Pre-beneficiation of Low Grade Diasporic Bauxite Ore by Reduction Roasting

A bauxite ore can be utilized in Bayer Process, if the mass ratio of Al2O3 to SiO2 is greater than 10. Otherwise, its FexOy and SiO2 content should be removed. On the other hand, removal of TiO2 from the bauxite ore would be beneficial because of both lowering the red mud residue and obtaining a valuable raw material containing TiO2 mineral. In this study, the low grade diasporic bauxite ore of Yalvaç, Isparta, Turkey was roasted under reducing atmosphere and subjected to magnetic separation. According to the experimental results, 800°C for reduction temperature and 20000 Gauss of magnetic intensity were found to be the optimum parameters for removal of iron oxide and rutile from the nonmagnetic ore. On the other hand, 600°C and 5000 Gauss were determined to be the optimum parameters for removal of silica from the non-magnetic ore.

Authors:

• K. Yılmaz
• B. Birol
• M. N. Sarıdede
• E. Yiğit

Keywords:

• Low grade diasporic bauxite
• magnetic separation
• reduction roasting
• separation index.

References:

[1] A. Pehlivan, A. O. Aydin, and A. Alp, “Alumina Extraction From Low -
Grade Diasporic Bauxite By Pyro - Hydro Metallurgical Process,” Sak.
Univ. J. Sci., vol. 16, no. 2, pp. 92–98, 2012.
[2] L. Y. Sadler and C. Venkataraman, “A process for enhanced removal of
iron from bauxite ores,” Int. J. Miner. Process., vol. 31, no. 3–4, pp.
233–246, 1991.
[3] C. Li, H. Sun, J. Bai, and L. Li, “Innovative methodology for
comprehensive utilization of iron ore tailings. Part 1. The recovery of
iron from iron ore tailings using magnetic separation after magnetizing
roasting,” J. Hazard. Mater., vol. 174, pp. 71–77, 2010.
[4] J. Pesl and R. H. Eric, “High temperature carbothermic reduction of
Fe2O3-TiO2-MxOy oxide mixtures,” in Minerals Engineering, 2002,
vol. 15, no. 11, pp. 971–984.
[5] H. Yang, L. Jing, and B. Zhang, “Recovery of iron from vanadium
tailings with coal-based direct reduction followed by magnetic
separation,” J. Hazard. Mater., vol. 185, no. 2–3, pp. 1405–1411, 2011.
[6] Z. Cui, Q. Liu, and T. Etsell, “Magnetic properties of ilmenite, hematite
and oilsand minerals after roasting,” Miner. Eng., vol. 15, no. 12, pp.
1121–1129, Dec. 2002.
[7] R. Kumar and J. Srivastava, and Premchand “Utilization of iron values
of red mud for metallurgical applications,” in Proc. Environmental and
Waste Management in Nonferrous Metallurgical Industries,
Jamshedpur, pp. 108–119, 1998.
[8] G. G. O. O. Uwadiale, “Magnetizing Reduction of Iron Ores,” Miner.
Process. Extr. Metall. Rev., vol. 11, no. October 2013, pp. 1–19, 1992.
[9] M. I. Nasr and M. a. Youssef, “Optimization of Magnetizing Reduction
and Magnetic Separation of Iron Ores by Experimental Design.,” ISIJ
Int., vol. 36, no. 1 996, pp. 631–639, 1996.