Experimental Investigation on Desiliconization of Low-Grade Bauxite by Flotation Process

摘要

Low-grade bauxite resources are abundant in China. However, the high content of silica can not meet the production requirments of alumina. Desiliconization experiments were carried out during the process of one roughing-one cleaning direct flotation in this work using diasporic high-silica bauxite as experimental ore samples, sodium oleate as collector and humic acid as depressant. The effects of flotation parameters on the alumina-silica ratio (A/S) and Al_2O_3 content from Henan province were investigated. The optimum conditions for roughing stage are obtained as follows: humic acid dosage of 20 g/t, sodium oleate dosage of 700 g/t, particle size (content of particles below 0.074 mm) of 85%. pH 9.0. And the dosage of humic acid and sodium oleate for cleaning-stage was a third of that in roughing-stage. The alumina content in the concentrate increases from 58.91 to 65.05%, while A/S rises from 3.27 to 7.97. This research can show a promising application of low-grade bauxite for alumina production.