Studying the Effect of Grinding Mechanism and Composition of Golgohar Concentrate on the Microstructure and Mechanical Properties of Pellets

Document Type : Original Articles

Authors

• Abouzar Eskandarinasab ¹
• Abouzar Eskandari Nasab ²
• Gholamhossein Akbari Fakhrabadi ²

¹ Department of Materials Science and Engineering, Shahid Bahonar University of Kerman, Kerman, Iran.

² Department of Materials and Metallurgy Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

10.22067/jmme.2025.90387.1162

Abstract

The effect of raw material composition and grinding process by ball mill and HPGR in Golgohar Complex on the properties of the final pellet was investigated. Tests were performed on the mixer input feed in the form of raw material composition analysis, granulation, moisture content and specific surface area measurement using two methods, Blaine and BET. Also, strength measurement and microstructural analysis were performed using SEM on raw and cooked pellets. In addition, the abrasion resistance and sphericity of the pellets were investigated. The results of the tests showed that the particle size produced by the ball mill was finer and had a higher specific surface area (1988 cm2/g). The morphology of the particles produced by the two milling methods was irregular and non-spherical and did not differ significantly from each other. The input feed of the pelletizing plant number one had a higher percentage of FeO, sulfur, and magnesium oxide. Also, microstructural studies of the pellets indicate a better distribution of fine particles and non-magnetic phases in the pellets produced in Plant No. 1. The pellets produced in Plant No. 1 have higher wet strength (WCS), while the dry strength (DCS) and fired strength (CCS) of the pellets produced in Plant No. 2 are higher. In addition, 96.3% of the pellets from the plant number one passed the dumpler abrasion test without crushing, and their sphericity was 0.824, which was higher than that of the pellets produced by the HPGR method.

Keywords

• Pellets
• Iron recovery
• HPGR
• Magnetite
• Granulation

Main Subjects

• Extractive Metallurgy

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References

[1] N. Tohidi, R. Vaghar, Load of iron and steel production furnaces. Tehran University Publication, 2021. (In Persian)

[2] K. Motamedi, S. Zandvakili, A. Hajizadeh, “A review on the effect of concentrate characteristics and the effective crushing method on pellet quality,” Iran National Conference on Materials Engineering, Metallurgy and Mining, 2018, pp. 1-17. (In Persian) https://civilica.com/doc/769023

[3] K. Meyer, Pelletizing of Iron Ores. Germany, Springer-Verlag, 1980.

[4] F. Przemysław, J. Mróz, “Ability for self-pelletization of iron ores and magnetite concentrates,” Journal of Iron and Steel Research International, vol. 18, no. 6, pp. 1-7, 2011. https://doi.org/10.1016/S1006-706X(11)60069-1

[5] P. Karimi, A. Noori Kuhbanani, S. M. Mousavi, “Investigating the effectiveness of HPGR and pelletizer combined circuits in the preparation of iron pellet factory feed, case study: factories of line 4 and lines 5, 6 and 7 of iron concentrate production of Gol Gohar Mining and Industrial Company,” First international conference on materials engineering, metallurgy and mining, 2021, pp. 1-11. (In Persian). https://civilica.com/doc/1250616

[6] S. Niksirat, M. H. Shahid Kalombari, M. R. Abutalebi, M. Adeli, “Investigation of the properties of raw pellets produced from iron ore concentrate of Chagharat mine by disk pelletizing method,” Seventh joint conference of Iran Metallurgical Engineering Association and Scientific Association Casting Iran, 2013, pp. 1-5. (In Persian) https://civilica.com/doc/224307

[7] S.K. Kawatra, V. Claremboux, “Iron ore pelletization: Part II. Inorganic binders,” Mineral Processing and Extractive Metallurgy Review, vol. 43, no. 7, pp. 813-832, 2022. https://doi.org/10.1080/08827508.2021.1947269

[8] K. Motamedi, S. Zandvakili, A. Hajizadeh, “The effect of softening mechanism of iron concentrate of Gol Gohar mine on quality indicators of raw pellets produced,” Journal of Mineral Resources Engineering, vol. 1, no. 5, pp. 143-160, 2020 (In Persain). https://doi.org/10.22067/jmme.2025.90387.1162

[9] A. Abazarpoor, M. Halali, “Investigation on the particle size and shape of iron ore pellet feed using ball mill and HPGR grinding methods,” Physicochemical Problems of Mineral Processing, vol. 53, no. 2, pp. 908-919, 2017. http://dx.doi.org/10.5277/ppmp170219

[10] J.A. Pal, S. Ghoari, A. Ammasi, S.K. Hota, V.M. Koranne, T. Venugopalan, “Improving reducibility of iron ore pellets by optimization of physical parameters,” Journal of Mining and Metallurgy, Section B: Metallurgy, vol. 53, no. 1, pp. 37-46, 2017. https://doi.org/10.2298/JMMB151206014P

[11] M. Iljana, T. Paananen, O. Mattila, M. Kondrakov, T. Fabritius, “Effect of iron ore pellet size on metallurgical properties,” Metals, vol. 12, no. 2, pp. 302, 2022. https://doi.org/10.3390/met12020302

[12] A. Abazarpoor, M. Halali, R. Hejazi, M. Saghaeian, V.S. Zadeh, “Investigation of iron ore particle size and shape on green pellet quality,” The Canadian Journal of Metallurgy and Materials Science, vol. 59, no. 2, pp. 242-250, 2020. https://doi.org/10.1080/00084433.2020.1730116

[13] H. Hanumanthappa, H. Vardhan, G.R. Mandela, M. Kaza, R. Sah, B.K. Shanmugam, S. Pandiri, “Investigation on iron ore grinding based on particle size distribution and liberation,” Transactions of the Indian Institute of Metals, vol. 73, pp. 1853-1866, 2020. https://doi.org/10.1007/s12666-020-01999-5

[14] W. Guo, Y. Han, Y. Li, Z. Tang, “Impact of ball filling rate and stirrer tip speed on milling iron ore by wet stirred mill: Analysis and prediction of the particle size distribution,” Powder Technology, vol. 22, no. 378, pp. 12-18, 2021. https://doi.org/10.1016/j.powtec.2020.09.052

[15] B. McNab , A. Jankovic , D. David, P. Payne, “Processing of Magnetite Iron Ores – Comparing Grinding Options,” In Proceedings of the AusIMM Iron Ore Conference, 2009, pp. 1-12.

[16] M. Reichert, C. Gerold, A. Fredriksson, G. Adolfsson, H. Lieberwirth, “Research of iron ore grinding in a vertical-roller-mill,” Minerals Engineering, vol. 15, no. 73, pp. 109-15, 2015. https://doi.org/10.1016/j.mineng.2014.07.021

[17] Z. Zhang, B. Kumar, “The Characteristics and Reduction of Wustite,” Iron Ores and Iron Oxides - New Perspectives, chapter 4, IntechOpen publication, 2023. https://doi.org/10.5772/intechopen.1001051

[18] S. Dwarapudi, T. K. Ghosh, A. Shankar, V. Tathavadkar, D. Bhattacharjee, R. Venugopal, “Effect of pellet basicity and MgO content on the quality and microstructure of hematite pellets,” International Journal of Mineral Processing, vol. 99, no. 1–4, pp. 43-53, 2011. https://doi.org/10.1016/j.minpro.2011.03.004

[19] C. Scharm, F. Küster, M. Laabs, et. al, “Direct reduction of iron ore pellets by H2 and CO: In-situ investigation of the structural transformation and reduction progression caused by atmosphere and temperature,” Minerals Engineering, vol. 180, p. 107459, 2022. https://doi.org/10.1016/j.mineng.2022.107459

[20] A.H.M. Najafabadi, A. Masoumi, S.M.V. Allaei, “Analysis of abrasive damage of iron ore pellets,” Powder technology, vol. 331, pp. 20-27, 2018. https://doi.org/10.1016/j.powtec.2018.02.030

[21] J.A. Halt, M.C. Nitz, S.K. Kawatra, M.  Dubé, “Iron ore pellet dustiness part I: factors affecting dust generation,” Mineral Processing and Extractive Metallurgy Review, vol. 36, no. 4, pp. 258-266, 2015. https://doi.org/10.1080/08827508.2014.928876