Peer Eric Günther, TU Bergakademie Freiberg, Germany

Co-Author:
Erik Oldinski, TU Bergakademie Freiberg / Institut für Eisen- und Stahltechnologie
Lukas Neubert, TU Bergakademie Freiberg / Institut für Eisen- und Stahltechnologie

Abstract:
As part of the degree programme "Materials Science and Materials Technology" in the specialisation Steel Technology, a mini blast furnace was designed, built and operated by the students of the Institute for Iron and Steel Technology. The aim was to apply the basic knowledge of the blast furnace process from the lectures in practice. After the first hours of operation, the furnace was tapped for the first time and liquid pig iron and slag were obtained. The charge materials and products were analysed and the process evaluated. The results of the experiment showed that the blast furnace process can be demonstrated on a small scale with simple methods.

Nicholas Aubry, Hatch, Canada

Abstract:
Tuyere zone blast furnace reactions are reviewed from an energy standpoint. Simplified mass and energy balances are outlined to improve the accuracy of flame temperature calculations.

Hiroshi Nogami, Tohoku University, Japan

Co-Author:
Shinsuke Taya, Tohoku University
Seiya Ueda, Tohoku University
Shungo Natsui, Tohoku University

Abstract:
In ironmaking blast furnace, the raceway zone is one of the most important regions, since it strongly relates to the efficiency and the stability of the blast furnace process. Thus, the understanding the characteristics of the raceway zone is quite important in designing and operation of blast furnace operation. In this study, formation behavior of raceway in cold model was numerically analyzed and was discussed. A mathematical model of particle and fluid dynamic behavior was developed. The model tracked particle behavior by using the discrete element method and solved fluid flow field by using traditional computational fluid dynamic technique. These methods were combined through the distribution of void fraction and the flow resistance in the packed bed. The model was applied to some conditions in cold model experiments, and the raceway behaviors were successfully reproduced. The cold blast extruded the particles just in front of the tuyere and formed a cavity. Then the particle circulation was induced. The model also successfully revealed the transient variations of gas flow pattern, pressure distribution and inter-particle contact force network as well as the particle motion. Under the fixed bed condition, the formation behavior and the final size of the raceway were strongly affected by the initial packing condition. Contrarily, the size and the flow behavior of the formed raceway were almost independent of the initial packing. Additionally, the particles were numerically tracked, and the motion and the force balance were analyzed along the particle trajectories.

Henrik Saxen, Abo Akademi University, Finland

Co-Author:
Debanga Nandan Mondal, Abo Akademi University
Olli Mattila, SSAB Europe Raahe
Timo Paananen, SSAB Europe Raahe
Yalcin Kaymak, VDEh Betriebsforschungsinstitut
Hauke Bartusch, VDEh Betriebsforschungsinstitut
Weiqiang Liu, Abo Akademi University

Abstract:
The gas distribution plays an important role for the blast furnace process as it affects the thermal and chemical conditions in the shaft, and also the pressure drop and burden descent. The distribution of the gas is usually indirectly evaluated based on temperature and composition measurements at several points over a radius or diagonal by above-burden or in-burden probes. Novel acoustic techniques can estimate the gas temperature over the full cross section of the throat. However, an inherent problem is that the gas is redistributed in the upper bed and particularly above it, so measurements above the stockline may no longer reflect the conditions in the shaft. The paper studies the fate of the gas in the region between the stockline and gas uptakes by a CFD model. Heat transfer is neglected so the study is focused on the redistribution of the gas and its effect on the temperature. It is shown that a strong redistribution and downward-swirling flows may occur, creating non-intuitive gas flow patterns in certain parts of the throat region. The role of burden layers charged at different points is also analyzed, giving rise to different flow patterns above the bed. A brief study of the dynamics of the changes is also undertaken. Finally, the findings are compared with measurements based on acoustic techniques, demonstrating similarities in the patterns. The results of the study highlight the complex flow patterns that can be encountered in the top region of the blast furnace, and can partly explain anomality seen in the measured temperature patterns.

Peter Warren, British Steel Ltd, United Kingdom

Co-Author:
Maarten Geerdes, Geerdes Advies
Jacob Tyszka, British Steel

Abstract:
The blast furnace process is very variable, which is -among other things- manifest from large variability its thermal state: hot metal temperature and silicon content. So, at every operating blast furnace the thermal level is continuously controlled. However, when comparing blast furnace thermal control methods in various plants, there are large differences. Thermal control is analyzed from the perspective of the “melting capacity” of the bosh gas, that is the amount of heat available to melt the ferrous burden and slag in the lower part of the blast furnace. Since the major part of the heat requirement is used for driving direct reduction reactions and hydrogen is an efficient reducer at high temperature, the role of hydrogen in thermal control is discussed as well. A theoretical analysis is made to calculate the additional melting capacity that would be generated when coal rate is increased with and without an increase in oxygen enrichment to maintain flame temperature. This is applied to a real example of actions taken to prevent a blast furnace from severe cooling, and why these actions work, and to possible actions to take when coal rate is reduced due to supply problems whilst oxygen enrichment is maintained. Finally the importance of maintaining a minimum blast kinetic energy is discussed, along with the improvement made when tuyeres are clayed to maintain a minimum kinetic energy at low productivity.

Reinoud van Laar, Danieli Corus BV, Netherlands

Co-Author:
Co Author, Hyundai Steel Company
Reinoud Van Laar, Danieli Corus

Abstract:
Dust emissions are occurring at the blow-down and shut-down of a Blast Furnace if the bleeder valves are used. Modern societies and their governments are therefore imposing more stringent legislation and permitting, which may necessitate interim plant modifications. A new clean gas vent line has been developed and demonstrated at Hyundai Steel Company to eliminate any dust emissions at blow-down and shut-down procedures as the gas will be cleaned by the wet scrubber before its release to ambient air. A comprehensive health and safety analysis has been executed to ensure that any operations and maintenance risks would be eliminated. The system design has been optimized to prevent any changes to the original standard operating procedures for blow-down and shut-down. The project contract to commissioning has been realized within four months and the clean gas vent line has since then been successfully used at multiple occasions.

Arndt Wilhelmi, Lechler GmbH, Germany

Co-Author:
Eduardo Bernauer, Lechler GmbH
Willi Jansen, Lechler GmbH

Abstract:
When cleaning off gases e.g. from blast furnaces, many different factors have an influence on the performance of venturi scrubbers or other wet cleaning systems e.g. coke quenching towers. Even small components, such as nozzles and separators, can have a big influence on the overall performance of these systems. The correct nozzle selection is essential, with the knowledge of pressure, volumes, process conditions, positions and the resulting precise droplet spectrum. This influences important factors such as exhaust gas saturation, reduction of dust deposals, dust wetting, pre-separation and the overall performance, etc. In addition, after the scrubber, the separation of the droplets, with the dust particles inside, is very important. For example, spin vane separators have a very poor efficiency with a high-pressure drop. In modern applications, special adapted and designed lamella separators are installed in order to achieve very low emission levels with low-pressure drops. The investment and maintenance cost are normally lower compared to other installations.

Jan Altgaßen, Beck u. Kaltheuner Feuerfeste Erzeugnisse GmbH & Co. KG, Germany

Co-Author:
Ansgar Schepers, Beck u. Kaltheuner Feuerfeste Erzeugnisse GmbH & Co. KG

Abstract:
In recent years, nanoscaled materials have gathered significant importance in the production of refractory castables and gunning/shotcreting products. The reason for this trend lies in the reduction of the refractory microstructure down to the nanometre range and an associated significant improvement in the physical and mechanical parameters. The main objectives for nanomaterial applications are to improve compressive strength, tensile strength, elasticity, resistance to thermal shock, abrasion, chemical corrosion and a favourable ratio of strength to Young’s modulus. Moreover, along with better performance nanoscaled binders make shorter turnaround times and thus reduce energy consumptions feasible. In this paper, we report on the progress made in the development of colloidal silica-based sol-gel refractories for the blast furnace hearth, the main and tilting runner. These nanobonded refractories can be applied via casting, dry gunning and shotcreting. Sol-gel refractories are often associated with low green strength after demoulding and preshapes are susceptible to cracking at the shop floor stage. Technological approaches to work with precast and shotcreted sol-gel bonded refractories will be presented. Furthermore, different developments to overcome some of the challenges that occur while handling sol-gel bonded refractories are presented.

Fabian Perret, RWTH Aachen University, Germany

Co-Author:
Alexander Babich, RWTH Aachen / IEHK
Dieter Senk , RWTH Aachen / IEHK

Abstract:
The raceway parameters such as the temperature (RAFT and real temperature), the temperature distribution, and the ignition/combustion characteristics of injected auxiliary reducing agents (ARA) have a strong impact on the operational parameters of the blast furnace process. Due to the fact that various factors influence the raceway conditions, it is necessary to monitor these conditions under changing blast parameters, e.g. hot wind volume, hot wind temperature, oxygen content and the injection rate of auxiliary reducing agents (ARA). Using various BF operational conditions, it is crucial to gain a deeper understanding of the adjustments necessary to achieve a high PC and a low coke rate. This contribution focuses on the applicability of thermovision camera (TVC) measurements for the analysis of raceway conditions, and in particular for an investigation of the interplay between the blast furnace parameters and the raceway conditions, in order to optimise the BF process. To analyse the influence of these process parameters, two TVC measurement campaigns were conducted at two different European blast furnaces during coal injection. The TVC measurements were used to investigate the temperature distribution of the injected coals (PC) in the raceway and their influence on the blast furnace. The statistical software programme Stata was used for data analysis. The results will be used to improve and support raceway and shaft models, as well as predictions of the effect of PC residues (such as char) and their behaviour on the BF operation. Unburnt coal or PC conversion degree affects both measured temperature and RAFT.

Thomas Nanz, K1-MET GmbH, Austria

Co-Author:
Michael Harasek, TU Wien ICEBE
Magdalena Schatzl, K1-MET GmbH
Johannes Rieger, K1-MET GmbH
Hugo Stocker, voestalpine Stahl Donawitz GmbH
Christoph Feilmayr, voestalpine Stahl GmbH
Franz Hauzenberger, Primetals Technologies Austria GmbH
Markus Bösenhofer, K1-MET GmbH / TU Wien ICEBE

Abstract:
Injection of auxiliary reducing agents (ARAs) is a common approach to replace metallurgical coke in the blast furnace iron making process. A variety of ARAs is currently used, e.g. natural gas, coke oven gas, pulverized coal, heavy and waste oil, biomass, and carbonaceous dust. Conversion rates of ARAs are hardly available in literature, which makes the optimization of the ARA injection process and the evaluation of new ARAs troublesome. Identifying new ARAs requires suitable experimental setups and accurate methods for the extraction of the conversion rates. Experiments should reproduce the conversion conditions of the raceway zone of blast furnaces. Significant temperature and species concentration stratification might occur in such experimental equipment. A combined methodology using CFD simulations and experimental data can be used to obtain accurate conversion rates. Spatially resolved temperature, velocity, and species concentration profiles can be obtained via CFD simulations. In addition, accurate residence times can be extracted from these simulations via Lagrangian particle tracking. In case of strong stratification effects, the simulated profiles are superior to the typically assumed constant temperature, velocity, and species concentrations. Usually residence times are estimated by assuming plug flow. These residence times deviate from the experimental ones, since flow phenomena, e.g. vortexes or radial velocity profile, are neglected when assuming plug flow. Using realistic temperature and species concentration profiles as well as residence times refines the accuracy of the extracted conversion rates and kinetic parameters. In this work, we first introduce a CFD approach for the simulation of experimental equipment and the methods to determine the transient temperature and species concentration profiles. Subsequently, we introduce and discuss a computer aided kinetic extraction algorithm and compare their results with kinetic parameters determined by traditional approaches.

Yakov Gordon, Hatch, Canada

Co-Author:
Andrei Sorokin, NLMK
Vladislav Listopadov, NLMK
Vladimir Titov, NLMK
Larisa Gileva, Ural Federal University
Sergei Myasoedov, NLMK
Sergei Filatov, NLMK
Segei Zagainov, Ural Deferal University

Abstract:
Based on the result of theoretical analysis, it has been shown that injection of pulverized coal supports process conditions either to provide higher smelting rate or achieve minimum coke specific consumption. In case of coke and natural gas replacement, two conflicting factors can be observed: gas amount per minute is reduced thus having a favorable effect on gas dynamics both at upper and lower zones of the furnace; porosity is decreased in slag formation zone. It determines extreme correlation between PCI (pulverized coal injection) consumption and blast furnace performance. It has been established that increasing ratio of PCI to natural gas (NG) consumption is followed by lower coke and total carbon in fuel specific consumption at slowdown. High smelting rate can be achieved with this ratio within the range of 2.0-2.5.

Fabian Perret, RWTH Aachen University, Germany

Co-Author:
Dieter Senk, RWTH Aachen / IEHK
Alexander Babich, RWTH Aachen/ IEHK

Abstract:
Despite measures to increase pulverised coal (PC) conversion, part of the injected PC leaves the raceway as char, particularly at high injection rates. The coke/PC replacement ratio and, consequently, the blast furnace (BF) operation efficiency depends on the consumption of char by reactions of sec-ondary gasification and added burden. This contribution focuses on the change in streaming condi-tions in different BF zones when coal particles leave the raceway. To investigate this, a 2-D physical BF cold model was used. Tests were conducted after injecting various amounts of PC and under various gas flow rates. Particle movement and accumulation were examined by measuring the pres-sure drop at different positions in the model. To evaluate the effect of PC on the gas permeability in vertical and horizontal directions, calculations using the Darcy-Weisbach/Ergun equation were per-formed. The results will be used to improve CFD-modelling and the prediction of char behaviour in the BF.

Bartosz Smaha, thyssenkrupp Steel Europe AG, Germany

Co-Author:
R. Klock, thyssenkrupp AT.PRO tec GmbH
C. Morrison, Primetals Technologies Limited
W. Edmond, Primetals Technologies Limited
H. Bartusch, VDEh-Betriebsforschungsinstitut GmbH
M. Juen, thyssenkrupp AT.PRO tec GmbH

Abstract:
The SIP technology developed by thyssenkrupp in-house is the first of its kind and the Schwelgern 1 blast furnace is the first blast furnace in the world to be equipped with it. The system fits perfectly into thyssenkrupp Steel’s strategy to produce carbon-neutral steel of known quality by 2045. The carbon-based metallurgy of the blast furnace route is expected to give way to hydrogen-based technologies. The SIP Oxygen Pulsing technology was commissioned in late 2020 on the 40-tuyere thyssenkrupp Steel Europe Schwelgern BF1 in Germany, and demonstrated immediate improvements in eta-CO. The technology makes it possible to optimize the use of reducing agents. Innovations such as the SIP process enable the necessary efficiency gains and CO2 savings in the existing infrastructure until the technology change is complete. This paper presents the effects of the new technology on the performance and CO2 emissions during regular operation of the blast furnace.

Hannah Lomas, The University of Newcastle, Australia

Co-Author:
Hannah Lomas, University of Newcastle
Richard Roest, University of Newcastle
Hui Wu, University of Wollongong
Zhengyi Jiang, University of Wollongong
Richard Sakurovs, CSIRO Energy
Aaron Anderson, University of Newcastle
Anthony Edwards, University of Newcastle
Tori Hill, University of Newcastle
Merrick R. Mahoney, University of Newcastle
Arash Tahmasebi, University of Newcastle
Brody Brooks, University of Newcastle

Abstract:
One of the major reasons it is difficult to predict the strength of metallurgical coke is its heterogeneity. The mechanisms by which coke degrades under applied loads or stresses are not only dependent on coke composition and microstructure but also the different forms of carbon that the coke comprises, which constitute the coke microtexture. Furthermore, the ordering of the carbon domains within the microtextural constituents and the integrity of the interfaces between them are key contributors to coke strength, including its resistance to abrasion. We have developed a novel approach which applies tribological (i.e. wear) testing techniques to examine the factors that influence coke abrasion. Moreover, we have developed the capability to assess coke abrasion resistance in-situ at elevated temperatures of up to 950°C and in controlled gas atmospheres. Bosh coke samples retrieved from an operating blast furnace and a near-matched feed coke were examined in this study. The key findings include: • High temperature abrasion resistance for both cokes was lower than at room temperature. Parallel work has shown that the reduction in abrasion resistance occurs for both the RMDC and IMDC, and at interfaces. • CO2 attack during pre-reaction of feed coke samples was found to ‘level’ coke properties, to some extent, and effectively overwrite the effects of prior CO2 exposure in the blast furnace. • Bosh coke IMDC showed more severe damage than in feed coke at 950°C, suggesting that the thermal damage to the IMDC is accentuated by prior gasification. • In the blast furnace, the fines generated by abrasive wear may act as a lubricant or they may adversely impact the permeability of the furnace and thus its efficient operation. • A parallel study using pilot oven cokes from single Australian coals of varying properties has indicated that deterioration in abrasion resistance occurs at 400°C, and is accentuated at 950°C.

Marc Schulten, thyssenkrupp Steel Europe AG, Germany

Co-Author:
Heike Liszio, thyssenkrupp Steel Europe AG
Oliver Donnes, thyssenkrupp Steel Europe AG
Viktor Stiskala, thyssenkrupp Steel Europe AG

Abstract:
thyssenkrupp Steel Europe (tkSE) operates a pilot coke oven lab in Duisburg. Main target of the lab is to support the operations of coke plant Schwelgern. The lab can only be an assisting to plant operations if the pilot ovens produce comparable data. This includes also coke parameters such as texture and phase distributions. To get additional insight tkSE was participating in the research project ForeCoke. The paper outlines the carried out comparison study between industrial and pilot oven coke and detectable impacts on coke quality.

Maria Lundgren, Swerim AB, Sweden

Co-Author:
,
Lena Sundqvist Ökvist, Swerim AB

Abstract:
The use of processed biomass (bio-coal) as source for carbon in the reduction of iron ore to metallic iron in the blast furnace is one option for decreasing the CO2 emission from integrated steel plants. Trials with addition of bio-coal to the coal blend for cokemaking have been conducted in technical scale at DMT retort with different types of bio-coals and amounts. Characterization of bio-coal as chemical composition and produced bio-coke involves changes in strength, reactivity and microstructure as well as dilatation, maximum fluidity and estimated wall load compared to reference coke and blend. Potential usage of bio-coal as partially replacement of coking coals and possible methods for maximizing the added amount are discussed.

Anne Heikkilä, University of Oulu, Finland

Co-Author:
Timo Fabritius, University of OUlu
Mikko Iljana, University of Oulu
Aki Koskela, University of Oulu

Abstract:
A blast furnace (BF) is the dominant process for making iron in the world. The blast furnace is charged with coke and iron burden materials including iron ore pellets, sinter and/or lump ore. Coke has several functions in blast furnace process. Coke acts as a fuel in the blast furnace, it acts as a reducing agent for iron bearing materials and it provides support for the charge material inside the blast furnace providing permeability structure that enables gases to flow upwards. Compression strength of coke is one way to describe coke’s ability to act as a skeleton of the blast furnace charge. This work focuses on the compression strength of two different coke types after gasification. The gasification experiments were conducted in two different dynamic atmospheres acquired from an actual industrial blast furnace (CO-CO2-N2 and H2-H2O-CO-CO2-N2). Compression strength after reaction was studied with Gleeble 3800 thermochemical simulator. Light optical microscopy was used together with image analysis to gather information about pore area. Differences were found in pore areas as well as in compression strengths between the coke types as expected. Furthermore, the differences in atmospheres (with/without H2 and H2O) also yielded different results making strain at breaking point happen to a narrower scale when hydrogen and water vapor were presence at the atmosphere.

Arash Tahmasebi, The University of Newcastle, Australia

Co-Author:
Stephen Brant, BHP
Kim Hockings, BHP
Brody Brooks, University of Newcastle
Apsara Jayasekara, University of Newcastle

Abstract:
The importance of reducing CO2 emission linked with blast furnace ironmaking is widely recognised. Among proposed strategies to reduce CO2 emission, partial replacement of coal by biomass in coal blends has gained increasing interest. Woody biomass, such as charcoal and torrefied biomass used in previous studies, was identified to negatively impact coal rheology and coke strength due to the fibrous nature of these species. This paper introduces the use of microalgal biomass to the coking blend to increase the share of renewable carbon in cokemaking. Microalgae species are primarily composed of lipids, proteins, and carbohydrates, which, unlike woody biomass, do not form a fibrous structure during the carbonisation process. This is expected to mitigate the negative impact of biomass addition on coal rheological properties and coke strength compared to woody biomass. Microalgae can also be produced locally on a large scale for bio-fixation of CO2 from off-gas streams in integrated steel mills. The paper evaluates the impact of the addition rates of up to 10% microalgae Chlorella Vulgaris on the fluidity behaviour of three Australian metallurgical coals varying in rank, fluidity, and maceral composition. Custom-designed laboratory-scale experimental facilities including the 4kg dual-heated coke oven and permeability/ dilatation test facilities were utilised to measure thermoplastic parameters, including the plastic layer permeability, thermo-swelling, and internal gas pressure. The experimental results showed that the thermoplastic properties of premium Australian metallurgical coals were largely unaffected by microalgae addition, while a deterioration of thermoplasticity was recorded for the semi-hard low-vitrinite coal. The research outcomes provide guidance in selecting appropriate parent coals for microalgae blending.

Priyanthi Hapugoda, CSIRO, Australia

Abstract:
The reflectance measurements of macerals have a prominent role in the assessment of coals. As vitrinite reflectance is used as a rank index, the reflectance of all macerals can be used to predict a coals behaviour during coke making. Whilst these measurements are traditionally done manually, semi-automated imaging and characterisation methods provide an alternate means for acquiring this information. CSIRO have developed a semi-automated optical reflected light imaging and analysis system, Coal Grain Analysis (CGA), which provides high resolution reflectance and composition information on a large individual coal particles. This paper presents the process of vitrinite reflectance analysis of coking coal samples using this system to complement the traditional manual process which have some inherent limitations. First, continuous calibrated high-resolution images are collected across the settling plane on standard petrographic grain mounts in immersion oil using a 20X oil immersion objective following the standard calibration procedure similar to that detailed in [6]. The mosaicked images are then processed to obtain reflectance information, size, and compositional information for each individual particle in the image. The CGA processing software can export random reflectance measurements of vitrinite as well as inertinite information from individual particles. This provides reflectance information for tens of thousands of individual particles in a single sample; significantly higher than what is obtained by the industry standard manual method. This reflectance information can be used to compile maceral reflectance histograms which provides unique information to the industry for assessing the contribution of each of the macerals to coking performance.

Hauke Bartusch, VDEh-Betriebsforschungsinstitut GmbH, Germany

Co-Author:
Tatjana Mirkovic, Salzgitter Flachstahl GmbH
Marcel Kloos, Salzgitter Flachstahl GmbH
Matthias Kozariszczuk, VDEh-Betriebsforschungsinstitut GmbH
Thorsten Hauck, VDEh-Betriebsforschungsinstitut GmbH
Hauke Bartusch, VDEh-Betriebsforschungsinstitut GmbH
Pavel Ivashechkin, VDEh-Betriebsforschungsinstitut GmbH

Abstract:
The dust in the blast furnace top gas has for a long time been regarded only as a process residue which must be handled somehow. Correspondingly, little attention was paid to the time course of the dust concentration - although it carries important information about the furnace’s working state. Excessive dust generation was proven to signalise upcoming operational issues which detract efficiency and production. A proper combination of online dust supervision and fingerprinting with operational data evaluation allows to predict operational problems in advance. This early error recognition enables to improve process control and efficiency: good reason to monitor the dust formation. Therefore, VDEh Betriebsforschungsinstitut has developed an online top gas dust concentration measurement system based on the soft-sensor principle. In the first step, part of the top gas is washed in a small scrubber and the slurry is directed to the MAGS sensor. The mass of dust separated on a magnet is continuously measured. In the second step, this value is transformed by a software model to the information about the total dust concentration in the top gas to deliver continuous knowledge about the current furnace state. The sensor MAGS has been applied to blast furnace B at the Salzgitter Flachstahl site. The obtained data reveals new information about the dust formation during charging of different materials, but also about the dust concentration arising from the process in between the chargings. A clear relation between dust formation and process state could be shown. Proper interpretation of the MAGS measurements enables a new facet of blast furnace working state monitoring. This article informs about the technical concept of the soft-sensor and provides an insight about the so far received knowledge from analysis of the obtained data. The sensor is currently in a long-term trial at the Salzgitter Flachstahl site.

Bernd Weiss, Primetals Technologies GmbH, Austria

Co-Author:
Johannes Niel, TU Wien
Walter Wukovits, TU Wien
Stefan Tjaden, K1Met
Bernhard Rummer, Voestalpine Stahl Linz

Abstract:
Iron and steel making requires a wide range of different raw materials significantly influencing process performance which demands a continuous optimisation of process routes also with respect to energy efficiency as well as environmental emissions. Steadily changing raw material prices and qualities, market situations and product variations are challenging integrated steel plant operators in production planning and cost optimization. Primetals decided to develop a comprehensive metallurgical flow sheet model library for simulation and optimization of integrated steel plants. Intensive development efforts were taken in order to migrate existing well-established calculation and engineering routines as well as integrate newly developed models. The generated model library enables the setup of mass and energy balances for integrated steel plants, development and evaluation of new process concepts as well as investigations on impacts of raw material changes and trace material distributions. Recently coking plant operation data of an European coke producer was evaluated and based on a wide literature study predictive models for CRI, CSR, I10 and I40 developed. In a new approach the models were incorporated in a global mathematical optimization routine for strategic operations planning of integrated steel plants. Insight will be given on the models for prediction of coke parameters and its influence of overall operation optimization.

Christian Dengler, Paul Wurth S.A., Luxembourg

Abstract:
Automation is an essential component of modern plants. In addition to automation systems that operate the plant in hard real time, dedicated systems are used more and more to analyze important processes and suggest or even plan maintenance tasks with less and less human interaction. These systems perceive the current state of the plant and suggests actions based on sensor data combined with digitized knowledge, e.g., known process equations or the plant’s dimensions. Digitized knowledge is diverse and managing different forms of digital knowledge for complete plants is no simple task. The digital twin brings together all information available on the plant, from the engineering phase to simulations and operation data. Coupled with data analytics, a holistic tool for visualization and generation of recommendations supports the operators in their daily tasks. In this contribution, we present an overview of the developments and solutions by SMS-Group in relation to the digital twin and expert systems for the steel and iron making industry. The focus of the presented work lies on the digital solutions created using modern tools in order to generate value during operation.

Yale Zhang, Hatch, Canada

Co-Author:
Nicholas Aubry, Hatch
Julie Kim, Hatch

Abstract:
Using AI and Digital Twins to Improve Blast Furnace Operations Julie Kim, Nicholas Aubry, Mitren Sukhram and Yale Zhang Abstract: Successfully managing an ironmaking plant is a complex task. The need to satisfy the competing interests of efficiency, quality, and cost, while adhering to ever-higher standards of safety and sustainability puts immense pressure on people and systems. To meet the stringent expectations for today’s blast furnace operation, operational intelligence is a must for plant managers, process engineers, and shop-floor operators. Hatch’s Digital Twin Platform fulfills this need; it delivers operational intelligence from three strongly linked aspects: integration, intelligence and interaction. In this paper, a use case of a blast furnace digital twin is presented. The case focuses on predicting the thermal state of blast furnace using artificial intelligence. Advanced outlier filtering and stacked machine learning models, are used together with fundamental blast furnace mass and energy calculations. The model provides operators with a consistent understanding of the furnace thermal state, which results in a better hot metal temperature and silicon control strategy. The paper concludes by summarizing best practices learned from blast furnace digital twin development and deployment. Key words: Blast furnace, Ironmaking, Digital Twin, Artificial Intelligence

Dieter Bettinger, Primetals Technologies, Austria

Co-Author:
Harald Fritschek, Primetals Technologies
Martin Schaler, Primetals Technologies
Petra Krahwinkler, Primetals Technologies
Adnan Husakovic, Primetals Technologies

Abstract:
The revival of Artificial Intelligence (AI) promises to offer solutions in particular for complex systems that are difficult to model with classical methods. An overview of AI solutions in ironmaking is provided, their strengths and weaknesses are discussed: Topics as the applicability for typical problem groups, preconditions regarding required data quality and completeness of data sets, reliability, combination with classical approaches are covered. Further the deployment and integration of black box models into control systems and the related stability are discussed.

Olivier Mersch, Paul Wurth S.A., Luxembourg

Co-Author:
Christian Dengler, Paul Wurth S.A.
Fabrice Hansen, Paul Wurth S.A.
Marc Schweitzer, Paul Wurth S.A.

Abstract:
Driven by the growing pressure to maximize production efficiency, the digital transformation has gained momentum within the industrial sector. Data-driven solutions will take over a crucial part in future production and increasingly improve processes across the entire life cycle of plants. The following contribution puts maintenance of one of the core technology in today’s blast furnace iron making in the light of the digital age: the Paul Wurth Bell Less Top® charging system. With the overall objective to ensure a long service life, optimum performance and reliable operation, the Bell Less Top needs to be continuously monitored. During operation, the system may output phenomena that are not easy to detect using a programmable logic controller. Key for a reliable monitoring is lying in the detection of short-, medium- and long-term trends, the recognition of recurrent events, the comparison of current states with historical baselines and particularly the recognition of dependencies between several phenomena. Reliable monitoring allows to efficiently implement maintenance processes in order to optimize the use of resources and reduce downtime. Maintenance can be scheduled on real condition and advanced statistics rather than on preventive actions. This contribution gives insights on how BLTXpert™, a condition and performance monitoring system for the Paul Wurth Bell Less Top, provides significant added value to the operator as well as maintenance staff and paves the way from fail and fix to prevent and predict.

Thomas Hahn, Beck u. Kaltheuner GmbH & Co. KG, Germany

Co-Author:
Jan-Philipp Altgaßen, Beck u. Kaltheuner GmbH & Co.KG
Stephan Hermann, Beck u. Kaltheuner GmbH & Co.KG

Abstract:
Drones are more and more involved in taking professional video footage of all kinds. Previous generations however had only a minor role in inspecting high temperature, dust loaded or dark facilities due to technical difficulties. In recent years improvements on lighting and camera systems have led to better visibility in dust loaded and dark rooms and newer Li-Ion technologies have led to longer flight duration. Flight stabilisation via route vectoring and internal sensors make it possible to have a smooth operation. With a cage housing drones are even possible to operate in small spaces without risk of colliding. This altogether widened the field of possible facilities to be inspected to e.g. cowpers, blast furnaces, and all sorts of second heat furnaces and flues and made drone inspections a reliable source for imaging with the option to have the data available even after years. Software aided analysis of the video footage can be completed with a full 3D Model and thus gives a good overview of the actual damage of the scene, or possible spots for preventive maintenance. With health and safety issues being a foremost important point in all companies worldwide, an operator that has not to undergo risks of going directly into the production facilities another point in favour to using drones is made. Also time consuming construction of scaffolding or the use of cranes is not necessary.

Florian Markus Penz, Primetals Technologies, Austria

Co-Author:
Hans Joerg Baumgartner, Primetals Technologies

Abstract:
As the whole steelmaking world is at the edge of transformation to decarbonized production, iron ore pellets will play a central role as a high-quality iron bearing feed. Therefore, not only productivity but mainly requirements on pellet properties will rise to the possibly highest level to serve for high quality and low carbon production in downstream iron and steelmaking. Primetals Technologies pelletizing simulation tool was developed to calculate with a complex and highly flexible numerical model all important process data of any type of induration machine (e.g. travelling grate and grate kiln). Gas and solid flows of the pellet layers are calculated by solving 150 differential equations in each cell. Implemented parameters are fully validated through experimental results at Primetals Technologies pellet pot or at customers’ production facilities. Therefore, this tool can be used both for design of new pellet plants as well as for optimization of the entire induration process of existing pelletizing plants under consideration of productivity, product quality, energy consumption and environmental aspects at the same time. For the first time, such sophisticated numerical model can be integrated in an advanced Level 2 expert system as support of daily operation to enable early reaction on changing conditions such as e.g. changing raw material qualities. The paper will give an insight into Primetals Technologies simulation tool, its features, capabilities and different applications.