Hans Bodo Lüngen, on behalf of Steel Institute VDEh, Germany

Abstract:
Opening of the conference by the chairman

Stefanie Brockmann, Steel Institute VDEh, Germany

Abstract:
Welcome address by the host

Frank Hohlweg, ArcelorMittal Bremen, Germany

Abstract:
123

Georges Rassel, Paul Wurth & CEO Region Europe SMS group, Luxembourg

Abstract:
Exploring Paul Wurth's latest technological developments: How are we in SMS group building on our metallurgical expertise to advance green iron & steelmaking?

Alexander Fleischanderl, Primetals Technologies, Austria

Abstract:
Steel is an invaluable material for many sectors. However, in the context of the climate crisis, the sector has come under increased scrutiny due to its reliance on carbon-intensive fossil fuels, primarily coal. Steel production accounts for around 9% of total global carbon emissions, and its hunger for coal continues to drive excavation. In recent years, governments across the world have been looking for ways to meet the goals of the 2015 Paris Climate Agreement, and as such, the political pressure on the sector to decarbonize is also mounting. But it is not only the governments putting the pressure on. Increasing financial pressures like the price of carbon and the rise in the popularity and credibility of Environmental, Social and Governance scores amongst a more environmentally conscious generation of investors looking to put their money where their morals are. According to several leading organizations the sectors transformation will see a phased approach. Short term, the existing integrated mills will implement major de-carbonization measures, reduce the specific fossil consumption, improve energy efficiency and implement a circular economy. In the mid-term fuel switching and electrification of processes will play a significant role. In this phase we might see two major trends, the implementation of EAFs into integrated mills (hybrid mills) with highest charge mix flexibility and new DR-based minimills. Since scrap supply will remain an undersupply alternative virgin feed from iron ore will remain important. Due to the availability limitation of high-grade iron ore, DR plants will have to utilize also lower grade ores, which has an impact on the steelmaking operation. Primetals Technologies is addressing this challenge and has been developing the hydrogen-based fine ore reduction HYFOR pilot project in Austria. What separates HYFOR from its green steel peers, is what

Markus Dorndorf, TENOVA LOI Thermprocess GmbH, Germany

Co-Author:
Pablo Duarte, TENOVA HYL
Andre Esterhuizen, TENOVA South Africa Pty Ltd
Jorge Martinez, TENOVA HYL

Abstract:
The move of steelmaking industry, as part of the decarbonisation of Europe’s economy by Carbon Direct Avoidance CDA, is towards natural gas-based (short-term) and hydrogen-based (long-term) iron reduction as substitute for carbon-based processes. But this path represents an extreme challenge, especially under the difficult economic conditions and the general global political situation. The key elements, the so called transition technologies, like the ENERGIRON-ZR® Direct Reduction Technology and melting technologies for iron making (SAF/OSBF) provide reliable tools to support each phase of this transformation process and represents the perfect interim solutions with highest flexibility and minimized negative economic impact. From an economic point of view, two approaches are particularly target-oriented and sustainable: • The combination of the ENERGIRON process with its flexible use of gaseous reducing agents (natural gas, CH4/CO/H2) and a smelting reduction furnace (SAF/OSBF) offers the possibility of continuing to use the existing steel route via the BOF to its full extent and replacing only the blast furnace (BF) in the process chain by direct reduction and smelting reduction. The liquid pig iron produced via the new process route has the same properties as conventionally produced pig iron, but with a significantly lower carbon foot-print, allowing the new technology concept to be seamlessly integrated into existing steel making facilities. • A centrally located plant of maximum size and the production of Cold DRI or HBI, with the unique flexibility for ~1% to 4,6% carbon, offers the possibility for several end users to use sus-tainably produced DRI/HBI to process it directly into steel in the EAF or FMF with other charg-ing materials such as scrap and liquid pig iron. The paper explains in detail innovative and forward-looking concepts for steel manufacturers and shows a way forward under the current difficult economic conditions and the tension between international competition and local environmental regulations, political conditions and costs.

Sean Boyle, Midrex Technologies, Inc, United States

Abstract:
The mitigation of greenhouse gas (GHG) emissions is becoming critical in the steel industry. The natural gas based MIDREX® Process paired with an electric arc furnace (EAF) has the lowest CO2 emissions of any ore-based steelmaking route with options to lower even further. As green hydrogen becomes available, it can be injected in the MIDREX process with minimal modifications, thus reducing emissions further. Ultimately, MIDREX H2™ can make use of hydrogen both as the energy source and the reductant to produce a near-zero carbon footprint metallic, which can then be used as feedstock for steelmaking. The ArcelorMittal Hamburg project will be the world’s first direct reduction plant on an industrial scale to demonstrate the technology readiness. Unfortunately, green hydrogen is not currently available at sufficient scale and low cost for rapid adoption. Additionally, the capital requirements to convert from BF to DR-EAF are enormous. Therefore, the rapid conversion to hydrogen steelmaking is unrealistic, so other ways to reduce CO2 emissions during the transition phase must be explored, such as the use of HBI in a BF/BOF. Hot Briquetted Iron (HBI) is a compacted form of Direct Reduced Iron (DRI) that is manufactured with well-defined, consistent chemical and physical characteristics that make it very suitable for handling, shipping, and storage with minimal yield losses during those steps. HBI can be used in an EAF to produce high quality steel products and in Blast Furnaces to increase productivity and lower coke consumption, ultimately lowering CO2 emissions. As such, HBI produced outside of one’s facility should be considered in all steelmaking operations as a flexible metallic source during the hydrogen transition. As a merchant product, HBI can be produced in large scale operations at a location where logistics and reducing gas (including hydrogen) can be advantageous and transported in the right amount to

Rénard Chaigneau, Baffinland, Netherlands

Co-Author:
Maarten Geerdes, Geerdes Advies

Abstract:
Numerous studies have been done to determine the best properties of each of the components of the blast furnace ferrous burden like for sinter, for pellets or for lump ore. The more difficult and interesting question is: how does the burden as a whole behaves inside the blast furnace when facing reduction, softening and melting. More difficult, since studies inside the furnace are nearly impossible and laboratory simulations never can cover the complete process. The present paper shows data that have become available from analysis inside the furnace as well as resulting from laboratory tests. The following conclusions are reached: - Reducibility: it was found, that the reduction degree of materials with very different reducibilities are at 900-950 °C more or less identical. Furthermore, reducibility is the weighted average of the properties of each of the components. - Softening of a blend is much closer to the softening temperature of the material with the highest softening temperature. Softening and melting of a blend is not a weighted average of the properties of each of the components. An example is shown, where in a blast furnace the pellet ratio is increased and what options exist with respect to pellet type (fluxed, acid, olivine) in conjunction with sinter basicity. The conditions for burden distribution at high pellet% are indicated and a strategy for using lump ores under varying conditions is discussed. Understanding the interaction of reduction, softening and melting in conjunction with burden distribution is important as they are main contributers to blast furnace productivity. The inherent know how on ferrous burden should also be applied to existing and newly developed shaft based direct reduction processes

Maarten Geerdes, Geerdes Advies, Netherlands

Co-Author:
Yongzhi Sha, Chinese Institute of Iron and Steel Industry

Abstract:
There was about 1.28 billion tons of hot metal produced in 2019 with various operations of blast furnaces around the world. The present paper describes similarities and differences in BF operation based on hands on experience and operational results. The focus is on large blast furnaces (≥12 m hearth, ≥3200 m3 IV). The paper starts with comparing results in productivity, coke rate and total fuel rate. A comparison is made of: - The effect of BF size on operation results. - Raw materials being used, slag volume and composition as well as the effect of slag volume on PCI rates and productivity. - Operating philosophies: consistent versus variable blast volume. - Tuyere parameters like velocity and blast momentum. - PCI rates and oxygen enrichment. - Use of burden distribution.for optimizing BF operations. This includes the ferrous and coke layers that are being used as well as methods for using two sizes of sinter. In the discussion the authors address the question what operators can learn from each other. Note: this is the farewell lecture of Dr Maarten Geerdes, who leaves the BF community after turning 70 in March 2021

Hans Bodo Lüngen, on behalf of Steel Institute VDEh, Germany

Co-Author:
Peter Schmöle, Schmöle Consulting

Abstract:
The integrated steel works in Western Europe operate modern plants to produce a wide variety of high-grade steel products. Currently, the blast furnace-basic oxygen furnace (BF-BOF) route for steel production is the main production route within Europe with a share of 57.3 % at total crude steel production in 2021. The other 42.7 % is produced by scrap-based Electric arc furnaces. The integrated BF-BOF-route is today operated close to its theoretical minimum in carbon consumption, but it is still the main CO2 emitter in iron and steelmaking. This needs to be changed, because the requirements of the society to stop the climate change and to limit temperature increase to 2° C by the year 2050 compared to the pre-industrial decades of the late 19th century require massive efforts for the steel industry to reach the target of CO2-free steel production. The key ways to reduce CO2 emissions in iron and steelmaking can be summarized under the general terms “Smart Carbon Usage” (SCU) and “Carbon Direct Avoidance” (CDA). SCU covers on the basis of carbon carriers as reductant incremental measures at the conventional blast furnace converter route and the CO2 mitigation measures by applying so-called “end-of-pipe” technologies like CCS (CO2 Capture and Storage) and CCU (Carbon Capture and Usage). CDA covers the scrap based electric arc furnace route and the iron ore based steelmaking route via direct reduction plants and electric arc furnaces by the use of natural gas and/or hydrogen as reducing agent, which means the complete avoidance of coal and coke for the reduction of iron ores. The application of CCU at the conventional blast furnace converter route, which means the conversion of process gases into chemical raw materials, as well as the implementation of the direct reduction technology with hydrogen and subsequent smelting of the DRI (Direct Reduced Iron) to steel in an electric arc furnace or a combination of a submerged arc furnace and a basic oxygen steel converter require an immense amount of hydrogen and CO2-free electric energy. The transformation of the integrated BF-BOF route to DR-EAF route requires huge amount of capex and higher rates of opex.

Tianjun Yang, University of Science and Technology, Beijing, China

Co-Author:
Jianliang Zhang, University of Science and Technology Beijing
Zhengjian Liu, University of Science and Technology Beijing
Kejiang Li, University of Science and Technology Beijing

Abstract:
In recent years, the situation of continuous growth of Chinese ironmaking industry is changing with a lower growth rate. The development of Chinese large-scale blast furnace has made a great achievement. The number of blast furnaces with a volume larger than 4000 m3 is 23, while that larger than 5000 m3 is 9. With many new technologies such as refinement of raw materials, increase of blast temperature, increase of PCI rate, optimization of BF operation, the fuel consumption has decreased with a high utilization factor, while ultra-low emission has become the new target for many enterprises. Due to the huge production capacity and the existence of many medium-sized blast furnaces, there is still a long way to go to achieve energy-saving and emission-reduction. Chinese ironmaking experts are devoting to the development of low-carbon ironmaking technology and carrying out fundamental research on hydrogen metallurgy. Meanwhile, HBIS Group has planned to constructed a 1.2 million tons metallurgical demonstration project through international cooperation. Baowu Group has started the cooperation with other organizations to to develop nuclear energy for hydrogen production and hydrogen energy metallurgy. China is working hard to develop new processes to promote the development of the ironmaking industry.

Richard Elliott, Hatch Ltd., Canada

Co-Author:
Don Tu, Hatch Ltd.
Ian Cameron, Hatch Ltd.

Abstract:
The total CO2e footprint of all ironmaking technologies is linked to their material and energy inputs. The CO2e costs embedded in the production of these feed materials are non-trivial, and complete accounting of these costs – from mine to metal – is necessary for a holistic comparison of the emissions footprint of the various ironmaking technologies. Thanks to an array of life cycle analyses reported in the literature, sufficient information is now available to perform this accounting. This work presents a collection of factors for the embedded CO2e cost of ironmaking feed materials and employs them in a comparative analysis of alternative ironmaking technologies based on available data. Results are presented and discussed in the context of Scope 1, 2 and 3 emissions. Of interest is the sensitivity of the total emissions of each technology to the reductant mix employed and the potential of each to mitigate global CO2e ironmaking emissions.

Rainer Radloff, RWTH Aachen University, Germany

Co-Author:
Ali Abdelshafy, Wissenschaftlicher Mitarbeiter
Grit Walther, Chair of Operations Management - RWTH Aachen University

Abstract:
Hydrogen-based direct reduction is a promising route to decarbonize the production process of primary steel. Nonetheless, as its value chain is significantly different than the conventional technology (i.e. blast furnace), the transformation of steel industry towards hydrogen will be associated with crucial changes. Hence, this study presents a case study from Western Germany via quantifying the changes in the regional material and energy flows in the state of North Rhine-Westphalia. The quantitative analysis firstly presents a detailed material and energy flow model that depicts the existing supply chain of the regional industry and intersectoral relations. Thereafter, the derived process model of the hydrogen-based steel is integrated into the initial models in order to track the changes associated with the regional roadmaps for reaching zero-carbon steel. The analyses show that these structural changes will require more than 47 TWh renewable electricity per year. As this figure represents approximately one tenth of the current German power production, there are doubts that the renewable resources can satisfy this significant demand, especially if the sectors are taken into account. Therefore, more resilient strategies are needed in order to make sure that decarbonization plans can be achieved even with lower volumes of renewable electricity. For example, deploying natural gas as a reductant along with other technologies such as carbon capture and storage can significantly decrease the demand for electricity. Moreover, as hydrogen and natural gas use the same facilities, such approach can also help in upscaling the required infrastructure in the future. Keywords: primary steel; direct reduction; green hydrogen; energy and material flow model; process model; renewable electricity; natural gas

Wim Van der Stricht, ArcelorMittal, Belgium

Co-Author:
Tobias Plattner, Primetal Technologies
Prabhakar NAIR, LanzaTech
Alexander Fleischanderl, Primetal Technologies

Abstract:
Technological solutions, to utilize process gases from the iron and steel industry for production of fuels and chemicals, are an attractive sustainable and economic approach for industries today. This innovative approach converts carbon and hydrogen-rich off-gases, such as coke oven gas, blast furnace top gas and also converter gas into liquid based energy sources through a biological gas fermentation process to produce preferably ethanol or other chemicals. To produce ethanol, an integrated fermentation system with additional downstream installations is required to treat the fermentation product and waste streams. The treatment of the fermentation waste streams results in a number of by-products, usable for internal or external applications. By returning the by-products to an integrated steel plant or recovering the inherent energy, the fermentation system can be operated in circular system, with minimal waste. The first European commercial scale application of this technology is being developed at the ArcelorMittal steel plant in Ghent with the objective of producing 80 million liters of ethanol per year to be used as renewable transport fuel in a first stage, and as chemical building block on the longer term. We will present the latest developments in the construction of the plant and potential GHG reductions in the steel sector.

Yichao Hu, The University of Queensland, Australia

Co-Author:
Mengran Li, Delft University of Technology
Tom Rufford, The University of Queensland
Geoff Wang, The University of Queensland
Liangyuan Hao, Hesteel Group Company

Abstract:
As the most significant carbon consumer in the integrated steel mill, the blast furnace (BF) is expected to undertake the most considerable contribution to reduce CO2 emission and achieve a sustainable iron and steelmaking process. Currently, carbon capture and utilisation (CCU) to BFs is considered one of the hotspot technologies to sufficiently support the large CO2 emission reduction. A potential way is to capture CO2 from the ironmaking process and convert it into a reductant for the iron ores, feeding back to the blast furnace. This paper integrated the CO2 capture, electrochemical CO2 conversion and top gas recycling technology to improve the traditional blast furnace. Our work focuses on exploring different pathways of CCU, BF and hot blast stoves and evaluating their environmental performances through a two-stage mass and energy modelling with respect to minimise CO2 emission. With different integrated CCU ironmaking system pathways, the overall ironmaking process could save 80 kg/tHM of fresh coke or abate around 80% CO2 emission compared to that of the traditional ironmaking process. The electricity required of the current CCU system causes higher energy consumption than the traditional blast furnace. However, future progress in CO2 conversion technologies with high energy efficiency would improve the competitiveness of the integrated CCU ironmaking system. This work is expected to provide a guideline for allocating and using different CO2 emission sources to achieve a carbon-neutral blast furnace ironmaking process.

Maarten Geerdes, Geerdes Advies, Netherlands

Abstract:
Summary. Biocrude oil for ironmaking Frans Goudriaan and Jaap Naber, BioFuel B.V., Rendorppark 30, 1963AM, Heemskerk, The Netherlands, info@biofuel.com Maarten Geerdes, Geerdes Advies, Mient 3B, 1901AB Castricum, The Netherlands, geerdes@mgeerdes.nl Paper submitted to ECIC & ICSTI 2022 Joint Conference, Bremen, 29. August - 2. September 2022 The Hydrothermal Upgrading Process (HTU®) is capable of producing biocrude from biomass and consolidates ~70% of the energy content. Biomass residues from sugarcane, palm oil, forestry or cultivation of energy crops can be used. The process is technically feasible as shown in a pilot plant producing from 500 kg dry biomass 200 kg biocrude/day. The next step is construction of a demonstration plant, that will process 25.000 ton biomass to 10.000 ton biocrude per year. The biocrude produced from the Hydrothermal Upgrading Process (HTU®) is separated by extraction to a minerals-free light crude (LCR) and heavy crude (HCR). Application of biofuels for ironmaking will be discussed. • Injection of LCR into blast furnaces, which is similar to heavy fuel oil injection used extensively for ironmaking until the mid-1970’s. LCR injection can replace most if not all coal injection in blast furnaces. • From HCR coke can be produced. The product is similar to pet-coke with a very low S-content. Pet coke percentage in the coal blend for coke making can reach 25-30% of the coal blend. • The biocrude and/or LCR can be used in direct reduction plants (DRI). The crudes can be injected with or without gasification by some additional oxygen. The injected crude will be converted to syngas in the DR reactor replacing natural gas and/or hydrogen. In total an estimated 50% of carbon used for ironmaking in blast furnaces can be replaced by a sustainable source. The HTU® process can produce LCR at a cost of 7 €/GJ, or 245 €/ton.

Bart de Graaff, Danieli Corus, Netherlands

Co-Author:
Jan De Weerdt, Danieli Corus
Michael Skorianz, Danieli Corus

Abstract:
In the light of European climate actions the steel industry is faced by the challenge to reduce its substantial carbon footprint. This works focusses on the evaluation of low and medium scale investments to reduce the CO2 emissions for the production of liquid hot metal. A comprehensive and easy to use methodology for estimating the (change in) carbon emissions is provided and several real life case studies are described to serve as example.

Nicholas Aubry, Hatch, Canada

Co-Author:
Tom Honeyands, University of Newcastle / Newcastle Institute for Energy and Resources
Ben Ellis, BHP
Xinliang Liu, BHP
Kyle Lefebvre, Hatch Ltd.
Ian Cameron, Hatch Ltd

Abstract:
As part of the European Community’s Ultra-Low Carbon Dioxide Steelmaking (ULCOS) program, blast furnace top gas recycling was tested to reduce CO2 emissions using the LKAB experimental blast furnace. During tests from 2007-2010, the blast carbon rate was reduced by about 25% when CO recovered from blast furnace top gas was re-injected into the furnace stack using a second bustle pipe. Hatch and BHP have re-visited the top gas cycling concept to assess if additional technologies such as hydrogen and hot oxygen injection could be implemented to further reduce CO2 emissions beyond what was achieved at the experimental blast furnace. Using a 2-stage heat and mass balance model, viable operating conditions were established for a low carbon rate operation, significantly less than what was achieved in the ULCOS trials. Details of the enabling technologies to reach such low CO2 emission rates will be presented.

Fabio Muscolino, Paul Wurth Italia, Italy

Co-Author:
Zak van der Westhuizen, METIX
Joe Bartholme, Paul Wurth S.A.
Stefano Magnani, Paul Wurth Italia
Fabio Cravino, Paul Wurth Italia

Abstract:
Smart combination of new Midrex direct reduction plants in existing blast-furnace-based integrated plants: solutions for lowering OPEX and CO2 emissions vs the stand-alone approach

Richard Elliott, Hatch Ltd., Canada

Co-Author:
Ian Cameron, Hatch Ltd.
Laura Mariani, Hatch Ltd.
Sa Ge, Hatch Ltd.

Abstract:
Hydrogen-based ironmaking is widely accepted as a critical enabling technology for the decarbonization of the steel industry. As adoption of this technology progresses, low-carbon and carbon-free DRI will become increasingly available for use in electric steelmaking. Traditionally, EAF operators have valued the carbon present in DRI for the operational benefits it brings. While decarbonizing the ironmaking process promises significant environmental benefits, these must be reconciled with the practical requirements for carbon in steel and consider the most effective route to deliver carbon into the steelmaking process. Process models of typical iron and steelmaking technologies are used to consider the environmental, technical, and economic advantages and limitations involved in the use of low-carbon and carbon-free DRI in EAF steelmaking. In doing so, guidance will be provided on the practical implications of a future where hydrogen-based ironmaking is commonplace.

Kyle Chomyn, Hatch Ltd, Canada

Co-Author:
Terrence Koehler, Hatch Ltd
Sa Ge, Hatch Ltd

Abstract:
The future of steelmaking requires changes to achieve significant reduction of green house gas emissions, using new process flowsheets. One approach commonly considered is the use of direct reduced iron (DRI) with an electrical arc furnace (EAF); however, this poses significant challenges when using lower grade ores / pellets and when using hydrogen-DRI. This paper describes a method to improve the process yield and efficiency, using an electric melting furnace. The melting furnace efficiently converts DRI into pig iron, for downstream use in an EAF or basic oxygen furnace (BOF). The melting furnace leverages advanced furnace technology developed over 60+ years for iron / ferro-nickel applications. This new approach eases the shift to green steelmaking by using existing facilities and pellet supply chains, and provides higher yields and reduced lifecycle costs.

Axel Sormann, K1-MET GmbH, Austria

Co-Author:
Michael Zarl, K1-MET GmbH
Axel Sormann, K1-MET GmbH
Bernhard Geier, voestalpine Stahl Donawitz GmbH
Christoph Thaler, voestalpine Stahl Linz GmbH
Johannes Schenk, Montanuniversitaet Leoben

Abstract:
Climate change, mainly caused by gaseous emissions like CO2, is globally one of the most important subjects. Significant efforts are required to solve this problem within the following decades. The European Commission´s low carbon roadmap suggests a reduction of CO2 emissions of 80 % by 2050 compared to 1990 levels. The steel industry, which contributes around 6 % to the worldwide anthropogenic emissions of CO2, is asked to decrease the greenhouse gas emissions. There are two possible pathways to perform low-C economy: Carbon Direct Avoidance (CDA) and Smart Carbon Usage (SCU). In the case of SCU, process integration with reduced carbon input and carbon capture and usage are being performed. CDA includes hydrogen- and electricity-based metallurgy to remove carbon as a reducing agent for iron ore. In this paper, CDA using hydrogen as a reducing agent for iron ore will be presented. Since 1980, laboratory investigations at the Montanuniversitaet Leoben/Austria have been shown that hydrogen – especially in the plasma state – is an excellent reducing agent for iron oxides. Based on the results of these investigations and previous laboratory work, a consortium of scientific and industrial partners decided to go a step ahead and build a bench-scale plant for HPRS (Hydrogen Plasma Smelting Reduction). The upscaling from the laboratory to bench-scale ranges from 100 g to 100 kg of iron ore. In this bench scale plant, which is located at the Donawitz site of voestalpine, smelting reduction tests using hydrogen in gas mixtures are being carried out. A transferred plasma arc will reduce and meltdown fine-grained iron ore in one step while the ore is fed into the plasma arc through a hollow electrode. One of the challenges is to generate a stable process for the plasma arc. For this purpose, investigations are carried out regarding the influence of the electrode material

Alexander Redenius, Salzgitter Mannesmann, Germany

Co-Author:
Peter Juchmann, Salzgitter-Flachstahl GmbH
Alexander Redenius, Salzgitter Mannesmann Forschung GmbH

Abstract:
To reach the environmental goals 2045/2050, a fundamental reduction of CO2 emissions has to be achieved in all areas. The steel industry is one of the most energy intensive sectors, but also offers the highest and most energy efficient potential for CO2 migitation. Since 2015 together with Fraunhofer-Gesellschaft and in technical cooperation with Tenova S.p.A., Salzgitter AG has been developing its well-known SALCOS concept aiming at a stepwise and flexible decarbonisation of steel making by carbon direct avoidance (CDA). Here, green hydrogen will replace carbon as reduction agent and energy carrier. This most promising approach of low-CO2 steel production is based on proven industrial-scale technology, which could be implemented immediately. Today`s BF/BOF process will be substituted by a direct iron ore reduction/electric arc furnace (DRP/EAF)-route. The DR process is predestined for a flexible switch and mixture of natural gas and green hydrogen. Right from the beginning the use of CH4 offers a significant reduction in CO2 emissions by more than 60 %. After a complete transition to 100% hydrogen from renewable energy a total decrease of CO2 emissions by more than 95% is possible. The presentation will give an overview of the ongoing SALCOS-transformation at Salzgitter-Flachstahl GmbH and includes current demonstration and accompanying research activities.

Amaia Sasiain, K1-MET GmbH, Austria

Co-Author:
Katharina Rechberger, voestalpine Stahl GmbH
Andreas Spanlang , voestalpine Stahl GmbH
Hermann Wolfmeir, voestalpine Stahl GmbH
Christopher Harris, voestalpine Stahl GmbH

Abstract:
The iron and steel industry accounts for approximately one-quarter of the global industrial CO2-emissions. As the reduction potentials of the current steelmaking routes are rather low, the transfer towards breakthrough-technologies is essential to achieve the climate neutrality by 2050, in line with the European Green Deal. The hydrogen-based direct reduction in combination with an electric arc furnace is one of the most energy efficient approaches to accomplish a CO2-lean steelmaking process. Therefore, the state-of-the-art natural gas based direct reduction acts as a basis for the first step of this transition. This process is already operated with a syngas containing CO and H2 produced out of natural gas. The high flexibility of the DR-route allows the gradual substitution of natural gas by hydrogen and, in a long-term view, running the process with pure hydrogen. The aim of this work is the analysis of the hydrogen-based direct reduction process from a technical and economical point of view. The results obtained; as the energy- and reactants demand, CO2 reduction potentials and production costs; were compared with the blast furnace and direct reduction process with natural gas, considered respectively as the reference- and the bridge technology route between both processes. The techno-economic assessment performed here, conforms the basis for the roll-out plan on behalf of the decarbonization of the steel industry

Brett Belford, SMS group GmbH , Germany

Co-Author:
Tim Kleier, SMS group GmbH
Gawie Lötter, Metix (SMS group)
George Farmer, Metix (SMS group)

Abstract:
Factors Affecting Throughput and Configuration of an Open Bath Furnace for the Production of Hot Metal Brett Belford , George Farmer, Gawie Lötter , Tim Kleier 1 Abstract The decarbonization of steel making is of importance to support the limitations on global warming stipulated in the Paris Agreement. Multiple technology options are emerging in the race to minimize the historically CO2-intensive iron production stage. One leading candidate is the combination of the well-proven direct reduction of iron ore using a shaft furnace (referred to generically in this paper as a direct reduction plant or DRP) and an open bath electric furnace (OBF). The DRP-OBF technology stands out as a viable candidate to significantly lower the CO2 footprint of the iron making stage, meeting many criteria that other technology options are not immediately able to satisfy. In conjunction with real-world plant operators, the authors have undertaken a number of case studies exploring configurations of DRP and OBF for the iron making stage, both in existing-, and greenfield sites. These studies have revealed that potential plant operators often seek guidance on the primary factors influencing plant throughput, energy consumption, capital- (CAPEX) and operational expenditure (OPEX). OBF configuration and plant layout are inextricably linked to the throughput, and also to the associated risk of an inherently new scale of operation. Given that the DRP-OBF plant configurations are not well known, an opportunity arises to link throughput, configuration, layout and risk considerations in a single paper. Keywords: openbathfurnace, OBF, smelter, hotmetal, decarbonization, greensteel, sustainability, ironmaking

Christian Weichbold, voestalpine Stahl Donawitz Gmbh / K1-Met GmbH, Austria

Co-Author:
Elmar Schuster, voestalpine Stahl Donawitz GmbH

Abstract:
Sinter is a dominant operational material for the blast furnace and represents a continuous inhomogeneous material flow. Depending on the process step, different material flow structures can be found in the material flow. In order to be able to describe such material flow and its relevant attributes, sub-areas were analyzed in the SmartSinter-project and a model concept was developed. Sieves and conveyor lines can be relatively easily overserved and described in terms of material flow. Sinter coolers or bunkers in the stock house pose a challenge, as their interior cannot be observed. In order to examine the flow characteristics of these sub-areas, a physical bunker section model, bunker simulation (DEM) and tracer studies (RFID & color tracer) were used in the operating facilities. A transition function for the material flow was found for the cooler. This function describes the system’s response when input properties change. In the storage bunker area, we investigated the applicability of the RFID-technology. In the bunkers there is a pronounced core flow, which was confirmed with all three used methods. The DEM-Simulation was able to quantify this core flow and also provided important information about the segregation process when filling and emptying the bunker. Coarse material collects near the bunker wall, while finer parts concentrate in the core (center). In the first phase of emptying the bunker, more fines dominate and in the final phase the coarse fraction is discharged. So it was determined that the original smooth grain distribution leaving the sinter plant fluctuates greatly after the bunker system. Online measurement techniques for determining the grain size distribution were investigated and the challenges of these systems were explained. The observed different chemical analyzes in the individual grain classes and the findings from the bunker investigations can influence the downstream blast furnace process.

Thomas Steinparzer, Primetals Technologies GmbH, Austria

Co-Author:
Alexander Fleischanderl, UP TI

Abstract:
Energy and environmental technologies become a decisive factor for iron and steel industry. Emissions as well as energy efficiency directives are issued by every government in the world and the requirements become more stringent from year to year. For sinter plants the patented MEROS® technology has become a recognized solution and has recently been extended to by-product treatment to achieve almost zero waste. For direct reduction technologies dry dedusting and waste heat recovery are also the basis for modern production. The dry gas cleaning technology (MEROS) reduces the emissions of SO2, heavy metals and dioxins from sinter plants safely below the required emission levels all around the world. Such low emission levels are maintained by a multi-component additive injection upstream of a high-performance fabric filter, while the installation of a (selective) waste recirculation technology minimizes the investment cost for the gas treatment and reduces the fuel consumption. Residues and by-products arising from the gas treatment are often disposed, leading to consumption of valuable landfilling volume and high cost. The innovative leaching process is closely linked to the MEROS plant and reduces on site the residue volume to a minimum. The proposed solutions can be applied to existing and greenfield plants. This novel residual treatment technology has been applied in past year at a Japanese steel plant. Direct reduction technologies will see a booming market perspective due to their significant reduction of carbon dioxide emissions compared with other ironmaking technologies. A new dry dedusting system based ceramic filter elements as well as waste heat recovery boiler helps plant operators to undershoot all emission and energy efficiency requirements. The paper will summarize state-of-the-art environmental solutions as well as achievable performance figures including operational results and give an overview on the latest executed projects in a brown-field as well in a green-field environment.

Luke Balzan, Scantech International, Australia

Co-Author:
Henry Kurth, Scantech International

Abstract:
Accurate and timely control of a process is critical in the iron and steel making industry. As sensor technology improves and develops, controlling a process in real time becomes more viable and is essential for a modern plant to ensure optimal performance. Scantech's GEOSCAN range of elemental analysers have been used for more than two decades in a range of different industries, including both iron ore and for active real time control of cement plants. Using its extensive experience in these two industries, Scantech has been able to adapt the GEOSCAN for accurate real time measurement of sinter feed. From the elemental composition, basicity can be calculated and used for control. The high specification of the equipment enables accurate analysis of all the critical elements: silicon, aluminium, calcium and magnesium, which in turn enables better measurement of basicity and thus control via limestone dosing and additives. This paper discusses how the GEOSCAN is used, as well as giving a number of European examples where the equipment has been successful in improving control of sinter feed basicity.

Rongshan Lin, AG der Dillinger Huettenwerke, Germany

Co-Author:
Nadine Ziegler, AG der Dillinger Huettenwerke
Benjamin Blaß, AG der Dillinger Huettenwerke
Dieter Georg Senk, RWTH Aachen

Abstract:
Sinter is the major iron-bearing burden material in many integrated steelworks worldwide. Therefore, the sinter quality is of crucial importance for the blast furnace operation. The sinter production is usually monitored by periodic testing of the chemistry and metallurgical properties. However, the sinter properties are dependent not only on the chemical composition, but also strongly on the phases present after sintering and cooling, Sinter has a multiphase microstructure. Some phases are also multicomponent systems. The amount and morphology of the crystalline phases, amorphous phases and pores play an important role in the sinter properties. Experimentally, it is not possible to cover all these features with only one characterization technique. Therefore, in this work the microstructure of an industrial sinter was characterized by means of light microscopy, scanning electron microscopy (SEM), also using the chemical elemental mapping by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results of each technique are complementary and are discussed together to provide a broader picture of the sinter microstructure of an industrial sinter.

Roland Mežibrický, K1-MET GmbH, Austria

Abstract:
Ideal phase assemblages in the sinter matrix are essential for a high-quality sinter in terms of its strength. Individual mineral phases are considered as suitable or not suitable for a high sinter strength, however, there are limitations of the chemical composition because of the blast furnace requirements. Furthermore, sinter with e.g. calcium ferrites as the only bonding phase is almost impossible to produce. In this study, phase assemblages of industrial sinter were examined and coupled with the productivity index of a sinter plant. The results showed a strong relationship between the sinter quality and the sinter matrix. The phase assemblages influence the initial melting conditions as well as the strength after crystallization. The expected negative impact of silicates was found to be suppressed if appropriate phase assemblage formed in the sinter matrix. A simple calculation tool for the prediction of the sinter matrix composition and related sinter productivity has been developed.

Daisuke Maruoka, Tohoku University, Japan

Co-Author:
Tsubasa Shima, Tohoku University
Taichi Murakami, Tohoku University
Eiki Kasai, Tohoku University

Abstract:
Reduction of CO2 emissions has been strongly required for the ironmaking processes. In the sintering process of iron ores, coke breeze is utilized as main agglomeration agent. Its replacement with iron bearing materials such as metallic iron, wustite and magnetite is a promising way to reduce CO2 emissions from the process. Most of coke particles disappear due to combustion, while iron bearing materials remain in the sintering bed as their oxidized phases after heat generation through their oxidation reactions. Therefore, iron bearing materials will significantly affect the permeability of sintering bed and quality of produced sinter. Since the oxygen partial pressure in the sintered bed decreases with the combustion of coke, it is necessary to understand the oxidation behavior of the iron bearing materials under lower oxygen partial pressure conditions. In this study, influence of oxygen partial pressure on the high temperature oxidation of metallic iron was examined to evaluate the possibility to utilize it as an agglomeration agent. Thin plate samples of metallic iron were heated up to 1200℃ under N2 atmosphere by using TG. After reaching to the holding temperature, atmosphere was changed to the oxygen partial pressure of 0.001 - 0.21 atm, which was controlled by using N2 or CO2 gas. Thickness of wustite layer formed at the sample surface increased up to 300 s and follows parabolic manner. The wustite layer thickness decreases after 300 s, instead the thicknesses of magnetite and hematite layers drastically increased. It appears that the rate-determining step is changed when all metallic iron is oxidized to wustite. At PO2 = 0.01 atm, only wustite layer is observed and the oxidation proceeds in the CO2 base than in the N2. It implies that O2 is supplied by the decomposition reaction of CO2 gas.

Chikashi Kamijo, Nippon Steel Corporation, Japan

Co-Author:
Shin Tomisaki, Nippon Steel Engineering Co., Ltd.
Yutaka Ujisawa, Nippon Steel Corporation
Koki Nishioka, Nippon Steel Corporation
Kaoru Nakano, Nippon Steel Corporation
Hiroshi Sakai, Nippon Steel Corporation
Kazumoto Kakiuchi, Nippon Steel Corporation
Kohei Sunahara, Nippon Steel Corporation
Hirokazu Yokoyama, Nippon Steel Corporation
Yoshinori Matsukura, Nippon Steel Corporation

Abstract:
COURSE50, CO2 Ultimate Reduction System by Innovative technology for cool Earth 50, is the national project for reduction of CO2 emission from steelworks in Japan. Three steel companies, NIPPON STEEL CORP., JFE Steel Corp., and Kobe Steel Ltd, and one engineering company named NIPPON STELL ENGINEERING CO., Ltd. join this project supported by NEDO (New Energy and industrial technology Development Organization). The target of COURSE50 is reduction of CO2 emission from steel works by 30 %, 20 % by CCS and 10 % by operation of blast furnace. In order to realize the CO2 emission form blast furnace by 10 %, H2 utilization technology has been developing using 12 m3 experimental blast furnace. The experiments have been taking place form 2016. From 2016 to 2017, 10 % reduction of CO2 emission achieved by using three methods, gaseous reductant injection from tuyeres, gaseous reductant injection from shaft tuyeres, and high reducibility sinter ore charging. In order to improve the reduction CO2 emission technology, hydrogen-based gaseous reductants and high reducibility sinter were used form 2018. Two campaigns, 32 days each, were taken placed in 2018 and 2019. Three types of H2 concentrate gaseous reductants were injected. As a result, it is clarified that the reduction ratio of CO2 emission was affected by the H2 concentration. Over 10 % of CO2 emission was reduced with highest H2 concentration gaseous reductant injection.

Mehdi Baniasadi, Paul Wurth, Luxembourg

Co-Author:
Cristiano Castagnola, Paul Wurth
Maryam Baniasadi, Paul Wurth
Klaus-Peter Kinzel, Paul Wurth
Philipp Bermes, Paul Wurth
Florent Mauret, Paul Wurth
Stephan Hojda, Dillingen Hutte
Rongshan Lin, Dillingen Hutte
Henrik Saxon, Abo Academi

Abstract:
Although concepts for future carbon neutral steelmaking with green hydrogen are on their way, their economic feasibility is often not yet given. Enhancing the traditional BF-BOF route, responsible for 70% of steel production, towards CO2 saving is, therefore, of vital importance. A key technology for significant CO2 emission reduction of the blast furnace is to inject hydrogen-rich syngas at the shaft level. This injection enables high injection rates of hydrogenous gases such as coke oven gas, natural gas, and syngas at the tuyere level. Nevertheless, the influence of hydrogenous gas injection through tuyere and shaft on the BF internal state and overall performance needs to be thoroughly investigated before industrial application. Considering the hostile environment inside the furnace, numerical modelling is the most promising approach for acquiring the required knowledge. In this contribution, a newly developed two-dimensional and multiphase mathematical model for describing the flows and thermo-chemical behaviour of a BF is used. A thorough validation of the model has been carried out using operational data such as in-burden measurements and top gas conditions. Simulations were then carried out to predict the effect of gas injection into the BF shaft. The results show that the shaft injection brings the cohesive zone root up while remaining controlled below the syngas injection point. An increase of the reduction degree and gas temperature in the wall region is also observed. This study demonstrates the potential of the newly developed numerical model to quickly and accurately investigate innovative BF processes with minimum CO2 emissions also for cases of high hydrogen load and low coke rate.

Rongshan Lin, AG der Dillinger Huettenwerke, Germany

Co-Author:
Andreas Feiterna, AG der Dillinger Huettenwerke
Alexander Babich, RWTH Aachen University
Jean-Paul Simoes, RWTH Aachen University
Dieter Senk, RWTH Aachen University

Abstract:
Reduction of CO2 emission is an important challenge for integrated steel plants. Injection of hydrogen rich gas into the blast furnace is one of the most suitable and ready accessible measures to substitute carbon input and consequently to reduce the overall CO2 emission. For almost 3 years, started in November 2017 at ROGESA (Roheisengesellschaft Saar mbH) coke oven gas (COG) was injected at pilot scale and, since June, 2020 at industrial scale into No. 4 and No. 5 blast furnace. The pilot project has been launched to investigate and gain valuable experience on different aspects. First, the pilot installation was configured to be able to inject coke oven gas through the copper tuyere at high flow rates in order to reduce the overall carbon-dioxide emissions. Secondly, the pilot installation was adapted to enable adding simultaneously minimal required quantities to the transport gas of the pulverized coal in order to improve the ignition and conversion of the coal at the tip of the oxy-coal-lance. Thus, the pilot installation delivered us to gain valuable information for the industrial up-scaling on different injection technologies, on the handling H2-rich gas from safety aspect and the behavior of H2 as ignition gas to improve the gasification-conversion of the coal. In parallel, laboratory trials under blast furnace simulating conditions have been performed at the RWTH Aachen University in order to testify the effect of adding coke oven gas to the transport gas of the pulverized coal. Based on these investigations, an industrial plant has been built and commissioned. This paper presents the results obtained at the laboratory trials at the RWTH Aachen University, at pilot installation in Dillingen and the first industrial results obtained on No. 5 blast furnaces of ROGESA.

Mohamed Efetürk, Hüttenwerke Krupp Mannesmann GmbH, Germany

Co-Author:
Andreas Janz, Hüttenwerke Krupp Mannesmann GmbH
Rosa Peter, Hüttenwerke Krupp Mannesmann GmbH
Marten Sprecher, Hüttenwerke Krupp Mannesmann GmbH

Abstract:
The European steel industry has broadly committed to the European climate targets by developing decarbonisation plans. A common dominator of these plans is a transformation step, which includes a technology shift from carbon-based blast furnaces to green hydrogen-based direct reduction processes. This will happen around 2030, resulting in a significant CO2 reduction. Hüttenwerke Krupp Mannesmann GmbH (HKM) operates an integrated steel mill in Duisburg and generally agrees with the common decarbonisation plans. Despite these future action plans within the European steel industry, HKM already started to take action aiming for a significant CO2 reduction with the existing facilities before the transition point of 2030. Until this transition point, it is HKMs aim to make processes as CO2-efficient as possible. HKM has gained significant experience injecting natural gas (NG) into its blast furnaces through the tuyeres in the noughties. Regular injections were stopped as PCI became available in 2010. The re-establishment of NG-injection replacing pulverized coal (PC) will reduce the CO2 emissions of the blast furnace. Furthermore, as HKM operates no rolling mills, there is an excess of low-pressure, high hydrogen-containing (>70%) coke oven gas (COG), which is currently used for power generation. This article discusses how coke oven gas and other hydrogen-containing gases are utilized as additional reducing agents for the blast furnace and how it lowers the carbon footprint of HKM’s crude steel significantly.

Nicholas Aubry, Hatch, Canada

Co-Author:
Don Tu, Hatch Ltd.
Ian Cameron, Hatch Ltd.

Abstract:
The addition of DRI to the Blast Furnace (BF) has known benefits for increasing productivity and decreasing coke rate. The impact of DRI additions has been revisited as a strategy to reduce blast furnace CO2 emissions. Technology changes are needed to overcome the challenges of low top gas temperature. We estimate the maximum amount of DRI that can be added to a blast furnace operation and the related carbon dioxide savings. BF operational strategies of various regions around the world dictate the maximum DRI charge to the BF and resulting CO2 saving. A discussion on how operational strategies can be modified to charge more DRI is provided.

Gerald Wimmer, Primetals Technologies Austria GmbH, Austria

Abstract:
The iron and steel industry is the second largest global industrial CO2 emitter. Direct reduction using low-carbon hydrogen is the most promising solution to achieve the industry target of climate neutrality. The common solution is an EAF for processing of DRI which is only beneficial in case based on high-grade ores. However, most of the iron ores globally available is of lower grade and new solutions for processing of such lower-grade direct reduced iron is required. A two-step process combining a Smelter with a BOF converter can handle such lower grade ores and is predestined for implementation in existing integrated plants. Depending on the capacity of the smelter required, round or rectangular smelters are used.

Yakov Gordon, Hatch, Canada

Abstract:
Gas dynamics and gas distribution in cross-section of shaft furnace play crucial role in increase of furnace productivity, reduction in natural gas rate and DRI quality improvement. Optimum design parameters of gas distribution devises were investigated by means of mathematical modelling, pilot plant and industrial installation studies. New heat transfer co-current schematics of gas and material movement with self-reforming of natural gas in metallization zone, was invented, patented and tested at pilot plant. New Shaft furnace design and improvements where proposed and some new gas distribution devises implemented for shaft furnaces, providing savings in fuel rate, increase in productivity and improvements in quality of DRI.

Mohamed Bahgat, Hadeed a SABIC Affiliate, Saudi Arabia

Abstract:
One of the challenges facing steel producers that rely on direct reduction technologies is the sticking tendency of iron ore pellets, which might lead to disrupting operational procedures. In an effort to reduce the sticking tendency of iron ore pellets, suppliers apply inactive coating materials and steel producers apply an additional coating in the form of slurry prior to charging pellets to the furnace. In this work, the suitability of steel plant’s by-products to be used as a secondary coating material is investigated. In order to determine the optimum coating conditions, their influence on pellets reducibility and sticking index was quantified. The coating condition in question includes dosage amount and slurry concentration of the coating material. Coating amounts were varied in the range of 1-5 kg per ton of ore and slurry concentrations were varied in the range of 5-30% in this study. Thermogravimetric analysis was used to measure the relative reducibility of the pellets under different coating conditions. The reduction conditions were set to simulate reduction temperature and reducing gas composition in Midrex shaft furnace. The samples that exhibited higher reducibility were those at coating condition of: • 20% slurry conc. & 3.0 Kg /ton iron ore • 30% slurry conc. & 3.0 Kg /ton iron ore • 30% slurry conc. & 4.0 Kg /ton iron ore Sticking index measurements were determined according to ISO 11256 for these samples that showed relatively higher reducibility. Since the samples showed similar sticking index values, an additional optimization analysis in terms of operational cost was carried out. It was concluded that the coating conditions with optimum reducibility and adequate sticking resistance are 3.0 kg per ton of ore and 30% slurry concentration.

Hans Bodo Lüngen, on behalf of Steel Institute VDEh, Germany

Abstract:
Blast furnaces need coke for iron ore reduction and melting of the ores to liquid hot metal whilst separating a part of the gangue components of the blast furnace charge materials via a liquid slag from the hot metal. Coke was always rated as the necessary evil of the blast furnace especially in those years, when cokemaking facilities had problems in environmental protechtion. Direct reduction of iron ores is done in the solid stage without the need of coke. Just the main content of the oxygen is removed from the iron ores without melting and without slag metallurgy. This means, that all the gangue materials remain in the product sponge iron, called Direct Reduced Iron (DRI). Direct reduction processes can be classified by its kind of used reducing agent in gas-based processes and coal-based processes. Gas-based processes are shaft furnaces, retorts and fluidized beds. Coal-based processes are rotary kilns, rotary hearths and the multiple heath. The advocates of the direct reduction technologies have forecast a quick penetration of these processes from the 1970ies on and a replacement of blast furnaces with especially the gas-based reduction processes. This never occurred. The worldwide production of DRI was 114 mil. t in 2021 whist the hot metal production of blast furnaces 1340 mill. t. The gas-based direct reduction processes have a share of 75 % at total DR production and this is mainly done in regions with cheap natural gas prices. The main processes are the Midrex and the HyL/Energiron shaft furnace technologies. These have been developed to high level and most efficient processes with an industrial scale-up to 2.5 mill. t DRI production per year in a single module. In Europe a Midrex DR plant was built a very early stage as the second industrial unit worldwide in 1971 in Hamburg, Germany, with a capacity of 400.000 t DRI/year. With respect to the high gas prices in Europe and the steady increase of blast furnaces size and efficiency it was the only DR installation by now. Due to its use of natural gas as reductant the DR-EAF route has lower CO2 emissions compared to the blast furnace converter route. On the background of the current European target to become a climate neutral region by 2050 the DR technology based on natural gas and hydrogen used in DR shaft furnaces for DRI production currently gain huge importance.