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: (column+ball)>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.