Abstract
Oxide pellets are widely regarded as high-quality raw materials for BF ironmaking and direct reduction iron processes due to their excellent strength, performance and environmental properties. The decrease in the availability of magnetite resources has made the steel industry increasingly relying on hematite pellets. Therefore, understanding the reduction behavior, especially the swelling mechanism, and improving the reduction behavior of hematite pellets in coal-based reduction processes is of paramount importance. In this study, high grade hematite pellets were selected as the raw material, and the basicity was adjusted for the evaluation of coal-based reduction behavior. The results showed that natural basicity hematite pellets could achieve a maximum reduction expansion of 55.20%. Increasing the pellet basicity significantly improved the post-reduction swelling, ultimately leading to normal swelling, with a metallization rate exceeding 94%. Through mineral analysis and microscopic morphology analysis, it was found that an increase in basicity leads to a denser grain structure, reducing the reaction rate and thus decreasing the strain forces generated during reduction. Additionally, the growth of iron grains results in the formation of a denser iron layer after reduction, further lowering the RSI (Reduced Swelling Index).
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Wang XD, Jin YL (2021) Strategy analysis and testing study of high ratio of pellet utilized in blast furnace. Iron Steel 56(05):7–16 (in Chinese). https://doi.org/10.13228/j.boyuan.issn0449-749x.20210081
Sha YZ, Maarten G, Song YS (2019) Technical and economic analysis of blast furnace operation with high pellet ratio in China. Ironmaking 38(06):1–5 (in Chinese)
Tian JQ, Qing GL, Liu CJ, Li YX (2018) Production experiment of low silica alkaline pellet by limestone. China Metall 28(04):13–16. https://doi.org/10.13228/j.boyuan.issn1006-9356.20170272. (in Chinese)
Xun HJ, Shi XF, Zhang YY, Wan XY, Cao XE (2015) Experiment of coal-based direct reduction of high phosphorus oolitic hematite. J Iron Steel Res 27(12):30–35. https://doi.org/10.13228/j.boyuan.issn1001-0963.20140294. (in Chinese)
Chen J (2007) Non coking coal metallurgical technology. Chemical Industry Press. ISBN:9787502593223 (in Chinese)
Wu H, Chun TJ, Wang P, Zhou S, Zhou TB (2022) Consolidation mechanism of fluxed hematite pellets. J Iron Steel Res Int 29(10):9. https://doi.org/10.1007/s42243-022-00744-0
Sarkar A, Sinha O P, Mandal A K (2016) Utilization of lime fines as an effective binder as well as fluxing agent for making fluxed iron ore pellets. J Inst Eng (India), Ser D. Metallur Mater Eng Mining Eng. https://doi.org/10.1007/s40033-015-0079-3
Dwarapudi S, Ranjan M (2010) Influence of oxide and silicate melt phases on the RDI of Iron ore pellets suitable for shaft furnace of direct reduction process. ISIJ Int 50(11):1581–1589. https://doi.org/10.2355/isijinternational.50.1581
Guo YF, Liu K, Chen, F, Wang S, Zheng FQ, Yang LZ, Liu YZ (2021) Effect of basicity on the reduction swelling behavior and mechanism of limestone fluxed iron ore pellets. Powder Technol Int J Sci Technol Wet Dry Particulate Syst 393291-300. https://doi.org/10.1016/j.powtec.2021.07.057
Qing GL, Wang CD, Hou EJ, Liu HS, Ma L, Wu K (2014) Compressive strength and metallurgical property of low silicon magnesium pellet. J Iron Steel Res 26(04):7–12. https://doi.org/10.13228/j.boyuan.issn1001-0963.2014.04.010. (in Chinese)
Shi Y, Zhu DQ, Pan J, Guo ZQ, Lu SH, Xu MJ (2022) Improving hydrogen-rich gas-based shaft furnace direct reduction of fired hematite pellets by modifying basicity. Powder Technol 408. https://doi.org/10.1016/J.POWTEC.2022.117782
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2024 The Minerals, Metals & Materials Society
About this paper
Cite this paper
Zhu, D., Li, B., Pan, J., Guo, Z., Yang, C., Li, S. (2024). Improving the Reduction Swelling Behavior of Fired Hematite Pellets by Increasing Basicity. In: Peng, Z., et al. Characterization of Minerals, Metals, and Materials 2024. TMS 2024. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-031-50304-7_49
Download citation
DOI: https://doi.org/10.1007/978-3-031-50304-7_49
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-031-50303-0
Online ISBN: 978-3-031-50304-7
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)