Abstract:The zeta potential measurements show that the flotation separation of diaspore from kaolinite, illite and pyrophyllite could be achieved in the range of pH 4-6.5 with cationic collectors. A special quaternary ammonium salts(DTAL) shows better selectivity than that the dodecyl amine(DDA) does for the flotation of three silicates. The closed-circuit flotation results show that the reverse flotation de-silicate can be achieved with DTAL as collector, a new inorganic reagent(SFL) as depressant and MIBC as frother to obtain a bauxite concentrate m(Al₂O₃)/m(SiO₂)＞10, Al₂O₃ recovery＞86%).

Key words:  aluminum-silicates; diasporic-bauxite; reverse flotation; quaternary ammonium salts