Novel Process and Mechanism for Chemical Desilication from Kaolinite-Rich Diasporic Bauxite

doi:10.12068/j.issn.1005-3026.2019.10.011

Abstract

Abstract: For the kaolinite-rich diasporic bauxite， a process route using chemical desilication was firstly proposed. The relationship between the equilibrium solubility of silica and the mass concentration of alumina， and the effect of lye concentration， temperature and time on the chemical desiliconization ratio of ore were studied. The results showed that the desilication ratio can reach 70% and the w_{○Al▲2O▲3}/w_○SiO▲2 of bauxite increases from 4.97 to 8.5 in the alkali solution with Na₂O concentration of 230g·L^-1 at 90℃ for 90min. The formation of DSP reduces the pre-desilication ratio and causes the loss of alkali. However， the conversion of kaolinite to DSP does not reduce the effective w_{○Al▲2O▲3}/w_○SiO▲2 of desilicated concentrate.

Key words: bauxite, kaolinite, Bayer process, chemical desilication, DSP

CLC Number:

TF111.2

WU Yan， PAN Xiao-lin， HAN Yue-jiao， YU Hai-yan. Novel Process and Mechanism for Chemical Desilication from Kaolinite-Rich Diasporic Bauxite[J]. Journal of Northeastern University Natural Science, 2019, 40(10): 1424-1429.

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