Abstract: The deep desilication of mid-high aluminate concentration solution was investigated with the addition of calcium sulfate dihydrate. The desiliconization efficiency of the Al2O3 concentration (200, 180, and 150 g/L) was affected by the temperature, time, CaSO4×2H2O concentration, molar ratio of alumina to silicon (ak), and stirring speed. Under the conditions of 95℃, ak=1.5, stirring speed of 867 r/min and CCaSO4×2H2O=30 g/L, after 2 h, to the Al2O3 concentration of 200 g/L, the silica module was above 3815, to the Al2O3 concentration of 180 g/L, the silica module was above 4082, and to the Al2O3 concentration of 150 g/L, the silica module was above 4260. The residue was analyzed by XRD technique. The desiliconization mechanism with calcium sulfate dehydrate was also discussed in the text.

Key words: calcium sulfate dehydrate, sodium aluminate solution, deep disiliconization, mechanism

摘要： 以二水硫酸钙为脱硅剂对中高浓度的铝酸钠溶液脱硅进行了研究，分别考察了温度、时间、二水硫酸钙用量、搅拌速度及铝酸钠溶液苛性比ak对浓度为200, 180, 150 g/L的铝酸钠溶液脱硅效果的影响. 在95℃及ak=1.5、二水硫酸钙用量30 g/L、搅拌速度为867 r/min条件下脱硅2 h后，200 g/L铝酸钠溶液中硅量指数达到3815，180 g/L铝酸钠溶液中硅量指数达到4082，150 g/L铝酸钠溶液中硅量指数可以达到4260. 通过XRD对脱硅后的渣相进行了分析，并探讨了二水硫酸钙的脱硅机理.

关键词: 二水硫酸钙, 铝酸钠溶液, 深度脱硅, 机理