拜尔法氧化铝赤泥浮选工艺研究

对郑州铝厂拜尔法产生的氧化铝赤泥使用浮选再回收的问题进行了研究。扫描电镜和筛析研究表明;氧化铝在赤泥各粒级中呈不均匀分布,粗粒级含Al_2O_3较高,细粒级含Al_2O_3较低。铝矿物以一水硬铝石为主,约占70～85％,它被水云母、水合钙铝硅酸盐和细分散态的铁的氧化物所包裹,矿粒表层以Ca、Fe、Si为主。因此,若用浮选法回收拜尔法氧化铝赤泥,就必须对试料进行分级和再磨,剥离表面覆盖层,并创造新生表面。+0.043mm粒级浮选后的精矿产品含Al_2O_352.75％,作业回收率77.85％,铝硅比7.53,基本达到浮选回收极限。-0.043mm粒级的可选性很差。

STUDY OF A1_2O_3 FLOTATION FROM BAYER PROCESS ALUMINA RED SLIME

The property of alumina red slime from Bayer Process, Zhengzhou Aluminum Plant, and a new flotation method for reusing the aluminum from red slime are described in this paper. Scanning electronic microscope analysis and size analysis indicate that A12O3 is not evenly distributed in different size fractions. Coarser fractions of the red slime contain more A12O3 than finer fractions. Diaspore is the major aluminum mineral (amounting to 70～85%) in the red slime and inclosed by hydromica, hydrating Ca aluminosilicate and oxide iron minerals. After leaching, the surface of the red slime particles contain mostly Ca, Fe, Si. So for cleaning the surface and creating a new surface, a classification followed by re-grinding process is necessary for successful flotation of aluminum minerals from the Bayer Process red slime. The aluminum flotation concentrate containing 52.75% A12O3 and 7.01% SiO2 with 77.85% A12O3 recovery was obtained for plus 0.043mm size fraction of the red slime, but the flotability of minus 0.043 mm size fraction was proved very poor.