Study on efficient desulfurization and desilication process of low-grade bauxite

Bauxite was treated by suspension roasting alkali leaching desilication, and the effects of roasting temperature, caustic concentration and alkali leaching temperature on baked ore alkali leaching silicon were studied. The results show that with a better temperature of suspension roasting of 930 ℃, when the liquid-solid ratio is 8:1, desilicate time is 30 min, caustic alkali concentration is 110 g/L and desilicate temperature is 95 ℃, a higher esilicate rate can be obtained, up to 49.24%. With the loss rate of Al₂O₃ down to 2.03%, the concentrate Al/Si can be raised to 8.21, and the actual dissolution rate of suspended baked silica concentrate can reach 94.79%. With lime as the desilication agent, after the desilication of alkali-immersed lyate, the roasting ore can be recycled for cycle desilication. After desilication, the Al/Si ratio of the concentrate can reach more than 7 so that the alkali liquor after desilication can be recycled.