Document Type : Original Research Paper

Authors

1 Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood University of Technology, Shahrood, Iran

2 Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood University of Technology, Shahrood, Iran

3 Research and Development Manager at Jajarm Alumina Company, Jajarm, Iran

Abstract

The global growth of aluminum demand with the modernization of our society has led to the interest in developing alternative methods to produce aluminum from non-bauxite and low-grade resources such as shale bauxites. For such reserves, the conventional Bayer process is challenging and is not efficient to extract aluminum, and the sintering process is known to be effective. Thus, this study aimed to scrutinize the technical feasibility of alumina extraction from an Iranian low-grade (shale) bauxite ore containing 36.22% Al2O3, 22.11% SiO2, 20.42% Fe2O3, 3.33% TiO2, and 3.13% CaO. In this regard, the sintering process with lime-soda followed by alkaline leaching was adopted to extract alumina, and response surface modeling was employed to assess the important parameters such as the sintering temperature, Na2O(caustic) concentration, CaO/SiO2 molar ratio, and Na2O/Al2O3 molar ratio. The findings indicated that the extraction rate improved by increasing the sintering temperature and CaO/SiO2 ratio and decreasing the Na2O(caustic) dose and Na2O/Al2O3 ratio. It was also found that the Na2O(caustic) concentration, sintering temperature, and interactive effect of Na2O(caustic) concentration with Na2O/Al2O3 ratio had the greatest influence on the extraction efficiency. The process optimization was conducted applying the desirability function approach, and more than 71% of Al2O3 was extracted at 1150 °C sintering temperature, 2.1 CaO/SiO2 molar ratio, 0.9 Na2O/Al2O3 molar ratio and 30 g/L Na2O(caustic) dose. Ultimately, it was concluded that a lime-soda sintering process at 1150 °C followed by one-step alkaline leaching with Na2O(caustic) at 90 °C could be metallurgically efficient for treating the low-grade (shale) bauxites.

Keywords

Main Subjects

[1]. Mavhungu, S.T., Akinlabi, E.T., Onitiri, M.A., & Varachia, F.M. (2017). Aluminum Matrix Composites for Industrial Use: Advances and Trends. Procedia Manufacturing, 7, 178-182.
[2]. Guan, R.G., & Tie, D. (2017). A Review on Grain Refinement of Aluminum Alloys: Progresses, Challenges and Prospects. Acta Metallurgica Sinica (English Letters), 30, 409–432.
[3]. Nnanwube, I.A., & Onukwuli, O.D. (2023). Characterization and kinetics of alumina leaching from calcined Akpugo kaolinite for potential aluminum recovery. South African Journal of Chemical Engineering, 43, 24-37.
[4]. Wang, C., Li, S., Guo, Y., He, Y.Y., Liu, J., & Liu, H. (2023). Comprehensive treatments of aluminum dross in China: A critical review. Journal of Environmental Management, 345, 118575.
[5]. Brough, D., & Jouhara, H. (2020). The aluminium industry: A review on state-of-the-art technologies, environmental impacts and possibilities for waste heat recovery. International Journal of Thermofluids, 12, 100007.
[6]. Verma, A., Corbin, D., & Shiflett, M. (2022). Extraction of aluminum and iron from bauxite: A unique closed-loop ore refining process utilizing oxalate chemistry. AIChE Journal, 68(2), e17477.
[7]. Smith, P. (2009). The processing of high silica bauxites — Review of existing and potential processes. Hydrometallurgy, 98, 162–176.
[8]. Dhawan, N., & Agrawal S. (2023). Comparison and evaluation of alumino-silicate samples as a dual source of alumina and potash values. Canadian Metallurgical Quarterly, 62(1), 71-84.
[9]. Wang, P., Qi, T., Li, X., Wang, Y., Shen, L., Liu, G., Zhou, Q., & Peng, Z. (2023). Comprehensive extraction of silica and alumina from coal fly ash via reduced and oxidized roasting-low temperature alkaline leaching and Bayer digestion. JOM, https://doi.org/10.1007/s11837-023-06285-5.
[10]. Habashi, F. (1999). A Textbook of Hydrometallurgy, 2nd edition, Métallurgie Extractive. Québec/ Laval University Bookstore "Zone", Quebec City, Canada.
[11]. Kaußen, F.M., & Friedrich, B. (2016). Methods for alkaline recovery of aluminum from Bauxite residue. Journal of Sustainable Metallurgy, 2, 353–364.
[12]. Azof, F.I., Vafeias, M., Panias, D., & Safarian, J. (2020). The leachability of a ternary CaO-Al2O3-SiO2 slag produced from smelting-reduction of low-grade bauxite for alumina recovery. Hydrometallurgy, 191, 105184.
[13]. Valeev, D.V., Mansurova, E.R., Bychinskii, V.A., & Chudnenko, K.V. (2016). Extraction of Alumina from high-silica bauxite by hydrochloric acid leaching using preliminary roasting method. IOP Conference Series: Materials Science and Engineering, 110, 012049.
[14]. Le, T., Ju, S., Lu, L., Peng, J., Zhou, L., & Wang, S. (2017). A novel process and its mechanism for recovering alumina from diasporic bauxite. Hydrometallurgy, 169, 124–134.
[15]. Le, T., Ju, S., Ravindra, A.V., Li, X., & Wang, Q. (2019). Effect of microwave roasting on aluminum extraction from diasporic bauxite-sodium carbonate-calcium hydroxide mixtures. JOM, 71, 831–837.
[16]. Toama, H.Z., Al-Ajeel, A.A., & Jumaah, A.H. (2018). Studying the efficiency of lime-soda sinter process to extract alumina from colored kaolinite ores using factorial technique of design of experiments. Engineering and Technology Journal (Part A), 36(5), 500-508.
[17]. Wang, Y., Zhang, T., Zhang, Y., Lyu, G., & Zhang, W. (2019). Mineral transformation in treating low-grade bauxite using the calcification–carbonization process and preparing cement clinker with the obtained residue. Minerals Engineering, 138, 139–147.
[18]. ElDeeb, A.B., Brichkin, V.N., Kurtenkov, R.V., 7 Bormotov, I.S. (2019). Extraction of alumina from kaolin by a combination of pyro- and hydrometallurgical processes. Applied Clay Science, 172, 146-154.
[19]. Mahecha-Rivas, J.C., Fuentes-Ordonez, E., Epelde, E., & Saldarriaga, J.F. (2021). Aluminum extraction from a metallurgical industry sludge and its application as adsorbent. Journal of Cleaner Production, 310, 127374.
[20]. Tang, J., Liu, G., Qi, T., Zhou, Q., Peng, Z., Li, X., Yan, H., & Hao, H. (2022). Two-stage process for the safe utilization of secondary aluminum dross in combination with the Bayer process. Hydrometallurgy, 209, 105836.
[21]. Ghaemmaghami, E., Samadzadeh Yazdi, M.R., Darvishi, M.A., Sadati, A.A., & Najafi, A. (2022). Alumina extraction by lime-soda sinter process from low-grade bauxite soil of Semirom mine. Journal of Mining and Environment, 13(4), 1159-1169.
[22]. Zhou, G., Wang, Y., Zhang, Y., Qi, T., Zhou, Q., Liu, G., Peng, Z., & Li, X. (2023). A clean two-stage Bayer process for achieving near-zero waste discharge from high-iron gibbsitic bauxite. Journal of Cleaner Production, 405, 136991.
[23]. Sun, Y., Pan, A., Ma, Y., & Chang, J. (2023). Extraction of alumina and silica from high-silica bauxite by sintering with sodium carbonate followed by two-step leaching with water and sulfuric acid. RSC Advances, 13, 23254-23266.
[24]. Kar, M.K., Ӧnal, M.A.R., & Borra, C.R. (2023). Alumina recovery from bauxite residue: A concise review. Resources, Conservation & Recycling, 198, 107158.
[25]. Xiao, Y.D., Jin, H.X., Wang, M.L., & Guo, Y.L. (2023). Recycling of iron and alumina from red mud after co-sintering with phosphogypsum. Journal of Sustainable Metallurgy, 9, 408-422.
[26]. Liu, W., Yang, J., & Xiao, B. (2009). Review on treatment and utilization of bauxite residues in China. International Journal of Mineral Processing, 93, 220–231.
[27]. Yu, H.Y., Pan, X.L., Wang, B., Zhang, W., Sun, H.L., & Bi, S.W. (2012). Effect of Na2O on formation of calcium aluminates in CaO−Al2O3−SiO2 system. Transactions of Nonferrous Metals Society of China, 22(12), 3108-3112.
[28]. Bezera, M.A., Santelli, R.E., Oliveira, E.P., Villar, L.S., & Escaleira, L.A. (2008). Review response surface methodology (RSM) as a tool for optimization in analytical chemistry. Talanta, 76(5), 965-977.
[29]. Ooi, T.Y., Yong, E.L., Din, M.F.M., Rezania, S., Aminudin, E., Chelliapan, S., Rahman, A.A., & Park, J. (2018). Optimization of aluminium recovery from water treatment sludge using Response Surface Methodology. Journal of Environmental Management, 228, 13–19.
[30]. Houshmand, A.R., Azizi, A., & Bahri, Z. (2023). Recovery of lead from the leaching residue derived from zinc production plant: process optimization and kinetic modeling. Geosystem Engineering, https://doi.org/10.1080/12269328.2023.2292984.
[31]. Nozari, I., & Azizi, A. (2020). Experimental and kinetic modeling investigation of copper dissolution process from an Iranian mixed oxide/sulfide copper ore. Journal of Sustainable Metallurgy, 6, 437–450.
[32]. Arslan, V. (2022). Optimal Factor Evaluation for the Extraction of Alumina from Clays by Sulfuric Acid Leaching Process Using Box–Behnken Design Methodology. Russian Journal of Non-Ferrous Metals, 63(2), 146–156.
[33]. Khani, M.R., & Karamoozian, M. (2019). Modelling and optimization of digestion efficiency of bauxite in Bayer process: Iran Alumina company. Journal of Mining and Environment, 10(3), 799-809.
[34]. Kaußen, F.M., & Friedrich, B. (2018). Phase characterization and thermochemical simulation of (landfilled) bauxite residue (“red mud”) in different alkaline processes optimized for aluminum recovery. Hydrometallurgy, 176, 49-61.
[35]. Tam, P.W.Y., Panias, D., & Vassiliadou, V. (2019). Sintering optimisation and recovery of aluminum and sodium from Greek bauxite residue. Minerals, 9(10), 571.
[36]. ElDeeb, A.B., Brichkin, V.N., Bertau, M., Savinova, Y.A., & Kurtenkov, R.V. (2020). Solid state and phase transformation mechanism of kaolin sintered with limestone for alumina extraction. Applied Clay Science, 196, 105771.
[37]. Xie, M., Lv, H., Liu, F., & Zhao, H. (2023). Study on phase transformation and reaction behavior of alumina extraction process by calcification of aluminum dross. Journal of Materials Research and Technology, 25, 6000-6010.
[38]. He, L., Shi, L., Huang, Q., Hayat, W., Shang, Z., Ma, T., Wang, M., Yao, W., Huang, H., & Chen, R. (2021). Extraction of alumina from aluminum dross by a non-hazardous alkaline sintering process: Dissolution kinetics of alumina and silica from calcined materials. Science of the Total Environment, 777, 146123.
[39]. Meher, S.N., & Padhi, B.K. (2012). Effects of MgO and Na2CO3 additives, sintering temperature and leaching conditions for extraction of alumina from Bayer’s process waste residue (red mud). Chemical Science Transactions, 1(2), 456-462.
[40]. Alp, A., & Selim Goral, M. (2003). The effects of the additives, calcination and leach conditions for alumina production from red mud. Scandinavian Journal of Metallurgy, 32(6), 301–305.
[41]. Bai, G.H., Wei, T., Wang, X.G., Qin, J.G., Peng, X.U., & Li, P.C. (2010). Alkali desilicated coal fly ash as substitute of bauxite in lime-soda sintering process for aluminum production. Transactions of Nonferrous Metals Society of China, 20, s169–s175.