Experimental Study on Flotation of Low-grade High-iron Bauxite in Western Guangxi

There is a high-iron-containing low-grade bauxite ore in West of Guangxi Province, with Al₂O₃ content of 44.40%, SiO₂ 4.51%, alumina-silica ratio only 3.06, and Fe₂O₃ 22.43%. The main aluminum minerals in the ore are diaspore, and the main iron minerals are limonite and hematite. A view of the characteristics of low Al₂O₃ content, Al-Si ratio and high Fe₂O₃ content of the ore, the flotation results can be improved effectively by using of the combined depressants of sodium hexametaphosphates and sodium carbonate inhibition, as well as self-developed collector EM505 collecting agent. Aluminum concentrate with A/S ratio of 6.23 and Al₂O₃ recovery of 78.12% was obtained by the flotation closed-circuit test. This experiment has made breakthroughs in key technologies, providing a new method for the development and utilization of this difficult flotation of high-iron bauxite resource.