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  • 1.
    Eklund, Nicklas
    et al.
    LKAB.
    Lindblom, Bo
    LKAB.
    Wikström, Jan-Olov
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Operation at high pellet ratio and without external slag formers: trials in an experimental blast furnace2009In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 80, no 6, p. 379-389Article in journal (Refereed)
    Abstract [en]

    Blast furnaces that operate with pellets and sinter normally use high basicity sinter and acid pellets to balance the slag chemistry. When external additives are used, irregular slag formation occurs due to their uneven distribution in the burden. If basic sinter is used together with a large amount of acid pellets, all additives are incorporated in the iron bearing materials with an improved burden mixture as a consequence. During a campaign in the LKAB Experimental Blast Furnace, pellets and sinter were operated at an ultra low slag volume. A high amount of pellets was balanced with high basicity sinter. An improved blast furnace operation is shown when operating at ultra low slag volume and without external slag formers. During the test period, the blast furnace operation was smooth and stable, and the reductant rate was decreased.

  • 2.
    Hilding, Tobias
    et al.
    Luleå tekniska universitet.
    Gupta, Sushil
    University of New South Wales.
    Sahajwalla, Veena
    University of New South Wales.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Wikström, Jan-Olov
    Degradation behaviour of a high CSR coke in an experimental blast furnace: effect of carbon structure and alkali reactions2005In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 45, no 7, p. 1041-1050Article in journal (Refereed)
    Abstract [en]

    A high CSR coke was tested in the LKAB's Experimental Blast Furnace (EBF) at Luleå. The evolution of physical and chemical properties of the centre-line coke samples were analysed by Light Optical Microscopy (LOM), BET N2 absorption and SEM/XRF/XRD. Alkali distribution in the EBF cokes was examined by XRF/SEM and EDS. Thermo Gravimetric Analysis (TGA) was used to measure isothermal and non-isothermal CO2 reactivity of the cokes. The crystalline order of carbon and the concentration of alkalis were found to increase as the coke descended through thermal reserve zone to the cohesive zone of the EBF. The crystallite height (Lc) of EBF coke carbon displayed a linear correlation with the measured EBF temperatures demonstrating the strong effect of temperature on carbon structure of coke in the EBF. Alkali concentration of the coke was increased as it descended into the EBF, and was uniformly distributed throughout the coke matrix. The CO2 reactivity of lower zone cokes was found to increase when compared to the reactivity of the upper zones cokes, and was related to the catalytic effect of increased alkalis concentration. The deterioration of coke quality particularly coke strength and abrasion propensity were related to coke graphitisation, alkalization and reactivity. Coke graphitisation is shown to have a strong influence on the coke degradation behaviour in the EBF.

  • 3.
    Hilding, Tobias
    et al.
    Luleå tekniska universitet.
    Kazuberns, Kelli
    Cooperative Research Centre for Coal in Sustainable Development (CCSD), School of Materials Science and Engineering, University of New South Wales, Sydney.
    Gupta, Sushil
    Cooperative Research Centre for Coal in Sustainable Development (CCSD), School of Materials Science and Engineering, University of New South Wales, Sydney.
    Sahajwalla, Veena
    Cooperative Research Centre for Coal in Sustainable Development (CCSD), School of Materials Science and Engineering, University of New South Wales, Sydney.
    Sakurovs, Richard
    CSIRO Energy Technology, Newcastle.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Wikström, Jan-Olov
    Effect of temperature on coke properties and CO2 reactivity under laboratory conditions and in an experimental blast furnace2005In: Proceedings of the Iron & Steel Technology: May 9 - 12, 2005, Charlotte, North Carolina, U.S.A., Warrendale, Pa: Iron and Steel Society , 2005, p. 497-505Conference paper (Refereed)
    Abstract [en]

    Physical and chemical properties of coke samples excavated from LKAB's Experimental Blast Furnace (EBF) at MEFOS in Lulea, Sweden were characterized. A thermal annealing study the raw coke used in the EBF was also conducted in a horizontal furnace in a neutral environment at a range of temperatures up to 1650DGC. Carbon crystallite height of the EBF coke and of the cokes treated in the laboratory furnace were measured by XRD while mineral phases were characterized by using SEM/EDS. The CO2 reactivity of the EBF cokes was measured by thermo-gravimetric analyser (TGA). The study demonstrated the strong effect of temperature on the modification of coke properties with special focus on carbon structure both under laboratory and experimental blast furnace conditions. The coke reactivity in the EBF was accelerated due to presence of recirculating alkalis in the coke, which increased as the coke descended in the EBF. The growth of carbon crystallite height of coke in the horizontal furnace was found to be of similar order as observed in the EBF under a similar range of temperatures. Comparison of carbon structure of laboratory treated cokes and the EBF excavated cokes indicated that carbon ordering of cokes is predominantly enhanced by the temperature rather than reacting gases or recirculating alkalis. The deterioration of coke quality such as coke strength (CSR) and abrasion propensity were related to coke graphitisation, alkalization and reactivity such that coke graphitisation was shown to have a strong impact on coke degradation behaviour. The study further implied that alkalis have a potential to influence the coke reactivity without affecting their graphitisation behaviour. The study also highlights the limitations of the CSR test for assessing the coke behaviour in an operating blast furnaces as it cannot simulate impact of graphitisation of cokes which is significant only at much higher temperatures.

  • 4.
    Hilding, Tobias
    et al.
    Luleå tekniska universitet.
    Wikström, Jan-Olov
    Jahnsen, Urban
    Kerkkonen, Olavi
    Investigation of coke properties while descending through as experimental blast furnace2005In: Proceedings, 5th European Coke and Ironmaking Congress, Jernkontoret , 2005, p. Mo2:4/1-Mo2:4/14Conference paper (Refereed)
  • 5.
    Hooey, Lawrence
    et al.
    Oulun Yliopisto, Laboratory of Process Metallurgy, Oulu.
    Riesbeck, Johan
    Swerea MEFOS AB.
    Wikström, Jan-Olov
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Role of ferrous raw materials in the energy efficiency of integrated steelmaking2014In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 54, no 3, p. 596-604Article in journal (Refereed)
    Abstract [en]

    The role of ferrous raw materials and iron ore agglomeration in energy consumption of integrated steelmaking has been evaluated using a system-wide model. Four steelplant cases were defined: typical European steelplant with sinterplant; Nordic steelplant with sinterplant; European steelplant with sinter:pellet ratio of 50%, and Nordic steelplant charging pellets and a small amount of briquettes. Energy consumption in the mining system were estimated from published statistics at 150 MJ/t for lump ore and sinter fines, 650 MJ/t for pellets made from magnetite and 1 050 MJ/t for pellets made from hematite. An integrated steelplant model including all major unit operations was used to calculate overall system energy consumption from iron ore mining to hot rolled coil. Adjustments were made accounting for energy benefit of ground granulated blast furnace slag in cement production, energy required for cement production required for briquetting, and excess BF and BOF gas producing electricity in a 32% efficient power plant. The system-wide net adjusted energy in the first three steeplant cases showed marginal improvement with use of high grade sinter fines and decrease of pellet/sinter ratio to 50% compared to typical European case. Nordic steelplant charging pellets and briquettes had a reduction in system-wide energy of 5% to 8% for charging pellets from hematite or magnetite respectively compared to the typical European steelplant charging sinter and pellets made from hematite ore. Replacement of sinter with pellets was mainly responsible for the improvement with smaller contributions from magnetite ore in pelletizing.

  • 6. Larsson, Mikael
    et al.
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Ohlsson, H.
    Rutqvist, Staffan
    SSAB.
    Wikström, Jan-Olov
    Ångström, Sten
    Comprehensive study regarding greenhouse gas emissions from iron ore based production at the integrated steel plant SSAB Tunnplåt AB2004In: SCANMET II: 2nd International Conference on Process Development in Iron and Steelmaking, Luleå: MEFOS , 2004Conference paper (Other academic)
  • 7. Larsson, Mikael
    et al.
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Ohlsson, Hans
    SSAB Tunnplåt AB.
    Rutqvist, Staffan
    SSAB Tunnplåt AB.
    Wikström, Jan-Olov
    Ångström, Sten
    Swerea MEFOS AB.
    Comprehensive study regarding greenhouse gas emission from iron ore based production at the integrated steel plant SSAB Tunnplåt AB2006In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 3, no 2, p. 171-183Article in journal (Refereed)
    Abstract [en]

    During the years 2001-2002, a comprehensive study regarding CO2 emissions related to the steel production for the integrated steel making production route, was carried out. The study was financed by SSAB and carried out by a research group with members from SSAB, MEFOS and LTV. The aim was to study the emissions from the existing system and how these could be influenced by process changes and by process modifications. The calculations were made using a global spreadsheet model for calculating the CO2 emissions, developed from an existing energy and process integration model of the same system. The calculated cases included the existing BF/BOF route as well as integration of other processes, e.g., an electric arc furnace, DR processes, COREX and a new future smelting reduction process concept (Sidcomet). All new existing alternative ore based process technologies would increase the specific CO2 emission from the system. A technology transfer to scrap based metallurgy would significantly decrease the emission level, but is not feasible for SSAB, due to the future product mix and the structure of scrap availability. In a 5-20 year perspective, the existing steel making process route with the use of magnetite ore for pellet production has the lowest specific CO2 emission. In a long-term perspective, 20-50 years, alternative process routes, e.g., based on H2 and DRI, could be of interest. Studies on such changes are, however, big projects and should be carried out as joint European and/or international efforts

  • 8. Ryman, Christer
    et al.
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Franck, Per-Åke
    CIT Industriell Energianalys AB.
    Wikström, Jan-Olov
    Similarities between pinch analysis and classical blast furnace analysis: possible improvement by synthesis2005In: Proceedings of the International Green Energy Conference: IGEC-1, Waterloo, Ontario: University of Waterloo , Dept. of Mechnical Engineering , 2005Conference paper (Refereed)
    Abstract [en]

    Pinch analysis originated at UMIST in the 1970's. It has since then been used as a method for energy analysis and optimisation of industrial systems. The blast furnace process for reducing iron oxide to molten iron is a very important process unit in the metallurgical industry. It is a counter-current shaft process with a wide temperature range and gaseous, solid and liquid phases present in different zones. Because of this the blast furnace acts as a system of different sub-processes rather than a single process. The analysis tools developed to describe the process are in some respects similar to the tools of pinch analysis. The exchange between the two fields of knowledge has yet been negligible. In this paper the methods are described and compared. Problems, possibilities and advantages with an exchange and synthesis of knowledge are discussed.

  • 9.
    Sahajwalla, Veena
    et al.
    School of Materials Science and Engineering, University of New South Wales.
    Hilding, Tobias
    Luleå tekniska universitet.
    Oelreich, Anne von
    Department of Materials Science and Engineering, Division of Metallurgy, Royal Institute of Technology.
    Gupta, Sushil Kumar
    School of Materials Science and Engineering, University of New South Wales.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Wikström, Jan-Olov
    Fredriksson, Patrick
    Department of Materials Science and Engineering, Division of Metallurgy, Royal Institute of Technology.
    Seetharaman, Seshadri
    Department of Materials Science and Engineering, Division of Metallurgy, Royal Institute of Technology.
    Structure and alkali content of coke in an experimental blast furnace and their gasification reaction2004In: Iron & Steel Technology Conference proceedings: Nashville, Tennessee, September 15 - 17, 2004 / [ed] Ronald E. Ashburn; Margaret A. Baker, Warrendale, Pa: Iron and Steel Society , 2004, p. 491-500Conference paper (Refereed)
    Abstract [en]

    Coke samples excavated from LKAB's Experimental Blast Furnace (EBF) at MEFOS in Lulea, Sweden were used to observe the influence of in-furnace reactions on the changes in chemical structure of cokes and their influence on kinetics of CO2 reactivity. In addition to growth of carbon crystallite of coke, alkali concentration particularly potassium and sodium were found to increase as coke descended towards lower part of the EBF. The increase in carbon structure could be linearly related to measured temperature profiles of EBF. Isothermal and non-isothermal TGA measurements are shown to indicate that CO2 reactivity of coke becomes progressively faster as it moves towards lower part of blast furnace. The study suggests that alkali enrichment of cokes in an operating blast furnace could have a strong catalytic effect on the CO2 reactivity. Further research is expected to clarify the mechanisms of influence of coke minerals on reactivity and their implications in a blast furnace.

  • 10.
    Sundqvist, Lena
    et al.
    Swerea MEFOS AB.
    Lundgren, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Wikström, Jan-Olov
    Swerea MEFOS AB.
    Eklund, Nicklas
    LKAB.
    Raceway and hearth conditions relative process conditions in the LKAB experimental BF2011In: Proceedings: METEC InSteelCon 2011 : Düsseldorf, Germany, CCD Congress Center Düsseldorf, 27th June - 1st July, 2011 ; it unites for international congresses/conferences under one roof: ECIC, 6th European Coke and Ironmaking Congress; ECCC, 7th European Continuous Casting Conference; EECRsteel, 1st International Conference on Energy Efficiency and CO2 Reduction in the Steel Industry; STEELSIM, 4th International Conference on Modelling and Simulation of Metallurgical Processes in Steelmaking, Düsseldorf, 2011Conference paper (Refereed)
  • 11. Wang, Chuan
    et al.
    Johnsson, A.
    Swerea MEFOS AB.
    Wikström, Jan-Olov
    Engdahl, J.
    SSAB Tunnplåt AB.
    Asp, Björn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Dahl, Jan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Modeling analysis on potential energy saving in a Swedish rolling mill2011Conference paper (Refereed)
  • 12. Wang, Chuan
    et al.
    Larsson, Mikael
    Ryman, Christer
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wikström, Jan-Olov
    A model study on CO2 emission reduction in integrated steelmaking by optimisation methods2007In: 3rd International Green Energy Conference: Proceedings of IGEC-III, Västerås: Mälardalens högskola , 2007Conference paper (Other academic)
  • 13. Wang, Chuan
    et al.
    Larsson, Mikael
    Ryman, Christer
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wikström, Jan-Olov
    Johnsson, Andreas
    Swerea MEFOS AB.
    Engdahl, Jonas
    SSAB Tunnplåt AB.
    A model on CO2 emission reduction in integrated steelmaking by optimization methods2008In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 32, no 12, p. 1092-1106Article in journal (Refereed)
    Abstract [en]

    The iron and steel industry is a large energy user in the manufacturing sector. Carbon dioxide from the steel industry accounts for about 5-7% of the total anthropogenic CO2 emission. Concerns about energy consumption and climate change have been growing on the sustainability agenda of the steel industry. The CO2 emission will be heavily influenced with increasing steel production in the world. It is of great interest to evaluate and decrease the specific CO2 emission and to find out feasible solutions for its reduction. In this work, a process integration method focusing on the integrated steel plant system has been applied. In this paper, an optimization model, which can be used to evaluate CO2 emission for the integrated steel plant system, is presented. Two application cases of analysing CO2 emission reduction possibilities are included in the paper. Furthermore, the possibility to apply the model for a specific integrated steel plant has been discussed. The research work on the optimization of energy and CO2 emission has shown that it is possible to create a combined optimization tool that is powerful to assess the system performance from several aspects for the steel plant.

  • 14. Wikström, Jan-Olov
    et al.
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Larsson, Mikael
    Ångström, Sten
    Swerea MEFOS AB.
    Ways to reduce CO2-emissions at SSAB Luleå works2004In: Proceedings: 2nd International Conference on New Developments in Metallurgical Process Technology, Milano: Associazione Italiana di Metallurgia , 2004Conference paper (Other academic)
  • 15. Yan, Jinyue
    et al.
    Ryman, Christer
    Swerea MEFOS AB.
    Grip, Carl-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wikström, Jan-Olov
    Swerea MEFOS AB.
    Preface2006In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 3, no 2, p. 115-Article in journal (Other academic)
1 - 15 of 15
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  • harvard1
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