-stock for both Blast Furnace (BF) and Direct Reduction (DR) processes. This paper presents promising results obtained at lab scale on Ouéléba ore that show acceptable physical and chemical properties in both sintering and pelletizing for both BF and DR routes. The results of laboratory characterisation and basket tests for the DR shaft process on a sample of Ouéléba DR pellet were also positive, and an assessment of DR pellets based on Pic Du Fon ore ongoing.

Matthias Gabriel, Metso Outotec Oy , Germany

Abstract:
Most forecasts for the global steel industry agree that the steel production will grow until 2050 by another 50%. Scrap smelting and the direct reduction route will account for the lions share of the growth, but the absolute amount of steel produced with the blast furnace route will remain almost the same. This shows that iron ore pelletizing will keep its paramount role to deliver high quality feed material for direct reduction shafts and blast furnaces. Amid the transition of the steel industry towards net-zero carbon, the pelletizing technology must also reduce their own carbon footprint and comply at the same time with the increasing quality requirement for the pellets. Metso Outotec as undisputed leader since the invention of pelletizing technology follows with the NextGen Pelletizing the clear vision to strive for the carbon neutral and fully autonomous pellet plants of the future. For the CO2 reduction the focus is lying on a further increase of the energy efficiency and heat recuperation of the induration process, new combustion concepts as well as the replacement of fossil fuels by means of Hydrogen burners or the substitution of solid fuel by biocarbon. Energy efficiency is also improved by the further implementation of new digital solutions. Metso Outotec’s proven advanced process optimizer Optimus is constantly complemented by new modules like the online measurement and control of the green pellet size, the pellet mix plasticity or the quality of the hardened pellets. All this performance improvements have also significant effects on the process stability and flexibility, the plant productivity and the product quality and finally on the operational cost.

Sven Jensen, Dürr Systems AG, Germany

Abstract:
Gas prices in Europe will remain on a high level. Therefore, any gas fired process should be examined in regard to energy efficiency measures. Gas fired ovens are widely used in the steel industry. Very often the temperature of the exhaust gas at the stack is still in the range of 300 °C to 600 °C. The so called high-temperature ORC technology is an ideal tool to make use of that waste heat. Taking the example of an innovative ORC system installed at the site of a German steel mill, the lecture will present the achievements and challenges of two years of operation. In this project, the residual heat of the exhaust gases of a walking beam furnace is transferred in one-step to the ORC working media by using direct evaporation technology. As a consequence of capturing the thermal energy at high temperature levels of around 450 °C, the water-cooled condenser of the ORC system can be operated at an elevated temperature of up to 90 °C. The ORC system provides a two-fold benefit to the Customer. The turbogenerator feeds up to 500 kW electric power to the factory and, thus, reduces the expenses for purchasing power from the grid. Moreover, the ORC system transfers around 2.3 MW of heat to a district heating network. After commissioning in July 2020, the plant has been running several thousand operating hours. The presentation analyzes operating data and compares it to the project targets. Further explanations are given how the ORC system is integrated into the operational regime of the gas-fired walking-beam furnace. Finally, an exemplary economic calculation provides insights to the business case and highlights the benefits of an investment into a high-temperature ORC system as an energy efficiency measure: CO2 reduction, income from electricity produced, income from secondary thermal energy provided.

Björn Glaser, KTH Royal Institute of Technology, Sweden

Co-Author:
Marcus Holmström, KTH Royal Institute of Technology
Herbert Köchner, KTH Royal Institute of Technology/ASENSO
Daniel Sundberg, ScanArc Plasma Technologies AB
Asier Arteaga Ayarza, Sidenor Investigación y Desarrollo
Nora Egido Perez, Sidenor Investigación y Desarrollo
Raffaello Pio Iavagnilio, Politecnico di Bari

Abstract:
Marcus Holmström1, Björn Glaser1, Herbert Köchner2, Daniel Sundberg3, Asier Arteaga4, Nora Egido Perez4, Raffaello Pio Iavagnilio5 1Kungliga Tekniska Högskolan, Department of Materials Science and Engineering, Brinellvägen 23, 10044 Stockholm, Sweden 2ASenSo GmbH, Am Birkengraben 12, 50259 Pulheim, Germany 3ScanArc Plasma Technologies AB 4Sidenor Investigacion y Desarrollo SA 5Politecnico di Bari Keywords: Ladle preheating, plasma heating Preheating of steelmaking ladles is a prerequisite to minimize thermal shock and wear of the refractory and to reduce temperature losses of the liquid steel during tapping and holding times. Standard preheating technology using conventional gas-fired burners is unfavorable regarding thermal efficiency (5-15%), energy consumption and emissions. A novel technique using plasma heating offers a more flexible ladle preheating procedure with a higher thermal efficiency (80-95%) and aiming at reduced gas consumption and emissions. The current RFCS pilot and demonstration project PLASMAPILOT investigates the necessities, technical requirements and opportunities of ladle preheating procedures using plasma by combining measurements, numerical modelling of ladle preheating processes and pilot trials at a plasma heater test rig with a full-scale steelmaking ladle. First results will be presented on assessment of plasma technology with regards to economic and environmental benefits, together with results from plant trials and laboratory investigations on refractory lifetime.

Krzysztof Hornig, ANDRITZ Metals Germany GmbH, Germany

Co-Author:
Vasile Jechiu, ANDRITZ Metals Germany GmbH

Abstract:
Modern humankind will continue to need the products of the metal industry in the future, similar to the products of other key industries. Especially in the field of energy-intensive thermal processes in the steel industry, the high demand for process heat supplied today by the oxidation of fossil fuels is required in terms of process technology. The reversal from fossil fuels is the core task of the transformation towards sustainable thermal process technology. Therefore, traditional energy sources are replaced with CO2-neutral alternatives, i.e., green electrical energy and green hydrogen. On the path to sustainable thermal process technology, however, the following simultaneous efforts are fundamentally important as well: • A further increase in the thermal efficiency of the process while reducing emissions as harmful as NOx or dust emissions. • A reduction in material loss within the production chain. For example, material loss occurs during the heating process due to scale formation. • An optimal interlinking of the individual production steps to increase the production chains' overall efficiency. • All-round use of intelligent, connected, and user-friendly automation systems. These measures have a particularly sustainable effect in modernizations and upgrades, where omitting additional cumulative CO2 emissions due to the reuse of the already produced assemblies improves CO2 balance of the retrofitting effort. In the article, the innovative and practical solutions for heating systems in industrial furnaces for the steel industry are presented with the help of concrete examples. Furthermore, the complexity of the requirements for the industrial heating systems is analyzed. In particular, the latest developments with regenerative burners and hybrid heating systems

dissHEAT- Workshop, Workshop, Germany

Abstract:
9:00 AM Welcome and general dissHEAT-overview Andreas Johnsson 9:25 AM 5 dissHEAT topics presentations: Findings, analysis and outlook Oliver Hatzfeld: Heating and burner technology Filippo Avellino: Modelling and control (level 2) of entire furnaces Nico Schmitz: Sensors and control (level 1), standards, regulations Hugo Uijtdebroeks: Materials in the furnace and product quality Andreas Johnsson, Gustav Häggström: Heat transfer, heat recovery, productivity, economy 10:00 AM Hugo Uijtdebroeks: dissHEAT draft roadmap for future research 10:10 AM Coffee break 10:25 AM 3 guest presentations: current questions in research on industrial heating and outlook Victor Cuervo (ArcelorMittal) topic: tbd Jonas Engdahl (senior expert at SSAB and chairman of the Swedish iron and steelmaking association Jernkontoret´s focus area TO51- Energy and furnace technology) topic: tbd Enrico Malfa (Tenova) topic: tbd 11:25 AM Panel discussion: Panel list: Victor Cuervo, Jonas Engdahl, Enrico Malfa and Thomas Echterhof (IOB, RWTH-Aachen) Topics: future research research gaps in industrial heating

Adnan Husakovic, Primetals Technologies Austria, Austria

Co-Author:
Klaus Grasserbauer, Primetals Technologies Austria
Andreas Melcher, Primetals Technologies Austria
Dietmar Hofer, voestalpine AG
Wolfgang Höfer, voestalpine AG
Anton Tushev, Primetals Technologies Germany
Ali Abbas, Primetals Technologies Austria

Abstract:
Green steel production requires a better knowledge of processes and their optimization. The advances in data science and hardware capabilities within recent decade provided new digitalization methods. Two of the most prominent areas recently discussed in science are computer vision and data-driven process modelling. The scrap consistency and EAF-process model gain additional insights and potentials towards EAF-process stabilization and improvement. Within the scope of this paper, we show the importance of Computer Vision and data-based modelling on two use cases: scrap composition monitoring and EAF-process modelling. It summarizes the benefits for the steel producer.

Matthias Werner, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Martin Hubrich, VDEh-Betriebsforschungsinstitut GmbH
Matthias Kozariszczuk, VDEh-Betriebsforschungsinstitut GmbH

Abstract:
Due to climate change, water shortages are developing worldwide, which amplifies the existing water stress and is now also occurring regionally in European countries. This is accompanied by a change in the water composition, such as the increase in mean conductivity by a factor of 2.5 and in the chloride content by a factor of 7 in the period from 2013 to 2019 in an exemplary surface water body. The effects for the iron and steel industry, in which water is an essential process medium, are an increased demand for freshwater due to earlier reaching of the limit conductivity and an increase in corrosion in the pipe systems due to increased chloride contents. This results in the need for the development of a prognosis tool to predict emerging bottlenecks and the development of suitable methods for tapping alternative water sources to ensure the water supply. In the application case, an integrated iron and steel works consisting of the units blast furnace, hot rolling and cold rolling mill as well as its central waste water treatment plant (CWTP) is considered in more detail. The focus of BFI-work is the desalination of the CWTP effluent using membrane-based capacitive deionization (MCDI). Furthermore, as part of the project work, the digital representation of the entire water management system with more than 20 circuits and a wide variety of water compositions was created in the SIMBA# software environment. This forms the basis for the development of the forecast simulation tool. Based on the results of the sampling and tests, various scenarios relating to the chloride content in the surface water and the effects of returning the treated effluent from the CWTP were examined using simulation technology. Further work focuses on the integration of geodata in the developed simulation model for forecasting water bottlenecks.

Yale Zhang, Hatch Ltd. , Canada

Co-Author:
Sa Ge, Hatch Ltd.
Nooshin Nekoiemehr, Hatch Ltd.

Abstract:
Climate change has quickly become the focal point of both challenges and opportunities for today’s iron and steel industry. The industry-wide focuses have shifted from pursuing mainly economic objectives to balancing with environment-centric KPIs such as GHG emissions, energy and raw material efficiency. Many steel producers are facing great challenges on transitioning towards green steel, including: (1) undertaking serious commitments on carbon emission reduction; (2) responding to stakeholder’s pressure on visibility of product carbon footprint; and (3) developing optimal strategy to deal with the impact of carbon pricing. Among many emerging disruptive technologies of Industry 4.0, digital twins have received a high adoption rate due to the steadily growing maturity of IoT, cloud computing and increased number of successful applications. This paper focuses on how digital twin technology can help in driving and optimizing steel producers’ decarbonization strategy. A novel concept of “Carbon Twin” is proposed from the following three perspectives: Product carbon footprint tracking, to monitor GHG emissions in near real-time and calculate product carbon footprint across entire value chain to create a reliable and transparent GHG emission disclosure to customers and stakeholders. Carbon reduction scenario analysis to conduct what-if analysis to assess the impact of different decarbonization technologies, flowsheet variations, process and operation decisions, raw material selection on GHG emissions reduction, to support decarbonization roadmap development and project implementation priorities. Integrated cost and emissions optimization to introduce carbon taxes and/or green premiums into the integrated steel value chain cost modeling, offering the opportunity to optimize overall profitability by considering process, logistics, and emission constraints, and determine the best strategy to achieve balance between production cost and carbon emissions. Several industrial project examples will be discussed in the present paper to demonstrate significant benefits of carbon twin.

Paula Pomaro, Vetta, Brazil

Co-Author:
Lis Soares, Vetta
Thiago Maia, Vetta

Abstract:
Seeking to meet the environmental agreements and climate conventions, a lot of effort and resources have been made to decarbonize industrial sectors. The steel sector alone is responsible for 7% of global emissions and 5% of emissions in Europe. However, besides the energy crisis, base industries in Europe are facing unfair competition with industries from countries that do not have the same level of ambition in climate matters. Despite the huge challenge, key factors are helping to drive the transition towards carbon-friendly steel products and maybe the most powerful and effective aspect is the change in customer requirements. There is an increasing trend in the steel-consuming industries, such as the automotive industry, of eliminating carbon emissions from their entire value chains and these customers are even willing to pay more for the steel produced under reduced emissions. In order to help steel industries to manage their emissions and create added value by differentiating their products, Vetta®, an SMS group company, has developed a digital solution for the management of emissions. This work presents Viridis Carbon, a digital solution for the management of gaseous and particulate emissions applied to the steel industry, from scopes 1, 2, and 3. The tool is able to issue reports on CO2 and GHG emissions in real time, generating transparency for stakeholders, policymakers, and competent authorities for taxation. It is also capable of tracking the emissions generated by each billet of steel produced, issuing emission certification seals, which makes it possible to differentiate products and increase added value for an increasingly demanding market with environmental commitment.

Andreas Wolff, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Stefano Dettori, Scuola superiore di studi universitari e di perfezionamento Sant'Anna

Abstract:
As a result of strong globalization and rapid scientific progress in almost all subfields relevant to industry, large industrial companies increasingly embrace the advantages accompanying the use of digital twins’ automation, and of analysis and optimization of previous process structures. In addition to these changes, the industry faces challenges such as reducing CO2 emissions, efficiency and optimization processes across the entire value chain driven by global competition, and the minimization of waste products. This is particularly relevant in the steel industry, where the identification of optimal process parameters for complex control models is often a limiting factor for improving efficiency and reducing CO2 emissions. To achieve a carbon-free steel industry and further improve their gas and steam networks and management practices, established approaches need to be reconsidered to reduce CO2 emissions and waste and increase overall efficiency. In this paper, we propose an approach that leverages Machine Learning and the Koopmann approach to improve the accuracy of digital twins. By demonstrating this approach using case studies from recent projects within the Research Fund for Coal and Steel (RFCS).

Emanuel Kashi Thienpont, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Tobias Kleinert, RWTH Aachen University
Elmar Schuster, voestalpine Stahl Donawitz GmbH
Kerstin Walter, DK Recycling und Roheisen GmbH
Thorsten Hauck, VDEh-Betriebsforschungsinstitut GmbH
Stefan Wienströer, thyssenkrupp Steel Europe AG
Ralf Schwalbe, thyssenkrupp Steel Europe AG

Abstract:
Sinter with high and consistent quality, produced with low costs and emissions is very important for iron making. Transport and storage degrade sinter quality, generating fines and segregation effects. Conventional sinter quality monitoring is insufficient as it is slow and expensive. Therefore, short-term fluctuations of sinter quality can only be represented inadequately. It is therefore difficult to draw conclusions about the actual process parameters of sinter production or they are based on empirical experience. Consequently, also a data analysis between sinter quality and its effects on daily blast furnace operation is extremely non-transparent and in need of optimization. In this work, a new approach will be introduced to strengthen the data base that describes the sinter quality in short term periods at two different sinter plants from VASD and DK. New on-line measurements will be established, combined, and analysed with Big Data technologies and should allow short term conclusions of the produced sinter. Based on this comprehensive data compilation, Machine Learning (ML) algorithms are trained to predict sinter quality indices. In this paper, the development of the novel measurement systems, the data preparation, feature selection and first results of the predicted indices are presented. This break-through in continuous high resolution quality monitoring should help to get continuous quality indices for sinter and will support the combined optimization of sinter plant and blast furnace.

Sudhanshu Kuthe, KTH Royal Institute of Technology, Sweden

Co-Author:
Andrey Karasev, KTH Royal Institute of Technology
Rössler Roman, voestalpine Stahl GmbH
Izaskun Alonso Oña, Sidenor Investigación y Desarrollo
Björn Glaser, KTH Royal Institute of Technology

Abstract:
Considering the advantage of achieving rapid and efficient process control with artificial intelligence (AI), the use of applied data-driven strategies is in demand among today's steelmakers. One important application is the online optimization of material additions during ladle refining. As every steel grade is unique, developing distinctly trained machine learning (ML) models seem significantly demanding. A data-centric ML approach can solve this problem by focusing on what AI systems must learn from unique datasets generated by specific steel grade production. Moreover, such data-driven process models may be simpler to integrate into existing production servers compare to the physics-driven models. In the proposed work, an operator-assisted decision support system (DSS) was developed using applied data-centric ML to optimize calcium additions required for producing ultra-clean low alloyed calcium-treated steels. Real industrial process parameters were collected before and after calcium additions for three steel grades. The collected process data were examined to design a base algorithm by continuously monitoring the characteristics of non-metallic inclusions at various stages of ladle refining. The predictive result obtained using the proposed DSS, and the response obtained from the actual process were compared and verified for each studied steel grade. Special efforts were taken to generate self-adapting output for each produced "heat" of a specific steel grade to avoid any degradation in predictive performance. The optimizer named "ClogCalc" was introduced based on the programming architecture of DSS for utilization and integration inside the industrial environment. Initial attempts were made to deploy this novel optimizer inside the production environment. The authors believe that this proposed approach could support operators in making dynamic decisions to optimize calcium additions. Keywords: Artificial intelligence, Industry 4.0, Online-monitoring, Steelmaking, Machine learning

Emanuele Trucillo, Danieli & C. Officine Meccaniche s.p.a., Italy

Co-Author:
Stefano Pantarotto, Marcegaglia s.p.a.
Claudio Rossi, Marcegaglia s.p.a.
Alessandro Ferraiuolo, Marcegaglia s.p.a
Nobile Matteo, Danieli & C. Officine Meccaniche s.p.a.
Luciano Vignolo, Danieli & C. Officine Meccaniche s.p.a.
Alessandra Primavera, Danieli & C. Officine Meccaniche s.p.a.

Abstract:
Coating Finishing processes, such as Color Coating or galvanizing, require the product to be accurately pickled. The most common method to accomplish this is acid pickling. Danieli has a long history of proposing the Turboflo solution, which allows for acid pickling speeds of up to 400 m/min. A common problem in pickling plants, however, is the scarce level of process automation and the heavy reliance on on-the-spot decision. These decisions not only regard pickling speed, but also the un coiling speed of the input coil and its coiling speed at the output. One of the reasons for this reliance on spur of the moment decisions is the difficulty of pinpointing the actual duration of “dead times” such as welding and cutting phases. Therefore, a set of innovative sensors to characterize scale and quantify overpickling, feeding an MPC control architecture core are presented here, which attempt to optimize the three main “levers” for the process, which are process speed, uncoiling speed and coiling speed, together with other secondary levers such as bath temperature, recirculation speed and fresh acid flow. The architecture is coupled with statistical evaluations of dead times through modern Data Science approaches.

Matthias Schops, Aperam Genk, Belgium

Co-Author:
Emmanuel Placier, AMI Automation
Saul Gonzalez, AMI Automation
Thierry Koeger, AMI Automation
Bastien Soete, APERAM Genk
Matthias Schops, APERAM Genk

Abstract:
The complexity of the stainless-steel production process requires precise control of the electrical and chemical energy input to avoid material or energy losses and deviation from the required bath chemistry. Facing this challenge, an agreement was reached between Aperam Genk and AMI in 2022 to install the SmartFurnace EAF optimization system including the DigitARC PX3 Electrode Regulator and SmartARC for electrical energy optimization, and the Oxygen Module for chemical energy optimization. Aperam Genk in Belgium is a steel plant dedicated to the production of high-quality stainless-steel grades for the worldwide market. The AC Electric Arc Furnace with 120 tons capacity and 80 MVA transformer has also significant chemical energy available for assisting the scrap melting. The SmartFurnace system and the SmartKnB platform recently developed by AMI integrates a wide range of technologies including real-time data acquisition and analytics, dynamic control based on complex process logic, and machine learning models all in the same user-friendly environment. The capabilities to follow the process from the raw material intake, analyzing its characteristics in advance to optimize the melting and final steel composition and continuously evaluating correlations between the process and usage of consumables to find the most favorable operating point are some of the functionalities implemented in this platform. Using the available data from the Aperam Genk process, the AMI system AI algorithms take real-time decisions for the control of the electric power input, and the flow of gas and oxygen given the operation goals and requirements of every heat. After the successful approval of this project, received in November 2022, the next stage in this collaboration is the Slag Module development, optimizing the slag practices using AMI algorithms. Details of the installed system are presented in this paper, as well as the reported results.

Holger Behrens, SMS group, Germany

Co-Author:
Michael Brühl, Salzgitter Flachstahl GmbH
Oliver Meyer, Salzgitter Flachstahl GmbH

Abstract:
Salzgitter Flachstahl GmbH, Germany, successfully commissioned the new Continuous Galvanizing Line (CGL) FV 3 for the production of galvanized high strength steel coils. The new line plays an important role in SZFG’s strategy and secures regional employment. Galvanizing ultra high strength steels pays in on light weight construction and sustainability. We also increase the vertical range of manufacture in our product mix. The line is supplied by SMS group and is located in Salzgitter, Germany. On July 23rd 2022, the first galvanized prime coil was produced. Besides the design and production of the mechanical equipment as well as the complete electrics and automation package, the furnace and process technology was part of the supply scope of SMS group, except the laser welder. Each year, 500,000 tons of galvanized steel strips for automotive structural components, white goods and industrial applications will be produced. Among other sophisticated technologies, the DREVER annealing furnace allows higher annealing temperatures, followed by faster strip cooling and longer dwell times. The configuration of the line as a whole also fulfills the structural as well as technical requirements to implement further innovative material concepts for the future. The new hot dip line can handle higher strength steels and support enhanced formability, and consequently also more complex component geometries. The continuous galvanizing line is equipped with a DUMA-BANDZINK air-knife system that ensure an optimum setting of the coating thickness plus a high surface quality of the zinc coating applied. The strip movement is stabilized additionally by the integrated electro-magnetic strip stabilization system. The main themes for this paper are the current and future product capabilities and the target market. Furthermore, the paper will emphasize the line concept and the process technology.

Marcel Giese, Federal Institute of Materials Research and Testing, Germany

Co-Author:
Volker Wesling, Clausthal University of Technology
Thomas Kannengießer, Federal Institute of Materials Research and Testing
Dirk Schröpfer, Federal Institute of Materials Research and Testing
Kai Treutler, Clausthal University of Technology
Antonia Eissel, Clausthal University of Technology

Abstract:
The targets for reducing CO2 emissions are closely linked to the development of highly efficient and economical steel components in plant, process and power plant technology, which require wear protection coatings tailored to the application and steel material for high combined corrosive, tribological, thermal and mechanical stresses. In addition to increasing demands to replace conventional cobalt alloys with nickel alloys as a result of price and supply risks, there is a growing demand in industry for defined functional surfaces of high quality for these coatings. Milling is a standard process for finish machining. The desired properties of wear resistant alloys imply significant challenges for the milling process due to high tool wear and surface defects. Besides the hardness of the coating materials, especially due to the precipitations, inhomogeneous, anisotropic weld structures of the claddings lead to further deteriorations of milling processes due to unstable milling conditions and process forces. A joint project of BAM and ISAF of TU Clausthal (Fosta P1550/IGF 21959 N) investigates the optimization of these challenging machining conditions by means of alloy modifications of the welding powder for plasma transferred arc cladding, without reducing the wear protection potential and using ultrasonic assisted milling process. In this paper, the influence of the microstructure and precipitation morphology adjusted by means of alloy modification on machining is investigated. The alloy used is a NiCrMoSiFeB alloy (trade name: Colmonoy 56 PTA). Through metallurgical investigations and in-situ measurement of cutting forces and temperatures at the cutting edge during the milling process as well as the subsequent investigation of tool wear and surface integrity, a detailed analysis and correlation between microstructural properties and machinability is feasible. The findings allow recommendations for standards and processing guidelines, enabling safe and economical production of highly stressed steel components with non-critical, cost-reduced materials.

Michel Boyer, John Cockerill, Belgium

Co-Author:
Nauwfel Amimi, ArcelorMittal Liège Jemeppe
Lionel Goiset, john Cockerill
Sergio Pace, Centre de Recherches Métallurgiques
Eric Silberberg, Centre de Recherches Métallurgiques

Abstract:
In 2016, the ArcelorMittal Group became the first steelmaker to industrialize the vacuum deposition technology to galvanize steel strip. Known under the name of "Jet Vapour Deposition (JVD)", this new type of zinc coating technology in which a zinc vapor is continuously deposited onto a steel strip in a vacuum chamber. Compared to Electro-Galvanizing (EG) and Hot-Dip Galvanizing (HDG), the JVD technology allows to apply with high productivity single-side, as well as double-sided coatings with zinc thicknesses that can differentiate from one side of the steel to the other. Circumventing the major constraints of these conventional coating processes, the JVD technology allows for the optimal coating of Advanced High Strength Steels (AHSS). As such, the JVD technology prevents the hydrogen embrittlement identified as a major drawback of the EG process for the coating of AHSS. Additionally, the JVD technology also overcomes the negative influence of steel surface oxidation when using the HDG process for the coating of certain types of AHSS Today, after 6 years of production, the industrialization of the JVD steel coating line is a success. At the end of 2022, the JVD line produced over 800,000 tons of galvanized steel strip. To address all industrial constraints and make the JVD technology a high-speed deposition line exceeding the present limit of 200 m/min set by conventional EG & HDG lines due to physical limitations, numerous developments were necessary. An overview of these developments will be presented during the lecture, as well as the deployment of the JVD technology to other steelmakers worldwide through license agreements proposed by John Cockerill. Keywords Vacuum evaporation, Jet Vapour Deposition, automotive, industry, Zn coating, Advanced High Strength Steels, hydrogen, corrosion protection, environmentally friendly

Paul Trunner, Primetals Technologies Austria, Austria

Co-Author:
Paul Trunner, Primetals Technologies Austria
Julian Glechner, Primetals Technologies Austria

Abstract:
"Transformation of the steel sector is likely to see a large number of new EAF installations in integrated steel works. For these plants requirements in terms of environmental impact are significantly more stringent since plants must stay within the actual environmental performance. Within multiple studies, projects, and investigations Primetals Technologies has developed appropriate solutions to minimize the emissions of these installations in regard of particulate matter, gaseous components, and noise emissions. Typical requirements and challenges of European steel plants will be introduced. High performance off-gas treatment solutions including intelligent sensors as well as control strategies to capture and treat any of these emissions to achieve these requirements will be presented. Besides gaseous or airborne emissions, noise emissions to the surrounding have a major impact on the environmental permitting. Intelligent layout arrangement as well as proper plant operation and noise insulation solutions such as furnace enclosuers or special designed bag filter systems will be introduced based on reference cases. To further reduce carbon footprint and increase energy efficiency of the plant off-gas waste heat recovery is a further element for future proof off-gas treatment systems. Highly efficient waste heat recovery plants with compact layout arrangements for new installations as well as typical waste heat utilization examples are presented. All solutions will be explained on an exemplary reference case of a European steel plant."

Alessandra Negri, Tenova S.p.A., Italy

Abstract:
A. Negri1 1 Tenova S.p.A., Italy Key Words: emission, pollutant, steelmaking, fumes treatment plant, FTP, EAF, electric arc furnace, metallic charge, performance improvement, revamping. Abstract The main goal of fume treatment plants installed after electric arc furnaces have been, till today, to control temperatures, quenching and diluting the primary with the secondary fumes, and to remove dust with electrostatic precipitators or bag filters. Injection of activated carbon in the dust removal equipment often is present as a safety measure for the control of the micro-organics pollutants. Possible future scenarios can require different treatments, to comply on one side with presence of pollutants in the furnace off gas coming with low quality scrap, and on the other side with more stringent environmental requirement referring also to other source of pollution. It is therefore fundamental to identify first which of the above pollutants can be present in the fumes. This depends on the metallic charge melted in the furnace, and on the charging and melting method. Each component may be controlled in different ways: the reactions of oxidation, reduction, absorption and adsorption occur at different conditions, mainly related to a determined temperature window, turbulence and presence of reagents. This underlines the importance of designing a fume treatment plant locating each treatment in the position where it can be performed in the most economical way, e.g. promoting the reactions occurring at correct conditions of temperature and turbulence, avoiding the use of expensive catalyst and reagents as much as possible. In this paper considerations of basic engineering and cost estimation of the implementation of air pollution control known technologies to the electric arc furnace application are carried out.

Cristiano Castagnola, Paul Wurth Italia S.p.A., Italy

Co-Author:
Teresa Annunziata Branca, Scuola superiore di studi universitari e di perfezionamento Sant'Anna
Valentina Colla, Scuola superiore di studi universitari e di perfezionamento Sant'Anna
Alice Petrucciani, Scuola superiore di studi universitari e di perfezionamento Sant'Anna
Antonella Zaccara, Scuola superiore di studi universitari e di perfezionamento Sant'Anna
Ismael Matino, Scuola superiore di studi universitari e di perfezionamento Sant'Anna
Luca Spadoni, Paul Wurth Italia S.p.A.
Lorenzo Micheletti, Paul Wurth Italia S.p.A.

Abstract:
In the framework of European Green Deal, steel companies are facing a deep transformation towards ever more carbon-lean processes. Besides studies focused on direct reduction processes, several research works deal with the decrease of the impact of existing routes, for instance, by decreasing the use of fossil fuels. Effectively, the transition from standard integrated route to a direct reduction-based route requires efforts and time but, considering the climate changes and the environmental issues, it is of extreme importance to reduce urgently the greenhouse gases and hazardous air pollutant emissions. In this way, during the transition, brownfield processes can contribute actively and gradually to the Green Deal. This is the context of this study, which focuses on the investigation and development of a process allowing a further treatment of blast furnace gas for ensuring a reduction of NOx when it is used in hot blast stoves and, in particular, at high temperatures. Pushing hot blast stoves at higher temperatures means obtaining higher temperatures of preheated air to be injected in blast furnaces, decreasing coke demand and, consequently, CO2 emissions. The presented treatment is based on a spray-scrubber whose main aim is the reduction of cyanide compounds in blast furnace gas due to their direct link with NOx emissions. The scrubber also allows chlorides removal by reducing corrosion problems. Auxiliary to the gas washing process, a H2O2-based water treatment was invelstigated to reduce the content of cyanides in the blast furnace gas washing water to allow its recirculation and to make purges suitable for discharges. Different kind of analyses were done to develop the process and prove its effectiveness and potential, including literature and data analyses, development of ad-hoc models for scenario analyses, laboratory tests and optimal design of process and unit operations.

Matteo Tomba, PERT Srl, Italy

Abstract:
The Fume Treatment Plant sizing has to be highly customized. This is a common need both for the iron ore-route production (based on Blast Furnace or Direct Reduced Iron plants) and for the scrap route production (based on the Electric Arc Furnace). The steelmaking equipment characteristics and arrangement, the general site layout, the environmental local regulations and the Best AvailableTechnologies (BAT) for the pollution control have to be taken into account. The final choice implies always the comparison among different solutions regarding the fume capturing, the pollutants abatement devices, the possible energy saving, the cooling equipment and so on. The choices for FTP are also linked to the Water Treatment Plant. Often we are asked to improve the current situation with a revamping activity, where only part the existing plant needs to be modified to meet the increased production requirements or the more stringent environmental limits.

Oday Daghagheleh, Montanuniversität Leoben , Austria

Co-Author:
Johannes Schenk, Montanuniversität Leoben, K1-Met GmbH
Michael Zarl, K1-MET GmbH
Heng Zheng, Montanuniversität Leoben
Manuel Farkas, K1-MET GmbH

Abstract:
Alternatives to fossil fuels are worth developing to shift to carbon-free iron making. Accordingly, replacing coal, coke and natural gas with H2 is the current trend. H2 is mainly produced through steam reforming and partial oxidation, which are not carbon neutral. A promising method to produce H2 is the decomposition or pyrolysis of natural gas using plasma technology. If the required energy for pyrolysis is provided from a renewable source, the CO2 footprint can be further minimized. Using thermal plasma pyrolysis in combination with hydrogen-based iron making in a fluidized bed can lead to an enormous decrease in CO2 emission. Thermal plasma converts electrical power to thermochemical energy and offers temperatures up to 10000 k. This temperature range requires no catalytic effect for the decomposition reaction to occur. The other advantages of plasma are the relatively small and simple technology, high-efficiency rate, low energy demands, and high grades of Carbon Black (CB) products besides the enriched H2 gas. CB, as a worthful byproduct, can be forwarded for applications in, e.g., the mobility, plastic, or agriculture industries. The methane pyrolysis is tested on a laboratory scale using a DC-transferred plasma arc system with a maximum power of 8 kW, providing a voltage range of 20-100 V and a maximum current of 150 A. The arc is initiated between a hollow graphite cathode and the graphite pin anode. The plasma gas (2l/min Ar) and methane (1-1.5 l/min CH4) are introduced to the reaction zone through the cathode. The off-gas could flow out for further analysis, and the arc could be seen through the openings at the top. The results show a CH4 conversion rate of 50 to 95 % depending on the testing parameters. The produced carbon black is fluffy and fine with high purity. Its structure can be amorphous or turbo.

Klaus Franz, Primetals Technologies Germany, Germany

Co-Author:
Gerd Becker, Primetals Technologies Germany
Klaus Weinzierl, Primetals Technologies Germany GmbH

Abstract:
"In the production of green steel, it is necessary to provide green hydrogen in sufficient quantities. This can be produced from green electricity by means of electrolysis. It is particularly important to produce the hydrogen as cost-effectively as possible. To achieve this, on the one hand the electrolyzer has to be operated at the highest possible utilization rate, and on the other hand only when energy costs are low. This means a conflict of objectives, which can be resolved by supplementing the electrolyzer with a battery energy storage system. This combination requires an intelligent predictive control system that actually operates this production process at its optimum cost. The paper describes a model-predictive approach that takes into account energy costs, capital costs, and the costs due to wear of the entire plant. The approach is universal and can easily be extended to include other plant components, such as a direct reduction plant, a hydrogen storage unit or a wind power plant. Simulation results show the advantages of the approach."

Daniel Ernst, Montanuniversität Leoben , Austria

Co-Author:
Johannes Schenk, Montanuniversität Leoben
Michael Zarl, K1-MET GmbH
Isnaldi R. Souza Filho, Max-Planck-Institute for Iron Research

Abstract:
Carbon Direct Avoidance (CDA), Smart Carbon Usage (SCU) and Circular Economy are strategic pathways that the European Steel Association's members created to reach a CO2-neutral European steel industry. Climate change can only be tackled by reducing the anthropogenic greenhouse gas emissions, particularly CO2 ones. The iron and steel industry must also contribute to mitigating CO2 emissions, as it accounts for 5.7% of the European Union's overall emissions and is even responsible for 7% of global anthropogenic CO2 emissions. To achieve the goals of the European Green Deal and reduce emissions by at least 55% from 1990 levels by 2030, today's steel industry and its processes must be completely transformed. Highly promising process technologies use hydrogen (H2) as the primary reducing agent instead of carbon-carrier substances (coke) to simultaneously reduce iron ores and achieve the climate target, thus following the CDA pathway. The Hydrogen Plasma Smelting Reduction (HPSR) exploits the highly energetic hydrogen species (e.g. H, H+) existing in a hydrogen-containing plasma arc as reducing agents for the ore. The high energy of such hydrogen plasma species helps overcome the reaction’s activation energy, leading to a 15 times higher reduction potential than the gaseous molecular hydrogen. The plasma species are created by the thermal energy of a DC-transferred arc between a hollow graphite electrode (HGE) and the melting bath, enabling a one-step direct production from iron ore to steel. Introducing iron ores with different pre-reduction degrees into the reaction zone (plasma/melt interface) influences the hydrogen utilization degree, the total process time, and the metal phase's microstructure. With this knowledge, optimal combinations of pre-reduction states via direct reduction and subsequent processing with hydrogen plasma to crude steel can be achieved to obtain the highest H2 utilization and optimal steel quality.

Henri Pauna, University of Oulu, Finland

Co-Author:
Daniel Ernst, K1-MET GmbH
Michael Zarl, K1-MET GmbH
Isnaldi R. Souza Filho, Max-Planck-Institute for Iron Research
Hauke Springer, RWTH Aachen University
Marko Huttula, University of Oulu
Johannes Schenk, Montanuniversität Leoben
Timo Fabritius, University of Oulu
Dierk Raabe, Max-Planck-Institute for Iron Research

Abstract:
Hydrogen plasma smelting reduction (HPSR) has the potential to be a viable solution for both reducing metal-bearing oxides and treatment of metallurgical sidestreams for metal recovery. However, thermal plasmas are known for their erratic and sometimes unpredictable behavior where the plasma may e.g. jump from place to place or have circular movement from side to side around the furnace. Furthermore, plasmas are highly dynamic entities, as their properties change rapidly depending on, to name a few, the plasma composition, electron density, and length. Since the composition of the ore will change in the reduction process, the plasma’s properties will also change during the smelting reduction. The need for online in situ process control is evident to keep the metallurgical process and the application of plasma aligned with the desired end-product reduction degree, composition, and quality. To address the demand for process control, the reduction of iron ore was studied at two lab-scale HPSR set-ups at the Montanuniversität Leoben and Max Planck Institute for Iron Research together with a demonstration-scale facility at K1-MET GmbH. Optical emission spectroscopy (OES) was used to provide a qualitative outlook on the HPSR process from an OES point of view by looking at the radiating species within the plasma and linking them to what is happening inside the furnace. As a measurement method, OES offers a way to monitor the plasma's composition, temperature, electron density, and other characteristics from a distance so that the plasma is not affected by the measurement itself. Since the focus is on process control, the aspects of OES as a process control tool to monitor the plasma are discussed.

Arun Kamalasekaran, KTH Royal Institute of Technology, Sweden

Co-Author:
Pelle Mellin, Swerim AB
Christopher Hulme, KTH Royal Institute of Technology

Abstract:
Ferronickel (FeNi) alloys are widely used to manufacture stainless and heat-resistant steels. They are also used as an alternative binder in tools, replacing Ferro-Cobalt. Typically, FeNi alloys and alloy powders are produced by processes that use carbon as a reductant and emit large volumes of greenhouse gases. In the current work, FeNi alloy powders with varying compositions were produced by directly reducing Fe2O3-NiO powder mixtures using hydrogen to replace carbon as the reductant. This could prevent millions of tons of greenhouse gas emissions each year in Sweden alone, and reduce energy consumption significantly. The mixtures of Fe2O3 and NiO powders were directly reduced using hydrogen in a horizontal tube furnace in which the products were analysed using a gas analyser based on photoacoustic spectroscopy. The preliminary results from the gas analyser indicated that the mixtures reduced completely at a temperature of 700°C within 45 minutes. This was confirmed using X-ray diffractometry (XRD). The XRD data revealed the absence of oxides in the reduced powders and the presence of a single solid phase: gamma (FCC) or two solid phases: alpha (BCC) and gamma (FCC), depending on the ratio of the iron and nickel oxide powders in the initial mixture. Analysis using energy-dispersive X-ray spectroscopy in a scanning electron microscope showed that the average composition of a mixture of oxide powders that contained a mass ratio of 78 wt% iron and 22 wt% nickel was 85 wt% iron and 15 wt% nickel. This is promising enough to justify further investigation. Successful application of these results could replace traditional pyrometallurgical processes with a clean, lower-energy production route and thereby save large amounts of carbon emissions and energy.

Ko-ichiro Ohno, Kyushu University, Japan

Co-Author:
Tatsuya Kon, Kyushu University
Taro Handa, Kyushu University
Yuki Kawashiri, JFE Steel Corporation

Abstract:
In an oxygen blast furnace trial using an experimental blast furnace, it was confirmed that the oxygen blast furnace could operate at a high pig iron ratio of approximately twice that of a normal blast furnace. Owing to the higher productivity of the oxygen blast furnace compared to the standard blast furnace process, the internal volume can be reduced while maintaining the same productivity. This trend can help utilization of lump iron ore, which is generally not used in current blast furnace operation due to the low strength and poor reducibility of lump ore compared to sintered iron ore. To evaluate the possibility of utilizing lump ore in an oxygen blast furnace, slag formation behavior at the lump ore and limestone interface was investigated in this study. In order to evaluate the slag formation behavior in the cohesive zone, the softening behavior between pre-reduced lump ore and a CaO substrate in an inert atmosphere was measured under loading conditions using a softening simulator. From the results, the following results were obtained. When the lump ore melt intrudes to the CaO substrate, the solid part of lump ore penetrates into the CaO substrate with deformation of the CaO substrate, and the greater the degree of melt intrusion, the more lump ore penetrates. The melt intrusion behavior into the CaO substrate is strongly related to the presence or absence of Ca2SiO4 phase at the initial melt formation temperature. At 1300°C or lower, the gangue composition at the outer part of the lump ore decides intrusion behavior. At 1300°C or higher, the average gangue component of the entire lump ore is the main factor to make intrusion behavior.

Michael Alter, ALTER Blast Furnace Consulting, United States

Co-Author:
Andrii Moskalyna, ISI NASU
Mykola Izumskyi, ISI NASU
Vitaliy Lebed, ISI NASU
Bogdan Kornilov, ISI NASU
Oleksii Chaika, ISI NASU
Volodymyr Naboka, PJSC Zaporizhstal

Abstract:
The article discusses results of calculations of energy and exergy balances in blast furnaces with possibilities of new and existing technologies for reducing carbon dioxide emissions and reducing coke consumption, increasing production of pig iron by injection into the hearth hydrogen and hydrogen containing fuel additives (coke oven, BOF, or natural gases), use of scrap, enriched top gas, increasing blast temperature, reducing heat loss and improving gas utilization. Calculations were carried out using original mathematical model developed in the ISI NASU for blast furnace total energy balance. There were assessed impacts of different technologies on reducing CO2 emissions and technical and economic blast furnace operating indexes in depending on changes in pulverized coal consumption, hydrogen and hydrogen-containing fuel additives rate and their combinations in a wide range. Have been determined limits of hydrogen and hydrogen-containing fuel additives for injection into the hearth of blast furnace, by the following factors: degree of direct reduction of iron, RAFT range, the availability of oxygen for blast enrichment and top gas temperature. Outcomes of study disclosed that CO2 emissions of blast furnace ironmaking can be reduced up to 25-30% by evolution of blast furnace operations which depends on investments, quality of raw materials, available energy, level of existing blast furnace operations technology. The effects of injection of preheated enriched top gas, clean scrap additives use, heat losses drop, actions to increase hot blast temperature, and optimization of gas distribution in the blast furnace on carbon dioxide emissions decreasing and technical and economic indicators of blast furnace operation were investigated. The results can be useful for determining the economic feasibility of different technological actions to reduce CO2 emissions in blast furnace ironmaking.

Mehdi Baniasadi, Paul Wurth S.A., Luxembourg

Co-Author:
Florent Mauret, Paul Wurth S.A.
Peter Kinzel, Paul Wurth S.A.
Fernand Didelon, Paul Wurth S.A.

Abstract:
The steel industry, especially traditional ironmaking is among the largest contributors of greenhouse gas emissions, attributable to approximately 7% of total emissions, because the Blast Furnace (BF) process was initially designed for the utilization of carbon-containing fossil fuels. Considering economic reality and CO2 emission targets, Paul Wurth has reassessed the blast furnace route and ended up with a solution named EASyMelt™, Electrically Assisted Syngas sMelter. In this contribution, an in-house numerical model (BFinner model) is utilized to investigate the EASyMelt™ concept for a blast furnace. First, the validation of the BFinner model with operation data of processes with medium to high levels of H2 load will be deliberated. Then, the model gives an insight into the feasibility of the EASyMelt™ with high H2 load and a minimum possible coke rate resulting in a significant coke saving.

Pratyush Kumar, M. N. Dastur & Co., India

Co-Author:
Arnab Adak, M. N. Dastur & Co.
Atanu Mukherjee, Dastur Energy Inc.
Saptarshi Bhattacharya, M. N. Dastur & Co.
Soukarsa Das, M. N. Dastur & Co.
Arunava Maity, M. N. Dastur & Co.
Kaushal Kumar Sinha, M. N. Dastur & Co.

Abstract:
Currently approximately two billion tons of steel are produced annually. The rapid industrialisation of developing nations has contributed to an addition of nearly one billion tons steel capacity over the past 20 years. CO2-intensive BF-BOF has been the preferred process method due to its scale, robustness, and feed flexibility. The potential to instantly replace BF-BOF with clean technologies like H2-based DRI or scrap-based EAF is constrained by the maturity of the technology, the economic impact of stranded assets, and the availability of resources (scrap & green H2) at the right quantity and price. Over the last decade, significant consolidation has happened in the steel industry, enabling steel businesses to optimize and reconfigure plant assets in order to achieve sustainable and effective production. Our work demonstrates that replacement of old inefficient BFs with DRI plants fueled by waste gas or syngas can be the most effective near-term decarbonization strategy for steel plants having multiple BFs and/or having facilities at multiple locations. Our case demonstrates how the use of HBI in BF can reduce CO2 emissions by about 1.5 mtpa while maintaining the same level of crude steel production in a large (around 10 mtpa) BF-BOF-based integrated steel plant. The BF productivity would rise by about 10% with an increase of 140 kg/thm HBI, helping to shut down two smaller inefficient blast furnaces. With the reduction of the coke rate by at least 45 kg/thm and around 140 kg/thm HBI addition in burden, the older smaller sinter & coke oven plant could also be decommissioned. Procuring power from renewable sources or a greener grid will reduce the usage of gas in inefficient power plants operation. Available gas has been considered for DRI plant operation. Other options for fueling DRI plants like syngas from waste and/or biomass gasification will also be further evaluated.

Eric Schaub, Paul Wurth Deutschland GmbH, Germany

Co-Author:
Markus Engelmann, Paul Wurth Deutschland GmbH
Volker Dulz, Paul Wurth Deutschland GmbH
Stephan Bamberg, Paul Wurth Deutschland GmbH
Markus Bierod, Paul Wurth Deutschland GmbH
Ralf Allmannsdörfer, Paul Wurth Deutschland GmbH

Abstract:
Title: BF Hearth Condition Monitoring and Hearth Repair / Re-profiling Authors: CUSTOMER – not yet confirmed, R. Allmannsdörfer, S. Bamberg, M. Bierod, V. Dulz, M. Engelmann, E. Schaub Key Words: Blast Furnace, Hearth, Wear Monitoring, Hearth Repair, Hearth Re-profiling Abstract: The operation of Blast Furnaces (BF) became even more challenging during the last years. Harsh conditions, like frequent stoppages and low production, poor raw material and a general uncertain outlook because of the need to reduce the carbon footprint make it difficult for operators to operate their BFs and to plan for the future. In this context it’s quite important for operators to have proper information and feedback regarding the condition of their BF hearth refractory and the consequences of the operation on the BF hearth, but also with regard to the uncertain future to, to extend the service life as much as possible. Repairs, if required, are often reduced to a minimum and “smart” repair procedures are requested. So called Multi-Point-Temperature-Sensor-Probes (MTP) help to monitor the condition of a BF hearth and sometimes help to extend the service life. They give precise feedback regarding the condition of the BF hearth, also with regard to the operation of the BF. Defects in the BF hearth refractory can be detected by these MTPs. Re-profiling repairs allows to extend the service life of a BF, typically by several years, as long as accompanied by proper condition monitoring. The following paper will illustrate the working principle of MTPs, will show typical applications and found refractory defects and will also provide an overview about possible and executed repairs on BF hearths.

Floris van Laar, Allied Mineral Products, Canada

Co-Author:
Floris van Laar, Allied Mineral Technical Services
Maria Grguric, Allied Mineral Technical Services
Richard Chaykowski, Allied Mineral Technical Services

Abstract:
This paper will discuss campaign extension strategies using partial repairs to refractory systems in blast furnace hearths. As the industry continues to rely on fewer blast furnaces to maximize iron output, the need for campaign extension strategies that minimizes down time becomes vital. Furthermore, complete hearth relines can prove to be lengthy, with large costs associated to manpower, materials, equipment, reduced production, and impact on steel cost. Hearth diagnostic and monitoring assessments can help identify the areas of concern and plan the best activities to meet or exceed existing campaign targets, while keeping the total cost in check.

Radha Raman Abhyuday, Tata Steel Ltd , India

Co-Author:
Sambit Joshi, Tata Steel Ltd
Padmapal ., Tata Steel Ltd
Shivendra Kumar Dubey, Tata Steel Ltd
Subhashis Kundu, Tata Steel Ltd
Shambhu Nath, Tata Steel Ltd

Abstract:
‘D’ Blast Furnace installed in 1923, was a 400 tpd furnace. It was upgraded to 800 tpd in 1967. In 1998 up gradation, furnace was the second at Tata Steel and sixteenth in India to have carbon hearth. The furnace has produced 6.96 million tonnes in its current campaign. The furnace has been subjected to frequent on and off mode of Operation, primarily due to fluctuations in the demand since 2008. After 15 years of successful operation, the furnace started showing signs of ageing, especially in the lower stack, Bosh/Belly and Tuyere jacket area. The furnace was plague with the problem of hot spots in the above-mentioned area. This led to catastrophic failures of cooling plates, flame shooting around the mantle ring, necessitating frequent blanking of tuyeres, grouting shutdowns and a centrally biased burden distribution. The above problem was taxing both the fuel rate and productivity of the furnace and therefore a repair plan to prolong the campaign life of the furnace was necessary. The 3rd term repair of 'D' furnace was a unique repair in the history of Tata Steel as it was the second attempt to have a multi campaign on the same hearth. The Blast Furnace team was not having any past experience of blowing down the furnace with its own team till tuyere level and capping the red-hot coke below tuyere level to make the furnace gas free for carrying out the repair jobs inside the furnace. The repair plan consisted of blowing down the furnace to the tuyere level, manual coke raking after nitrogen quenching, removal and leveling of coke, capping of hearth and repairing throat, tuyere jacket, Bosh, belly area without disturbing the bricks in stack area and carbon hearth. Key Words - Blast Furnace, Blow down, Stack, Burden, and campaign life.

Andre Fiedler, thyssenkrupp Steel Europe AG, Germany

Co-Author:
Jan Vogt, Refratechnik Steel GmbH
Tim Kruell, Dominion Deutschland GmbH

Abstract:
Due to premature wear accompanied by hot spots on the shell in the bosh and belly area of Blastfurnace 2 in Schwelgern a shotcrete repair by roboter became necessary. With a hearth diameter 14.9m and a production of up 12.000t/d Schwelgern BF2 is the largest BF in Europe. For the bosh and belly area that means a diameter of approx. 20m and a depth of 25m. This was the first time for this kind of repair in this area of a BF at Schwelgern. This work shall give an overview of the planning and the execution of the work on site done by thyssenkrupp Steel Europe AG, Refratechnik Steel GmbH and Dominion Deutschland GmbH. Which means on the one hand the planning of the blow-down process with the aim of not having to remove burden via tuyere area. The activities done in the casthouse if this should have been necessary and an overview of the success of the blow-down procedure Additionally it will be given an overview of why the applied refractory, Refrajetcrete with Hybrid technology from Refratechnik Steel GmbH, was chosen. The third point will focus on the used shotcrete roboter from the compamny of Dominion Deutschland GmbH. With the focus on why it was choosen and what changes had to be applied on the roboter to grant success on site for the use in the bosh and belly area.

Paul Mark Geach, Primetals Technologies UK, United Kingdom

Abstract:
"Top fired stoves bring a number of operational advantages and therefore continue to increase in popularity. Various designs have been developed over recent years by a number of technology companies, with differing degrees of successful implementation. This results in an opportunity to identify the strong points of certain designs, and to have confidence in installation and operation with reference to particular designers. This paper will define the key features of a well-designed and constructed top fired stove, at the same time identifying the benefits (and problems) of different designs in terms of the stability of refractory construction, burner design, stove efficiency, environmental and CO2 emissions and operational longevity. The paper will identify why Primetals Technologies in collaboration with Yuxing Engineering & Technology propose particular designs of top fired stove, and why these designs can be trusted for implementation around the world. "

Akshay Bansal, ArcelorMittal, France

Co-Author:
Gérard Griffay, ArcelorMittal Global R&D
Dominique Sert, ArcelorMittal Global R&D
Antoine Moussalem, ArcelorMittal Global R&D
Elise Vouriot, ArcelorMittal Global R&D

Abstract:
Regenerative thermal exchangers are thermal devices capable of capturing & storing heat from a hot source and releasing the stored heat to a cold sink intermittently, repeating the cycles and therefore regenerating. In iron & steel industry, these exchangers are present in the form of hot blast stoves (hot air injected in blast-furnaces tuyeres) where the hot source is industrial gas combustion fumes, the cold blast constitutes the cold source and intermediate regenerator may typically be a checkerwork of refractory bricks or more recently a packed bed of refractory balls or pebbles. To support design and higher performance of pebble type regenerators, a numerical model of simplified combustion combined with heat transfer in a packed bed of pebbles is presented. Model results show a good order of magnitude of the bed temperature and its spatio-temporal gradient during both on-gas and on-blast cycles, in turn found to be aligned with experimental results in a laboratory scale pebble bed. The impact of the average pebble size on the heat transfer and therefore the global sizing of the regenerator is also discussed.

Ewout Tesselaar, Danieli Corus B.V, Netherlands

Co-Author:
Victor Van Straaten, Danieli Corus B.V

Abstract:
Before the introduction of dome combustion technology in the 1990s (ref. Kalugin first “shaftless” hot stove in operation in 1992), steel producers relied on either internal or external combustion chamber design hot blast stoves, with their advantages and disadvantages with respect to investment, process performance, reliability and maintenance requirement. Both these designs have reached a high level of maturity during nearly 150 years of use in the global steel industry. Over the past three decades, dome combustion technology was first embraced by the Russian steel industry and after the year 2000 by the Chinese steel industry. The design is currently considered the new industry standard for Greenfield Blast Furnace plants, in Asia in particular. Compared to the early design, later dome combustion hot blast stoves represent some steps forward, also driven by the implementation on a larger scale in the Chinese steel industry. This article analyses designs of early and later generations, also based on findings at systems that have been in operation for multiple years. The authors compare the designs with respect to mixing and combustion performance as well as condition and integrity of the refractories, presenting how the analyses and findings have resulted in the latest generation burner and refractory design features as implemented in three ongoing projects for steel producers in India.

Abdoulfatah Moustapha Houssein, Calderys Deutschland GmbH, Germany

Co-Author:
Dr. Pascal Hubert, Imerys Villach GmbH
Steffen Moehmel, Imerys Villach GmbH

Abstract:
The new climate and environmental challenges have made the iron making industry move towards a cleaner production and therefore to a greener refractories consumption. The blast furnace being the main vessel in the iron making process, its tapping mainly relies on the quality of the Taphole Clay (THC). For a long time, coal tar bonded Taphole Clays were used for their easy injection and good adhesion to taphole walls but their high toxicity led to the use of phenolic resins. Despite their lower toxicity level, these resins are recently presenting some health issues for the plant workers especially with their free-phenol content which sometimes may be present up to nearly 10% in the resins. In this study, two different resin binding systems: a conventional phenolic resin and a low free-phenol resin were examined and compared. On a first hand, the effects of these binding systems on general plastic behavior of the products were analyzed and also correlated to their physical and mechanical properties. A comprehensive understanding of the Taphole’s severe operating conditions such as high temperature, high pressure, corrosion by slag and molten pig iron is required. Therefore, the injectability of the studied samples was investigated at high temperature in order to characterize the setting of the material, the cracks formation and the outlet of volatiles during the plugging mechanism of the Taphole Clay in the blast furnace. A chemical analysis of the Polycyclic Aromatic Hydrocarbon (PAH) present in the samples was also performed.

Thierry Joly, Vesuvius Europe, France

Co-Author:
Mathieu Dombrowski, Vesuvius Sp. z o.o
Isenbarger Roger, Vesuvius

Abstract:
Taphole clay as a key element in the proper functioning of the ironmaking process as it protects the ceramic hearth over time from damage by pig iron or slag. Using poor quality clay can be detrimental and leading to higher costs and early maintenance of BF hearth. Markets needs for sustainable products were another important factor for this evolution. Development of a binder for taphole clays which does not contain Polycyclic Aromatic Hydrocarbon and Formaldehyde was a game changer in the industry that strives towards sustainable future, which is available worldwide with performance at least equivalent to standard product, allowing cure speed of the mass to be adjusted and short inter-cast times. However, in some rare cases, we observed a hardening of the taphole mass in the plugging machine - this phenomenon required further development. Performing analytics and tests to reduce this hardening phenomenon, correlated to the high temperature in the mud gun, by developing a binder-based Formaldehyde and PAH free-tech with a higher boiling temperature. By increasing the boiling temperature of the binder, we succeeded in shifting the setting of the binder to higher temperatures, which solved the hardening problem in a way that exceed our expectations. Our methodology includes study and field trail of the implemented approach with an objective to replace the binding system without changing the formulation of the taphole mix concluding that this evolution of the binder has a positive influence on the length of the tap hole, duration of the casting and the specific consumption of the taphole clay in grams per ton of hot metal. Application in the field shows increased performance relative to traditional binder systems and does not require any reworking of the THC formulation, it can be easily substituted currently supplied materials with positive impact on health & environment.

Youn-Bae Kang, Pohang University of Science and Technology , Korea, Republic of

Co-Author:
Michael Bernhard, Pohang University of Science and Technology
Kang-Ho Bang, POSCO
Soon-Jong Jung, POSCO

Abstract:
One of the industrial wastes after alumina production from bauxite, red mud, was assessed as an additive to lime, as a new desulfurization flux for the hot metal in the steelmaking process. Its role in facilitating the melting of the lime was primarily investigated. Keeping in mind that the desulphurization mechanism under mechanical stirring such as in the KR process is different from that without mechanical stirring, a series of laboratory scale tests were carried out with a device for inducing mechanical stirring in the hot metal. A number of variables (mixing ratio between lime and red mud, pre-reduction of red mud, mechanical stirring, and additives to the lime/red mud mixture) were employed in order to elucidate the desulphurization mechanism and optimum chemistry of the desulphurization flux. In order to assess the desulphurization efficiency in a more quantitative manner, a “DeS Index” was defined. This takes into account the extent, rate, and cost of the desulphurization simultaneously. With this index, it was found that the presently developed red mud-containing desulphurization flux showed almost similar desulphurization efficiency compared with those of commercially used desulphurization fluxes. It was even better than a typical lime/fluorspar mixed flux, which is now prohibited from being used in many companies due to its environmentally harmful character. It is emphasized that the desulfurization efficiency should be assessed under mechanical stirring in order to be used in the KR-type desulphurization process.

Daniel Cruz, TMT GmbH, Germany

Co-Author:
Volker Langer, TMT Tapping Measuring Technoloy GmbH
Claude Meisch, TMT Tapping Measuring Technology S.a.r.l

Abstract:
Casthouse and Digitalization appear to exclude each other at first sight. Especially considering application of Blast and Metallurgical Furnaces. Since more than 100 years they are acme of heavy industry, hard work and challenging environmental conditions. But how does digital evolution fit into it? It is driven on the requirements of better safety, reproducibility, predictability and documentation. Since more than 20 years, TMT Tapping Measuring Technology in Luxembourg and Siegen has developed with its customers and partners solutions for • Automation, • Visualization, • Data Management and • Virtualization, in order to meet above expectations. The usability for the user are remote commissioning, virtual training, asset performance management and significant stability and efficiency on the tapping process.

Marcia Pereira, Vesuvius Ghlin, Belgium

Co-Author:
Laura Grana Suarez, Vesuvius
Waldemir Moura de Carvalho, Vesuvius
Hervé Tavernier, Vesuvius
Marcia Maria da Silva Monteiro Pereira, Vesuvius

Abstract:
In today’s competitive market, the demand for high-quality, defect-free steel is unprecedented in industry history. Quality standards have been raised worldwide along with increasing market pressure to reduce and control pricing. Perhaps, the most challenging period is associated with the start-up of the continuous casting sequence. Unstable mould conditions will adversely affect the steelmaker’s ability to control this critical stage of casting. This can lead to conditions resulting in poor cast quality, defects, and even breakouts. In order to get a faster and good and stable lubrication state in the mould, and so decrease risks of sticking or cracks formation, a simple solution consists of adding an exothermic powder on top of the steel in the mould, prior to the continuous casting powder. Through the use of computational thermochemistry (Software FactSage) we can explore and study the influence of the different raw materials on the energetic behavior of multicomponent and multiphasic systems, such as the in-mould behavior of the Flux powder. The thermodynamic calculations can be used to identify the reaction products inside a primary metal smelter, to establish overall heat and mass balances of a process, and to generate phase mappings (such as phase diagrams and predominance diagrams). The method is based on identifying the equilibrium state of a system constrained by different conditions of temperature, pressure, volume, chemical potentials, chemical compositions, and more with a short computational time. Consequently, the method allows us to predict the system behavior and quickly adapt the composition of our exothermic powders to the different local working conditions, steel grades, or standard casting flux while keeping the right exothermic behavior.

Johan Richaud, Vesuvius Europe, France

Co-Author:
Anupkumar Nandakumar, Vesuvius India Limited
Soumya Bhattacharjee, Vesuvius India Limited
Rajkumar Gangadharappa, Vesuvius India Limited
Murali Sabhapathy, Vesuvius India Limited
Ganesh L, Hospet Steels Ltd.
Manoj Gupta, Hospet Steels Ltd.
P.L Satish, Hospet Steels Ltd.
Atluri Ratnaprasad, Hospet Steels Ltd.

Abstract:
The production of Re-Sulphurized steel, and other clogging prone grades is a challenge in terms of limited sequence length thus impacting both productivity and sustainability. The efficient production of these grades requires optimized tundish vessel functioning, which has historically been addressed through shaping tundish furniture -impact pad like. Turbostop® pad, dams, weirs and baffles. The design of these refractory components has shown significant impact on steel cleanliness in continuous casting. Tundish to mold steel can also be further improved by modifying flow controlling refractory designs like the stopper. In long product casters, generally argon injection through the stopper nose into the casting channel is avoided to prevent observed boiling in mold, which can cause operational and quality issues. This paper describes the improvement in the flow performance from the tundish to mold. The novel stopper design of Multi-Channel Argon injection through the stopper nose resulted in reduction in clogging occurrences near the stopper regulating surface and the SEN seat. This helps in achieving a stable stopper position throughout the tundish sequence and leading to a significant reduction in the rate of stopper rise required for extended sequence casting. Multiple trials were successfully carried out showing reduction in stopper rise rate as well as reduction of stopper flushing counts compared to conventional stopper design. Thanks to the stopper rise rate reduction, the sequence length could be extended from 2 heats/Tundish to 2.91 Heats/Tundish in average, thus improving productivity and caster yield leading to cost reduction and sustainability improvement - reduced tundish consumption, lower fuel costs. Additionally with this new stopper design quality of the final product also improved.

Maksym Goryuk, National Academy of Sciences of Ukraine, Ukraine

Co-Author:
Anastasiia Semenko, National Academy of Sciences of Ukraine
Yuriy Smirnov, National Academy of Sciences of Ukraine
Oleksiy Smirnov, National Academy of Sciences of Ukraine
Sergii Semiriagin, Scientific and Manufacturing Enterprise Dneproenergostal Ltd.
Vadym Osypenko, Scientific and Manufacturing Enterprise Dneproenergostal Ltd.

Abstract:
The PTIMA NASU proposed new concept of continuous casting of steel for small metallurgical plants. The idea is both reducing capital costs and amount of equipments. This is achieved by excluding “ladle-furnace” aggregate from technology, reducing number of metal overflows, performing in tundish the finishing liquid steel on temperature & chemical composition, and cleaning from non-metallics. As such multifunctional tundish, it is proposed a pilot magnetodynamic (MD) mixer-batcher for cast iron and steel, developed at the PTIMA NASU. This aggregate uses electromagnetic energy for melt heating, stirring and pouring, and constructively combines functions of induction channel furnace and electromagnetic pump. Such tundish, depending on steel grades produced, process productivity and design of continuous casting machine (CCM), can have one or two chambers, induction channels with inductors, electromagnetic devices for metal stirring and pouring, and also it can be additionally equipped with submersible plasmatron for melt refining. The proposed MD-tundish has following advantages: - adjustable induction heating and electromagnetic stirring of melt; - controlled low-pressure electromagnetic pouring of melt with possibility of distributing and stabilizing flow over the width of CCM mold; - possibility for periodic stop/restart at manufacturing small batches of cast ingots with various sections and from different steel grades; - reduction of metal losses and increasing metal yield; - increasing CCM work stability and productivity; - reduction of refractories’ consumption; - energy saving due to rational modes of melt heating and stirring; - exclusion of using special expensive systems for braking steel flows in CCM mold; - improving quality of cast ingots’ surface due to prevention of their cracking and swelling; - reducing porosity and number of non-metallics; - reducing risk of melt breakthroughs; - improvement of working conditions for personnel and ecology due to use of electrical energy, reduction of thermal radiation and harmful emissions.

Tim-Oliver Mattern, Carl Bechem GmbH, Germany

Abstract:
This paper evaluates modern grease technologies available for continuous casters and the impact to bearings and other aspects of maintenance. Grease performance for continuous casters can be largely impacted by the thickener technology, where resistance to water, steam, and high temperatures can degrade the grease. The mobility of the grease in centralized distribution systems can also be influenced by radiant heat before it is ever introduced to the bearing, adding another layer of complexity. Selecting the proper grease will impact the volume of grease consumed, how it behaves in the centralized distribution system, and how well it protects the bearings from this harsh environment.

Mohammad Sharif Sharifian, Hormozgan Steel Company, Iran, Islamic Republic of

Co-Author:
Hamed Jamshidinia, Hormozgan Steel Co
Ayoub Goudarzi, Hormozgan Steel Co
Omid Karami, Hormozgan Steel Co
Abbas Ali Barahimi, Hormozgan Steel Co

Abstract:
Ladle nozzle clogging is a problematic phenomenon in Continuous Casting of Aluminum killed Steels which output of ladle nozzle is reduced. It causes many problems in the production process, such as reducing productivity and increasing casting defects. In spite of extensive research on tundish nozzle clogging, few studies have been done on ladle nozzle clogging, especially in steels deoxidized only by aluminum. In this research, by using scanning electron microscopy analyze, the relationship between the chemical composition of non-metallic inclusions, molten steel and ladle nozzle clogging has been investigated. Due to optimization of calcium treatment in Hormozgan steel company, the number of ladle nozzle clogging and returned molten steel from continuous casting decreased significantly. As a result quantity and quality of produced slab increased.

Johan Richaud, Vesuvius Europe, France

Co-Author:
Sudip Banerjee, Vesuvius India Limited
Paromita Sarkar, Vesuvius India Limited
Roshan Ughade, Vesuvius India Limited
Kamruz Zaman, Vesuvius India Limited
Nagarjuna V L, JSW Dolvi
Sameer Patil, JSW Dolvi
Anil Gargi, JSW Dolvi
Neelesh Pande, JSW Dolvi
Sanjay Gurme, JSW Dolvi

Abstract:
Recent thin slab caster performance enhancements at JSW Dolvi Works with a clear focus to cast long sequences of higher quality grades produced at higher casting speeds, leading to higher throughputs have been possible with the application of the ElectroMagnetic Brake (EMBr). Along with this implementation, the increase in productivity has implied extension of the caster utilization time by reducing the process down time, the major portion of the process downtime is the regular sequence change time. To achieve these challenging conditions, the tundish and mold flow behaviour have been characterized and optimized along with implementation of higher refractories performance related to both their design and their material selection. Extensive numerical and physical simulations have been conducted to determine the different measurable parameters for tundish and mold flow improvements. Increased minimum residence time, improved inclusion floatation and turbulence reduction, better thermal homogeneity in tundish have been obtained after re-designing the internal tundish geometry. A new SEN producing stable meniscus flow and optimal mold temperature distribution allowing longer sequence to be cast in a thin slab caster. In addition to these refractory enhancements, JSW-D has significantly improved their casting parameters and stabilized the processes involved. Due to better co-ordination between the steelmaking & casting shop the casting speed fluctuations have been reduced and higher speeds of over 5.5 m/min corresponding to higher throughputs of above 4 tons/min have been realized on a consistent basis. Stable casting conditions have resulted in better refractory performance. The sequence length has increased by 15% on an average resulting in increasing the productivity of the shop with less unexpected stoppages or reduced numbers in slowdowns. Sustainability improvement has been achieved by increasing the number of heats/tundish and consequently the overall refractory consumption per ton of steel cast as well as the required energy have been reduced.

Angela Philipp, Alleima GmbH, Germany

Co-Author:
Felipe Beluche Lima, Alleima AB

Abstract:
Brazil is the largest producer of crude steel in the Americas by BOF process, and many challenges come along with the increasing market demand. In the BOF, a tubular wall hood structure has been showing premature failures related to the overlay welded tube technology in the hood wall. The main root causes were: thermal fatigue at 1800°C, hot spot formation, high heat-affected zone (HAZ) leading to stress cracking susceptibility, carburizing corrosion, and superficial wearing. Based on that, co-extruded tube technology (named composite tube) was the alternative chosen to enhance hood performance without compromising the BOF process. To rises safety and productivity, the composite tube has a 100% metallurgical bond assuring stable expansion, high heat exchange efficiency, better corrosion resistance, and less rough surface finishing. It was highly suggested to many other mills due to similar and existing reported cases. The paper describes the product co-extruded composite tube and the first successful installation in a tubular wall hood of a BOF. Keywords: BOF Hood; Co-extruded composite tube; Corrosion

Kyunghwan Kim, Hanyang University, Korea, Republic of

Co-Author:
Joohyun Park, Hanyang University

Abstract:
One of the most effective ways to reduce carbon emissions in the oxygen steelmaking process is to lower the hot metal ratio (HMR) in basic oxygen furnace (BOF). However, if the HMR is lowered, the amount of oxygen blowing during decarburization in the BOF converter increases due to a lack of heat source. As a result, the amount of the deoxidizer increases because the end point oxygen content in the molten steel increases, which results in a deterioration of the cleanliness of molten steel. Therefore, this study was conducted to ensure the molten steel quality even at a decreased HMR about 10%p compared to the current level to reduce carbon emission in a BOF steelmaking. An appropriate amount of silicon in hot metal was presented to maintain the lowered HMR, and a method of refining phosphorus when the silicon content in hot metal is varied for the lowered HMR was presented. Finally, even if the amount of scrap usage increases due to the application of lowered HMR operation, a process was improved to resolve the tramp elements issue.

Bart van den Berg, Danieli Corus B.V, Netherlands

Abstract:
Despite the fact that the price of scrap is usually higher than that of hot metal, environmental regulations are forcing ironmakers to decrease hot metal production as a key source of CO2 emissions. Steelmakers are for this reason looking for ways to increase the scrap ratio in the BOF charge mix. An overview of existing technologies and methods for increased scrap utilization in converter-type furnaces is set out in this paper. The study also deals with the economic and environmental reasons for increased scrap usage.

Champion Chigwedu , HT-PEACS LLC , Germany

Abstract:
Oxygen Steelmaking Reliable Production of Low Sulphur Steel Grades Without a Ladle Metallurgy Furnace The annual production of the Steelplant in question is 5 million metric tons of Flat Rolled Products. A significant percentage of the product mix requires final Sulphur levels of less than 50 ppm (0.0050 wt% [S]). When these steel Grades were scheduled, special steps were needed to minimize Downgrades and Cast Sequence Interruptions. The mandatory steps to be followed were: A -Desulphurize the incoming Hot Metal to 10ppm [S] or less B -Skim the “HECK” out of the Hot Metal transfer ladle, without regard to Yield losses C –Use only special low Sulphur scrap metal both at the BOF and at the Ladle Treatment Station as coolant D –Use special Low Sulphur Alloy Materials A careful study of the difference in chemistry between the final BOF-Slag and the required final LTS-Slag for a successful, final low Sulphur was carried out. In the end, new special steps, namely; E –Targeted control of the amount of BOF carryover slag F –Complete deoxydation of steel and carryover slag at BOF-Tap using Designed Deoxydation Cocktails G –Intensive and Efficient stirring at the LTS helped; -Reduce Hot metal skim losses, -Minimize Scrap metal cost -Optimize the use of expensive special low Sulphur alloy materials. Author; Dr.-Ing. Champion Chigwedu Technical Director of HT-PEACS LLC, USA. Tel.: +1 (703-350-7698) Email: cchigwedu@gmail.com cchigwedu@yahoo.com

Breno Maia, Lumar Metals, Brazil

Co-Author:
Marcelo Duarte, Lumar Metals
Willian Lima, Lumar Metals
Marcelo Guerra, Lumar Metals
Bernardo Braga, Lumar Metals

Abstract:
The integrated plants suffer the need to adapt their processes to contribute to carbon reductions. One option of many BOF converters is the replacement of scrap with hot metal. Building on theories from the 80s and using modern computational mathematical simulation resources, Lumar developed an innovative lance tip with afterburner on the face. Patented product with the differential of being a lance with three tubes and supersonic post combustion nozzles. The results show an average increase in scrap percentage, shorter blowing time and integrity of the lance conditions.

Stefan Griesser, qoncept technology GmbH, Austria

Co-Author:
Robert Pierer, qoncept dx GmbH
Sebastian Michelic, qoncept dx GmbH

Abstract:
Steelmakers across the globe are increasingly facing a decarbonization challenge. Recent developments in raw material and energy cost, supply chain volatility and CO2 regulations have put a lot of pressure on steelmakers which underlines the need for highly efficient and sustainable production processes. The switch to electric and hydrogen-based steelmaking in Europe brings additional challenges and requires the use of new raw materials (such as DRI), operation practices and adapted secondary metallurgical processes. This is partly a journey into the unknown and must be carefully navigated for successful implementation. The present paper presents a new digital solution for the optimization of existing electrical steelmaking processes and to answer the following questions: - How will new raw materials change my processes? - How can I predict the behaviour of new metallurgical processes? - How can I adapt to new equipment and technology? - How to define new operating practices? Metallurgical intelligence, cross-process optimization and sophisticated mathematical algorithms are at the core of this new application, which allows substantial cost savings, optimized production as well as reduced CO2 emissions. The influence of varying scrap composition, different types and amount of DRI, melting strategy, secondary metallurgical treatment and alloying strategies can be analysed and optimized in real-time. The presentation provides various practical examples, and the resulting cost and CO2 reduction is discussed.

Paulo Hopperdizel, Lumar Metals, Brazil

Co-Author:
Paulo Hopperdizel, Lumar Metals
Nerea Mendonza, ArcelorMittal Acindar

Abstract:
ArcelorMittal Acindar has a capacity of 1,500,000 TON and is an integrated steel production plant, consisting of MIDREX Direct Reduction, Electric Arc Furnaces, Ladle Furnaces, Continuous Casting and Rolling Mill Plants. It produces a wide variety of types of steels, low - medium - high carbon, free cutting, construction, aluminum quenched and low alloy. Leading steel company in the long steel market focused on to increase efficiency and cost reduction of the steelmaking process, planned to revamp the chemical energy package changing the equipment of oxygen and carbon injection on the two 110 ton EAF’s with the goal of decrease the consumption of injected carbon, oxygen and better slag foaming. The two EAF using scrap as charge and feeding DRI continuously with three ports of burner/oxygen and carbon injection. This project consisted in replacing the existing three ports of burner/oxygen and carbon injection for a new EAF chemical package, composed by copper blocks, burners and injectors of oxygen and carbon. Searching for the best technology currently available in the market, Acindar chose the chemical package developed by Lumar to EAF, composed by Protect Block, FlexOx and Power Carbon (to the needy carburization points). In this paper will be presenting the chemical package equipment implemented in these EAF’s revamp, as well the installation project, besides the operational results obtained during startup. The main results were the reduction of the consumption of the carbon, oxygen, improvement of the formation of foaming slag and reduction of power consumption of the furnaces.

June yong Eom, Hyundai Steel Co. , Korea, Republic of

Abstract:
As we already know, the Carbon Neutrality is the most essential global issue since 2010s. Many heavy industries, especially Iron & Steel producing industries, are being forcing to achieve extremely low emissions of carbon dioxide. There are lots of studies for the carbon neutrality of the steel making process, but the process transition from BF-BOF to DRI-EAF is considered to be one of the most certain methods. DRI makes it possible to manufacture the high-grade steels like AHSS by EAF process. It means, when we produce the same high-grade steel in the EAF process, carbon dioxide emission can be reduced as 40% to compare with BF-BOF process. However, DRI consists of 10~20% of gangue and FeO so it needs much more energy input in EAF process. Therefore, it is important to enhance the EAF’s energy efficiency for Securing economic feasibility. Oxygen injection from EAF’s side wall is one of the straight ways to improve the energy efficiency. High speed oxygen injection can generate the gas jet into the EAF, and this jet has two main functions. First, Oxygen jet mutilates the side wall scrap for accelerate the scrap melting speed. Second, after the plat bath formation, oxygen jet refines the impurity, enhances the slag foaming for higher arc stability, and improves molten steel agitation for heat transfer. In this study, a method for setting the advanced oxygen input pattern was presented through index data that can accurately predict dissolution behavior. Also, It was verified that the oxygen jet improvement by the certain reformation of nozzle design.

Piero Frittella, Feralpi Group, Italy

Co-Author:
L. Angelini, Feralpi Group
A. Landini, Feralpi Group
G. Foglio, Acciaierie di Calvisano
C. Di Cecca, Feralpi Group
M. Tellaroli, Feralpi Group
G. Tsymokh, Feralpi Group
B. Cinquegrana, Feralpi Group
F. Fredi, Feralpi Group
M. Bersani, Acciaierie di Calvisano
C. Senes, Acciaierie di Calvisano
F. Guerra, Acciaierie di Calvisano
G. Miglietta, Acciaierie di Calvisano
V. Duro, Acciaierie di Calvisano
A. Ventura, Rina Consulting – Centro Sviluppo Materiali S.p.A
D. Ressegotti, Rina Consulting – Centro Sviluppo Materiali S.p.A
F. Morandini, Feralpi Group

Abstract:
In modern steel productions the necessity to improve process performances became more and more a relevant target for both improvement of single product production in terms of quality and costs and also to enable variation in production scheduling thanks a flexible assessment of operating practices adopted. To enable the improvement on this approach a deeper understanding of the process phenomena occurring during the production is necessary to be able to understand which actions are necessary to improve the effectiveness of the reactions and heat transfer. For this reason the approach followed in Feralpi included different steps passing through development of modeling for the different process phases, implementing these modelling in off-line prediction model and online process control and including capability to describe process guidelines as support to the operators during the production. In particular these have been realized for the three main process steps EAF, LF and Continuous casting in order to be able to modify operating practices thanks to prediction model and to support the on-line process control thanks to derived trends KPI’s, in particular for both sites of Feralpi Siderurgica and Acciaierie di Calvisano. Furthermore a through process view is necessary to respect the process/quality constraints aiming at improvement of performances and productivity. Acciaierie di Calvisano and Feralpi Siderurgica strongly address its productions developments with adoption of new technologies and solutions Industry 4.0 for data analysis and process control also supported by RFCS funding scheme in the funding R&D projects. With the contribution of the R&D department, process technology, production areas and research partners, in Feralpi predictive mathematical models have been created for production phases and whole steelmaking process. This has been done internally in order to be able to better setup the optimal operating practices for each process phases.

Christian Koubek, Primetals Technologies Austria, Austria

Co-Author:
Richard Krump, Primetals Technologies Austria
Christoph Sedivy, Primetals Technologies Austria

Abstract:
"Melting steel has always been a challenging process. There has been a lot of development in automating this process in the past decades. However, most EAF steel is still produced using static melting profiles. Those profiles treat all the heats the same and are ignoring regular fluctuations. Fluctuations come from charged material eg scrap quality, alloying material, DRI/HBI quality as well as stability of electrical supply. Both have influence on the production results. For example, deviation in scrap or DRI/HBI quality or variation in primary voltage from the grid. The next level of process control is monitoring these variations and their impacts and applying countermeasures for process optimization and minimizing energy consumption. Sophisticated electrode control systems already have a huge amount of information, but typically this has not been used for process improvement. Recent developments combining the information already available are providing intelligent process derived strategies bringing a new level of process optimization. Integrating these improvements into the electrode control system enables the precise control of the electrical and chemical power input according to the current process needs. As a result, the fluctuations of the consumption figures and power on times will be minimized leading to greater production efficiency and reduced costs. The idea and implementation of such strategies as well as results achieved will be shown in this paper. "

Jiho Jeon, Hyundai Steel Co., Korea, Republic of

Co-Author:
Wongyeom Kim, Hyundai Steel Co.
Wonjin Choi, Hyundai Steel Co.
Honggil Moon, Hyundai Steel Co.

Abstract:
Vaccum degassing (VD) of steel melts during ladle treatment is an important process for removal and control of detrimental impurity elements. In order to complete homogenization and refining of molten steel in a short time, the molten steel is stirred by Ar gas injection from bottom of ladle during VD process. In the present study, a vibration-based monitoring system for gas injection was applied to consistently control the stirring intensity of volumetric Ar gas injection during VD process because various operation conditions in ladle affect the flow rate of Ar gas injection. The vibration energy generated by gas injection in the molten steel during VD process was measured on the wall of vessel in vacuum tank degasser. The vibration-based monitoring system was optimized by the various plant trials observing consistency of composition in the molten steel. The plant trials during VD process showed that the increase in stirring intensity enhances the removal rate of impurities and homogenization of molten steel in the ladle.

Kathrin Thiele, Montanuniversität Leoben , Austria

Co-Author:
Christoph Truschner, voestalpine Stahl GmbH
Christoph Walkner, Montanuniversität Leoben
Sergiu Ilie, voestalpine Stahl GmbH
Roman Rössler, voestalpine Stahl GmbH
Susanne Katharina Michelic, Montanuniversität Leoben

Abstract:
Continuous casting of Al-killed Ti-stabilized ULC steels is still linked to the problem of nozzle clogging. Until today the reason behind this phenomenon is not entirely clarified. One possible cause is the attachment of agglomerated deoxidation products (e.g., Al2O3) to the nozzle wall. Therefore, different tracing techniques are applied to track alumina inclusions and their possible modification over the production route. Besides the direct addition of rare earth elements (e.g., La, Ce) to the melt, a second method, the rare earth element (REE) fingerprint, is also discussed. The present study compares tracing on a laboratory scale with trials in the industry. The experiments in the laboratory were carried out in a resistance-heated Tammann-type furnace since an inert atmosphere can be adjusted, and the production route can be depicted through consecutive alloying additions and continuous sampling. In both cases, Lanthanum or Cerium was added to the melt after the deoxidation with Aluminium. Furthermore, samples were taken during the process to detect the change in morphology of non-metallic inclusions. Differences between the industrial and the laboratory scale appear mainly concerning the cooling conditions, the inclusion size and their amount. Moreover, the possibility of investigating the clogged material in the submerged entry nozzle leads to additional output from the industrial trials. Ti-modified REE-traced alumina inclusions were found in all experiments. Together with the investigation of the clogged material from the industrial trial, it can be suggested that preexisting deoxidation products agglomerate and attach to the nozzle wall. The traced inclusions form heterogeneous microscopic multiphase inclusions in all cases.

Julian Cejka, Montanuniversität Leoben , Austria

Co-Author:
Bernhard Sammer, Montanuniversität Leoben
Nikolaus Preißer, Montanuniversität Leoben
Gerald Klösch, voestalpine Stahl Donawitz GmbH
Susanne Katharina Michelic, Montanuniversität Leoben

Abstract:
The demand for higher scrap rates in European steel plants leads to increased amounts of tramp elements in steels, like copper, molybdenum and tin, and their further enrichment due to lack of possibilities for their removal. While other elements, especially the 16th group of the PSE like oxygen or sulfur, are well investigated, the effect of tramp elements on interfacial properties remain unclear. These phenomena are of high importance for different multiphase processes. While poor wetting of inclusions by steel at refining steps is preferred to transport inclusions from liquid steel to the slag, it can be detrimental in continuous casting due to the increased deposition of inclusions in the submerged entry nozzle and finally resulting in clogging. In this work an industrial medium carbon steel has been alloyed with ultra-pure tramp elements, namely Cu, Mo and Sn. The amounts of these increase gradually from standard-confirm levels up to values supposed to occur in future steel scraps. These samples are studied by means of drop shape analysis to quantify the influence of these impurities on the wetting angle on dense alumina and zirconia plates. With this method temperature and time dependency can be observed. Furthermore, the oxidic substrates and steel droplets are examined by metallography and SEM/EDS after the experiments to determine possible reactions. Thermodynamic calculations using FactSage are additionally applied.

Michael Bernhard, Pohang University of Science and Technology, Korea, Republic of

Co-Author:
Christian Bernhard, Montanuniversität Leoben
Sergiu Ilie, voestalpine Stahl GmbH
Youn-Bae Kang, Pohang University of Science and Technology
Won-Bum Park, Pohang University of Science and Technology

Abstract:
Worldwide steelmaking industry targets a CO2 emission-free production of high-quality steel grades based on hydrogen reduction metallurgy and by using renewable energy sources for melting of recycled scrap in electric arc furnaces (EAF) and electric smelting furnaces (ESF). A serious issue for steelmaking plants in melting scrap materials is the unwanted accumulation of tramp elements in the liquid steel bath, e.g. Cu and Sn. Beside those elements, also other present impurities, e.g. S and P are known to may cause quality problems in continuous casting (CC) process, which is the dominating process to produce flat sheets and long product with an amount of 95 % of the annual steel production. The current status of developing a self-consistent thermodynamic database for tramp elements and impurities in steel is presented. The binary and ternary subsystems were modeled according to the CALPHAD-approach, enabling precise calculations of phase diagrams and thermodynamic properties of multicomponent steel. The Modified Quasichemical Model (MQM) was used to formulate the Gibbs energy of the liquid phase to consider the strong short-range ordering (SRO) tendency in M-S and M-P (M = Fe, Cu, Sn) melts. Ferrite and austenite solid solutions and intermediate phases were treated by the Compound Energy Formalism (CEF). Numerous stoichiometric compounds, e.g. phosphides and higher-order sulfides, were modeled stoichiometrically. In the present study, selected examples are demonstrated, linking the database to an in-house developed heat transfer model for the CC process to predict the solidification progress and possible defect formation, e.g. hot tearing. Furthermore, the database is applied to calculate solid/liquid phase equilibria in the Fe-C-Cu-Sn-S system with respect to liquid metal embrittlement in high-temperature ferrous processing. Finally, future requirements on experimental research and modeling work will be also discussed.

Sailesh Kesavan, Swerim AB, Sweden

Co-Author:
Pooria Jalali, Swerim AB
Hyunjin Yang, Swerim AB
Pavel Ramirez Lopez, Swerim AB

Abstract:
SWERIM’s numerical model for continuous caster has been developed over the last decade through numerous projects. The model can predict the caster behaviour at a level of detail that it replicates industrial caster i.e., digital twin. This digital twin model can be used to optimise caster performance without the risk associated with the plant trials. The manuscript describes the methodology used to study the heat transfer in the continuous casting mould with an intumescent coating. The numerical modelling process starts with compiling a database of caster layout, process data, steel grade, and slag composition etc. A 3D virtual geometry of the industrial caster is built with details such as the SEN, mould with cooling water channels and one strand length after the mould exit. The flow, heat transfer and solidification are solved using Fluent CFD software. The reference case was compared with industrial process data such as shell thickness and cooling water rate through blind tests for validation. The heat transfer coefficient (HTC) of the intumescent coating was obtained from characterisation. The HTC value was patched to the mould walls in the validated reference case and a parametric study based on possible operational window was carried out. The resulting data from the digital twin was used to provide guidelines on the operation range with the intumescent coating to obtain optimal solidification in the final product. Keywords: Heat transfer coefficient, intumescent, slab caster, digital twin, solidification.

Tamara Gusarova, SMS group, Germany

Co-Author:
Stephan Six, SMS group
Arnoud Kamperman, Tata Steel IJmuiden B.V.
Roy Frinking, Tata Steel IJmuiden B.V.

Abstract:
Complaints from end-customers cost more than recycling of defect material produced. Therefore it is important to be sure about the quality of the cast steel material prior selling. Internal quality of cast material can be proved via etching / sulfur print or with the new ultrasound technique developed by SMS group GmbH under the name HD scan. The first industrial HD scan system was installed by Tata Steel IJmuiden in December 2018. Since then Tata Steel and SMS work in close cooperation for further optimization of quality evaluation. Several hundreds of samples were measured in production process, more than a hundred were additionally etched and results compared. In consequence, similarities and differences between etching and ultrasound methods were discussed. Most of the results match, however for some samples (normally steel grade specific) discrepancies were observed. Whereas by etching only one surface layer is analyzed, HD scan provides higher reliability of defect distribution due to volume information. Moreover, sometimes defects like cracks are smashed and hidden by sample preparation prior etching. For some other samples differences in results is a case for further studies. The key question to be considered is – what is the best technique for cast steel quality evaluation in modern digital world? Various measurement results from Tata Steel IJmuiden sample will be presented and discussed, as well as some information from other HD scan customers will be given.

Marc Köster, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Piero Frittella, Feralpi Group
Jörg Bellmann, ESF Elbe Stahlwerke Feralpi GmbH
Ralf Schuster, ESF Elbe Stahlwerke Feralpi GmbH
Matthias Groll, ESF Elbe Stahlwerke Feralpi GmbH
Waldemar Krieger, VDEh-Betriebsforschungsinstitut GmbH
Martin Schlautmann, VDEh-Betriebsforschungsinstitut GmbH

Abstract:
For the first time, a laser vibrometer system in combination with appropriate artificial intelligence methods for clustering of the measured vibration spectra has been tested at a continuous casting machine to receive information on the solidification status of the strand. Measurements with the laser vibrometer at a fixed strand position of the billet caster of ESF under conditions of incrementally increasing casting speeds revealed a transition in the population of the identified vibration clusters as a footprint of the passed crater end position with a change from a fully solidified strand to a strand with some liquid core at the measurement position. This was in accordance with the results from a three-dimensional dynamic temperature and solidification model which has been set up based on a state-of-the-art approach for solution of the heat flow equation with tailored sub-models for the different boundary zones of the ESF billet caster (i.e., mould, secondary spray water zones and radiation zones) and installed at the steel plant for online monitoring and control of the casting process. The application of the newly installed measurement and model-based information systems at ESF revealed significant improvements of their billet casting process in terms of reduced strand breakout rates and increased productivity.

Volodymyr Omelchneko, thyssenkrupp Steel Europe AG, Germany

Co-Author:
Sven Karrasch, thyssenkrupp Steel Europe AG
Christoph Toulouse, thyssenkrupp Steel Europe AG
Sascha Lang, thyssenkrupp Steel Europe AG

Abstract:
The Continuous Casting Machine (CCM) Bruckhausen is part of an integrated steel plant of thyssenkrupp Steel Europe in Duisburg. The main customers are the market leaders in the packaging, automotive and electrical industries, who set high standards regarding the surface quality of their products. Due to the closeness of CCM and hot-rolling mill in Bruckhausen, the transition time of the slabs from CCM to the hot-rolling mill is quite short. This shortness has two main advantages. Firstly, it allows to save energy which is needed for reheating of slabs. Secondly, slabs with short transition time have fewer micro cracks on the slab surface. The short transition time, however, brings a big challenge for the production process, since it limits the time available for the quality control of the slab surface and exclusion, if defects are detected. The most frequent defects on slabs are longitudinal and transversal flame-cutting burrs/beads and different types of cracks. In the past, the slab surface was controlled by means of thermal camera to detect those surface defects. This technique has reached its limits regarding the present challenges for the quality of the slab surface. To fulfill continuously increasing customers surface quality requirements, in March 2022 we implemented the first slab surface inspection system of thyssenkrupp Steel. It is a 3D Surface Inspection System (SIS) supplied by IMS Messsysteme. Within six months after the installation of the 3D SIS the internal quality costs as well as quality KPIs of our customers had been improved. After giving a brief introduction in the principals of 3D SIS technique we will present the main advantages of the 3D SIS in comparison to a basic thermal camera detection system, the recent impacts on quality results and next planned development steps.

Reinhold Leitner , Primetals Technologies Austria, Austria

Co-Author:
Christoph Aigner, Primetals Technologies Austria
Thomas Zauner, Primetals Technologies Austria

Abstract:
"The entire steel industry is going through the irreversible process of digital transformation and increasing plant automation to meet the requirements in terms of productivity, safety, quality as well as increased flexibility in production. A digital caster has many challenges and sub-tasks that must be achieved along the way to end up with a fully digitalized plant operation. The fully integrated casting platform with automatic controlled sequence operations starting from connecting the ladle on the turret to fully automatic tundish operation and start cast by means of robots and highly integrated automations systems limits the need of operator interventions to an absolute minimum. Thus, not only results in a reproduceable high quality caster operation but also increase operator and machine safety. One crucial aspect is controlling the casting speed of the plant by an advanced expert system right from start cast until the last slab has been cut. All influencing factors such as optimal soft reduction, the casting practice or machine restrictions are brought together to calculate an optimal casting speed throughout the entire casting process. The paper gives an overview about a digital caster and outlines the latest innovations in continuous casting automation on the way to a fully automated caster. "

Gerald Hohenbichler, Primetals Technologies Austria, Austria

Co-Author:
Marvin Zemni, Primetals Technologies Austria

Abstract:
Predictive Maintenance starts with IIoT. Excellent and reliable sensorics are the first hardware basement for lifetime and failure prediction for production machinery and plants. Therefore Primetals Technologies started technology development programs in data mining as well as condition monitoring and smart sensoric, even though the first approach has always been to perform condition monitoring without additional sensor implementation, where possible. A major source of unplanned downtimes of continuous slab casting plants are stuck bearings in the strand guide area. Hence Primetals Technologies has been realizing a prototype development creating a new middle bearing block with embedded sensors and an onboard tiny central processing unit, able to wirelessly transfer all interesting load data and performance indicators to the operators of the plant and to the maintenance personnel. The plant manager gets an overview about the overload events shift-by-shift or daily, weekly, and monthly, respectively. This paper provides a great insight into the first industrial prototype results.

Pierpaolo Rivetti, SMS Concast AG , Switzerland

Co-Author:
Stephan Feldhaus, SMS Concast AG
Shuai Niu, Nanjing Iron & Steel Co., Ltd.
Xinghua Chen, Nanjing Iron & Steel Co., Ltd.
Wei Deng, Nanjing Iron & Steel Co., Ltd.
Zhiyong Hu, Nanjing Iron & Steel Co., Ltd.

Abstract:
The present study focusses on the internal quality improvement of the spring (54SiCr6) and bearing (GCr15) steel blooms by optimizing the MSR (Mechanical Soft Reduction) and MHR (Mechanical Hard Reduction) process parameters on the continuous casting machine supplied by SMS Concast AG at Nanjing Iron &Steel Co. In addition to MSR and MHR, the caster is equipped with electromechanical stoppers, mold electromagnetic stirrer (M-EMS), final electromagnetic stirrer (F-EMS) and air-mist spray cooling. State of the art L1 and L2 software complete the technological packages for this machine. Solidification status of the blooms with sections of 255 mm x 300 mm and 330 mm x 420 mm were determined by using the verified FEMS solidification model provided by SMS Concast AG. Theoretical effective reduction region was proposed based on the simulated crater end position of the blooms. Intensive industrial trials were conducted to study the effect of the reduction rate on the V-shaped and centerline segregation of the blooms. The results show that obvious improvement of internal quality of the spring and bearing steel blooms of both sections could be obtained by increasing the reduction amount and applying a suitable reduction rate in the effective reduction region during casting.

Maria Thumfart, K1-MET GmbH, Austria

Co-Author:
Christine Gruber, K1-MET GmbH
Johann Wachlmayr, K1-MET GmbH
Roman Rössler, voestalpine AG

Abstract:
In the upcoming years, the steel industry faces major challenges due to the demands of CO2 reduction and a shift towards circular economy. These developments lead to a larger diversity in crude steel compositions and thus to increased demands for secondary metallurgy including the RHplant. To meet these increased demands the efficiency of the RH process needs to be improved. Such an improvement can be based on better process understanding, enhanced process models and improved measurement data. The results presented in this paper target the improvement of the process understanding by providing advanced analysis of high-quality images of the melt surface in the chamber. These images show a complex two-phase flow situation ranging from highly dynamic steel foam to the generation of small drops. Different situations can be linked to different process conditions. During oxygen blowing the generation of small drops is more likely, while during calmer degassing steps a coarse steel foam layer of significant thickness can be observed, emitting singular or lumps of liquid steel bubbles completely detached from the melt surface. In addition to these phase distribution phenomena a pulsating behaviour of the melt can be identified during foamy states showing regular eruptions. This dominant frequency has been detected based on the velocity of the visible objects in the chamber. These observations provide the basis for better process understanding and better process monitoring. The presence of a foam layer implies that the interfacial area between gas and liquid is much larger than expected while the dominant frequency of the velocity evaluation might be used to validate simulation models for the two-phase flow in the chamber. The visible difference between the different states in the chamber can be exploited for video-based process monitoring. These findings are a first step towards improving the RH process and its reliability.

Claire Dwyer, Tata Steel Ltd , Netherlands

Co-Author:
Manuel Atienzo, Tata Steel Ltd
Robert-Jan Pielkenrood, Tata Steel Ltd
Aart Overbosch, Tata Steel Ltd
Huijuan Ding, Tata Steel Ltd

Abstract:
The injection of gas through the porous plugs during ladle treatment is important for the homogenisation of both steel chemistry and temperature and is critical to ensure the production of high quality steel. It is important to monitor the stirring performance as it is difficult to visually observe by the operators, even with the help of the surveillance camera and there can be leakages in the system or blockages of the porous plugs that affect the operation. To be able to objectively assess the stirring of a ladle during treatment at Ladle Furnace 22, in the steel plant of Tata Steel IJmuiden, a uniaxial accelerometer was installed on the ladle transfer car. This data was then processed and wirelessly transmitted on a per second basis to both the production PLC and a historical storage server. This data was then modelled and the output was shown to the operators on a screen in the pulpit. There were many learnings throughout the implementation process. This paper will elaborate the experiences during the project and what was achieved. After a period of preparation, a setup was installed and commissioned successfully. Since implementation all ladles are objectively rated and with this proof of concept complete it can be rolled out to the second plug of the ladle and then to all the other ladle treatment stations.

Eunju Jeong, POSCO, Korea, Republic of

Abstract:
Recently, many steel companies has been developing technologies for the realization of SMART steel making process. POSCO is also highly interested in automation process using smart technology in each process field to realize the smart factory. Papers and patents on automation process easily searchable across countries, and commercial technology products are on sale. Most of the automatic refining technologies aim at the dynamic control linked to the real-time decarburization characteristics while the static control by statistics proceeds. In this paper, the refining automation system in the AOD process that is being carried out at POSCO is introduced. In general, control of Oxygen-Nitrogen(or Argon) blowing step, basic weight and input of raw materials and temperature measuring and sampling of sub-lance are all performed manually by operators in AOD. Although this works are carried out under the standard, there is an operating deviation due to human factors. Therefore, an automatic refining technique was developed to reduce these human deviation factors in this study. In this automatic refining system, the decarburization state in the vessel is tracked in real time using the off-gas analyzer, and the end point of the each decarburization step is determined according to the criteria set and the blowing step is switched automatically. The raw materials to be added in the AOD process in order to match the ingredients for the steel are set in advance before the operation. When the automation of blowing starts, the raw materials are automatically weighed and put into the vessel according to each blowing step. Sampling for temperature and component confirmation of molten steel is also automatically performed at the designated time. Through this automatic control technology, it is confirmed that the operation deviation and amount of oxygen consumption was reduced.

Johan Björkvall, Swerim AB, Sweden

Co-Author:
Dan Sandström, Swerim AB
Fredrik Sandin , Luleå University of Technology
Konstantinos Rigas, KTH Royal Institute of Technology
Jurki Pitkälä, Outokumpu Sweden AB
Niklas Grip , Luleå University of Technology
Nils Andersson , Swerim AB
Björn Glaser , KTH Royal Institute of Technology
Mikael Svensson , Uddeholms AB
Robert Vikman , Jernkontoret

Abstract:
Measurement of the vibrations from metallurgical processes may give an indirect description of the process performance, thereby providing means to improve the overall process control. This approach is applied to the gas stirring of a ladle during vacuum treatment and the AOD converter in the present work. Analysing the vibration signals is challenging when vibrations from other processes surrounding the ladle or converter may affect the measurements. Even do vibration measured on ladles and converters has been reported before, the installation of vibration sensors must be adapted to plant-specific conditions as the temperature of sensors’ mounting positions and surrounding processes create vibrations. Positions for mounting the accelerometer were found close enough to monitor the vibrations from the process but at the same time at a position where the heat from the steel melt did not overheat the sensors. The positions of the accelerometers did not negatively affect the logistic of the steel production or the regular working procedures at the steel plants. Different mathematical algorithms were used to evaluate the recorded signals as machine learning, wavelet transform and the commonly used Fourier change. A comparison of the results from these different algorithms with available process parameters shows that the vibrations of the process correlate to the process performance. The analysed results correlate to the regulated gas flow at the vacuum ladle treatment and deviations most likely caused by fewer working porous plugs. In the AOD converter, the refining steps may be followed as different vibration intensities.

Michael Aigner, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG, Austria

Co-Author:
Henk Bolt, Tata Steel Nederland Technology B.V
Danny Beentjes, Tata Steel Nederland Technology B.V
Thomas Trickl, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Leonel Elizondo, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Michael Brandner , Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Armin Paar, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Maximilian Reiter, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG

Abstract:
Graphitic HSS roll grades such as ESW’s brand VANIMO can be considered as the latest developments for the last finishing stands in hot strip mills. These roll grades are developed on the basis of the alloying concept of (Carbide Enhanced) Indefinite Chill work roll materials. During the development of VANIMO, the amounts and types of carbide-forming elements were increased and adjusted in the direction of cast HSS roll grades. The microstructure of graphitic HSS roll grades, therefore, consists of tempered martensite, cementite, and several different carbide types as well as a well-defined amount of free graphite. The main purpose of graphitic HSS roll grades is the combination of the high surface quality of Indefinite Chill alloys as well as the high wear resistance of HSS roll grades. The development and introduction of this very advanced roll grade at Tata Steel’s Direct Sheet Plant in The Netherlands were done in close cooperation between the customer and the roll supplier. Several systematic steps were taken to increase the wear performance from Carbide-Enhanced Indefinite Chill grades to the more advanced grades to reach the highest alloyed roll grade VANIMO. In every development step, the surface quality of the roll grades was carefully monitored. This paper describes the improvement of the wear performance for roll grades in the last finishing stands in the Direct sheet plant by introducing higher alloyed roll grades, up to VANIMO. Different appearances of the strip surfaces in relation to the work roll material are presented and the root causes for these phenomena are explained. Finally, some possible strategies to improve the surface quality of graphitic HSS roll grades are presented.

Sebastien Flament, CRM Group, Belgium

Co-Author:
Henk Bolt, Tata Steel Nederland Technology B.V
Gisele Walmag, CRM Group

Abstract:
Back-up rolls (BURs) in cold and temper rolling mills often exhibit very inhomogeneous wear rates over their barrel length. Wear rates and resulting BUR wear profiles are usually not understood and (thus) not well predicted. The BUR wear profile has, in turn, a large effect on the local work roll/back-up roll (WR/BUR) contact stress distribution along the BUR barrel length. This crucial parameter for rolling contact fatigue is also unknown as well as also highly inhomogeneous. Consequently, also the onset of local rolling contact fatigue (RCF) at the BUR surface is poorly predicted and may in fact differ strongly between consecutive mill campaigns of the same BUR, so that mills struggle to define adequate (= safe and economical) practical maximum BUR campaign length limits. An assessment of BUR wear and rolling contact fatigue phenomena by examination of worn BUR surfaces in association with rolling mill process data and profiles has enabled to determine the degradation mechanism of various rolls in different kinds of cold rolling and temper mills, stand positions and materials. This analysis, based on light optical microscopy, hardness, roughness and profile measurements was performed on-site at Tata Steel in IJmuiden. Further analysis of BUR wear and contact fatigue damage accumulation in the sub-surface region was enabled by microscopic analysis in cross section of samples extracted from two scrapped BURs, an ICDP BUR and a 3%Cr forged steel BUR. This paper will give an overview of back-up rolls degradation, surface aspects, mechanisms and important differences of selected cold and temper rolling mills.

Thomas Rasmussen, Åkers Sweden AB, Sweden

Co-Author:
Jonas Lagergren, SSAB AB
Stefan Wahlund, Union Electric Åkers
Johan Eliasson, Swerim AB
Hans Magnusson, Swerim AB

Abstract:
A new High Speed Steel (HSS) concept for heavy-duty cast roll materials has been developed. Target was to develop a suitable casting and alloying concept to yield an optimized structure of the HSS material, but still using established production processes. More specifically, the current alloying concept needed to be modified so that unwanted phase transformation of softer phases, ferrite and pearlite, should be pushed to longer times, in order to reach the harder phases martensite and bainite upon cooling after austenitization. With guidance from computational thermodynamics different alloying concepts were studied by simulating continuous cooling diagrams (CCT), with interest on critical cooling rates and with respect to the available process window. To validate and confirm these alloying ideas, small scale laboratory ingots were produced, and industrial heat-treatments were simulated by dilatometry. From dilatation experiments and characterization, it was confirmed that the optimized alloying was able to push unwanted phase transformations to longer times, which resulted in improved mechanical properties. Different tempering trials were studied by varying double and triple cycles. Different tempering temperatures was then decided and evaluated by both hardness and impact testing. Based on small-scale laboratory work and the confirmation of alloying ideas, together with a suitable casting and modified heating concept, a full-scale Plate Mill Work Roll has been produced. This new HSS roll concept is now running in a hot plate mill, results are here presented.

Thomas Trickl, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG, Austria

Co-Author:
Michael Brandner, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Leonel Elizondo, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Michael Aigner, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG
Armin Paar, Eisenwerk Sulzau-Werfen, R. & E. Weinberger AG

Abstract:
Materials development for rolling application has become a multi-disciplinary exercise, trying to merge know-how and competence of experts from various fields. ESW follows this path for all developments related to shell material. This paper presents the framework of the current activities in HSS material development for hot strip mills. In this present project, a European HSM, R&D institutions and ESW are working on improving performance and surface capabilities of HSS material. Special emphasis is laid on the work in the area of heat treatment. Here, the project goal was to develop a simulation model to identify critical points of time, time savings and to predict alternative heat treatment routes not previously used for HSS compound work rolls. The simulation was set up in an axisymmetric 2D model in the FEM software Abaqus. For model setup, thermophysical data as well as data from a temperature field measurement were used. The temperature field was recorded by an instrumented work roll containing 12 measuring thermoccouples at different axial and radial positions, during an entire heat treatment. The model was also validated with data from CCT and TTT diagrams as well as dilatometer and residual stress measurements.

Hartmut Pawelski, SMS group, Germany

Co-Author:
Alexander Ring, Thyssenkrupp Rasselstein GmbH
Martin Höß, Thyssenkrupp Rasselstein GmbH
Holger Pulst, SMS group
Christian Wietzig, SMS group

Abstract:
In the cold rolling business, the trend towards thinner and/or materials with higher strength or generally improved mechanical properties is unbroken. For the DCR process (double cold reduction) in tin plate industry, this means production of grades DR9.5 (AISI/ASTM 623) or beyond, final thickness towards 0.1mm, and reduction up to 50% in a single pass. When roll gap lubrication conditions and strip tensions already are at an adequate level, reduction of work roll diameter remains the most efficient way to achieve these goals. For an existing mill, normally this affords an extensive revamp. To overcome this situation, a cassette with two smaller rolls was developed, which exactly substitutes one of the large work rolls in the first stand of a DCR mill, so that in fact a 5-hi configuration is created. The change between 4-hi and 5-hi mode and back is as simple as a normal work roll change. In the presentation, the theoretical aspects of combination of small and large work roll diameter and the influence of these asymmetric conditions on process parameters, material flow and properties are discussed. A prototype system was designed by SMS group. It was built in cooperation with thyssenkrupp Steel - Packaging Steel (Rasselstein) in Andernach and successfully tested in the first stand of Rasselstein‘s DCR mill NWW4. Technological features regarding drive situation, horizontal forces and flatness control are described. Measured process data is presented, which illustrates the potential, regarding roll force decrease in combination with high strip thickness reductions.

Livio Taccani, Tenova S.p.A., Italy

Abstract:
Over the recent years industry trends pushed further the roll shop automation from automatic to automated, making the roll grinding process more independent from the human intervention. Pomini Tenova, with a solid ground of three decades of successful experience in designing and delivering total automated solutions, combines the adoption of proven solutions with modern technologies effectively matching to the actual industry trend. Several automation engineering developments, enhanced roll inspection systems, application of latest digital technologies as well as high level software controlled CNC loading dedicated cranes, allow a smooth workflow of rolls across the roll shop with enhanced operational safety, repeatability and plant productivity.

Thomas Haschke, SMS group, Germany

Co-Author:
Thorsten Huge, SMS group
Michael Lipowski, SMS group
Christian Mengel, SMS group
Bettina Fischer, IMS Messsysteme GmbH
Horst Krauthäuser, IMS Messsysteme GmbH
Ingo Leckel, Salzgitter Flachstahl GmbH

Abstract:
An excellent width performance is indispensable to enable stable, efficient and sustainable production. Since width control in hot rolling mills is almost exclusively possible in the roughing mill, the width measurement in the roughing mill is of particular importance. Radar technology has proven to be suitable for such applications due to its robustness and precision even under the harsh environmental conditions including steam, dust and high temperatures. In the hot strip mill in Salzgitter, a radar width measurement is installed between the slab sizing press and the roughing mill immediately upstream to the edger and used for several tasks in order to optimize the transfer bar and therewith finally the finishing strip width: First, the width error coming from the slab sizing press is calculated by comparing the slab width measured in the radar gauge and the setup width of the press. A possible width error is corrected by an adaption model in the pass schedule model PSC® and given as an additional offset to the slab sizing press for the subsequent slab. Second, the measured strip width is considered in the PSC® within the recalculations of the reversing passes in the roughing mill. Based on the reliable measurements, updated width information are used to calculate new setups for the next subsequent combinations of width- and thickness-reductions in the roughing mill. Third, the information from the radar gauge are used in the level 1 control system for plausibility checks in order to optimize the tracking accuracy and therewith the short stroke control at the slab ends in the edger. With these measures, the width errors and above all the excess width at the strip end could be significantly reduced. Further improvements can be achieved by considering the measurements in the short stroke control to avoid necking respectively excess widths.

Michael Breuer, SMS group, Germany

Co-Author:
Georg Padberg, SMS group

Abstract:
The flat product market increasingly demands hot strip for direct further processing. Thin hot strip is applied in many industries. In general: all cold rolling applications that do not require heavy deep drawing operations and a high surface quality can be replaced by thin hot strip. Plant owners may optimize or reduce the process steps. Cold rolling passes and/or intermediate annealing can be omitted or even be canceled completely, resulting in increased profitability and energy savings. There are special hot mill concepts on the market, which focus specifically on the thin strip demand. However, they come with a drastically reduced product range and weakened flexibility to react on process disturbances. The process control in a hot strip mill has to face special challenges arising with the production of strip with thicknesses of less than 2 millimeters. Some of the typical challenges that occur during thin-strip rolling are: • Ripped strip end • Pinching caused by unflatness • Steering control • Increased roll wear • Save coiling • Speed limitations These challenges may cause a deterioration of the yield due to increased off-gauge lengths and the number of cobbled coils. SMS group is aware of these challenges and offers customers a “toolbox” to improve the behavior of the hot strip mill when “going thin”. The “toolbox” consists of mechanical and automation equipment and software. Beside fast mechanical actuators, a number of strip guiding systems are part of the toolbox. The strip steering control module has an important task in achieving a straight transfer bar and avoiding cobbles and ripped strip ends. Also, the operator is released from the leveling task and can focus on the rolling process. Beside strip steering control, the paper will give insights into other related topics and their impact on the production of thin gauges. Some operational results will be presented as well.

Jakob Schwarzmann, IMS Messsysteme GmbH, Germany

Co-Author:
Horst Krauthäuser, IMS Messsysteme GmbH

Abstract:
Cold rolled steel plate contains a variety of defects. Some optically visible defects cannot be reliably classified by OIS due to missing depth information. Defects not protruding trough the material surface, like non-metallic inclusions (NMI), are invisible for optical inspection systems and can disturb further processing. Therefore, a complete online inspection for hidden defect detection is required to ensure proper material quality, prevent disturbances during further processing and enable defect root cause identification by augmenting OIS data. A proven detection method for hidden defects in ferromagnetic materials is magnetic flux leakage, which is widely used as magnetic powder testing. IMS extended this method to moving material by developing an online MFL inspection system using GMR magnetic field sensors which generate a complete magnetic image of the strip (inclusion detection System – IDS). The generated images are processed by an advanced processing software which reliably finds defects in the background noise and enables their classification based on configurable features. The position of the magnetic field sensors is automatically adapted to varying material thickness. Optical and capacitive sensors permanently check the strip for folds and monitor the gap between the sensors and the material. In case of line disturbances, a rapid retraction of the sensors is contrived by spindle and pneumatic drives. The latter also allows to move the system out of line for maintenance. All relevant elements are liquid-tempered for operation under various ambient conditions. While initially being developed for thin cold rolled plate, tests have shown the suitability of the IDS for usage on thicker material. A promising sensitivity was achieved for thicknesses of up to 2 mm, opening up new applications like automotive cold rolled plate. This paper and presentation show the concept and implementation of this inspection method as well as results for various types of defects and materials.

Ahmet Mithat Avsar, İsdemir, Turkey

Abstract:
The innovative technology and sophisticated control systems for hot rolling mills has opened up new possibilities for designing and engineering of efficient systems and overcome common problems specific to processes. Performance of rolling mills and subsequent processes such as coil box equipment are key to successful production in today’s World of steel manufacturing. In the Coilbox, the transfer bar which is coming out of the roughing mill is coiled. Unwinding is effected in the reverse direction. The tail end of the bar runs first into the finishing mill. The Coil Box Stabilizer 1 is installed on the Cradle Roll 1A/1B that guide the transfer bar into the Coil Box. Stabilizers consist of stabilizer plate and guide rods, and are used for centering the coil position. The stabilizers are operated by means of hydraulic cylinders with position transducer to ensure the stability of a coil during coiling and uncoiling operation. In this paper, When the transfer bar starts coiling to the defined diameter, the stabilizer moves to short stroke position – set point is function of slab width, offset and short stroke value with position control. The control mode is switched to force control when the guide plate comes into contact with the transfer bar. But this process can lead to cobble situation especially tail end starts to open… This paper introduces In this paper …tail ..problem is examined Succesfully applied solution is presented… by improving working principle of stabilizers… intelligent mechanism is adapted o existing working modes… intelligent force control first by sensing if … occurs then prevenitive measure is taken by switching the mode from position control to force control if force level exceeds certain limit .. and then.. stability of tail of transfer bar mqaintained… thus preventing transfer bar to stuck in down stream equipments such as stabilizer 2, FM Stands

Ion Rusu, BM GROUP POLYTEC S.p.A., Italy

Abstract:
The robotic workstation allows to cut, remove and break the steel strap used in the binding process of the cut coils entering the ERW Tube Mill. A 3D computer vision system can identify with high precision the position of the strap and the start of the coil to identify the best cutting position in order to avoid any damage of the external surface of the coil. This automated solution allows complete operator safety in the production process.

Kosei Tsuji, Primetals Technologies Japan, Japan

Co-Author:
Ichiro Maeno, Primetals Technologies Japan
Shinichi Yasunari, Primetals Technologies Japan
Takehiko Saito, Primetals Technologies Japan
Konrad Krimpelstaetter, Primetals Technologies Austria

Abstract:
"Actual mega trends like electro mobility, energy transition and urbanization require rapidly increasing amounts of non-grain oriented (NGO) and grain oriented (GO) electrical steels with improved magnetic properties for building high-efficient motors, generators, and transformers. Especially future electric cars will need more thin-gauge high-permeability NGO electrical steel for traction motors with low power losses to increase their cruising range. GO steels are the best choice for transformers, due to its outstanding magnetic properties in the rolling direction, and the demand will certainly rise with increasing electrification. In order to give newcomers, the possibility to enter the electrical steel market and to serve existing high-end producers with the best process technology, Primetals Technologies has developed and introduced many innovations to support a profitable production of NGO and GO electrical steel. This paper introduces best of the market technologies and references for the production of high-grade NGO electrical steels, like the advanced APL (Annealing Pickling Line) with new inline Silicon Reduction, the well-established 6-high cold rolling mill HYPER UC-MILL with additional features like edge-drop control (EDC), Minimum Quantity Lubrication (MQL) and Strip Temperature Guidance (STG). Further key technologies for GO production are described in the paper, like the new generation of 20-high mill HZ-MILL with advanced features to handle ultra-thin, hard, and brittle material grades while keeping highest geometrical tolerances and product quality."

Elmira Montazerozohour, Primetals Technologies Austria, Austria

Co-Author:
Bo Yang, Primetals Technologies Austria
Sergey Bragin, Primetals Technologies Austria
Carlo Piemonte, Primetals Technologies Austria
Andreas Jungbauer, Primetals Technologies Austria

Abstract:
With the limitations of conventional technologies, the development of electrical steel grades is rather challenging and requires lot of experience, such as ensuring uniform thermomechanical conditions along the length and width of the strip. Contrary, the endless operation of Arvedi ESP (Endless Strip Production) delivers uniformity naturally by its process design. Moreover, this environmentally friendly technology leaves zero-carbon emission with minimum energy consumption which fulfils the global trend of green steel production. The hot strip produced on the ESP line shows high quality and the necessary properties, as well as energy and cost saving benefits, for a wide range of electrical steels. This paper presents an analysis of the ESP process characteristics with their influence on the final properties and quality of electrical steels.

François Dumortier, John Cockerill, Belgium

Abstract:
Climate change is the biggest threat that humankind has ever faced. The decarbonization of transport is a crucial part of the solution to reducing greenhouse gas emissions and global warming. One of the most notable trends in this field is the considerable growth of the electrical vehicle market that is forecasted to become exponential in the coming years. Consequently, the production capacity of non-grain-oriented (NGO) electrical steel will have to increase at the same pace in order to fulfill the drastically and rapidly growing market needs. While addressing this challenge, electrical steel producers will also have to find ways to produce thinner strip and increase its silicon content to make vehicles lighter and considerably improve the efficiency of electric motors. To address the extremely difficult rolling of this type of advanced electrical steels, John Cockerill has developed a new 6-Hi reversing mill called: E-Qual® Mill. Its innovative design features an optimized work roll diameter specifically designed to avoid the roll flattening of thinner gauge electrical steel strip, all while providing the torque requirements for the first passes. Since this type of electrical steel is very brittle at ambient temperature, the E-Qual® Mill’s new design foresees the installation of an inductive heater on the pay-off reel pass line to avoid strip breakage at the first pass. Additionally, its upgraded cooling system allows for the highest degree of thickness homogeneity required to produce highly-performant electrical motors. The technical paper will present the new multi-functional mill design and the main technical characteristics of the mill.

Armin Büttgen, thyssenkrupp Steel Europe AG , Germany

Abstract:
New process for hot rolling of high-strength pipe steels A. Büttgen, A. Kern, C. Konrad, A. Latz, C. Straub thyssenkrupp Steel Europe, Duisburg Due to the ecological and economic situation worldwide and the resulting steadily increasing demand for pipelines, more and more efficiency of the hot strip manufacturing process to produce pipe steels is required. To achieve the demanding mechanical properties of modern pipe steels in terms of strength and resistance to brittle fracture, a very fine ferritic microstructure is crucial. So far, thermomechanical rolling with final rolling temperatures as low as 780 °C has been the method of choice. Unfortunately, this process reduces the plant performance due to noticeable delay times between roughing and finishing. Moreover, inhomogeneities become more pronounced along the strip, which deteriorates the performance of the product. To overcome this problem, a new rolling strategy for high-strength pipe steels was developed supported by numerical modelling of the microstructure and mechanical properties. In conjunction with a simultaneous adjustment of the cooling strategy with increased cooling rates, roughing and especially finishing can be carried out more gently. The resulting ferritic or ferritic-bainitic microstructure leads to at least a consistent product performance. This paper gives an overview on the characteristics of the new rolling strategy and presents first production results: The operational rolling results of pipe grade X70 show that the novel process leads to an increase in the performance of the hot strip mill compared to classical thermomechanical rolling. At the same time, the system load was significantly reduced and the product performance in terms of strength and resistance to brittle fracture was kept constant.

Mario Thome, SMS group, Germany

Co-Author:
Susanne Zeller, SMS group
Regine Ahrem, SMS group

Abstract:
The latest requests for ERW pipe mills were characterized by challenging conditions: the product range is more and more extended to pipes with extreme wall thickness and higher yield strength. At the same time, dimensional tolerances for pipes and profiles become stricter. Moreover, mill owners ask for technological support regarding easy and fast dimensional changeover in combination with traceability of process parameters and product quality. To comply with these demands machine and process design are transferred to a digital twin, which allows the designer to find the best mill configuration for revamped and new-planed mills. In combination with the mill automation the digital twin enables the operating personnel to find optimum settings in short time, taking in account induced deformation throughout the whole mill. This is big advantage for production, as the online model helps realizing the influence of the individual forming steps on the final quality. This saves valuable time and material, especially when dealing with a big variety of profile dimensions and pre-material conditions. In the first step towards the “digital twin” the complete pipe forming sequence was mapped as a parametric analytical calculation model, calibrated by FEA and practical experiences. Taking into account the interaction between stand usage, roll design and load limits, the model evaluates the optimum combination with regard to metal forming and economic aspects. Moreover, reliable initial setting values for the well-established “X-Pact® Quicksetting” system are calculated to accelerate commissioning new products or material grades. But also a process feedback is visualized online to indicate process limits and/or design limits. Up to now, the pre-forming section (lineal forming or breakdown forming) as well as forming section (fin-pass) and sizing/profiling have been added to the digital modelling approach. In future, a systematic process feedback enables a (self-)learning model to the point of a

Timo Haimi, Metso Outotec Oy, Finland

Abstract:
Case study: Three different feeds to a DRI smelting furnace Timo Haimi, Metso Outotec Metals Oy Abstract The decarbonization of Iron and Steel Industry has been progressing rapidly in the recent years with many projects advancing into next stages. The standard solution for lower CO2 emissions in steel making has been using the shaft kiln based direct reduction plant and a scrap melting electric arc furnace instead of blast furnace. However, if the majority of the primary steel making plants would follow the same approach, there would be a shortage of DRI-quality iron ore and high quality steel scrap. Hence there is a need to utilize new technological solutions to enable use of standard, blast furnace grade iron ore, especially to deal with the excess gangue and higher amount of slag. Metso Outotec has been checking whether the existing non-ferrous and ferroalloys smelting furnaces could be used in smelting of direct reduced iron feed, with the target of removing the slag from the DRI feed without causing extra iron losses into the slag. As there are many different types and qualities of DRI available for the smelting feed, there is also a need to evaluate the differences of each feed and all different DRI types would naturally generate different type of metal product as well. The following paper describes three case studies about different DRI feeds into the Metso Outotec DRI smelting furnace. The first case is high quality DRI with 0% carbon content, the second case is BF-grade DRI with 0% carbon content and the third case is BF-grade DRI with 4% carbon content. The carbon contents of these product metals made out of these feeds have been assumed to be 1%, 2% and 4% respectively. The case studies are showing different process parameters for each cases

Stefan Tjaden, K1-MET GmbH, Austria

Co-Author:
Christopher Harris, voestalpine Stahl GmbH
Bernhard Rummer, voestalpine Stahl GmbH
Bernd Weiss, Primetals Technologies Austria
Walter Wukovits, TU Wien
Andreas Spanlang, voestalpine Stahl GmbH

Abstract:
Steel plants in Europe are committed to reduce their carbon emissions by 80-95% by 2050 in accordance with the EU Climate targets. Today the majority of the global steel production is performed via the conventional BF-BOF route and responsible for 7% of global carbon dioxide emissions. While most of European steel plants are already running at a high efficiency through various optimization strategies, the transition towards more sustainable steel production routes such as the DR-EAF route is needed to further reduce the carbon emissions. In this study the potential reduction of carbon dioxide emission for the voestalpine Stahl Linz plant is simulated by partially switching the steel production of one BF to a DR-EAF. For the assessment of the theoretical carbon dioxide emission reduction, a digital twin of the voestalpine Stahl Linz site was implemented in its as-is conventional BF-BOF route set up and compared to a theoretical substitution one of voestalpine’s BF by a DR-EAF plant. Therefore, the voestalpine Stahl Linz plant is depicted through the m.simtop metallurgical process modelling library in form of a flowsheet and validated with process data. In a subsequent step the flowsheet was modified by removing one BF and introducing a DR and an EAF to form a hybrid steel plant. For further CO2 reduction the use of coke oven gas at the blast furnace or in the DR process was simulated and the changes in the energy network of the steel plant are investigated.

Joachim von Scheele, Linde plc, Germany

Co-Author:
Pravin Mathur, Linde Inc.

Abstract:
Most of the world steel production takes place in countries that have already committed to achieve net-zero carbon emission goals, and many producers have set carbon neutral goals over the 2030-2050 timeframe. Although the pace of reaching green steel production will vary across different regions of the world based on the individual preconditions, similar pathways could be considered, potentially with geographical dislocation of supply chains. Naturally, direct carbon avoidance solutions like increased scrap use and electrification are the first steps to achieve sustainability and decarbonization. Between the years 2000 and 2010, the world steel production grew by more than 700 Mt/a, and this is resulting in a massive increase in availability of scrap for decades to come, especially in China. Electrification, based on clean power supply, is the route to decarbonize many processes, however, many unit processes in steel production are extremely difficult to electrify. These include processes for iron ore reduction as well as heating processes which use large scale high temperature combustion. For such processes, the main options include use of oxyfuel combustion to achieve increased energy efficiency, introduction of low carbon fuels, and carbon capture. Ultimately, the use of clean hydrogen as a reductant as well as a fuel source is the endgame that steelmakers will adopt when a viable supply of hydrogen becomes available. Accordingly, there is here a general pathway to decarbonization: 1. Oxyfuel combustion for increased energy efficiency 2. Use of low carbon fuels 3. Carbon capture for storage or use 4. Use of clean hydrogen as reductant and fuel This paper discusses and exemplifies proven solutions and technologies ready for implementation along each pathway, including, for example, full-scale use of hydrogen as fuel in electric arc furnaces and reheating (scheduled for 2023), and DRI production using gasified waste and carbon capture.

Christian Dengler, Paul Wurth S.A., Luxembourg

Co-Author:
Olivier Mersch , Paul Wurth S.A.
Volodymyr Kuskov, Paul Wurth S.A.
Dirk Malcharek, Paul Wurth S.A.
Fabrice Hansen, Paul Wurth S.A.

Abstract:
Following the old proverb that you cannot manage what you cannot measure, tracking of important production metrics is a requirement for staying competitive in the global market for iron and steel. The digital transformation promises new insights for production improvements through, among others, an increase in advanced data analytics, newer and smarter sensors and an improved exchange and display of information. Leveraging such potential through the realization of value adding digital solutions poses its own challenges for many plant operators in the iron and steel sector, foremost the lack of available work force with the required qualifications and the development time and costs for such software. For technology suppliers, this implies developing and delivering tools that provide immediate benefit and sufficient flexibility to integrate new diagnostics for specific problems or plants. Paul Wurth is continuously improving and developing such tools. Recent developments of such tools and their added value for ironmaking are topics of this article. In the article, we present how we reduce the time to product for condition monitoring and process optimization solutions using our low-code development platform DataXpert and show the general approach for the development of such systems using this platform. We then provide tangible examples of existing template solutions in ironmaking that are developed using this platform. Those template solutions deliver a set of existing functionalities and can be adapted or extended to the needs and requirements of specific plants. Added value is illustrated on several examples: monitoring of high level metrics for slag granulation, diagnostic analytics for coke machines or predictive maintenance for the bell less top.

Boris Marcukaitis, DANGO & DIENENTHAL, Germany

Abstract:
Forging manipulators are large machines used in open and closed-die forging and ring rolling. They can easily weigh as much as 1,000 tons and are used to position workpieces of up to 350 tons, moving them safely in all six degrees of freedom. They can only fulfill their function if the axes are reliable and precise, and the hydraulic control system works perfectly. Such highly dynamic machines are typically the bottleneck in manufacturing. If the manipulator stops working, so do the press and furnaces. This usually also impacts downstream processes like heat treatment and machining. The growing need to save both on maintenance and spare parts calls for new methods to keep systems operational. To increase the availability of these machines, DANGO & DIENENTHAL is developing a system for the early detection of failures of individual machine components. The system involves the installation of additional measuring systems to the standard sensors already installed. Various test programs employ a predefined movement profile to check the individual functions of the machine and record the registered times, vibration spectra, and pressure curves. The measured values thereby obtained are stored and compared with the results of the machine in new condition. The results are evaluated and a new remaining service life is calculated for the individual components. DANGO & DIENENTHAL will be able to offer this optional new functionality in the near future. The option increases machine availability and prevents unplanned system failures. It alerts customers to an impending breakdown, allowing them to obtain spare parts in time. Once these parts are available, the faulty parts can be replaced during the next scheduled shutdown.

Mark Haverkamp, SMS group, Germany

Co-Author:
Sebastian Kemper, SMS group
Thomas Nerzak, SMS group
Andre Peschen, SMS group
Karsten Weiss, SMS group

Abstract:
Digitalization is currently the focus of the steel industry in order to optimize plant planning, production, maintenance, service and training. Due to the large system dimensions and according complexity, intelligent solutions are in demand today more than ever. The "XR Plant Inspector" (XRPI) is such a solution. It was developed by SMS group to visualize complex plant models in 3D. In contrast to conventional CAD programs, this software can display entire steelworks in full detail by techniques deduced from the game world. XRPI creates a digital image of the real system, which e.g. helps to analyze maintenance tasks quickly and effectively. During training, XRPI supports participants in surveying the complete system virtually and collaboratively, thereby significantly enhancing qualification. Through this immersive training, the customer gains an immediate deep insight and can identify directly with his system, even in an early planning stage. Furthermore, the XRPI facilitates the commissioning process. Here, open questions, changed boundary conditions and solution approaches can be documented and discussed through the direct connection to the 3D data, preventing miscommunication. But that's not all, the software has recently been expanded to include important additional features, in particular the link to other SMS plant apps, providing an coherent overall concept to the customer. The XRPI new developments include e.g. the automated 3D model creation, the integration of 3D animations, an interface to eDoc (direct link to technical plant documentation) as well as an open MQTT interface, which enables the connection to other SMS apps such as Genius CM (predictive maintenance app). The publication describes these new developments. The use cases listed here give an insight into the wide range of potential applications and advantages for the plant operator.

Dieter Bettinger, Primetals Technologies Austria, Austria

Co-Author:
Klaus Stohl, Primetals Technologies Austria
Bernhard Voglmayr, Primetals Technologies Austria
Harald Fritschek, Primetals Technologies Germany
Martin Schaler, Primetals Technologies Austria
Thomas Kronberger, Primetals Technologies Germany

Abstract:
"Ironmaking facilities are very capital-intensive plants. There is a variety of smart solutions that provide guidance and support to avoid critical operational situations, warn in advance of system failures or equipment problems and support efficient maintenance. For new plants such advanced systems are frequently considered as essential, as they support cost efficiency and reduce the carbon footprint. However, also for plants in operation and in particular for plants at the end of the life cycle these systems provide important guidance to extend the lifetime avoiding disturbances, failures and critical situations. Various solutions from smart sensors to relevant aspects of process control and process optimization systems as well as predictive maintenance systems including digital assistants are presented. The possibilities to integrate legacy systems with advanced technologies and paths to an efficient interplay are illustrated and discussed. "

Matt Anderson, Primetals Technologies US, United States

Co-Author:
Paras Patel, Primetals Technologies US
Ruth Kirkwood-Azmat, Primetals Technologies US

Abstract:
"Primetals Technologies Long Rolling is at the forefront of applying the latest smart digital solutions in the industry. Their vision systems, developed over several years, provide an extremely strong, smart digital portfolio with a focus on improving safety, reliability and maintenance, while increasing production, yield and quality. In addition, these systems provide previously unattainable insights into the rolling process. Prevention is far more economical than problem fixing. Primetals Technologies promotes a proactive, predictive, and preventive maintenance approach for all our customers. Vibration analysis allows accurate prediction for mill maintenance; enabling improved downtime scheduling. Data is collected both periodically and continuously by our proprietary condition monitoring and analysis systems. Long-term partnerships have been developed with our customers, using our vast predictive service knowledge and over a century of long-rolling experience. Sub-optimal roll cooling can lead to premature roll wear, reduced yield, and catastrophic failure. Primetals Technologies has developed a new roll cooling system with a quick-change, additive manufactured cartridge, which along with sensors, helps to ensure rolls are receiving consistent, optimized cooling. With increasing focus on safety, operators are restricted from approaching the mill to perform manual checks on section size, equipment status or adjust settings. A new guide series provides continuous feedback on section size, equipment condition and allows remote adjustments. In addition, an alternative section measurement system has recently been brought to market. The main focus of this portable device is again to keep operators away from the mill during production, while providing accurate, objective measurements. Other recent developments include crop length optimization, Laying Head/Stelmor vision control system, and a roll-change robot. The paper gives practical examples how the implementation of smart digital solutions in long rolling leads to an improved plant performance, optimized maintenance strategy and safer operation."

Frédéric van Loo, CRM Group, Belgium

Co-Author:
José Luis Garcia Cimadevilla, ArcelorMittal España
Beate Froehling, BASF SE
Noelia Vega, ArcelorMittal España
Jose Barros Lorenzo, ArcelorMittal Maizières Research
Martin Ciarán, Tata Steel UK Ltd
laurent Fraikin, CRM Group
Yanping Xiao, Tata Steel Nederland Technology B.V

Abstract:
The cold-bonded agglomeration is a method to prepare materials with small particle sizes by turning them into larger pieces (agglomerates) which enable the use of these materials in dedicated processes. Several technologies are available and typically rely on the addition of a binder followed by a compaction step to maximize the contact between the particles of the source material. The suitability of the agglomerates produced for one particular process depends on its propension to maintain a sufficient cohesion between the constitutive particles in a given context : absence of fines generation on transportation belt, maintaining shape during its processing in steelmaking furnaces, … In the ironmaking context, cold-bonded agglomeration could complement high-temperature sintering and pelletizing for the production of the Blast Furnace burden. It does not require a costly and highly CO2 emitting firing/induration and, in the recycling context, could be applied to a larger range of by-products, wastes and other secondary materials. The novelty of the present study is to avoid the use of cement as a binder, removing the detrimental slag addition that the use of cold-bonded agglomerates would have involved. Therefore, the challenge of the partners involved in the project was the production of cement-free cold-bonded agglomerates able to maintain their physical coherence in the conditions of the blast furnace shaft. Two paths were pursed to achieve this result : firstly the use of novel polymeric binders, secondly the selection of the optimal agglomeration technology between vacuum extrusion and roll-press briquetting. The suitability of the samples was tested according to metallurgical standards and in particular the mechanical and reduction strength. We demonstrated that the selected polymeric binder combined with extrusion provides a suitable mechanical resistance at low and high temperatures (upper and lower shaft). The recipe developed becomes a suitable candidate for testing at industrial scale.

Yaowei Yu, Shanghai University, China

Co-Author:
Lixiang Yan, Chongqing Zhenyan Energy Saving and Environmental Protection Technology Co., Ltd.,
Huiting Chen, Shanghai University
Yonggang Zang, Guizhou University
Yuandong Xiong, Shanghai University
Ying Li, Shanghai University

Abstract:
Return fines of sinter (return fines) is used to prepare cold-bonded briquette (CBB). The powder generation rate, compressive strength, reduction disintegration index (RDI) of RDI+3.15 and compressive strength after RDI experiment of CBB are higher than that of sinter. For microscopic morphologies after RDI experiment, cracks initiate in the area of the return fines but don’t propagate through the whole matrix of CBB. Reduction index (RI) of CBB is lower than that of sinter, conversely, the compressive strength of CBB after RI experiment is higher than that of sinter. The CBB has been successfully utilized in the blast furnaces in northwest China, thus replacing 5-15% of sinter.

Awadh Kishor Gupta, Tata Steel Ltd , India

Co-Author:
Debaprasad Chakraborty, Tata Steel Ltd
Vipul Mohan Koranne, Tata Steel Ltd
M. Ramesh Kannan, Tata Steel Ltd

Abstract:
In an integrated steel plant, each process in iron and steel making value chain generates some revert materials in the form of LD sludge, LD slag, ESP dust, Flue dust etc. These materials cannot be thrown out easily as they contain many valuable components – Fe, CaO, SiO2, Carbon etc. Also, nowadays due to stringent environmental laws – outside dumping is not feasible. So, in these scenarios recycling these materials become an inevitable process. Sintering being a versatile agglomeration process has potential to accommodate these revert materials. But utilization of these materials possess challenges as some of them contain harmful elements as such Phosphorus, Zinc & Alkali. These elements limit their usage in sintering, but with proper planning consistency in the consumption of revert materials can be maintained without disturbing the process. At different locations of Tata Steel, consumption of solid waste varies from 60 to 120 kg/tSn. Cold Briquetting, Micro Pelletizing, Online pile making model, Phosphorus management framework to maximize LD Slag consumption, Separate conveyor system and some other modifications in the system enabled to maintain the consistency of supply & quality of revert materials. In addition, Zinc balancing from SP to BF enabled at Meramandali to optimize the consumption of zinc-based materials.

Yakov Gordon, Hatch Ltd., Canada

Co-Author:
Erick Bubniak, DIPROINDUCA  
Jose Senra, Diproinduca Canada Limited
Takshi Sachdeva, Hatch Ltd.

Abstract:
To decrease the environmental impact and increase the value of the by-products produced in the steel industry, recycling of by-products is imperative. This paper identifies three technologies as potential solutions to process low-grade feed as well as strategies to decarbonize these technologies. Oxycup process, Tecnored process and SL/RN Xtra are the three technologies being discussed. The raw materials targeted include fines, sludge material and mill scale. Since decarbonization of the steel industry is critical to meet the 2050 goal Sustainable Development Scenario (SDS) of limiting the rise in global temperature to 1.5 ֯C, a transition of these technologies to H¬ydrogen gas or Biomass as a reductant is also looked at. This paper summarizes the raw material specifications, capital cost, operating cost, environmental regulations and preliminary risks for each of the listed technologies.

Bertrand Orsal, Dassault Systèmes, France

Abstract:
The Steel industry is at a tipping point where sustainability and greenhouse gas emissions are top items on CEOs’ agendas. The old philosophy of engineering and production for profit is giving way to engineering and production for sustainability. Steel producers are adapting their business models, changing their priorities, and shifting their strategies as a response to the shifting market conditions. We know that this involves a transformation towards new ways of production limiting emissions like the direct reduction, but also capturing the CO2 emissions and optimizing the whole production chain. Dassault Systèmes provides a collaborative work environment (3DExperience) and comprehensive set of solutions that focus on green steel to enable and help accelerate this transformation. Solutions range from design, engineering and industrial process simulation capabilities to environmental assessment tools to calculate the impact of a plant over the course of its lifecycle. It includes a set of solutions to operate facilities such as integrating planning & scheduling. It provides capabilities for certification of green steel production through tracking of all plant data in a single source of truth platform. Find out how Dassault Systèmes and the 3DExperience platform make it possible to manage all industrial projects for green steel in the same collaborative space, for all roles involved, from design to production.

Bernd Koch, Matplus GmbH, Germany

Co-Author:
Alex Miron, Matplus GmbH
Igor Alperovich, Matplus GmbH

Abstract:
For structural applications, steel already has the best overall recycling rate of all materials - however, steel for structural components, automotive chassis and bodywork is today largely produced via the classic blast furnace route, which is still associated with high CO2 emissions for the foreseeable future. A key aspect in reducing the overall life cycle balance is the step towards the "circular economy", in which largely complete recycling is to be achieved. To this end, a holistic view of the production, usage and end-of-life processes is required. For steelmaking this task is faced with a “scale” issue – the actual processes are highly sophisticated and detailed down to atomistic chemical reaction scale, but the overarching material and energy flows are in the kiloton / GWh regime. While for both extremes process and simulation tools are available – classical LCA for the macroscale for instance – a universal modelling tool is missing, which bridges between the detail of process simulation and measurement and the macroflows, allowing to balance all efforts and outputs in a mathematically sound and cohesive manner. In this paper an innovative approach is presented, integrating well-established flow analysis methodology in a state-of-the-art materials knowledge system. Concrete approaches for mapping and modelling EAF steelmaking processes in terms of material and energy flows from input scraps to steel and recyclate output are presented, and concepts for bridging the scale gap are developed. Finally, the vision of a universal communication platform based on this model and data structure for all concerned parties, from waste managers over steelmakers to producers, is established.

Uwe Diekmann, Matplus GmbH, Germany

Co-Author:
Petra Becker, Matplus GmbH
Dominik Zuegner, voestalpine Forschungsservicegesellschaft Donawitz GmbH
Sabine Zamberger, voestalpine Forschungsservicegesellschaft Donawitz GmbH

Abstract:
A key challenge for steel manufacturers and users is the rapid creation and use of new technologies with improved environmental performance as a product of lightweighting and circularity. The acceleration of development processes can be achieved through the use of modern simulation techniques that also draw on extended knowledge bases. One element of the extended knowledge base is VDEh's Stahldat SX. Beyond standard data the Stahldat SX knowledge base includes research reports of applied steel research (FOSTA) and a growing number of models for transformation kinetics (TTT, Jominy), plasticity (flow curves) and compliance information (CAS-numbers). In practical application the information is extended by own results from material qualification projects along the process chain as well as specific CAE interfaces. For green steel technologies the mass- and energy flows as time series data along the process chain are subject of evaluations. Practical results with regard to accelerated development of new steel technologies are presented. This includes the consideration of energy demands along the process chain and comparisons to LCA data.

Didier Morice, AST Technology S.A.S. France, France

Co-Author:
Fabrizio Masia, AST Technology
Said Alameddine, AST Technology
Geraldo Ferreira, AST Technology

Abstract:
The quest for global optimization of Industrial processes to tackle environmental management recently took a new path thanks to the advent of big data analysis, IIoT, machine learning and artificial intelligence. During the last three decades, the industry in general has accumulated vast amounts of data but only a very small amount was generally explored and exploited. The new techniques mentioned, however, will enable the maximum benefit from all the accumulated data. The authors explain through tangible examples how supply chain and trade flows as well as available environment open-source databases can be pooled in the same data lake along with process data and explored with powerful analysis tools to twin not only the industrial process chain but also its footprint and impact on the environment. The authors conclude with a new emerging paradigm called “The Green AI”. This new paradigm will be used more and more extensively in the next decade to the benefit of Environmental Management. The obvious payback of this paradigm will be accompanied by major improvements of process and environmental factors.

Giovanni Bavestrelli , Tenova S.p.A., Italy

Co-Author:
Christian Leoni, Tenova S.p.A.

Abstract:
Metal scrap is a strategic raw material for the steel industry, accounting for a demand of nearly 30% of the metallic charge required for the global crude steel production, with the share that is foreseen to increase in the mid-term future. In scrap recycling steel mills, the scrap is typically loaded into an Electric Arc Furnace (EAF) in a controlled manner, tracking what goes in the charge mix and relating it to the quality of the liquid steel. Accurate tracking of scrap material from the time it enters the plant to the time it exits the furnace as liquid steel requires multiple technologies. The presentation describes the machine learning applications implemented in Ori Martin’s Steel Mill in Brescia, Italy, as part of the Lighthouse Plant “Acciaio_4.0” project in collaboration with Tenova. The project was selected by the Italian Smart Factory Cluster (Cluster Fabbrica Intelligente), on behalf of the Italian Ministry of Economic Development (MISE). The project created a Smart Factory in Ori Martin Steel Plant by integrating the enabling technologies of Industry 4.0 in the steelmaking process. The presentation focuses on the following solutions: • Automatic metal scrap classification • Identification of bulky material on Consteel® to prevent damaging EAF electrodes • Finding correlation between loaded scrap material and tramp elements in liquid steel • Optimization of charge mix with strict requirements on residual elements content • Rating of scrap suppliers based on production results The solutions involve the use of convolutional neural networks for image classification and various machine learning algorithms for process and sensor data.

Hyoungkeun Choi, Hyundai Steel Co. , Korea, Republic of

Co-Author:
Kyunghwan Lim, Hyundai Steel Co.

Abstract:
In the steelmaking process, the input of ferroalloy, especially Mn, causes a lot of heat loss. In this situation, the importance of the ladle furnace is gradually increasing as the production of high-grade steels containing a lot of alloys increases. However, due to the characteristics of LF operation, it is difficult to standardize operation, so automation is being developed later than other secondary refining facilities such as RH. However, with the recent development of machine learning techniques, it is possible to develop models with high accuracy, and it is also easy to connect the calculation results of these models with systems such as PLCs. As a result, demand for automation system development is increasing in LF as well. Our company developed a high-accuracy model for temperature prediction and completed a field test, and also developed a linear programming-based model for calculating the ferroalloy input. Based on the operator's operation performance, the pattern model according to the situation was configured as a rule-based system, and the automation system was developed by combining the previously developed temperature and ferroalloy model. As a result of applying an automated system that minimizes operator intervention to the operation, it was confirmed that more standardized and less variance operations were possible.

Christine Gruber, K1-MET GmbH, Austria

Co-Author:
Maria Thumfart, K1-MET GmbH
Johannes Wachlmayr, K1-MET GmbH
Roman Rössler, voestalpine Stahl GmbH
Birgit Palm, VDEh-Betriebsforschungsinstitut GmbH
Bernd Kleimt, VDEh-Betriebsforschungsinstitut GmbH
Sudhanshu Kuthe, KTH Royal Institute of Technology
Björn Glaser, KTH Royal Institute of Technology
Izaskun Alonso Oña, Sidenor Investigación y Desarrollo
Vito Logar, University of Ljubljana
Dejan Gradisar, Institute Jozef Stefan
Miha Glavan, Institute Jozef Stefan
Mojca Loncnar, SIJ Acroni d.o.o.
Pavel Ettler, Compureg Plzeň S.r.o.
Matjaz Demsar, Siemens Trgovsko in storitveno podjetje, d.o.o.
Zdravko Smolej, SIJ Acroni d.o.o.

Abstract:
The INEVITABLE project applies digital technologies for an optimized and improved performance of different metalmaking processes with focus on steelmaking but also for nonferrous alloy casting. The aim is the development of high-level supervisory and control systems for different production plants and their demonstration in operational environments to enable an optimized operation of the processes, going hand in hand with a reduction of resource consumption and CO2 emissions. The digital transformation and upgrade of the processes include data acquisition, processing and analytics of datastreams, standardization of relevant data interfaces and storage, and application of the functionalities of smart sensor technologies, cognitive control and Industry 4.0 concepts. The INEVITABLE project revolved around various steelmaking processes, ranging from electric arc furnace (EAF) and secondary metallurgy up to the cold rolling mill. This talk gives an overview over the cognitive control solutions developed in the project. For the EAF operations, process models and optimization framework have been developed, based on both theoretical and data-driven approaches using operational data. Their aim is to allow continuous online estimation of the bath temperature and oxygen level, offline process simulation for scenario testing, and optimization of the energy consumption via improved EAF inputs. In secondary metallurgy, ladle furnace and vacuum degassing processes have been considered. Based on vibration sensors and image data, the stirring behavior has been monitored. Together with the evaluation of other process data, model-based advisory systems for process control and decision support as well as predictive models for cleanliness and castability of liquid steel have been developed. Furthermore, a system for supervision, optimisation, and condition monitoring of cold rolling mills has been developed. Strip speed sensors and an x-ray thickness measurement have been introduced, and an overall upgrade of the databases has been implemented, including communication interfaces between sensors, edge devices and cloud database.

Yakov Gordon, Hatch Ltd., Canada

Abstract:
Minimization of CO2 emissions required changes in reducing gas composition from mixture of CO and H2 to pure H2. Changes in properties of reducing gas leads to changes in process parameters, furnace productivity, consumption numbers and quality of product. Phenomenological analysis of furnace operation was performed to analyze furnace operation with H2 as pure reducing gas. Similarity numbers were evaluated and expected changes in furnace performance were estimated. Influence of lower grade pellets on furnace performance was also analyzed and potential furnace parameters were studied. These findings are used to consult DRI plants on expected changes in DRI furnace performance.

Richard Elliott, Hatch Ltd. , Canada

Co-Author:
Ian Cameron, Hatch Ltd.
Gino De Villa, Hatch Ltd.
Jeff Eastick, Hatch Ltd.
Julia Allard, Hatch Ltd.

Abstract:
Shaft furnace direct reduction technology has proliferated globally over the past half century and more than 100 modules are currently operating. Choosing where to build these furnaces has been generally straightforward: build where natural gas is inexpensive and abundant. The next generation of direct reduction modules faces a more complex choice. Net zero scenarios for the iron and steel industry call for doubling the number of installed modules in half the time it took to deploy the existing fleet. Many of these new facilities will eventually use hydrogen as a reductant and must consider how their location affects their ability to transition partially or completely to hydrogen, electrify heating, access a competitive global iron ore market, and respond to accelerating legislated and voluntary decarbonization drivers. A transition to hydrogen-based ironmaking also forces a discussion on where to produce the required green hydrogen. Producing the hydrogen locally requires abundant green energy and freshwater; transportation from other regions, by pipeline or liquid ammonia conversion, may struggle to economically supply the immense volumes of hydrogen required for ironmaking. So, if the goal is decarbonization of the steel industry, why not move iron instead? DRI is already an effective means of ‘virtually’ exporting natural gas, enabling movement of solid iron rather than liquified gas, and can serve a similar export function in a future hydrogen economy. This paper aims to provide guidance for assessing the complex and competing factors affecting the choice of location for the next generation of direct reduction modules. These factors will be analyzed on a global basis and used to highlight the most promising regions for producing natural gas-based DRI while enabling a transition to hydrogen-based ironmaking. This paper will also compare technical and economic aspects concerning the export of hydrogen-based DRI with the export of hydrogen energy carriers.

Jose Senra, Diproinduca Canada Limited, Canada

Co-Author:
Erick Bubniak, Diproinduca Canada Limited
Joel Morales, Tenova S.p.A.

Abstract:
To demonstrate the technical and operational feasibility of processing briquettes made from iron fines in a Direct Reduction HYL Plant (DRP). An industrial trial was conducted by loading the DRP HYL reactor with a mixture of Iron Ore Pellets and Recycled iron Briquettes (RiB) made of iron ore pellets fines and sludge from the settling ponds. The physical properties of the RiB before the reduction process allows for conventional handling with industrial equipment to be fed to the reactor. The quality of the reduced RiB in Metallization and Carbon content is superior to the quality of the DRI pellets. Reduced RiB shows a compressive strength similar to or superior to the DRI pellets processed with the current Iron Ore Pellets. The results of the Industrial Trial carried out at a Direct Reduction HYL Plant, have sufficient physical and metallurgical properties to demonstrate the technical feasibility of the RiB technology. This allows the recycling of the iron ore pellet fines and sludge from the settling ponds in the direct reduction plants by producing RiB and mixing them with the iron ore pellets.

Milena Amábilis Ribeiro Gomes, RHI Magnesita GmbH, Austria

Co-Author:
Lukas Konrad, RHI Magnesita GmbH
Antoine Ducastel, RHI Magnesita GmbH
Taco Janssen, RHI Magnesita GmbH

Abstract:
In the steelmaking industry, the largest share of CO2 emissions comes from the reduction of iron ore. A switch from the blast furnace (BF)/basic oxygen furnace (BOF) route to the direct reduced iron (DRI) process with natural gas followed by the electric arc furnace (EAF) already enables CO2 savings of up to 38%. However, in order to meet the mid- to long-term CO2 targets of the iron and steel industry, further measures are required. Most DRI plants are currently operating on natural gas, which results in approximately 60% hydrogen in the process gas. However, currently projects are underway to determine if DRI units can operate at hydrogen levels at or close to 100%, which could further reduce CO2 emissions by more than 80%. In this context, it is important to consider the impact of hydrogen on the refractory lining in the DRI shaft kiln. Previous studies have shown that hydrogen can permeate through refractories and reduce ceramic oxides under certain process conditions. Silica-containing materials are reported to be especially susceptible to hydrogen attack. However, a deeper understanding of corrosion mechanisms is still needed. This article presents the first results of modelling and experimental work carried out by RHI Magnesita on the impact of hydrogen on refractory systems. Investigations were conducted regarding the thermodynamics and kinetics of ceramic oxide reduction by hydrogen as well as the effect of hydrogen exposure on the microstructure and properties of refractories. This enables refractories to be identified that are suitable for lining a DRI shaft kiln where hydrogen is used as a reductant and supports the development of novel hydrogen-resistant refractory solutions.

Sangram Keshari Mohapatra, Calderys France, France

Abstract:
Direct reduction of iron technologies have proven to have lower CO2 footprint compared to the conventional blast furnace routes and are further moving towards higher hydrogen content in the reducing gas in order to minimize the direct CO2 emissions. High hydrogen concentration in the reducing gas may react with the refractory and change its texture, resulting in an alteration of chemical composition, thermal profile and affect the mechanical load bearing capacities of the refractory linings. This paper reviews the functional requirements of the refractory linings of a DRI reactor with higher percentage of H2 in the reducing gas and recommends optimum total solution, brick, monolithic and jointing products, based on the past experience and recent experimental studies.

Arndt Wilhelmi, Lechler GmbH, Germany

Abstract:
To design or implement a quenching skid or a gas cleaning system in an off gas clearing system has many factors to be considerate.

Soumi Chattaraj, Tata Steel Ltd, India

Abstract:
Chloride in sinter comes from raw materials including iron ores, reverts, Coke breeze and fluxes. Taking into account the thermo-chemical properties of the chloride compounds, sinter product contains less chloride (~20%), but gets accumulated to a greater extent in the waste gas dust. As the waste gas dust (ESP dust) is reused in the process, progressively chlorine enrichment happens. Literature suggests, the alkaline chloride raises the electric specific resistance of dust surface and thereby decreases the electrostatic precipitator (ESP) performance. With continuous increase in the chloride value of dust, ESP performance deteriorates, thereby increasing the dust content in the stack gas. Chloride level increases with field number of ESP as more finer and more chlorine concentrated dust is captured in the last fields. Alkali –K2O & Na2O follows the same trend: more alkali in the final field as alkali remains mainly with finer dust (Cl remains mostly as alkali chloride). To combat the chloride effect there is a study and a trial taken to lessen chloride input to the system by evacuating the “most concentrated” ESP dust of last field and breaking the enriching chloride cycle. Study shows that weekly or in certain frequency bleeding of the last of field dust for a day will help to reduce the chloride load . Our observations shows with this initiative, there is a significant amount of reduction in dust content in stack gas. To reutilize the dust, cleaning this extracted dust is also carried which shows very promising result.

Tobias Plattner, Primetals Technologies Austria, Austria

Co-Author:
Alexander Fleischanderl, Primetals Technologies Austria
Robert Neuhold, Primetals Technologies Austria

Abstract:
"For a green steel production the environmental requirements are rising and ever stricter regulations by governmental institutions require lowest emission levels and utilization of by-products for existing and greenfield iron- and steelmaking plants. The dry gas cleaning technology (MEROS®) reduces the emissions of dust, SOx, NOx, heavy metals and dioxins from agglomeration plants, like sinter or pelletizing plants, safely below the required emission levels. Such low emission levels are maintained by a multi-component additive injection upstream of a high-performance fabric filter. Residues and by-products arising from the gas treatment are often disposed, leading to consumption of valuable landfilling volume and high cost as such material has to be stored under special conditions to avoid uncontrolled leaching of salts and heavy metals. The innovative by-product leaching process is closely linked to the MEROS plant and minimizes on site the residue volume. After the leaching step, the suspended solid like iron oxide will be utilized to the primary process. The brine will be treated in a series of wastewater treatments steps which are designed as a modular system. These treatments steps ensure the compliance with the most stringent discharge emission limits prior to the release of the clean brine into the sea. As an alternative for plants which are not located close to the sea a desalinization step can be installed and product (salt) can be gained by crystallization. How the MEROS and the Leaching technology can fulfill the environmental targets for a green steel production, shall be illustrated based on the latest results achieved with the MEROS systems installed at a plant in Italy and a Leaching plant, realized downstream a MEROS plant in Japan"

Nicholas Walla, Purdue University Northwest, United States

Co-Author:
Chenn Zhou, Purdue University Northwest
Kurt Johnson, Cleveland-Cliffs Burns Harbor Inc.
Armin Silaen, Purdue University Northwest
Chukwunedum Uzor, Purdue University Northwest
Anurag Karambelkar, Purdue University Northwest

Abstract:
Decarburization of the steel industry emission gases have led to extensive research into the use of hydrogen as a fuel source in many of their operations. Research has shown that burning hydrogen fuel in a reheating furnace may cause higher NOx levels in the flue gases which can be harmful to the environment. Several techniques have been studied to mitigate this effect including staging the hydrogen combustion. This work modeled the application of hydrogen fuel using the staged combustion approach with a robust computational fluid dynamics (CFD) model to investigate the potential to reduce NOx emission. Three scenarios were considered for the investigation. Results from the study show that staging the hydrogen combustion reduced the NOx emissions. However, the average temperature of the furnace was also seen to slightly drop. Staging 17.5% of the combustion air showed the best result with a NOx reduction of 14.5%.

Durgesh Gupta, H2 Green Steel, Sweden

Co-Author:
Anatoliy Meyko, Midrex Technologies, Inc.
Marco Perato, Paul Wurth Italia S.p.A.

Abstract:
H2 Green Steel is on a mission to decarbonize hard-to-abate industries, and the steel industry is a prime place to start. Steel production is the source of 7-9% of global CO2 emission, 5% of CO2 output in the European Union, and 14% of CO2 generated in Sweden, the home country of H2GS AB. Sweden possesses an abundance of natural resources necessary to support green steel production via the direct reduction-electric arc furnace route (DR-EAF). H2 Green Steel is bringing together the technology expertise of Midrex in processing iron ore into steel products, creating green hydrogen with giga-scale electrolysis, and developing a circular supply chain to become the first commercial-scale supplier of green steel by 2025. The story of how H2 Green Steel decided to undertake a steel project in northern Sweden – 45 mile south of the Arctic Circle, development of the technical scope of the project, and what will be involved in the steel mill reaching its design capacity of 5 million metric tons/year is the focus of our presentation. We will discuss the further steel-related plans of H2 Green Steel and how the Boden project will provide the technical blueprint for future green steel projects.

Gunilla Hyllander, Hybrit Development AB, Sweden

Co-Author:
Christer Ryman, Hybrit Development AB
Marcus Henriksson, Hybrit Development AB
Hannes Wikström, Hybrit Development AB
Petrus Hedlund, Hybrit Development AB
Damian Guido, Hybrit Development AB
Nicklas Eklund, LKAB
Per Lundström, LKAB
Hedda Pousette, SSAB AB
Anna-Maria Suup, Hybrit Development AB
Per Hellberg, Hybrit Development AB
Jenny Wikström, LKAB
Shabbir Lakdawala, LKAB
Joel Carlsson, SSAB AB
Niklas Kojola, SSAB AB
Johan Riesbeck, Hybrit Development AB
Gunilla Hyllander, Hybrit Development AB

Abstract:
The iron and steel industry contributes globally with a share of up to 7% to greenhouse gas emissions. The goal of the HYBRIT initiative is to realize a fossil-free iron and steel production value chain. In this value chain the fossil CO2 emissions associated with the traditional blast furnace route are eliminated by using a 100% green hydrogen based direct reduction process. Starting from today's conventional natural gas based direct reduction technology, a shift to hydrogen as reduction gas introduces significant changes to the process chemistry and thermodynamics. A direct reduction pilot plant, including all safety installations required for hydrogen operation, has been designed and commissioned to develop best practices under semi-industrial conditions. The plant has a capacity of 1 tonne DRI per hour. Typically, the plant is run in campaigns where continuous operation takes place for a period of about 6-8 weeks. After initial design and construction of the pilot plant the trials started at the end of 2020 with natural gas and continued in early 2021 with the use of hydrogen as reduction gas. This paper provides key operational results from H-DR test trials conducted in the approximately 43 weeks of operation until today. DRI and HBI products have been successfully produced on pilot-scale under stable process conditions using 100% green hydrogen as reduction gas. Sponge iron produced with hydrogen as reduction agent is a carbon-free product. This DRI product has better physical, mechanical, chemical and reactivity characteristics compared to conventional DRI produced with natural gas. The results also demonstrate the technical feasibility to define a process window for production of DRI and HBI in an industrial DR plant based on green hydrogen.

Matthew Boot-Handford, Calix, Australia

Co-Author:
Mark Sceats, Calix
Geoffrey Brooks, Swinburne University of Technology
Phil Hodgson, Calix
Andrew Okely, Calix
Matthew Gill, Calix
Thomas Dufty, Calix
Isis Rosa Ignacio, Calix
Bintang Ayu Nuraeni, Swinburne University of Technology
Andrew Adipuri, Calix
Yun Xia, Calix

Abstract:
Calix is extending the application of its indirectly heated Calix flash calcination (CFC) technology to the decarbonisation of iron and steel production. The Zero Emissions Steel TechnologY (ZESTY) can be used to process low- and high-grade iron ore fines to a hydrogen direct reduced iron (H-DRI) product, avoiding the need for pelletisation or agglomeration. The small particle size range of the iron ore charge facilitates fast rates of metallisation allowing for significantly shorter residence times (in the order of 60s) and lower temperature operation than a conventional blast furnace such that the stickiness problem is avoided. Pilot-scale testing at Calix’s Centre for Technology Development in Victoria, Australia has shown that the ZESTY technology can produce a H-DRI product approaching commercial grade. The ZESTY technology is compatible with intermittent operation and can therefore be heated using renewable energy sources. ZESTY is targeting the theoretical minimum hydrogen use of 54 kg/t H-DRI as green hydrogen is used only as the reductant and is recycled in the process. Several scenarios are being explored for the downstream processing of the ZESTY DRI product including hot briquetting, direct flash melting and processing to green steel through integration with an electric arc furnace. Calix’s Low Emissions Intensity Lime and Cement (LEILAC) technology can be used to supply a zero-emissions lime fluxing agent to the EAF and other steel making processes. This paper will introduce the technology and discuss the status of ZESTY pilot testing and development.

David Leigh, Rio Tinto plc, Australia

Co-Author:
Chris Dodds, Chemical and Environmental Engineering, The University of Nottingham
Michael Buckley, Rio Tinto

Abstract:
Rio Tinto has been working on technology pathways which do not require the use of coal for processing Pilbara iron ores to iron and steel for well over a decade. Use of natural gas, hydrogen and biomass as reductants has been studied with a unique option combining microwave energy with raw sustainable biomass (rather than char) showing strong potential. Testwork with single “briquettes” made from a range of raw sustainable biomass including agricultural wastes, purpose grown energy crops, macro and micro algae with Pilbara iron ore fines indicated the potential of the process at laboratory scale. Initial scale up to 1000 briquette batches confirmed the early testwork and has positioned the technology for development of a 1 tonne per hour continuous pilot plant.

Anderson Agra, Tecnored Desenvolvimento Tecnológico S.A., Brazil

Co-Author:
Ismael Flores, Federal University of Rio de Janeiro
Manoel Gonçalves, Tecnored Desenvolvimento Tecnológico S.A
Bruno Flores, Federal University of Rio Grande do Sul
Alex Campos, Tecnored Desenvolvimento Tecnológico S.A
Ronald Lopes, Tecnored Desenvolvimento Tecnológico S.A
Guilherme Gonçalves, Tecnored Desenvolvimento Tecnológico S.A
Stephen Potter, Tecnored Desenvolvimento Tecnológico S.A

Abstract:
The iron and steel production sector accounts for 7-9% of the total CO2 emitted worldwide, being one of the most energy-intensive and large-volume production industries. As a result, governments and companies are committed to mitigating its CO2 emissions, an important requisite for the future development of the steel industry. Most of the world's steel is obtained through the blast furnace-basic oxygen furnace (BF-BOF) route, with the blast furnace being responsible for roughly 90% of the total carbon emissions of the entire steelmaking route. However, reducing BF CO2 emissions is challenging due to the technology's high maturity and raw materials. Tecnored company has extensive experience developing cold agglomerated briquettes for its smelting reduction technology, which is 100% fed with self-reducing briquettes and fuel briquettes. With the increasing demands for CO2 reduction in the iron and steel sector and Tecnored background, two low-carbon briquetting solutions were developed for hot metal production (BF). The first one is a bio-briquette for cokemaking (BBC). The replacement of coking coals by biomass-based materials for coke production is challenging, usually limited to no more than 1-2% only. BBC has promising results indicating up to 10% replacement ratio while keeping high coke quality. The second low-carbon solution developed by Tecnored is the catalyzed briquette for blast furnace (CBB). CBB is a combination of carbonaceous sources (coking/non-coking coals, biocarbon, etc.), a catalyst (iron and calcium bearing materials) and binders, which is carbonized in mild conditions to produce a material with the ideal composition and strength for blast furnace application. The utilization of CBB associated with the sinter layers in BF has the potential to decrease reserve zone temperature hence coke consumption. In this study, the main characteristics and features of the briquetting solutions (BBC and CBB) were discussed regarding their potential for use, process impact and potential for CO2 mitigation.

Hedda Pousette, SSAB AB, Sweden

Co-Author:
Joel Carlsson, SSAB/HDAB
Niklas Kojola, SSAB AB
Pär Ljungqvist, SSAB/HDAB
Liviu Brabie, Swerim AB
Ulf Sjöström, Swerim AB
Erik Sandberg, Swerim AB
Magnus Heintz, Swerim AB
Xianfeng Hu, Swerim AB

Abstract:
The global climate crisis demands that CO2 emissions are reduced. This is especially the case for the steel industry, which contributes to 7% of annual CO2 emissions. Steelmaking using an Electric arc furnace (EAF) and hydrogen reduced Direct Reduced Iron (DRI) as iron input is a possible replacement for the blast furnace steelmaking route. All research work has been conducted within the Hybrit development project, a joint venture between SSAB, LKAB and Vattenfall. For steel production in the EAF, carbon-sourcing materials (typically anthracite and carbon in the steel scrap) play an important role as an alloying agent, a slag foaming agent, and a reducing agent. Biocarbon is investigated as a possible replacement for anthracite in order to eliminate fossil CO2 emissions during the melting of H-DRI in the EAF. This paper highlights development results from the Hybrit development program with focus on the application of biocarbon during the melting of H-DRI in a pilot scale EAF. The performance of several different biocarbon materials was evaluated in terms of carbon yield in the steel, slag foaming behavior, off-gas and dust compositions. Fixed carbon content, ash, and volatiles have varied between the tested biocarbon materials. Size and form have varied as well. The results show that biocarbon is a feasible replacement for anthracite. However, properties of the biocarbon have a significant impact on its performance during EAF steelmaking. This is an important aspect for the continuing development of a fossil-free steelmaking value chain.

Elsayed Mousa, Swerim AB, Sweden

Abstract:
Agglomeration is an essential part in the metallurgical industries, and it comes in the core of circular economy. The agglomeration can play a substantial role not only in enhancing the residue recirculation in the steel plant, but also in introducing the neutral biocarbon for replacing the fossil fuels and consequently mitigate the fossil CO2 emission. The agglomeration can be performed through different techniques such as sintering, pelletising, and briquetting. This study demonstrates the recent trends in pelletising and briquetting as potential pathways for sustainability transitions from the traditional iron and steel making route to the next generation H2-based steel route. Developing biocarbon briquette and/or biocarbon containing agglomerates with the quality fulfil the shaft furnace and/or electric arc furnace will be discussed. In addition, developing and optimizing pellets/briquettes using innovative binders are key approaches to improve the process efficiency, reduce the slag generation, and decrease the energy consumption. In this context, the developed agglomerates will be evaluated in terms of cold mechanical strength, hot mechanical strength, reduction behaviour, softening and melting which are essential parameters to judge the quality of the agglomerates. Keywords: Pelletising, Briquetting, Organic binders, Biocarbon, Recycling, Ironmaking, CO2 emission, Circular economy

Günther Schnell, Friedrich Kocks Gmbh & Co KG, Germany

Abstract:
While most of the Kocks 3-roll blocks are popular as finishing blocks in long product rolling mills, there are also applications, where a Kocks block can suit as alternative to a roughing as well as an intermediate mill. The smooth and gentle reduction behavior of the 3-roll pass, the most flexible stand change system in combination with a very compact and modular design allows an implementation in a very tight space. Especially in existing rolling mills space is very limited. Still being able to add additional reduction capacities grant some very crucial advantages. Bigger billet sizes can be used, or a different, more flexible distribution of the reduction in the stands is feasible. Which in consequence is a key factor in order to optimize the quality of the finished product. As a result, the productivity of the plant can be increased, and the rolling process can be optimized. New, more difficult to roll material grades, can be added to the product portfolio. All of this without major changes of the layout of the rolling mill. This paper describes the application and the unique advantages of the Kocks 3-roll technology, when used in a roughing but also in an intermediate mill.

Elmar Krieg, SMS group, Germany

Co-Author:
Wolfgang Scheffel, SMS group

Abstract:
Over the recent years, Jumbo Beam and Section Mills were newly built, modernized and successfully commissioned or are under construction. Such heavy rolling mills require special technologies and equipment like thermo-mechanical rolling as well as in-line water quenching. Furthermore, rolling of beams up to more than a ton per meter poses special requirements on the rolling mill equipment design and layout. In particular, solutions for covering a very wide range of product program will be introduced. Beside the introduction of the mill equipment and its technologies, the paper will focus on the today’s and tomorrow’s possibilities to provide digital solutions for process and quality optimization, data and energy management, lifecycle and predictive maintenance strategies. We will demonstrate how AI can be utilized to achieve prescriptive maintenance with significant operational cost improvements.

Faisal Alghamdi, SABIC, Saudi Arabia

Abstract:
Medium carbon steels are mostly used for spring and nail manufacturing applications. In this paper, the drawability and cold headability performance of wire rods, AISI 1040 and AISI 1045, produced using pollard-type nitrogen shroud casting were investigated. The material has been characterized “as hot-rolled” using several analytical methods: Decarburized depth/Core segregation, optical microscopy, and Nonmetallic Inclusion rating analysis. Both grades of AISI 1040 and 1045 were then deep drawn to wire to size 2.87 and 1.3 mm, respectively. Produced medium carbon steel wire rod had high ductility and excellent drawability with limitation in cold headability.

Antti Kaijalainen, University of Oulu, Finland

Abstract:
Formed steel sections are widely used in construction applications due to their relatively high strength and stiffness properties. Especially, cold-formed welded hollow sections provide cost-efficient and environmentally friendly alternatives compared to hot-formed sections. Cold deformation causes work-hardening of the material, which resulting in enhanced strength, although a corresponding loss of elongation and toughness. The aim of this work is to compare mechanical properties of i) as produced, ii) artificial aged (250 °C for 1 h) and iii) naturally 5-years aged cold formed S700 rectangular hollow section. The investigated hot rolled steel strip was produced thermomechanical rolling followed by direct quenching. The dimension of the investigated hollow section was 120x120x10 mm and the corner radii and the other tolerances compliant with EN 10219. Tensile properties and Charpy-V impact toughness were determined for the flat and corner area of the hollow section. The results showed that the tensile strength in the corner was slightly higher in comparison with the flat side, revealing higher cold deformation rate in the corner. Artificial ageing increased the strength level relatively higher than cold forming without losing any elongation properties. The impact energies were at the high level at -40 °C and -60 °C in cold formed and aged materials. Even at -80 °C, the CV results were 118 J/cm2. It is also notable that no difference in CV values between the flat and the corner samples were observed. Thus, the results showed that the flat side specimens testing provides sufficient information of mechanical properties of the cold formed rectangular hollow sections and no need demanding corner sample testing when the structural hollow section is produced by using the thermomechanical controlled and direct-quenched base material. Furthermore, results showed that cold formed S700 is excellent for offshore steels, as steels are used even colder conditions as before.

Kosho Matsuda, Nippon Steel, Japan

Co-Author:
Ryuta Ishino, Nippon Steel Corporation
Seiya Teruya, Nippon Steel Corporation
Kenichi Higuchi, Nippon Steel Corporation
Kaoru Nakano, Nippon Steel Corporation
Hiroshi Mio, Nippon Steel Corporation

Abstract:
The reduction of carbon dioxide emission is one of the most important issues in the steel industry due to the large CO2 emitter. The steel is mainly produced by reducing iron ore using a blast furnace (BF), and its reducing agent is mostly carbon. Therefore, a low Reducing Agent Ratio (RAR) operation of the blast furnace is one of the solutions for reducing CO2 emissions. Kimitsu No.2 BF has been trying the low RAR operation by optimization of burden distribution, improvement of burden materials quality and so on. To further reduction of the RAR, the high-temperature blast operation is suggested to be an effective improvement. Because the high-temperature blast can raise an input amount of heat in the furnace, and it leads to the reduction of the RAR. Before operating under the high-temperature blast, there were two considerations; i.e. the one was the evaluation of the RAR reduction, and the other was the upgrading the hot blast stove. The reduction of RAR under the high-temperature blast operation was evaluated using a 2-dimensional mathematical model, and it was estimated that the RAR could be reduced below 490kg/t-p by 1300°C. The original hot blast stove had a limitation at 1200°C due to a heat resistance of the checker brick bracket. Thus, the material of the checker brick bracket was replaced with a high heat-resistant one. This new material made it possible to raise the blast temperature over 1300°C. The high-temperature operation was carried out in Kimitsu No.2 BF from 2019, and the RAR was able to be reduced to 492kg/t-p. This operating results were correlated well with the estimated value from the mathematical calculation.

Mikhail Kalugin , KALUGIN Top Combustion Solutions, Serbia

Co-Author:
Boris Prokofyev, KALUGIN JSC
Yury Murzin, KALUGIN JSC
Anton Subbotin, KALUGIN JSC
Sergey Ivlev, KALUGIN JSC

Abstract:
The global iron and steel industry is being impacted by a decline in steel demand and volatile situation in the global market of raw materials. Manufacturers are challenged to reduce the production cost of iron and steel by modernizing the existing production facilities in conditions of continuously growing requirements for provision of environmental measures. Iron and steel industry is considered as “dirty” production and many processes, including blast-furnace production, are sources of a big amount of combustion products and CO/NOx emissions. Many designs of hot stoves used for blast furnaces are not able to provide complete gas combustion during operation. On the contrary, top combustion stoves which have gained widespread use recently have proved its capability to remain environmentally “clean” during long-term operation. KALUGIN Company has developed and successfully implements top combustion hot blast stoves of its own design representing advanced and economically efficient technology meeting today’s high environmental requirements. Nowadays, modernization of existing stoves is being performed with different modernization options from replacement of existing burner design to full replacement of the stove. This paper gives a comprehensive assessment of various modernization options on the basis of such parameters as productivity, capital expenditures, project implementation period, reduction in CO and NOx emissions, which enables to choose the best option for modernization of existing facilities to improve productive efficiency and significantly reduce harmful emissions having adverse environmental impacts.

Hiroaki Sumikawa, NIPPON STEEL ENGINEERING CO., LTD., Japan

Co-Author:
Yu Kurakake, NIPPON STEEL ENGINEERING CO., LTD.
Takashi Fukuoka, NIPPON STEEL ENGINEERING CO., LTD.
Hironobu Ishikawa, NIPPON STEEL ENGINEERING CO., LTD.

Abstract:
One of the effective ways to decrease coke consumption and reduce CO2 emissions is to increase the blast temperature, but SCC caused by NOx and limited heat resistance capability of checker support lead to limits in dome temperature and waste gas temperature, respectively and therefore maximum blast temperature is, in general, 1200℃. NSE developed low NOx burner and new checker support so that the temperature at dome can be increased by 30℃ and waste gas by 100℃, allowing higher blast temperature. In addition, downsizing reduced initial cost of the new or modification of hot stove. We have delivered 5 units of this type of hot stove to large blast furnaces in Japan, and they are currently in stable operation. Furthermore in combination with our Waste gas Heat Recovery System（WHRS）for Hot Stove, further reduction CO2 emissions can be realized. Our WHRS is of heat medium circulation type, and has characteristics that enable to control the recovered heat and also provide the flexibility to install the heat receiving unit and heating unit separately, resulting in advantage of ①High efficiency of heat recovery, ②High layout flexibility ③Easy maintenance. In this paper, we describe the performance and recently orders of this equipment.

Floris van Laar, Allied Mineral Products, Canada

Co-Author:
Robert Byerman, Cleveland-Cliffs Burns Harbor Inc.
Robert Hansen, Hansen Refractory Consulting Services
Floris van Laar, Allied Mineral Technical Services

Abstract:
This paper will discuss novel repair methods for refractory systems in Hot Blast Stoves. The failure of refractory systems in a fast-paced industry creates demand for reliable repairs that offer the shortest timeline. Therefore, innovative solutions must improve the refractory design and installation methods to repair older, traditional refractory systems promptly. An alternative design with monolithic materials was successfully implemented in 2020 and 2021 at stove D1 and D3, and currently stove C4 at Cleveland Cliffs Burns Harbor. Failure of the traditional (brick) hot stove refractory system led to the casting of a complete monolithic dome and large sections of the walls. A post-construction analysis will demonstrate the validity and feasibility of the design.

Fiona Meier, RWTH Aachen University, Germany

Co-Author:
Andreas Janz, Hüttenwerke Krupp Mannesmann GmbH
Alexander Babich, Independent Ironmaking Consultant
Dieter Senk, RWTH Aachen University
M. Efetürk, Hüttenwerke Krupp Mannesmann GmbH
R. Peter, Hüttenwerke Krupp Mannesmann GmbH

Abstract:
Effect of the co-injection of PC and coke oven gas on the raceway and shaft phenomena in a blast furnace Injection of coke oven gas (COG) containing about 60% of pure hydrogen and nearly 25% hydrocarbons, has a potential for lowering the CO2 emissions from a blast furnace (BF). Hüttenwerke Krupp Mannesmann (HKM) in Duisburg has commissioned a COG injection system to operate blast furnaces with injection of PC and COG via two lances in the tuyere. In order to optimise this technology, a theoretical and experimental study on the raceway conditions, coal conversion, as well as pellets and sinter reduction behaviour while injecting COG has been conducted at RWTH Aachen University. In this contribution, first, the analysis of the COG influence on the BF process parameters and the effect of tuyere and lance design on PC conversion were undertaken. Then, injection trials using the MIRI plant were performed with varying PC and COG amounts while keeping constant blast temperature and oxygen enrichment. Furthermore, COG was replaced with natural gas. The conversion degree is determined based on the offgas analysis. Coal residues are undergoing microscopical investigations. Next, isothermal reduction test of pellets and sinter at three temperatures (850, 1000 and 1150°C) under two gas compositions with different contents of CO, CO2, H2, H2O and N2 were conducted using a 3-zone tube furnace. Mass losses were measured continuously during the test and the reduction degree was determined. In addition, changes in material microstructure and morphology were analysed using a scanning electronic microscope combined with EDX.

Ricardo Sebastião Nadur Motta, Ternium, Brazil

Co-Author:
Deilton de Oliveira Sousa , Ternium
Beatriz Lopes, Ternium
Deyvid Martins de Souza, Ternium

Abstract:
This work aims to show the industrial development carried out to expand the PCI plant capacity of Ternium’s blast furnaces in Rio de Janeiro-Brazil. Ternium has got two blast furnaces with a daily production of 7500 thm each. The PCI plant's original design features have got two 60 t/h pulverized coal mills with two injection stations with dual vessels allowing average PCRs of up to a maximum of 180 kg/thm for each blast furnace. Over the years, the PCI plant has presented capacity and availability problems regarding the coal injection and grinding stations, affecting the plant's hot metal production and leading to losses due to the lack of coal and consequent instability in the operation of the blast furnaces. The PCI expansion improved the injection stations with the addition of a third injection vessel, a new coal silo of 800 tons and a third coal grinding mill and drying plant with the same type and grinding capacity and with alternative pneumatic transport increasing the versatility of the plant in general. In addition, dual coal lances were implemented with dynamic distributor and closed loops control allowing uniform distribution of coal between lances and higher PCR up to 220 kg/thm.

Colin Morrison, Primetals Technologies UK, United Kingdom

Co-Author:
Rainer Klock, thyssenkrupp AT.PRO tec GmbH
Bartosz Smaha, thyssenkrupp Steel Europe AG
Hauke Bartusch, VDEh-Betriebsforschungsinstitut GmbH
William (Ross) Edmond, Primetals Technologies Ltd.

Abstract:
"When operating a blast furnace, the ability to positively influence raceway characteristics and improve the permeability of the process, are key features that can enhance performance. The Sequence Impulse Process (SIP) is an oxygen pulsing technology credited with providing a way for blast furnaces to realise such benefits, at scale, today. This paper explains the technology and provides operational feedback from Schwelgern BF1, Germany operated by thyssenkrupp Steel AG. It discusses how regular injection of high energy SIP oxygen, has enabled a shift in operational outcomes. The total reducing agent rate and the carbon footprint have been lowered, as have heat loads to the tuyeres and shaft areas of the blast furnace. These compounded changes lead to significantly reduced OPEX and a rapid return on investment for the plant. Through the use of SIP, the performance improvements have been experienced even during periods of reduced burden material quality and have realised greatly enhanced stability characteristics in the blast furnace when compared to conventional operation. Raceway material analysis reveals improved conditions for metal/slag removal providing a mechanism for better drainage such that production level increases could also be considered. In utilising SIP, blast furnace operators now have a tool that provides flexibility to shift their operational drivers between gas utilisation, productivity and material use according to the requirements dictated by a multitude of influencing factors,"

Hauke Bartusch, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Andreas Janz, Hüttenwerke Krupp Mannesmann GmbH
Fatima Demirci, Hüttenwerke Krupp Mannesmann GmbH
Thorsten Hauck, VDEh-Betriebsforschungsinstitut GmbH

Abstract:
Until 2030 the EU has the objective to decrease CO2 emissions by 55%. The steel industry plans to reach substantial emission reductions by shifting to new steel production process routes like direct reduction combined with electric melting – but those process routes require availability of hydrogen, or in the first step natural gas in huge amounts and at competitive prices. However, currently the energy crisis decreases the economic feasibility of those new process routes. Consequently, it is reasonable to think about fast feasible bridge technologies to enable maximum CO2 mitigation in current blast furnace based process routes. One such bridge technology, already followed by multiple steel producers, is increasing the ore reduction share by hydrogen in the blast furnace. Higher hydrogen concentrations in the reducing gas lead to a shift between direct and indirect reduction, but also influence the process gas density and viscosity. Especially in Europe there is only little experience on blast furnace operations points with such higher hydrogen loads. HKM already announced to increase the hydrogen content in their blast furnaces by injection of coke oven gas. To prepare this operation, a study was executed comparing several historical operation periods at HKM with mixed natural gas and coal injection to similar periods with coal only operation. This study comprises analysis of differences in data distributions for nearly all data series from a blast furnace often used to rate the furnace working state. This article presents the differences found e.g. for the top gas properties, stack wall pressure and temperature measurements as well as other operational parameters to work out the changes in blast furnace working states with a higher hydrogen reduction share.

Fabian Perret, Hüttenwerke Krupp Mannesmann GmbH, Germany

Co-Author:
Alexander Babich, Independent Ironmaking Consultant
Dieter Senk , RWTH Aachen University

Abstract:
It is almost impossible for the injected pulverised coal (PC) to be completely converted in the raceway at very high PC injection rates (≥ 200 kg/tHM). Therefore, it is crucial to understand whether the unburnt coal particles (Char) can be converted outside the raceway and, if so, to what extent. The incomplete coal combustion in the raceway leads to a decrease in the blast furnace (BF) productivity and operation efficiency and increases the specific coke rate. RWTH Aachen University intensively studies the properties, the behaviour, and the interaction of char with coke, iron burden, liquids, and gases outside the raceway. This contribution focuses on the fluid dynamics of gas-liquid flow in the dripping zone as well as the char effect on liquid products (hot metal and slag). To investigate these effects, an experimental BF dripping zone setup with ignited coke was developed. Several experiments including a reference test without injection were conducted with variable parameters such as the injected material (char, PC, coke fines), the injection rate, the hot metal temperature, the coke size, and the coke bed height. Thus, it was possible to evaluate the effect of these parameters on char behaviour as well as on static and dynamic holdups. In addition, the char effect of slag properties such as viscosity, basicity and melting range was examined using the simulation software FactSage™ and was afterwards compared with experimental measurements. These experiments and simulations are helpful for BF process monitoring and control as well as further prediction of char behaviour in the BF.

Christopher Long, Hatch Ltd., South Africa

Co-Author:
Hamid Ghorbani, Hatch Ltd.
Robert A MacCrimmon, Hatch Ltd.
William Wang, Hatch Ltd.
Lori Hay, Hatch Ltd.
Kyle Chomyn, Hatch Ltd.
Samantha Jarrett, Hatch Ltd.
Luis Felipe Gomez, Hatch Ltd.
Jorge Luiz de Oliveira, Gerdau Acominas S.A.
Lucio Eustaquio dos Santos, Gerdau Acominas S.A.

Abstract:
Gerdau’s integrated iron and steel plant at Ouro Branco, Minas Gerais State, includes a melt shop containing two basic oxygen furnaces (BOFs). The primary hot metal charging crane of 340t capacity has suffered structural damage including cracking and local deformations to girders and trolley structures after more than 30 years of operation. This damage presented a threat to the continued campaign life of the crane. Critical risks associated with this damage necessitated a thorough technical assessment to quantify the current structural condition, determine likely failure modes, and investigate possible options for continued safe operation. A campaign life assessment was performed, and life extension strategies were developed to minimize risk, maximize production, and improved reliability conditions. Root cause analysis and subsequent fitness-for-service assessment were carried out, including a strength and stability assessment, identification of cracking mechanisms. This led to the development of a range of options for mitigation and the associated constraints / monitoring requirements / etc. These strategies included short-term local repairs and monitoring strategies that could be completed without interruptions to overall production, as well as with long-term repairs, reinforcements, and local platework replacements to extend the campaign life until a replacement crane is procured and installed. These actions were successfully implemented, thus allowing for reliable continued operation of the crane, with major financial benefits to the melt shop facility. Keywords: Basic Oxygen Furnace; Melt Shop; Overhead Crane; Charging Crane; Fitness-for-Service; Campaign Life Extension.

Cameron Soltys, Hatch Ltd. , Canada

Co-Author:
Kyle Chomyn, Hatch Ltd.
Hamid Ghorbani, Hatch Ltd.
Jürgen Cappel, Hatch Ltd. Consultant

Abstract:
An integrated steel plant including two Basic Oxygen Furnaces (BOFs) in one melt shop identified the need and opportunity to enhance the refractory campaign life and furnace shell life of the BOFs. Hatch worked with the steel plant to understand the mechanisms that influence the lifespan of refractory and vessel shell campaign lives, including review of refractory material selection and thermomechanical evaluation. Based on the findings from this study, various options for enhancing the life of the converter were evaluated. These included options for increasing the life of a replacement converter vessel such as improved cooling systems, altering the refractory system to reduce shell heat loads, and a new material of construction. Changes to the refractory material selection and operational practice to improve lining performance were also investigated. The enhanced refractory design and equipment improvements implemented by the steel plant has allowed an optimized converter operation with an extended refractory campaign life. This optimization also lead to a reduction in shell temperatures, which will result in longer vessel campaign life. This has led to improved productivity, with key recommendations from the study also being applied to other BOFs at the plant. Keywords: Basic Oxygen Furnace; Melt Shop; Performance Optimization; Campaign Life Extension; Refractory Design

Christopher Bryce, Vesuvius UK, United Kingdom

Abstract:
The challenge in front of us with this prototype system has been significant, not only how to increase the speed of repair material delivery into the hot furnace, but more significantly, to do this immediately after the furnace has been emptied of molten slag. Successful repairs have taken place with lining temperatures measured by digital pyrometry at +1600 °c. Our internal objective to deliver one tone of gunning mass in less than five minutes has been exceeded consistently reducing the overall repair schedule time which typically takes up to twenty minutes after a furnace cooling down period. High speed gunning has not only achieved a record average repair gunning rate of 244kg/minute. We have achieved this consistently without any cooling down period. High speed gunning likens itself to a formula one racing car strategy for steelmakers, with fast set up, repair, and removal of equipment, all aspects of the system from material formulation to the equipment specification is designed to minimize repair time. The total repair downtime of 10 minutes has been achieved. Allowing the steelmaking cycle to restart immediately. A recent 5-day study of the technology in a 325t BOF Furnace has delivered a repair area lining thickness increase of 147mm from the high-speed application between 1776 to 1851 lives of the furnace, during this period ten high speed repairs took place. The repair speed, lining thickness increase, and overall time saving has Exceeded the steelmakers expectations of what is possible in the lower cone area of the hot BOF furnace. In the following paper we will present the system design advantages and share the results from industrial trial of the system.

Günther Staudinger, Danieli Corus B.V, Netherlands

Co-Author:
Michael Skorianz, Danieli Corus B.V
Willem Heijne, Danieli Corus B.V

Abstract:
Since the startup of Danieli Converter Technology in 2011, several BOF revamping projects have been realized and converters have been successfully brought in operation. Beside to keep the costs to a minimum, the most important tasks for revamping projects are: • Enlarge the inner volume but reuse as much as possible existing equipment • Maximize the lifetime of the converter vessel • Shorten the delivery time by keeping the quality level • Keep the shut down time during erection to a minimum Some recent examples which fulfill these requirements are presented. Additionally two special topics are brought under attention: • Revamping a converter by reusing an existing trunnion ring • Developing a measurement system for online monitoring the vessel shell temperature as well as its deformation The reusing of an existing trunnion ring is not a regular case but sometimes this could give added value for steel plants. Such approach has been successfully applied for a 160 t BOF in the Ukraine and will be realized for 2 x 65 t BOF in India. To serve this purpose, Danieli Corus developed a special technique which avoids high demanding welding as well as machining on site. For the measurement of the vessel temperature, Danieli Corus has already such sensors successfully installed in converter plants. For the next generation, Danieli Corus further developed this sensor. The most challenging topic is, to create a sensor which can operate at ambient temperatures of more than 250° C, which means, that consequently any electronic equipment cannot be applied. The solution was found by using proven techniques from the prior century when electronics did not even exist. This new sensor is basically a combination of a mechanical part, which enlarges the vessel deformation by a factor 5 or more and an electric resistance which transforms the mechanical distance into an electrical signal.

Gerald Wimmer, Primetals Technologies Austria, Austria

Co-Author:
Glenn Gosseye, ArcelorMittal
Dominik Jakob, Primetals Technologies Austria
Bernhard Voraberger, Primetals Technologies Austria

Abstract:
"One of the two 330t BOF converters at AM Gent, Belgium came to the end of lifetime and in 2018 Primetals Technologies was awarded with the contract to revamp the converter. Focus topic during the design phase of the new converter was to optimized reaction volume and shape of the converter vessel to further improve yield and energy efficiency towards absolute benchmark levels. Well proven equipment solutions like the Vaicon Link 2.0 vessel suspension and the Vaicon Drive for converter tilting were employed for the new converter. Existing equipment was reused as much as possible and e.g. the existing Vaicon Stopper for slag retention at tapping was installed with minimum modifications only on the new converter. Another focus topic in this project was the optimization of the project execution and especially the installation sequence. To minimize pre-assembly works on site and consequently the risks for quality issues and time delays the converter was fully assembled at the manufacturers site and transported in two pieces – the lower part of the vessel with the vessel suspension and the trunnion ring fully assembled and the upper cone of the vessel. Hence, onsite in final position only one circumferential weld was required. An optimized transport concept including lifting of fully assembled converter with a total weigh of more than 380t above a pipe bridge were required. Thanks to good planning and preparation, the tight 35-day timeline for the revamp could be met without any interruption in the ongoing production of the second converter in the melt shop during the shutdown. In the paper the main design features of the new converter as well as the highlights of the installation job will be presented."

Hans Jörg Krassnig, Primetals Technologies Austria, Austria

Co-Author:
Ali Hegazy, Primetals Technologies Germany
Miao Peng Sheng, Primetals Technologies China Ltd.
Michel Hein, Primetals Technologies Germany
Jörg Schwörer, Primetals Technologies Germany
Hagen Fuchs, Primetals Technologies Germany

Abstract:
"Today’s steel producers face immense challenges when working with an EAF. These challenges may include anticipating tomorrow’s more stringent environmental targets for green steel, achieving optimal energy efficiency, dealing with the constraints of weak electrical infrastructure, and operating a closed-roof EAF while attempting to maintain the highest degree of productivity with modest OPEX and CAPEX. The EAF Quantum from Primetals Technologies is a proven solution for these complex challenges. The EAF Quantum is the latest energy-efficient EAF technology, yet quickly becoming well-established and growing fast. Since its first introduction, 11 references are now successfully in operation. This presentation will describe the EAF Quantum process and provide an overview of the technology and design concept. Features of the lmost recent 2x150-t EAF Quantum for Tosyali in Turkey (start-up in Y2023), currently under erection, will be highlighted. Moreover, the real-world operational results of the 11 EAF Quantums will be presented, including project execution, productivity, and consumption figures. An outlook of the next-generation EAF Quantum (200-300t) will be briefly shared."

Andrea Grasselli, Tenova S.p.A., Italy

Abstract:
C. Leoni1, A. Grasselli1, P. Stagnoli1, B.B. Cheng2, J. Chen2 1 Tenova S.p.A., Italy, 2 Tenova Beijing Branch, China Key Words: EAF, electric arc furnace, Consteel®, energy efficiency, productivity, cost reduction, performance improvement, productivity improvement, revamping. Abstract The ever-changing steel industry requires thinking of production plants that can guarantee the flexibility and sustainability needed to compete in the steel market. The success that the Tenova Consteel® EAF system has earned over the years is proof of a winning approach to the steelmakers' demands. Continuous technological development leads to design increasingly high-performance and productive furnaces, being able to choose smaller heat sizes even for significant annual steel throughput. This opportunity makes it possible to reduce the overall investment costs of a new production site, linked proportionally to heat size, or to think about revamping existing plants that need ambitious productivity increases. The paper presents the results of a Tenova's reference plant in China: two 70 tons heat size Consteel® EAFs for the production of more than 2 million tonnes of carbon steel per year, to which will be added the third production line with the same characteristics now under commissioning.

Yehia Abdullah, Al Ezz Dekheila Steel Co., Egypt

Co-Author:
Ashraf Khamis Ismail, Al Ezz Dekheila Steel Co.
Hossam Eldin Hamdy Abdelmeguid, Al Ezz Dekheila Steel Co.

Abstract:
EZDK Flat Steel Plant (FSP) installed in Y1999 consisting of steel making SMP (1 arc furnace EAF,1 Ladle furnace LMF) and compact strip plant CSP (thin slab caster TSC, hot strip mill HSM), plant design capacity 1.0 MTPY HRC producing low Carbon, different ranges of Mn steel grades, Aluminum killed clean steel, thickness 1.0~14 mm, widths 900~1600mm. Aiming reaching 1.150 MTPY HRC, defining such one FSP line production bottle neck is mandatory especially after CSP upgrading in Y2017 after increasing TSC casting speeds for different casting widths So, SMP(EAF) is identified as the bottle neck due to prolong tap-tap time TTT (56 min./heat), high EAF energy consumption (575 kWh/t MS) which limit productivity at higher casting speed (>4.5 m/min.) for 1500 mm casting width. Decreasing EAF power on time, energy consumption (productivity driven factors) are put as a target which can be achieved by introducing new chemical energy modules for C-O in EAF with low project budget keeping the rest of EAF configuration such as transformer as increasing transformer capacity ‘increasing input electrical power ‘will require consecutive additional changes in EAF upper& lower shell, fume extraction system with huge investment budget. An Italian company ‘MORE’ offered a new module of C-O in EAF called ‘M-One’ which has the feature of Carbon, Oxygen & natural gas injection in one coherent jet giving higher efficiency of reaction points between C-O with equal uniform distribution of slag foaming around EAF, giving better Oxygen penetration into molten steel giving higher slag foaming index moreover, burner mode of M-One enables faster scrap melting time. After successful installation & commissioning of M-One in Nov.Y2022, very promising results are obtained in productivity (+5%), power on time (-11%), turnaround time (-15%), Tap-Tap time (-12%), energy consumption (-11%), C injection consumption (-30%), EAF electrode consumption (-8%) and EAF refractory consumption (-12%).

Jaroslav Brhel, HTT Engineering spol. s r.o., Czech Republic

Co-Author:
Andrea De Vito, Rina Consulting – Centro Sviluppo Materiali S.p.A
Daniele Gaspardo, Pittini S.p.A.
Matteo Chini, Pittini S.p.A.

Abstract:
Pittini plant Ferriere Nord is one of the major Italian plants operating 150t EAF. Within European Retrofeed project https://retrofeed.eu/, some new developments were tested in 2022. These include new EAF burner and modified injection system for utilization of alternative materials such as fine polymers and granulated tires as source of chemical energy in EAF, partially replacing natural gas and carbon. The paper will describe equipment and process development made and introduce some initial obtained results and experience.

Martin Dimmer, Celsa Steel UK, United Kingdom

Abstract:
Celsa group and Celsa UK are a recognized leader in scrap recycling and in sustainability. The scrap recycling paves the way to EAF slag-making process challenges due to scrap quality volatility in general and to Al2O3 slag content management in particular. Together Celsa UK and Lhoist implemented a cost-efficient slag making process managing the inconvenience of High and variable Al2O3 content of the EAF slag. The key lever was introducing dolime as a MgO source input to control and regulate the slag viscosity. Based on theoretical approach and calculations, a Al2O3 and MgO management of the EAF slag-making process was defined. This process was implemented and tested industrially at Celsa UK bringing positive impacts on material recovery, refractory wear, energy yield, CO2 emission intensity in particular. This paper will describe the theoretical approach and calculations as well as will present and discuss the industrial results of the new EAF slag-making management at Celsa UK leading to a more sustainable and cost efficient EAF process.

Roberto Treviño, AMI Automation, Mexico

Abstract:
Being the cost of Scrap the highest cost by far in Steel Melting, there are not that many systems and tools that help manage and use the Scrap in an optimum way. In this paper, we will describe the areas of opportunity around Scrap Management that helps melt a Heat at the lowest cost of Scrap possible. These areas include AI tools, the planning of the consumption as well as the acquisition of Scrap, the accurate account of Scrap movements once on site, and the optimized use of the equipment moving Scrap. All these applications help with big savings for most of the current operations managing Scrap.

Anna Mayrhofer, Primetals Technologies Austria, Austria

Co-Author:
Helmuth Aflenzer, Primetals Technologies Austria
Thomas Reindl, Primetals Technologies Austria

Abstract:
"The wide variation in the charged materials is the greatest unknown in the operation of electric arc furnaces. This circumstance makes the optimized operation of the furnace very difficult, especially when static profiles are used to control the process. The use of intelligent sensors and advanced process models enables a reaction to the actual situation in the furnace and thus advanced dynamic process operation. The paper shows the advantages of a dynamic process control for an electric arc furnace: An optimized operation can be reached regarding use of raw materials, electrical energy, process gases and the reduction of the CO2 footprint."

Michael Riedler, Primetals Technologies Austria, Austria

Co-Author:
Gerald Hrazdera, Primetals Technologies Austria
Thomas Lengauer, Primetals Technologies Austria
Josef Watzinger, Primetals Technologies Austria
Denijel Burzic, Primetals Technologies Austria

Abstract:
"In order to maintain a sustainable planet for our children, the objective of decarbonization is drastically reducing carbon dioxide emissions. In the steel industry this leads to the replacement of classical BOF production as well as a change in raw material towards HBI and DRI. This changed process routes confront continuous slab production with new challenges. While liquid steel input is changed in composition and residual elements, cast products have to maintain the same quality level as expectations on final product remain unchanged. These challenges require new, flexible sensors and actuators integrated into the continuous slab caster. In addition to the support provided by advanced automation systems, this includes, among other things, an increasingly fine setting of the casting gap and the application of innovative cooling practices, as well as an active flow control through electromagnetic actuators. In terms of immediate adaptation to the changing requirements, these systems and actuators should be selected in such a way that they can be integrated also into existing continuous casting machines. This article discusses successfully implemented systems in process routes with non-BOF steel production in combination with continuous casting plants."

Peter Presoly, Montanuniversität Leoben, Austria

Co-Author:
Daniel Kavic, Montanuniversität Leoben
Christian Bernhard, Montanuniversität Leoben
Susanne Hahn, Primetals Technologies Austria
Sergiu Ilie, voestalpine Stahl GmbH

Abstract:
Modern steel grades are subjected to constant development to perform weight reduction, energy-saving, and automobile safety performance. In the last decades, high strength and ductile steels were developed with increasing quantities of silicon and manganese. Three of these alloying concepts are Dual-Phase (DP), TRansformation Induced Plasticity (TRIP) and even TWinning Induced Plasticity (TWIP) steels. All these steel grades are based on the iron-carbon-manganese system with additions of ferrite former such as silicon and/or alumina, followed by micro-alloying elements. The main difference compared to previous steel grades are the significantly higher levels of ferrite formers. Apart from the research on these new steels' material and product properties, the knowledge about the production process, particularly the continuous casting (CC) and the initial solidification in a water-cooled copper mold, is of significant importance. In this regard, the high-temperature phase transformation temperatures and the thermodynamic properties play a particular role. An efficient pre-identification of hypo-peritectic steel grades by experiments or thermodynamics is relevant to ensure surface quality, productivity, and operational safety in the casting process. The potential of different laboratory experimental methods and thermodynamic approaches is critical evaluated in comparison with operational experience from voestalpine Stahl Linz. Since process data in the continuous casting process often overlap with different operating influences (e.g. casting speed changes, width adjustments…), a new approach is presented to identify the process behavior of peritectic steels without additional effects. For this purpose, operating data from the mold monitoring were processed statistically, and only data areas with a steady-state casting length of more than 100 m were used for further consideration. Using this data preparation method, the peritectic area in the continuous casting process can be clearly described. Statistically prepared process data and experimentally verified thermodynamic data are the basis for the development and validation of demanding process models.

Eloy Martinez Rehlaender, SvMet Engineering S.A., Mexico

Abstract:
Casting operating temperatures for thin slab casting are key to achieve production levels that are comparable to conventional slab casting. Casting temperatures also determine key quality factors like internal segregation. Even more important is the effect of superheat on mold powder behavior during casting. It is well known that mold powders can have critical transformations in the mold which in turn change the heat transfer characteristics. In this paper it is shown that achieving superheat control for thin slab casters can be done with the use of hybrid models. Hybrid models results show clear advantages such as very narrow window of operation for any steel grade. {15~30 C and 20~30 C}. It is also shown that heat sequence transition is much faster with the use of hybrid models.

Pavel E. Ramirez Lopez, Swerim AB, Sweden

Co-Author:
Anton Sundström, Swerim AB
Joakim Eck, Swerim AB

Abstract:
Steelmaking processes occur at high temperatures (in excess of 1500° C) which makes experiments and measurements on liquid steel very difficult. A good alternative to model the behaviour of liquid steel is to use low-melting point alloys with similar density and viscosity (for example: Bi-Sn, Tmelting: 150°C). SWERIM is home to one of the most advanced facilities for physical modelling with liquid metal for casting in the world. This facility is used as benchmark to test flow control devices such as nozzles, stoppers and sliding gates during continuous casting operations. The present manuscript describes recent work to increase the size of the simulator to full-scale for wide and thick slabs as well as reaching casting speeds and Argon flow rates equal to those applied in the Industry. The Simulator has been also equipped with a series of measurement techniques to monitor pressure, velocity, temperature, level fluctuations and vibration in order to fully characterize the metal flow in CC moulds. Finally, the present paper enumerates the main findings, challenges and limitations derived from extensive tests in the simulator with real ceramic nozzles/stoppers and their counterparts in stainless steel.

Simone Cicutto, ergolines Lab s.r.l., Italy

Co-Author:
Isabella Mazza, ergolines lab s.r.l.
Giovanni Schiavon, ergolines lab s.r.l.
Stefano Spagnul, ergolines lab s.r.l.

Abstract:
Ergolines’ Ultrasonic Level Detector technology is an innovative technological solution for the contactless measurement of steel level in open stream casting. This technological solution is based on real-time measurement of the thermal profile in discrete points, based on the time of fly of ultrasonic waves in the copper tube. This technology, contrary to thermocouples and optical fibres, is contactless and, being installed on the water jacket, requires no machining of the copper tube. UT-LEVEL is the application of this innovative technology finalized to measure the copper temperature in the meniscus area, generally covering a length of 210mm. Based on the thermal profile data gathered, a dedicated algorithm extracts the steel level position, namely meniscus. Thanks to the fast response of the sensor and the high-performance electronic computation, the dynamic of the solution is aligned with the radiometric technology, utilized for the steel level control in most of the continuous casting machines worldwide. In detail, UT-LEVEL field of application is open stream casting process. An additional advantage of this solution is that the data of the thermal profile are visible in a dedicated HMI, and the rear data are available to the CCM for process optimization. Some systems of this not-radioactive technological solution for steel level control have already been installed and are currently operative.

Paula Reimer, Linz Center of Mechatronics GmbH, Austria

Co-Author:
Jagoba Lekue, Linz Center of Mechatronics GmbH
Erik Parteder, voestalpine Grobblech GmbH
Andreas W. Nemetz, Johannes Kepler University
Thomas Kaltenbrunner, voestalpine Grobblech GmbH
Bodo Heise, voestalpine Grobblech GmbH
Stefan Falkner, voestalpine Grobblech GmbH
Thomas Gross, Linz Center of Mechatronics GmbH
Rupert Egger, voestalpine Grobblech GmbH
Klaus Zeman, Johannes Kepler University

Abstract:
As accuracy requirements for tolerances of heavy plates are continually increasing, precisely tuned process control is indispensable. The aim of this work is to characterize the relevant thermomechanical effects on a heavy plate mill depending on the pass configuration. This was done by performing a parametric study with a high-resolution 2D Finite Element (FE) offline model of the roll gap. Particular attention was paid to thermomechanical coupling. As a cross-section of the heavy plate moves through the roll gap, its temperature distribution is influenced by the heat flow within the plate, the heat exchanged with the work rolls, the heat generated by plastic deformation as well as frictional dissipation at the interface between work rolls and heavy plate. The implemented FE model considers the described effects as well as the elastic flattening of the work rolls. It also contains temperature dependent material behavior, identified by laboratory measurements, and a limit for the transmissible frictional shear stresses as a function of the current yield stress of the rolled material at its contacting surface. The calibration of non-measurable parameters like heat transfer coefficients and friction coefficients was accomplished based on a broad spectrum of measurement data extracted from the process. By incorporating all relevant physical phenomena, the employed FE model represents a benchmark for the prediction of the roll separating force, the roll torque, and the temperature distribution over the plate thickness. The results of the parametric study indicate which thermodynamic effects dominate in which area of the parameter range. Furthermore, they help to improve the overall comprehension of the system and open the door to the condensation of the model to a reduced online model that allows the calculation of one pass within milliseconds without substantial loss of accuracy.

Ion Rusu, BM GROUP POLYTEC S.p.A., Italy

Abstract:
A rolling mill plant basically consists of reheating furnaces, rolling mill and accessory devices. The economic efficiency of metal rolling processes is strongly correlated to the quality level of the end-rolled products. Rolling of flat steel products is a complex process where the quality of the product is influenced by a range of factors such as incoming material, mechanical and electrical equipment, operating parameters and automation and control strategies etc. The significant quality parameters are: - material thickness, - material shape and surface, - homogeneity of stress distribution. Product quality can only be effectively optimized if the mechanical, electrical and instrumentation equipment, as well as the control strategy solution combined, work together.

Chitoshi Mochizuki, Primetals Technologies Japan, Japan

Co-Author:
Shinya Kanemori, Mitsubishi Heavy Industries, Ltd.
Gerard Goessens, Tata Steel IJmuiden, B.V.

Abstract:
" Commonly in a commercial hot rolling mill the operator monitors the rolling situation at the mill pulpit. If the operator recognizes some abnormal rolling situation, he/she will intervene by adjusting the appropriate rolling mill actuator. Recognizing abnormal rolling situations and adjusting the actuators depends on the operator skill level. If instead a computer can detect the abnormal rolling situation and can automatically and appropriately correct the situation based on specific controlling logic, it is thought that the rolled strip quality could become better and more stable rolling could be achieved. For this purpose two kinds of rolling condition monitoring systems have been developed using image processing technology and those systems have been verified offline. Those systems are “strip shape trend monitoring system” and “strip pinching detection system”. The former has been achieved by utilizing the shape change of a reflecting light area on the strip, and the later has been achieved by utilizing the difference of the strip surface color between normal and abnormal rolling situation. The final target of this rolling condition monitoring system is to realize automatic intervention such as leveling or bending corrections by computer instead of manual intervention by operator. However, in the case of that the automatic intervention by computer is undesired, only manual intervention guidance indication for operators can be also selected. It enables detecting and notifying operators on critical conditions of rolling processes to increase quality and improve the productivity. With this paper we present an approach on how digital assistants can be deployed for industrial applications, especially hot rolling."

Simon Hain, Primetals Technologies Germany, Germany

Co-Author:
Andreas Maierhofer, Primetals Technologies Germany

Abstract:
"Silicon steel grade sheets are essential to e-mobility. The material is hard, thin, and brittle, especially at the edges. With thinner gauges, magnetic losses are reduced, but the filling factor increases with more sheets. Therefore, the permeability and magnetization diminish. Contactless flatness measurement is beneficial for reducing the risk of strip breaks from edge cracks and to control flatness also at lower rolling speed. Additionally, it helps to get faster into the tolerances at the strip head since the response time due to the measuring principle is constant. Compared with flatness rolls which have to turn to get measurement readings the contactless principle allows to measure independently from a rotating roll or strip movement. Primetals Technologies has developed contactless flatness measurement consisting of actuators to oscillate the strip and eddy current sensors to detect inhomogeneities of the internal tensions. Since there is no contact with the strip, surface quality is maintained, and no wear occurs. Because of the straight forward construction, compared to a flatness roll, a maintenance can be done on site by the service personal in short time."

Alexander Kofler, SMS group, Germany

Co-Author:
Klaus Pronold, SMS group
Christian Mengel, SMS group
Guido Eichert, EMG Automation GmbH

Abstract:
The target of the centerline control is to eliminate the need of manual interventions for steering of the hot strip in a finishing mill. The new system works based on the highly accurate and reliable HotCAM measuring system. It measures the lateral hot strip position between the finishing mill stands. The highly sophisticated steering control philosophy will be explained. Further, we present first results on improved head, body and tail rolling stability, productivity increase, impact on reduced work roll damages and therefore unexpected roll changes and improved strip surface defects of this latest installation. The results will show a tremendous improvement by this technology. These results will be presented as well as future steps to ultimately eliminate permanent human interventions for hot sheet rolling paving the path towards lights-out operation.

Frank Padur, GMT mbH, Germany

Co-Author:
Kristin Helas, GMT mbH

Abstract:
Realistic material simulation is becoming increasingly worthwhile as part of simulation projects. If tolerances are to be calculated within a few hundredths or temperature variations within a few kelvins, the associated material data and models must also have a high degree of accuracy and match the conditions in the production process. The paper illustrates the influence of experimentally determined data, such as flow curves, temperature-dependent properties and CCT diagrams, and realistic material models, such as the microstructure and transformation model. Possibilities are shown to the user to apply the material knowledge for individual simulation projects, too. Various application examples illustrate the influence of accurate and validated material data sets on the simulation results of forming processes and heat treatments.

Nadine Schubert, Fraunhofer Institute for Machine Tools and Forming Technology, Germany

Co-Author:
Verena Kräusel, Fraunhofer Institute for Machine Tools and Forming Technology
Marco Wendler, Technische Universität Bergakademie Freiberg
Jürgen Steger, Fraunhofer Institute for Machine Tools and Forming Technology

Abstract:
Resource conservation and energy savings in component manufacture play a paramount role in the development of novel materials. Under this premise, the development of metastable austenitic steels with TRIP/TWIP properties is being strongly promoted. The results obtained on cast Cr-Mn-Ni steels in particular stand out here. Despite their heterogeneous and coarsely dendritic cast structure, these alloys are characterized by excellent cold formability comparable with wrought alloys. This is due to forming-induced plasticity effects and dislocation sliding. In order to exploit the full potential of these materials for forming technology, a technology is being developed at Fraunhofer IWU Chemnitz that makes it possible to shape cast semi-finished products into the desired form without any hot forming. The aim of the material-adapted forming processes is a high-strength and simultaneously tough edge zone as well as a tough core in the component. In this way, structural elements that can withstand high cyclic loads can be produced, which bring with them a high material-specific safety factor. As a result of the TRIP effect, potential crack propagation is counteracted. In addition to the targeted property design in the component, the energy-economical aspects should also be emphasized here. The use of cast semi-finished products shortens the process chain enormously. Otherwise usual heating and heat treatment steps are omitted, making it possible to achieve annual energy savings of ~1.5GJ per ton of manufactured components. Compared with the conventional process for producing solid formed parts from austenitic steel, the process chain to be developed represents a novel, energy- and resource-efficient process whose enormous potential for solid forming has not yet been exploited.

Koos van Putten , SMS group, Germany

Co-Author:
G. Winning, Friedr. Lohmann GmbH

Abstract:
Cogging is an incremental forming, open-die forging process that is used to produce rectangular, round or hexagonal semi-finished products with high demands in terms of mechanical properties and microstructure and is applied in many industrial fields, e.g. the tool manufacturing and automotive industries. An industrial cogging process for a 3.3-ton X38CrMoV5.1 tool steel ingot and the material properties of the ingot are comprehensively analyzed as part of the process validation, with an emphasis on studying the core deformation and gaining greater process knowledge. Material properties are obtained from a 2-ton X38CrMoV5.1 ingot. Cross-sectional boards at the foot (F), half-length (M), and head (H) plus one longitudinal board are sawn out of the ingot. Hot-working yield curves are determined at three different radial positions in the cross-sectional boards (F, H, M). The yield curves obtained for the core, filet, and edge at all length positions show negligible differences. Furthermore, the yield stress in the foot and head differs less than 6% from that at half-length. The hot-working yield strength is quite homogeneous throughout the ingot and does not significantly differ from the yield strength of the forged material. A metallographic analysis is conducted with the aid of the “HD scan” ultrasonic inspection system. The sawn boards are scanned and analyzed. A typical cast structure, free of shrink holes but with imperfections in the core, is observed. Traditional metallography provides a reference for the microstructure. In-depth process data are obtained from thermographic measurements and data logging during the cogging process on a 10-MN hydraulic open-die forging press. The FE-simulation of the 12-pass cogging process corresponds closely with the real process sequence. The calculated force shows only slight variations, and the final temperatures agree closely with the measurements. The quite homogeneous equivalent plastic strain in the core along the length of the block exceeds 1.5 throughout and

Martin Wolfgarten, SMS group, Germany

Co-Author:
Frederik Knauf, SMS group

Abstract:
Radial forging is an incremental forming process, which is mainly used for the production of bars with high requirements regarding the mechanical properties and the microstructure and is applied in almost all industry fields, e.g. in aerospace or medical industry. Nowadays, pass-schedule design in radial forging only considers the characteristics of the forging machine regarding the required forces and kinematic, while additional support, like decisive properties of the workpiece and process such as the resulting strain and temperature distribution is not provided. To realize a pass-schedule design considering the workpiece properties, SMS group exclusively developed new stand-alone models for strain and temperature in radial forging called ComForge® Property Predictor® and will be hosted within the forging technology suite ComForge®. The ComForge® Property predictor is capable to predict these decisive workpiece properties within seconds. By coupling these models with the established pass-schedule calculation software ComForge® Pass Schedule Calculator, for the first time process-design and optimization based on the final properties of the workpiece becomes possible. This not only allows optimizing pass-schedules in terms of quality and with regard to the workpiece properties, but also provides economic benefit for the machine operator by enabling shortening process chains, reduced personnel requirements and so reduction of safety margins within the process. The hereby-presented analysis proves that the hydraulic radial forging machine SMX in combination with advanced and unique technology tools offers significant benefit to produce high quality bars at optimum efficiency. In future, the technology suite ComForge® will be further developed by coupling ComForge® Property Predictor to a microstructure calculation to enable direct calculation and optimization of the resulting microstructure. Furthermore, coupling the models to the control system of radial forging machine will allow for an online analysis of temperature, strain and microstructure in radial forging.

Martin Scholles, SMS group, Germany

Co-Author:
Axel Rossbach, SMS group

Abstract:
Digitalization and Industry 4.0 will rock the forging industry now and in the years to come and will become Key for Major breakthroughs in regard of Optimization of Energy Consumption and Minimizing of Downtimes by Predictive Maintenance. Under the brand name iForge SMS group develops “easy to use” Tools and Applications for its closed-die forging customers to provide them with Hands-on Solutions that support them to stay ahead of the competition. The presentation will show you an example from the iForge digitalization program to show how Industry 4.0 can be implemented in practice.

Olivier Jaouen, Transvalor S.A., France

Abstract:
During the ingot casting, several kinds of particles can appear or be introduced in the cavity by the bucket. Lots of different reasons can explain this kind of foreigner bodies in the ingot. Some of them come from the liquid metal initially in the foundry bucket, the sand mold interaction, the riser or the slag interaction. These oxides particles, sand particles or other kind of inclusions could induce issue of metallurgical health of the ingot after cooling but also in the forward steps. It’s why lot of scientific projects are working on the slag/liquid metal interaction, entrapment of powder and all kind of defects and inclusions. Some embedded abrasive and inclusion generation models are already available in the state of the art and already used in our THERCAST® solution. We can also introduce different kind of particles (size, density) and follow their trajectories during the pouring. The main idea is to provide an appropriate software able to anticipate each inclusion generation and tracking at the end of the ingot casting process. Thanks to the global ‘End-to-End’ process simulation approach offered by Transvalor platform, it is possible to estimate the consequences during the next step of the metal transformation (forging, heat treatment). This presentation will show us how THERCAST® manage this kind of phenomena and the integrated physical models.

Stefan Albers, PSI Metals GmbH, Germany

Abstract:
With increasing share of renewable energy, energy availability will become more volatile. To respect resulting energy consumption constraints from energy providers, to contribute to grid stability and reduce energy costs, we need to forecast energy consumption cross-line in the production planning and scheduling process. This requires product and process specific forecasting models for all operations. PSI Metals applies these models to forecast and optimize cross-line schedules respecting energy availability constraints. Using a KPI driven Qualicision solver, automated energy procurement buys and sells in day-ahead and intra-day trading. This enables easy adaptation to changes in consumption forecasting whenever production plans are altered due to actual situations. It further enables energy procurement to cash in on short-term energy prices. This paper outlines deriving the forecasting models from production and EMS data as well as the combination of detailed forecasting with KPI-driven automated energy trading systems.

Jonas Oswald, Dürr Systems AG, Germany

Abstract:
In a world of limited resources, the reuse of materials plays an important role for building a circular economy. An established process in the recycling industry for removal of impurities from steel and metal pieces is the pyrolysis process. Hydrocarbons are removed at elevated temperatures. The process generates excess heat if the syngas produced is being utilized as input fuel. The usage of this excess heat for electricity production and, if required, for providing useful heat is a significant step to lower the Carbon footprint in these processes and additionally to reduce the operating costs. Dürr Cyplan has executed a best practice example which can be the blueprint regarding energy efficiency for the above-described processes in the steel industry. In this project shredded Aluminum waste is being processed in a rotary kiln (pyrolysis reactor) and purified to high grade Aluminum granulate. The rotary kiln is fired with the flue gases of the burned syngas that was generated in the pyrolysis process. The remaining excess heat from the flue gases is utilized in a high temperature ORC process at a temperature level of ~500°C. The Dürr Cyplan high temperature ORC-module can cover the own consumption of electricity for the whole purification process line and can additionally cover partially the demand of electricity of the whole factory. This brings a saving of ~140tons of CO2 annually* and lowers the electricity bill significantly. The described operating principle can be applied for the upgrading of metal and steel waste. Dürr Cyplan ORC modules can utilize heat with different interfaces to convert high temperature heat into electricity and additionally useful heat for follow up processes. This operating principle can be described as an electricity producing heat exchanger and can be applied in various process steps within the variety of metal and steel processing.

Frank Mintus, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Susanna Bosi, ergolines lab s.r.l.
Loris Bianco, Feralpi Group
Matthew Phillips, Cardiff University
Min Gao, Cardiff University
Piero Frittella, ESF Elbe-Stahlwerke Feralpi GmbH
Tim Bause, ESF Elbe-Stahlwerke Feralpi GmbH
Nils Katenbrink, Quick-Ohm Küpper & Co. GmbH
Luca Petrucci, Centro Sviluppo Materiali SPA
Luca Innocenzi, Centro Sviluppo Materiali SPA
Ugo Chiarotti, Centro Sviluppo Materiali SPA
Matteo Chini, Feralpi Group
Daniele Gaspardo, Feralpi Group

Abstract:
In the steel industry, large amounts of waste heat are generated in nearly all steps of the steelmaking process. The recovery of this waste heat could be a key technology on the way to net-zero steel production. Various technologies are available for this purpose, including the use of thermoelectric systems for power generation. The research project InTEGrated (Funded by EU-RFCS Programme, No. 899248) investigates the use of thermoelectric generators (TEGs) to recover thermal energy from two different waste heat sources: 1) EAF cooling water circuit and 2) radiation from steel products. Small prototypes were developed and initially tested in the laboratories. Based on the laboratory results and simulations, advanced prototypes were developed and installed for long-term tests at the EAF cooling water system at Ferriere Nord (Italy) and at the hot rolling mill of ESF Elbe-Stahlwerke Feralpi in Germany. Prototype design, results of prototype laboratory tests, simulation results and initial outcomes of the long-term tests are presented.

Tetiana Rozhkova, Centre de Pyrolyse de Marienau, France

Co-Author:
Stéphanie Penerat, Centre de Pyrolyse de Marienau

Abstract:
“VITAL: Vitrinite Analysis” automatic measurement system of coal vitrinite reflectance, as well as maceral analysis was developed by working group composed of ArcelorMittal Dunkerque and Fos-Sur-Mer as well as ArcelorMittal Research SA and Centre de Pyrolyse de Marienau. The working group consisted of accredited by ICCP petrographer, plant and research specialists in coals and image analysis. VITAL system can be applied to all coking and semi-soft coking coals from 0,5% to 1,7% of vitrinite reflectance (i.e. reflectance in between lignite and anthracite coalification stages), of various organic and mineral composition (rich or poor in reactive vitrinite maceral group coals). The system offers rapid and automatic vitrinite reflectance and maceral analysis measurement with no intervention of experienced petrographer.

Ai Wang, University of Newcastle, Australia

Co-Author:
Bert Gols, Tata Steel Ltd
Tara Congo, The University of Queensland
Karen Steel, The University of Queensland
Arash Tahmasebi, The University of Newcastle
David Jenkins, The University of Newcastle

Abstract:
The addition of small fractions of non-coking coals into blends is often attractive to cokemakers, but there is the potential for reduction in coke quality. In particular, coke strength may be reduced due to poor quality IMDC-RMDC interactions. We investigate this issue using small coke samples with specifically chosen inertinite particles surrounded by vitrinite rich coal fractions. The coked samples are imaged using micro-CT and analysed to evaluate the quality of the interface. We present interactions between vitrinite-rich samples from 4 coking coals and inertinite particles from 4 non-coking coals. The results show that particular coking coal leads to poor quality interface with some non-coking coals.

Serhat Türkyılmaz, Ereğli Iron and Steel Works, Co., Turkey

Co-Author:
Erdal Ünal, Erdemir

Abstract:
Keywords: Plastic Waste, Cokemaking, Metallurgical Coke, Coke Production Coke is one of the main input raw materials of iron and steel production. Especially in blast furnaces, it is used as a heat source, reducing agent and burden supporter. In recent years, due to carbon emissions and environmental regulations, iron and steel factories are working on this subject. In this context, various studies are also carried out in cokemaking process, the use of plastic wastes in coke ovens is one of these studies. Plastic wastes can be used in coke ovens as a substitute for coal by adding certain proportions to the coal blend after several pretreatments. In this study, polyolefin-based HDPE (high density polyethylene) and polyaromatic-based PS (polystyrene) were added to the coal blend at 1% after briquetting with coal. The total briquetted coal ratio in the coal blend was set as 10%. Subsequently, the coking process was carried out in a laboratory scale coke oven with a capacity of 5 kg. Results showed that, with the addition of plastic waste to the coal blend, the reactivity and strength values of coke were not adversely affected, chemical and ash analyzes were found suitable for blast furnaces. However, the change in the amount of by-products in the coke process with the addition of plastic to the coal blend was investigated. It has been observed that each waste plastic has a different effect on coke by-products.

Christian Skelnik, thyssenkrupp Steel Europe AG, Germany

Abstract:
The coke plant Schwelgern uses nine to twelve different types of coal to produce a cokable feed mixture that meets operational safety, quality and economic requirements. The feed mixture is produced in a mixing bed using the chevron process. Procedural and logistical issues lead to inhomogeneities in the stacked mixing bed. The implementation of a control-based pile simulation model will detect and avoid these challenges through an adjusted stacking and planning strategy.

Jiangshan Zhang, University of Science and Technology Beijing, China

Co-Author:
Yuhong Liu, University of Science and Technology Beijing
Qing Liu, University of Science and Technology Beijing
Haibin Zuo, University of Science and Technology Beijing

Abstract:
Meshing is usually prerequisite and important as a pre-processing step in CFD studies, which determines largely the following convergence speed and simulation accuracy. Herein, we compare three different meshing tools, including two typical commercial ones, ANSYS-ICEM Meshing and FLUENT Meshing, and an in-house meshing tool, Script-Meshing. Commercial meshing tools follow the traditional sub-steps of geometric construction, decomposition and mesh generation; when adjustment in any sub-step(s) is needed, repeated work is required, which is time-consuming and tedious. Script-Meshing is a parameterized mesh generation tool that combines Python scripts with the OpenFOAM blockMesh utility, which can accomplish the geometry, decomposition and mesh generation in one step with controllable parameters; it can adjust the structural parameters and meshing arrangement by just modifying a few lines of code, which can greatly speed up the meshing/remeshing task. The concept of parametric meshing is especially suitable for the meshing of metallurgical vessels, as they normally feature relatively regular internal geometry, and their designs tend to be standardized. In addition, these three meshing tools are demonstrated for meshing of an industrial one-strand continuous casting tundish with an impact pad, weir, dam, long nozzle and stopper. The meshing speed, mesh quality, convergence speed and simulation accuracy are compared between the tools. It is found that Script-Meshing takes an equivalent time with commercial tools to generate hexahedral tundish grid, and the mesh quality is higher using the in-house tool. As a result, the quality mesh can accelerate the convergence speed and obtain results with high fidelity. Script-Meshing shows remarkable performance in structured remeshing, and more than 90% regeneration time can be saved. FLUENT Meshing is good at quickly generating unstructured meshes, however they are not suitable for high-order simulation and the calculation accuracy cannot be ensured.

Mansour Alharbi, SABIC, Saudi Arabia

Co-Author:
Brandao Jr. Renato, Retired
Neeraj Tewari, SABIC
Abdullah H. Kareem , SABIC

Abstract:
The objective of this study was to simulate the fluid flow performance of billet caster tundish using a mathematical model in order to optimize the tundish furniture style and location for best steel quality and/or effective flow control. A six-strand billet caster tundish presents various challenges such as being able to maintain the same casting temperature, homogenous chemistry and similar steel cleanliness in every strand. These challenges make the fluid flow phenomenon in a six-strand tundish more complex. The fluid flow characteristics and tundish performance were derived by performing the Residence Time Distribution (RTD) analysis. The model was developed successfully to simulate the flow characteristic and pattern inside the tundish. The simulation results were validated against the literature. The RTD analysis drove the conclusion that removing the current used flow modifier impact piece would help to enhance the discharging rate and reduce the dead volume zone inside the tundish. This then would enhance maintaining the molten steel temperature homogeneity during casting process.

Javad Gharagouzlou, Hormozgan Steel Company, Iran, Islamic Republic of

Co-Author:
Seyyed Asghar Madani, Hormozgan Steel Co
Mohammad Sharif Sharifian, Hormozgan Steel Co
Ali Keshavarzi, Hormozgan Steel Co
Esfandiar Pourali, Hormozgan Steel Co
Mohammad Molabeyk, Hormozgan Steel Co

Abstract:
Despite the existence of research sources on tundish hot corrosion in silicon killed steel, there are few researches on this issue in aluminum killed steel. In this research, using X-ray Diffraction, the main phases formed as a result of the reaction of slag-tundish mass have been investigated and formation causes of these phases and practical solutions to reduce the corrosion of tundish plaster are presented. According to the obtained results, monticellite phase is the main factor that causes the dissolution of MgO grains in the slag and the corrosion of tundish mass. And the end, the solutions to reducing of tundish mass corrosion in Aluminum killed steel are explained.

Masoud Al-Gahtani, SABIC, Saudi Arabia

Co-Author:
Faisal Al-Ghamdi, SABIC
Vinod Yadav, SABIC

Abstract:
EFFICIENCY OF USING POLLARD-TYPE NITROGEN SHROUD FOR MEDIUM CARBON STEELS ON MINIMIZING RE-OXIDATION DURING CASTING. Masoud Al-Gahtani, Faisal Al-Ghamdi, Vinod Yadav This paper discussed the effect of using pollard-type nitrogen shroud during production of medium carbon steel in order to minimize re-oxidation of the liquid steel. Polar-type nitrogen shrouds protection were mounted to tundsih nozzles at the bottom of the tundish provided an effective protection. The shrouds were designed with flow rate and investigated during production of medium carbon steel billets drawn for low thickness wire rods. Plant trials were used to examine the protection efficiency polar-type nitrogen shroud, and the mechanism of nitrogen entrapment during the casting of medium carbon steel billets was analyzed.

Ion Rusu, BM GROUP POLYTEC S.p.A., Italy

Co-Author:
Ion Rusu, BM GROUP POLYTEC S.p.A.

Abstract:
The paper depicts a robotic cell, which has been ad-hoc developed in order to be installed in the steel shop and support the operators during inspection, cleaning and replacement of the refractory components of the ladle sliding gate. This device is allowing opening the bottom of the ladle so that the liquid steel can run into the tundish of the continuous caster. The developed robotic cell represent an innovative attempt to create a cooperative environment where the technicians and a robot interact in a safe and ergonomic way. This system, which is installed and tested in an Italian integrated steelworks, allows improving both the health and safety condition of the workers and the quality and repeatability of the operations. It automatically manages the sliding gate maintenance, in order to increase safety and operational accuracy, stability in the repetitively and to optimize process times control. This multi-tool robotic cell is equipped with: Extraction/Insertion tool Refractory nozzle extraction tool Tool to remove fixed plate Nozzle cleaning tool

Iori Suetsugu, KROSAKI HARIMA CORPORATION, Japan

Co-Author:
Shunji Sadano, KROSAKI HARIMA CORPORATION
Akira Otsuka, KROSAKI HARIMA CORPORATION
Mamoru Yoshimura, KROSAKI HARIMA CORPORATION
Toshihiro Imahase, KROSAKI HARIMA CORPORATION
Yusuke Yamaguchi, KROSAKI HARIMA CORPORATION

Abstract:
Slide Gate mechanism is used world-wide by steel manufacturers to control the flow of molten steel in the steel making process. However, operation of Slide Gate and replacement of refractories still depend on the experience and skills of the operators. Krosaki Harima Corporation has developed one new slide gate called “R-Gate” having improved mechanism for face pressure loading/unloading along with plate refractory clamping. Its operation is simple that provides labor saving and reduced human intervention. So far, around 174 units of this new slide gate mechanism has been supplied to 23 customers worldwide. Further work is going on to make this R – Gate in automatic mode where the whole system including change of refractories parts will be controlled by a general robot “REX-ROBO”. By putting this system into practical use, it is possible to save the labor and reduced human error under severe environment and achieve customer satisfaction. In this paper, we introduce the results of R-Gate’s contribution to our customers through its features and plate life improvement, and an example of automated operations in refractory replacement by collaboration with R-Gate and Robots. In addition, we introduce our latest technology of R-Gate & REX-ROBO.

Gerhard Ney, Saarstahl AG, Germany

Co-Author:
Dirk Deckers, Saarstahl AG
Steven Fries, Saarstahl AG
Marco Abram, SMS Concast AG
Andre Wildhaber, SMS Concast AG
Luigi Alessio, SMS Concast AG
Steve Münch, SMS Concast AG
Anke Britz, Saarstahl AG
Matheos Czarnynoga, Saarstahl AG
Ralf Thome, Saarstahl AG

Abstract:
The new billet caster S1 at Saarstahl AG Saarstahl is one of the world leading suppliers of long products for demanding steel grades of special bar quality. The product portfolio includes a wide range of unalloyed and high-alloyed steel grades with a carbon content from 0.01 up to 1.0 wt.-%C, which are mainly utilized in the automotive sector. To underline its forefront technology position and to achieve further quality improvements, as well as production flexibility and capacity, Saarstahl ordered a new 5-strand billet caster named “S1” in 2017. Designed by SMS Concast AG, the caster produces 180x180mm2 billets. After the successful commissioning of caster “S0” and revamping of caster “S3”, this is already the third cooperation between both parties on a major caster project since 2005. The caster is equipped with Convex Mould Technology, consecutive stirring in mould (MEMS) and strand (SEMS) position, AirMist soft secondary cooling, Dynamic Mechanical Soft Reduction (D-MSR), automatic deburring, marking and sampling machines, speed and temperature measurements as well as an extended discharge concept including 4 silent turn over cooling beds. Among the technological equipment, the installation of the 12 MSR units, which are comprised by six double modules, must be highlighted. Each reduction roll is capable to apply up to 1000kN of force to ensure intense soft and hard reduction. The optimum steel grade specific reduction pattern are adjusted online automatically based on the process conditions and casting parameter to ensure lowest segregation and porosity levels and therefore highest internal quality. 24 months after awarding the contract to build the new “S1”, the caster had its first cast in November 2019. This paper shall outline the main technological features in detail and reflect the quality results that could already be achieved in standard production after an intensive hot commissioning and testing period.

Julien Berton, Vesuvius Europe, Belgium

Co-Author:
Andrzej Warchal, Vesuvius

Abstract:
Corrosion of zirconia containing refractory is one of the chronic issues that limits the service life of continuous casting nozzles resulting in shortening the casting time. In the present study, various degradation mechanisms of the lime-stabilized zirconia grains are discussed, focusing on microstructural and phase analysis. A classification of corrosion mechanisms is performed based on the phase assemblage and compositions of the reaction products resulting from the chemical interactions between mold-flux slag and zirconia containing refractories. A methodology was developed focusing on an experimental approach, thermodynamic modeling, and materials characterization techniques; this allows the development of new material composition and microstructure used in SEN/SES/MTSP sleeves. Several trials performed in the continuous casting operations demonstrate the benefit of new materials contributing to the longer service life of Vesuvius products generating a longer sequence length for the steelmakers. An industrial example performed in Tenaris Silcotub, Calarasi are given to describe the role of chemistry and fundamentals of chemical interactions between slag and refractory.

Carlo Cascino , SMS Concast AG, Switzerland

Co-Author:
Marco Abram , SMS Concast AG
Andrea Lanari , SMS group
Filippo Verlezza , SMS group

Abstract:
Sustainability and lowest carbon footprint with high productivity are the current and future challenges in the steel industry for the production of long products. The CMT® (Continuous Minimill Technology) process developed by SMS group is an inline endless casting and rolling process designed to reach these goals. A low emissions steelmaking facility supplies liquid steel to a high-speed casting machine directly feeding the rolling mill, eliminating the traditional fossil fuel fired re-heating furnace. The pairing of flat bath continuous scrap melting together with direct rolling of rebar or very compact coils concept drastically reduce up to 70% the overall direct emission on site of greenhouse gases, increasing the environmental sustainability of the CMT. Liquid steel is produced and refined by an advanced steelmaking plant, based on Allcharge® design coupled with AURA® IGBT electronic power modules, ensuring the lowest environmental impact in terms of CO2 and NOx emissions and opens the door to connection to renewable power. As the CMT concepts require high casting speed, special attention must be paid to mold and strand guiding design (SMS Concast CONREX technology), mold oscillation (SMS Concast CONDRIVE® electromechanical oscillation) and secondary cooling. The flexible CMT process can be designed for a wide range of products, from straight rebars to Vertical Compact Coils up to 8 tons (VCC). Integrated L1 and L2 automation systems, managing all production process aspects from the scrap yard logistics to the mill finishing area, as well as covering maintenance of the plant are also a key element to the efficient and cost effective production. This paper will highlight the main environmental advantages of this technology, as well as the various concepts for different range of production.

Gibeom Kim, Pohang University of Science and Technology, Korea, Republic of

Co-Author:
Jinyoung Kim, Graduate Institute of Ferrous & Energy Materials Technology
Chang-Hee Yim, Graduate Institute of Ferrous & Energy Materials Technology
Woong-Hee Han, POSCO
Soo-Chang Kang, POSCO
Dae-Geun Hong, Graduate Institute of Ferrous & Energy Materials Technology

Abstract:
In order to improve the efficiency of the decarburization reaction and control the ingredient of molten steel in the Ruhrstahl Heraeus (RH) degassing process, it is necessary to maintain an appropriate vacuum level and keep the refractory in contact with the molten steel clean. However, the temperature difference between the molten steel and refractories causes the steel skull and the solidified slag to adhere to the refractory, affecting the steel component deviation and steel product quality. Due to the absence of a quantitative measurement method for the present amount of steel skull in the RH process, it is difficult to establish an accurate relationship between operation variables affecting the precise element component control of molten steel. In addition, this leads to operation that relies on know-how of individual operator during the RH process. In this study, the quantitative measurement and its evaluation of the steel skull were conducted for improving the temperature control and adjustment of molten steel component during the RH operation. The amount of steel skull was estimated using cross-section images of vacuum vessel before and after the RH operation plant. The correlation between quantitative amount of steel skull and actual RH operation data including variables such as steel component, temperature and time was analyzed statistically technique machine learning. The steel skull amount as a dependent variable was categorized, and the machine learning modelling using the Random Forest (RF) and the Extra Tress (ET) algorithms was performed using approximately 620 data of RH operation. The obtained results have been discussed in context of the knowledge of steel making metallurgy. Physicochemical analysis about the change in the amount of steel skull and correlation between RH operation variables revealed the effectiveness of the proposed machine learning approach.

Marco Knepper, Hüttenwerke Krupp Mannesmann GmbH, Germany

Co-Author:
Torsten Müller, Primetals Technologies Germany
Willi Bühler, Primetals Technologies Germany
Wolfgang Brett, Primetals Technologies Germany
Sebastian Schäfer, Hüttenwerke Krupp Mannesmann GmbH

Abstract:
"A high degree of automation combined with a respective safety standard, reliable and user-friendly operation and a compact design are the requirements for modern ladle furnaces to be implemented in existing converter plants and steel mills. Primetals Technologies has successfully implemented its proven ladle furnace technology in combination with complex and high customer requirements with limited space availability at the HKM converter plant in Duisburg. In HKM, the entire production line is operated and monitored from a central control room. For this reason, all necessary work and functions must be controlled and supervised remotely, such as temperature and sampling, ladle stirring, etc. The ladle furnace is equipped with state of the art camera systems, robotics, automatic stirring gas coupling and a semi-automatic quick exchange for stirring gas lances to reduce manual tasks to a minimum. These complex automation processes require proven sensor technology to ensure a high level of operational reliability in the harsh environment of a steelplant as well as a holistic approach to combining different automated functions. Both individual components and combined automated processes of several plant parts, including the sensors used, are presented. Remaining user activities are explained, and security-related topics such as access to restricted areas and monitoring of the facility are described. Finally, the experience and operational results after more than 2 years of operation are presented to show the impact of the integration of a ladle furnace into an existing BOF meltshop in regards to the metallurgical impact and consumptions."

Mir Ishfaq, Indian Institute of Technology Bombay, India

Co-Author:
Manish M Pande, Indian Institute of Technology Bombay

Abstract:
Insoluble oxygen constitutes a substantial portion of total oxygen in the Al-deoxidized steels. The concentration of dissolved oxygen increases as the Al concentration increases beyond a certain critical value. In some steel grades, Al requirement is much higher than that is required for deoxidation. In the present work, the insoluble oxygen in such high aluminum steels has been estimated and compared using two different techniques: (i) two stage heating method in inert gas fusion infrared absorptiometry to differentiate soluble oxygen and insoluble oxygen. In the stage I, the sample was first heated to a temperature of 1873 K to remove all the dissolved oxygen. SEM studies showed that alumina inclusions were still present and were not removed by carbothermic reduction after stage I. In stage II, the sample was heated to 2613 K at which the alumina inclusions (insoluble oxygen) were reduced by the graphite. (ii) A Scanning Electron Microscopy Automated Inclusion Analysis (SEM-AIA) was used to estimate the size and number of inclusions in the steel samples. The insoluble oxygen was estimated, by Area Fraction (AF) method from the SEM-AIA data.

Andrea Grasselli, Tenova S.p.A., Italy

Co-Author:
Davide Masoero, Tenova S.p.A.
Naci Faydasıçok, Hasçelik Sanayi ve Ticaret A.Ş.

Abstract:
Key Words: EAF, electric arc furnace, Consteel®, Consteerrer®, ArcSave®, EMS, energy efficiency, productivity, cost reduction, performance improvement, quality steel, productivity improvement, revamping. Abstract The constant evolution of the steel industry emphasizes how sustainability and flexibility are strategic parameters of increasing importance in the production process of steel. Tenova, in cooperation with its partner ABB, has made available to the market the Consteerrer®, an innovative ArcSave®-based electromagnetic stirring technology jointly developed by ABB and Tenova for continuously charging EAF systems. The paper presents the main features of the technology that Hasçelik selected for its first electric furnace as the optimal solution to successfully meet the challenges of the Turkish market in which the plant will operate. Consteel® EAF combined with Consteerrer® helps producing high quality steel as well as significantly reducing the production cost, ensuring high flexibility in terms of both material charge and finished product. The solution chosen by Hasçelik will be the first continuously charged EAF in Turkey and will give the opportunity to leverage the inherent flexibility of the Consteel® EAF to tackle the declining scrap availability and quality as the continuous charge makes the process intrinsically robust to the variation of the scrap density, quality and content of volatile compounds. The combination with an optimized application of the Consteerrer® EMS reduces the thermal process losses, increases the melting speed, homogenizes the liquid steel and reduces the oxygen content of the bath.

Bernardo Sainz, AMI Automation, Mexico

Co-Author:
José Castillón, AMI Automation
Rommel Villarreal, AMI Automation
Jorge Haros, AMI Automation
Bernardo Sainz, AMI Automation

Abstract:
DC Electric Arc Furnaces have a higher complexity when compared to AC EAFs. The power rectifier and other electronic equipment require more maintenance and specialized skills from your personnel. The new DigiFCR X4 control platform is used to fully retrofit the Power Converter of a DC EAF, solving the obsolescence problems while eliminating downtime and high maintenance costs caused by outdated equipment. Incorporating smart products on Firing Circuit Replacements also expands the capability to monitor key performance indicators towards Industry 4.0. DigiFCR X4 native technology works with DigitARC® PX3 electrode regulator to stabilize the arc and work more efficiently. Furthermore, it integrates intelligence tools to get the most of your existing hardware by using real-time data to analyze, learn and predict the power converter performance, properly aligning your technology on the road to digitalization.

Jaroslav Brhel, HTT Engineering spol. s r.o., Czech Republic

Co-Author:
Pierre Guillaume, ArcelorMittal Industeel Belgium

Abstract:
Arcelor Mittal Industeel plant in Charleroi produce special high quality steels including stainless steel grades. Chemical energy package including burners and carbon injection lances on its 200t EAF has been revamped in 2022 resulting in improvement of energy efficiency and yield for all produced steel grades. The paper will discuss project execution, new equipment layout and performance as well as operating experience comparing results before and after revamping both for carbon and stainless steels.

Matti Aula, Outokumpu Stainless, Finland

Abstract:
High amount of refractory materials are consumed in steelmaking due to high processing temperatures. Refractory materials typically contain MgO, which is also an important slag former in electric arc furnace (EAF). A normal EAF practice is to operate with slag composition close to MgO saturation limit to decrease the potential of the slag to dissolve MgO-containing refractories. One method to provide MgO to the slag is to charge crushed spent refractory bricks to EAF. The most important parameter in utilization of bricks is the dissolution speed of the crushed bricks. If the recycled bricks do not dissolve fast enough to slag, the liquid part of the slag is not saturated with MgO and the refractory wear is increased. In this work the dissolution of three spent refractories of different grain sizes are tested in chamber furnace containing a magnesia brick as a crucible. The starting slag is synthetic slag similar in composition to EAF slag obtained in stainless steel production prior the MgO dissolution. In the trials different spent refractories are added to the synthetic slag mix to provide MgO. The holding time and temperature is set to obtain MgO saturation of slag when no sources of MgO are used in the original mix. The slag samples obtained from the chamber furnace are analyzed with x-ray fluorescence spectrometry (XRF) to obtain the overall composition and with scanning electron microscope (SEM) to acquire qualitative estimate of the presence of undissolved refractories in the slag. The change of total MgO content of the slag with different MgO sources is evaluated to obtain the estimate of the amount of undissolved spent refractory.

Axel Boeke, Vallourec, Brazil

Co-Author:
Savia Cristina Lacerda Poubel Pinheiro, Vallourec
Pedro Augusto Machado, Vallourec
Diego Bruno Santiago, Vallourec
Anderson José Santos, Vallourec
Axel Boeke, Vallourec

Abstract:
The better EAF refractory performance can be achieved combining refractory materials and practices, metallurgy process parameters and proper slag composition. These 3 factors are well known as the success key for Steel Shop productions. Vallourec Brazil Steelmaking (VSB) counts on a very singular Consteel EAF which uses Hot Metal supplied by a Charcoal Blast Furnace. Nowadays, the Steel Shop is operating in 2 main recipes, which means with and without Hot Metal in the charge. So that, the attention to have an adequate slag chemical composition is in the routine bases for process feedback and control. Particularly, slag saturation and basicity had been more studied in this work guiding actions aiming to evaluate this control and benefits in the EAF refractory lifetime. The taken actions were defined and slag composition was evaluated using quaternary oxide system of MgO-CaO-FeO-SiO2, also analyzing the dual (saturated with CaO and MgO) and MgO saturated EAF slag chemistry comparing the base and period of trials indicated an effect increasing the refractory lifetime.

Antonios Skarlatos, DANGO & DIENENTHAL, Germany

Abstract:
Nearly 300 SAM Series skimming machines have been installed in steelworks around the world, proving their worth every day under harsh operating conditions. These machines increase the yield of pure steel thanks to the precisely controlled movement of the skimming plate, which only removes the slag from the melt, leaving the liquid steel in the ladle. The maximum skimming force is 50 kN, the maximum range 9,500 mm. Even the basic machine gives operators the option of maintaining a constant immersion depth with a horizontal skimming boom. With the newly developed automated deslagging option, the slag skimming machine can perform a variety of programmed movement sequences. To execute these sequences, the skimming plate is moved parallel to the bath level at the desired immersion depth. Operators can select the distance to the ladle’s inner wall. The skimming plate also is lifted in the front area of the ladle to remove the slag via the spout in a collision-free process. Once the ladle has been placed in the ladle tilter and tilted until the slag begins to flow out of the pouring spout, the automated process can begin. Two skimming patterns can be chosen to process the entire bath surface: a “circular” or a “radial” pattern. The distance between the individual tracks depends on the degree of overlap. The entire bath surface can be processed repeatedly, and the patterns combined at will until only individual slag islands remain on the metal bath surface. These are then removed through a targeted selection of individual sectors. The deslagging process ends when the bath surface is free of slag and the ladle tilter has been tilted back to its basic position.

Klaus Jax, Primetals Technologies Austria, Austria

Co-Author:
Norbert Hübner, Primetals Technologies Austria
Wolfgang Oberaigner, Primetals Technologies Austria

Abstract:
"Continuous product improvement based on steel producers requirements is an essential part of the TPQC success story. But how can TPQC users take advantage of these? This paper describes the latest developments in the area of TPQC. Among the developments are improvements of the Statistical Process Control (SPC) functionality, now supporting an electronic logbook of changes and measures applied to the process, and digital guidance to select the right measures when SPC alarms occur. Other new features comprise extended support for data recording, visualization and evaluation for the liquid steel production and visualization of data for entire campaigns such as tundish sequences. Integration of prescriptive AI models make it possible to online react to process deviations to adapt the next process in order to reach the required product quality targets. TPQC is now available as subscription license to ensure that the system is always at the latest state and steel producers can benefit from the new features of the system and become a lifecycle partner of Primetals Technologies. The paper further explains success stories of projects in which TPQC is interacting with Primetals Technologies' production management system (PMS) and condition monitoring system (ALEX) to maximize the benefits and to make a big step towards the Digital Unity vision of Primetals Technologies. ALEX can provide valuable information about the condition of the production facilities to TPQC via a plug & play interface and such enabling TPQC to even more precisely decide on necessary measures to ensure that the products will meet the required quality. The interaction with the PMS ensures that the product transport and necessary further production steps can automatically be controlled based on on-line quality decisions and remedial measures proposed by TPQC."

Christoph Kirmse, SMS group, Germany

Co-Author:
Pallavi Mohta, SMS group
Ritwick Manatkar, SMS group
Agnieszka Zuber, Macrix Technology Group
Rashmi Murthy, SMS group

Abstract:
During continuous casting longitudinal facial cracks (LFC) can occur due to various root causes. LFCs are difficult to capture during the production process and are visible only in the final stages of a process. Some of the LFCs can open and lead to a breakout. This creates safety and environmental issues due to hot, liquid metal flowing outside the casting machine. It also leads to a loss in production time and potential damage to the equipment. The goal of this paper is the prediction of those breakouts during operations using deep learning models. The deep learning algorithm uses different signals at the mold to calculate a probability of a breakout. When the probability exceeds a threshold value, a breakout alarm will be triggered. Upon detection of an upcoming breakout, suitable countermeasures are suggested to prevent the breakout from happening. Early results suggest a reduction of breakout events of 50%.

Ahmad Rajabi, VDEh-Betriebsforschungsinstitut GmbH, Germany

Abstract:
Growing customer expectations together with increasing availability of relevant information and high flexibility of final product features are taking established Decision Support Systems (DSS) performing automatic release decisions continuously to their limits. Emerging machine-learning technologies could solve this problem, but concepts for their robust industrial application performing high-stakes decisions are missing. This paper aims to report our attempt to improve the automatic quality assessment of steel products by means of a holistic approach combining deep learning technology with sophisticated management of underlying training data to enable the optimal use of all available data sources and simultaneously simplify the configurability and maintainability of previous DSS.

Gerfried Millner, Materials Center Leoben Forschung GmbH, Austria

Co-Author:
Lorenz Romaner, Montanuniversität Leoben
Daniel Scheiber, Materials Center Leoben Forschungs GmbH
Manfred Mücke, Materials Center Leoben Forschungs GmbH

Abstract:
The production of steel coils with scrap material using an electric arc furnace (EAF) results in a very low CO2 emission compared to traditional production in blast furnace followed by basic oxygen steelmaking, but introduces many tramp elements by scrap. The impact of these foreign elements on the mechanical properties is in many cases not entirely understood and predicting the impurity effects on mechanical properties of steel from processing solely with physical models is not feasible. In this work we present a data-driven approach applying AI regression model techniques to predict r-value, tensile strength and other parameters of cold-rolled steel strip produced by voestalpine Stahl GmbH. The data includes a full chemical analysis, as well as many parameters measured during all working steps of the process and the resulting mechanical properties. As a prerequisite for training of AI models, the data needs to be understood, analyzed, checked, and unreasonable data be removed (data cleaning). The result is a machine-readable dataset fit for various modelling tasks. The used models include Random Forest Regression, Support Vector Regression, Artificial Neural Networks and Extreme Gradient Boost. Based on the insights gained, we present strength and limitations of different model types with the available data and number of features. In addition, we are presenting methods to calculate the feature importance and determine the impact of each feature in our models. Furthermore, we discuss possible improvements like introducing prior physical knowledge.

Christoph Nölle, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Asier Arteaga Ayarza, Sidenor Investigación y Desarrollo
Monika Feldges, VDEh-Betriebsforschungsinstitut GmbH
Martin Schlautmann, VDEh-Betriebsforschungsinstitut GmbH
Norbert Holzknecht, VDEh-Betriebsforschungsinstitut GmbH

Abstract:
A concept for estimating the risk of steel long products to develop surface defects during the production is presented, based on an advanced product tracking system and machine learning algorithms. The aim of the risk estimators is to identify products with a high risk for defects as early as possible in the production chain and to support operator decisions on corrective actions or the immediate recycling of a product in order to save resources for the further processing. In our use case, the secondary metallurgy, continuous casting and hot rolling processes are considered of relevance for the surface quality, and besides the raw process data also the results of a set of soft sensors are evaluated, which integrate physical process knowledge into the otherwise data-driven risk estimators to increase the reliability. Some challenges of the approach are discussed, such as difficult product tracking conditions, the need to retrieve aligned data from different sources and the availability of sufficiently broad datasets for training. A digital twin-based software platform for the integration of different data sources, soft sensors and risk sensors is presented, along with a data model based on international standards but adapted to our use case.

Nils Hallmanns, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Roger Lathe, VDEh-Betriebsforschungsinstitut GmbH
Andreas Wolff, VDEh-Betriebsforschungsinstitut GmbH
Detlef Sonnenschein, VDEh-Betriebsforschungsinstitut GmbH
Hagen Krambeer, VDEh-Betriebsforschungsinstitut GmbH
Monika Feldges, VDEh-Betriebsforschungsinstitut GmbH
Alexander Dunavitzer, VDEh-Betriebsforschungsinstitut GmbH

Abstract:
In flat steel production, flatness of steel strips and plates is of paramount significance for a safe and stable process operation and essentially defines final product quality. Although local flatness is controlled successfully during rolling, many steel plants face significant flatness problems for thin and/or high-strength steel products in downstream processes and after production. Especially the automotive industry has increasing demands for thinner and higher-strength steels. But this implies new difficult challenges for the aged plants and machinery run at their physical and technical limits to produce such highly specialized steel products. Additional limits are given in terms of cooling capacity, maximum required strip tension or the required rolling force, but most importantly by roll bending and continuous variable crown. HatFlat investigates cross-process influences on the development of flatness defects. For this purpose it will apply a unique way of combining existing models based on physical laws – so called first-principle models – and state of the art machine learning (ML) approaches. This so-called physics-informed ML approach allows to a) improve the prediction of flatness and flatness deficiencies, b) identify the influential factors of greatest impact on flatness and c) to make proposals for changing the processes (as long as the product quality specifications are not affected) for achieving a better flatness characteristic. The project will also utilize proven Industry 4.0 tools, such as digital product twins for hosting the prediction models. The models developed in HatFlat will be assembled into a holistic assistance tool for flatness prediction. Featuring a strong industrial participation of some of Europe´s biggest steel producing companies, plants allocated along the process chain of steel processing with strip and plate products, two highly reputed steel research institutes and a university, all working together to create one new tool for predicting, understanding and improving flatness.

Matteo Tomba, PERT Srl, Italy

Co-Author:
Nicola Tomba, PERT Srl

Abstract:
Grinding balls are used in mining, coal, and concrete making plants, to grind materials by impact, abrasion and crushing. Compared to casted/forged balls, rolling process guarantees the best product performance in terms of ball geometry and shape, higher productivity and lower production costs, better material yield. Inline heat treatments will ensure the required ball hardness, minimizing or avoiding any offline treatment. Balls sizes which can be rolled on PERT grinding ball rolling mills are ranging from diameter 15 mm to 150 mm, with hourly productivity, depending on ball size, ranging from 1 ton/h up to 35 ton/h. The described case history, will show at the audience all the project developments for an integrated mill starting from billet to the final steel ball production.

Kazutoshi Kitagoh, Toshiba Mitsubishi-Electric Industrial Systems Corporation, Japan

Co-Author:
Toshihito Shimotani, Toshiba Mitsubishi-Electric Industrial Systems Corporation
Masaki Nakaema, Toshiba Mitsubishi-Electric Industrial Systems Corporation
Min Zhang, Shougang Jingtang United Iron & Steel Co., Ltd.
Jixin Li, Shougang Jingtang United Iron & Steel Co., Ltd.
Zhankui Dong, Shougang Jingtang United Iron & Steel Co., Ltd.

Abstract:
We introduce and discuss two technical features of hot rolling in an endless line with the excellent application results. The first feature is functionality to establish rolling stability with high quality of products in endless rolling. The second feature is automation to enable multiple rolling modes. In an endless line, continuous caster and rolling equipment are directly connected via a tunnel furnace. There is a shear between caster and tunnel furnace. The line can be operated in 3 modes – “endless“, “semi-endless“ and “coil to coil“ rolling. With endless rolling, there is no shear cut between caster and tunnel furnace. The advantage of endless rolling is that ultra-thin coils can be produced stably with high product quality since, unlike a conventional hot rolling, there is no loss of tension at head/tail end. With semi-endless rolling, the caster output is cut into long slabs. The coiler entry shear is used to create several coils from a single slab. With coil to coil rolling, the caster output is cut into slabs. The mill and caster can operate at different speeds in semi-endless and coil to coil rolling. When rolling speed needs to be changed to satisfy production or operational requirements, coil to coil or semi-endless rolling can be selected. The multiple rolling modes feature provides flexible selection of rolling mode on a single line and expands both product types and operational flexibility. Finally, we show excellent control results in the actual line with the above technical features.

Kerstin Baumgartner, Primetals Technologies Austria, Austria

Co-Author:
Simon Grosseiber, Primetals Technologies Austria
Andreas Jungbauer, Primetals Technologies Austria
Jürgen Scholler, Primetals Technologies Austria

Abstract:
"The newest member of the Arvedi ESP family closes the gap between ultra-thin and thick gauges in endless production, being designed for 0.8 mm up to 25.4 mm with a yearly capacity of more than 3 Mt on a single strand. This paper introduces newest developments and features implemented in this latest ESP reference, such as the longest ESP caster ever sold with 8.5 t/min mass flow, the latest cutting edge split-core EMBR design and bulging compensation with the bender anti-bulging system. Special features of the rolling mill are the revolutionary inline work roll change system in the finishing mill, enabling to even double the current ESPs world-records regarding maximum rolled strip length within one TSCR sequence. Moreover, the Ultra Early Power Cooling system allows rapid cooling of thick gauges to coiling temperature already within the finishing mill before even reaching the cooling section in the run-out table, thus facilitating superior mechanical properties for demanding applications. These technological packages enable a fully endless production of the most challenging product mix ever seen on thin slab casting and rolling plants, while keeping the core features of Arvedi ESP lines like zero-carbon emission hot rolling and the well-known excellent coil quality. "

Björn Kintscher, SMS group, Germany

Co-Author:
Cosimo Cecere, SMS group
Tim Kleier, SMS group
Tristan Töpfer-Bergner, SMS group

Abstract:
In view of global warming and the international agreements on climate targets, the topic of sustainability is more urgent than ever and the steel industry must make its contribution to CO2 reduction. At the same time, demand for "green" steel is increasing, as the automotive industry, for example, has to consider the CO2 footprint of their products over the entire life cycle. The CSP® technology has been known since its introduction as a particularly efficient way to produce high-quality hot strip. With its further development, CSP® is not only offering the energy-optimized way of hot rolled coil production, but is also continuously closing the gap of achievable products compared to the conventional route. Recent modernization upgrades of the CSP® plants revealed new improvements and benefits to increase productivity, improve plant reliability, reduce energy consumption and lower the carbon footprint. Even though modernizations are the most common approach in Europe, a new steel plant is built - and as such, it is a novelty since decades. In 2025, the first carbon-neutral CSP® Nexus plant will go on stream as part of the H2 Green Steel project in Northern Sweden. The CSP® Nexus technology does not only move forward in terms of energy optimization but even makes the big step into carbon free steel production. In addition, it takes full advantage of high throughput casting and the latest developments in hot rolling, such as endless operation where beneficial. Thus, CSP® Nexus increases and enhances the product mix compared to other combined casting and rolling plants in terms of steel grades and strip dimensions. This paper will give an overview on technology of the CSP® Nexus plant for H2 Green Steel and the possibilities of the Nexus concept. In addition, it will highlight the approach for the modernization of existing CSP® plants.