Study on Structure and Reducibility of Iron Ore Sinter Containing Basic Oxygen Furnace Slag
Main Article Content
Abstract
Basic Oxygen Furnace (BOF) slag is a byproduct in the steelmaking process. The amount of slag produced in steel production lines is substantial, not only in Vietnam but also worldwide. Reusing this large amount of slag is an essential requirement, and this study assesses a solution for reusing BOF slag by incorporating it into the sintering process. Experiments were conducted using iron ore, coal, and the slag as raw materials for the sintering process using a suction fan apparatus. The sintered product was analyzed for its microstructure, reduction degree, and softening property. The results indicate that the reducibility of the sinter containing the slag is equivalent to that without slag. The yield of sintered ore decreases by approximately 1 % compared to when thel slag from steelmaking is used as a flux. The results show that the yield of sintered product meeting standards (size and strength) has values ranging from 59.5 to 71.9 %. Besides, the highest reduction degree was achieved with a 24 % slag at a basicity of 1.6 and a temperature of 1100 °C. In contrast, the reduction degree of the sintered ore was lower at 1000 °C. The initial softening temperature was determined to be 1200 °C. The microstructure of the sintered ore revealed the formation of a liquid bonding phase. It can be concluded that the main bonding phase is calcium ferrite. The liquid phase showed an even distribution of calcium, silicon, oxygen, and iron elements.
Keywords
BOF slag, iron sinter, reducibility, microstructure
Article Details
References
[1] D. F. Gonzáleza J. Prazuchb, I. R. Bustinzac,
C. G. Gascad, J. Novala, L. F. Verdejaa. The treatment
of Basic Oxygen Furnace (BOF) slag with concentrated
solar energy, Solar Energy, Vol 180, 1 March 2019,
pp 372-382
https://doi.org/10.1016/j.solener.2019.01.055
[2] I. Z. Yildirim and M. Prezzi. Geotechnical Properties of
Fresh and Aged Basic Oxygen Furnace Steel Slag,
Journal of Materials in Civil Engineering, October 2015.
https://doi.org/10.1061/(ASCE)MT.1943-5533.0001310
[3] M. Tossavainen, F. Engstrom, Q. Yang, N. Menad,
M. Lidstrom Larsson, B. Bjorkman. Characteristics of
steel slag under different cooling conditions, Waste
Management, Vol 27, 2007, pp 1335-1344
https://doi.org/10.1016/j.wasman.2006.08.002
[4] A. S. Reddy, R. K. Pradhan, S. Chandra. Utilization of
Basic Oxygen Furnace (BOF) slag in the production of a
hydraulic cement binder, International journal of Mineral
Processing, Volume 79, Issue 2, May 2006, pp 98-105
https://doi.org/10.1016/j.minpro.2006.01.001
[5] R. P. Bragat. Agglomeration of Iron Ore, Taylor &
Francis, 2019
https://doi.org/10.1201/9781315269504
[6] K. Higuchi, Y. Takamoto, T. Orimoto, T. Sato,
F. Koizumi, K. Shinagawa, H. Furuta, Quality
improvement of Sinter ore in relation to blast furnace
operation, Nippon Steel Technical Report, No 94, 2006
[7] D. F. González, I. R. Bustinza, J. Mochón, C. G. Gasca
and L. F. Verdeja, Iron ore sintering: Process, Mineral
Processing and Extractive Metallurgy Review February
2017, 38:4, 215-227.
https://doi.org/10.1080/08827508.2017.1288115
[8] T. Umadevi, S. Prakash Rao, Pankaj Roy,
P. C. Mahapatra, M. Prabhu and Madhu Ranjan,
Influence of LD slag on iron ore sinter properties and
productivity, Proceedings of the XI International
Seminar on Mineral Processing Technology (MPT2010), pp 747-757
[9] Y. Liu. The Operation of Contemporary Blast Furnaces,
Metallurgical Industry Press, 2021
https://doi.org/10.1007/978-981-15-7074-2
[10] Volodymyr Shatokha and Olexandr Velychko, Study of
softening and melting behaviour of iron ore sinter and
pellets, High Temperature Materials and Processes,
Vol 31, 2012
https://doi.org/10.1515/htmp-2012-0027
[11] A. Cores, L. F. Verdejia, S. Ferreira, I. R. Bustinza,
J. Monchon. Iron ore sintering. Part 1. Theory and
practice of the sintering process, Dyna (Medellin,
Colombia), August 2013
[12] Min Gan, Xiaohui Fan and Xuling Chen. Calcium ferrite
generation during iron ore sintering crystallization
behavior and influencing factors, Advanced Topics in
Crystallization, pp 301-321
[13] Yu, W., Zuo, H., Zhang, J., and Zhang, T. The effects of
high Al2O3 on the metallurgical properties of sinter,
Proceedings of the symposium in Characterization of
Minerals, Metals and Materials 2015 (The Minerals,
Metals and Materials Society), Orlando, FL, March 15-
19, 2015, pp. 419-425.
https://doi.org/10.1007/978-3-319-48191-3_51
[14] Yin, J., Lv, X., Xiang, S., Bai, C., and Yu, B. Influence
of CaO source on the formation behavior of calcium
ferrite in solid state, ISIJ International, 53, pp. 1571-
1579.
https://doi.org/10.2355/isijinternational.53.1571
C. G. Gascad, J. Novala, L. F. Verdejaa. The treatment
of Basic Oxygen Furnace (BOF) slag with concentrated
solar energy, Solar Energy, Vol 180, 1 March 2019,
pp 372-382
https://doi.org/10.1016/j.solener.2019.01.055
[2] I. Z. Yildirim and M. Prezzi. Geotechnical Properties of
Fresh and Aged Basic Oxygen Furnace Steel Slag,
Journal of Materials in Civil Engineering, October 2015.
https://doi.org/10.1061/(ASCE)MT.1943-5533.0001310
[3] M. Tossavainen, F. Engstrom, Q. Yang, N. Menad,
M. Lidstrom Larsson, B. Bjorkman. Characteristics of
steel slag under different cooling conditions, Waste
Management, Vol 27, 2007, pp 1335-1344
https://doi.org/10.1016/j.wasman.2006.08.002
[4] A. S. Reddy, R. K. Pradhan, S. Chandra. Utilization of
Basic Oxygen Furnace (BOF) slag in the production of a
hydraulic cement binder, International journal of Mineral
Processing, Volume 79, Issue 2, May 2006, pp 98-105
https://doi.org/10.1016/j.minpro.2006.01.001
[5] R. P. Bragat. Agglomeration of Iron Ore, Taylor &
Francis, 2019
https://doi.org/10.1201/9781315269504
[6] K. Higuchi, Y. Takamoto, T. Orimoto, T. Sato,
F. Koizumi, K. Shinagawa, H. Furuta, Quality
improvement of Sinter ore in relation to blast furnace
operation, Nippon Steel Technical Report, No 94, 2006
[7] D. F. González, I. R. Bustinza, J. Mochón, C. G. Gasca
and L. F. Verdeja, Iron ore sintering: Process, Mineral
Processing and Extractive Metallurgy Review February
2017, 38:4, 215-227.
https://doi.org/10.1080/08827508.2017.1288115
[8] T. Umadevi, S. Prakash Rao, Pankaj Roy,
P. C. Mahapatra, M. Prabhu and Madhu Ranjan,
Influence of LD slag on iron ore sinter properties and
productivity, Proceedings of the XI International
Seminar on Mineral Processing Technology (MPT2010), pp 747-757
[9] Y. Liu. The Operation of Contemporary Blast Furnaces,
Metallurgical Industry Press, 2021
https://doi.org/10.1007/978-981-15-7074-2
[10] Volodymyr Shatokha and Olexandr Velychko, Study of
softening and melting behaviour of iron ore sinter and
pellets, High Temperature Materials and Processes,
Vol 31, 2012
https://doi.org/10.1515/htmp-2012-0027
[11] A. Cores, L. F. Verdejia, S. Ferreira, I. R. Bustinza,
J. Monchon. Iron ore sintering. Part 1. Theory and
practice of the sintering process, Dyna (Medellin,
Colombia), August 2013
[12] Min Gan, Xiaohui Fan and Xuling Chen. Calcium ferrite
generation during iron ore sintering crystallization
behavior and influencing factors, Advanced Topics in
Crystallization, pp 301-321
[13] Yu, W., Zuo, H., Zhang, J., and Zhang, T. The effects of
high Al2O3 on the metallurgical properties of sinter,
Proceedings of the symposium in Characterization of
Minerals, Metals and Materials 2015 (The Minerals,
Metals and Materials Society), Orlando, FL, March 15-
19, 2015, pp. 419-425.
https://doi.org/10.1007/978-3-319-48191-3_51
[14] Yin, J., Lv, X., Xiang, S., Bai, C., and Yu, B. Influence
of CaO source on the formation behavior of calcium
ferrite in solid state, ISIJ International, 53, pp. 1571-
1579.
https://doi.org/10.2355/isijinternational.53.1571