Comminution property of bauxite and selective separation of Al and Si in bauxite

Abstract

This paper makes research on solving the problem in China concerning the suitable particle size for flotation and the optimum particle size of the concentrate required by the subsequent Bayer process. Grinding experiments under different conditions and flotation tests had been used to investigate the comminution property of bauxite and aluminosilicate as well as their separation by flotation. The results showed that different kinds of grinding medium led to different grinding effects, the following being the order of the selective grinding effect: (columnzball).ball.rod, and the separation between Al and Si in bauxite has been improved after selective grinding. It is indicated that the crystal structural difference between diaspore and aluminosilicate leads to their difference of comminution property. A demo plant built by the novel process of 'selective grinding-flotation' had been successfully commissioned in China since 2003.

Grinding Behavior and Potential Beneficiation Options of Bauxite Ores

“…The Bayer process can economically produce alumina when Al 2 O 3 to SiO 2 mass ratio in bauxite is greater than 10, while sintering or a combination of sintering and Bayer process can be used for ores with lower ratios. However, sintering is an energy-intensive process and increases the production cost of alumina [20][21][22][23].…”

“…Studies focusing on the removal of iron-bearing minerals include magnetic/gravimetric separation [24][25][26], reductive roasting followed by magnetic separation [17,22,27], froth flotation [28][29][30], leaching of iron oxides [31], chlorination followed by leaching [32] and microwave-magnetising roasting [33]. Other studies have attempted to upgrade bauxite ores through selective grinding by exploiting the different grindability between the minerals of interest, e.g., diaspore (6.5-7 Mohs hardness) and gangue minerals, e.g., kaolinite (2-2.5 Mohs hardness) and some other aluminosilicates [20,34].…”

Factors affecting nickel upgrade during selective grinding of low-grade limonitic laterites

“…Many studies have been carried out so far to optimize grinding of different ores and produce a concentrate that is suitable for further processing (Freeman et al 2000;Erdemog  lu and Sarikaya 2002;Gonçalves et al 2003). Ou et al (2008) studied the effect of selective grinding in order to optimize the Al/Si ratio in bauxites and improve the efficiency of flotation. Other studies investigated selective grinding of quartz-feldspar ores.…”

“…Ou et al. (2008) studied the effect of selective grinding in order to optimize the Al/Si ratio in bauxites and improve the efficiency of flotation. Other studies investigated selective grinding of quartz-feldspar ores.…”