贵州某铝土矿石灰拜耳法溶出试验研究

Experimental Study on Lime Bayer Process Dissolution of a Bauxite Ore in Guizhou

贵州某高硅中低品位铝土矿石Al_2O_3品位为57.62%、SiO_2含量为9.54%,铝硅比为6.04。为实现氧化铝高效溶出,进行了铝土矿石灰拜耳法溶出氧化铝工艺试验。结果表明:在溶出温度为265℃,溶出时间为65min,磨矿粒度为-0.074 mm含量90%,石灰添加量为1.4,矿浆液固比为4,搅拌转速为500 r/min条件下,可以获得氧化铝溶出率83%以上,赤泥平均铝硅比为1.33的溶出指标。试验结果可为该类铝硅比较低的铝土矿资源的合理开发利用提供借鉴。

A high-silicon low-grade bauxite ore in Guizhou contains 57.62% Al2O3,SiO2 content is 9.54%, mole ratio of aluminum to silicon is 6.04. To high efficiently dissolve alumina, alumina dissolution by Lime Bayer Process test was conducted on bauxite ore. Results indicated that, with leaching temperature 265 ℃, leaching time 65 min, grinding particle size -0.074 mm content 90%, lime addition 1.4 according to mole ratio of calcium to silicon, slurry liquid to solid ratio 4, and agitation speed 500 r/min, the leaching index of alumina over 83% and red mud average aluminum to silicon ratio 1.33 were obtained. The test results can provide reference for the rational development and utilization of this kind of bauxite resources with low bauxite-silicon content.