Abstract: The influences of anions (SO42-, CO32- and Cl-) on deep desilication of sodium aluminate solution were investigated. The optimal conditions of desilication were studied by examining the temperature, time, anion and Al2O3 concentration, ak and stirring speed. Under the conditions of 95℃, Al2O3 150 g/L, ak 1.5, and stirring speed 867 r/min, after 110 min the silica module was above 3815, and at the Al2O3 concentration of 30 g/L, the silica module was above 3943, 3545 and 3221. When the concentration of anion was 0~70 g/L, deep desilication was promoted by SO42-, but deep desilication was promoted firstly and then inhibited by CO32- and Cl-. Silica residue was analyzed by XRD, and the desilication mechanism by SO42-, CO32- and Cl- clarified.

Key words: sodium aluminate solution, deep desilication, SO42-, CO32-, Cl-

摘要： 研究了不同阴离子(SO42-, CO32-, Cl-)对铝酸钠溶液深度脱硅的影响. 通过对Na2SO4, Na2CO3和NaCl用量、反应温度、时间、Al2O3浓度、溶液苛性比ak、搅拌速度影响的考察，确定了最佳工艺条件. 在95℃, Al2O3 150 g/L, ak=1.5及搅拌速度867 r/min条件下脱硅110 min后，铝酸钠溶液中硅量指数达2938，在杂质用量30 g/L时，含SO42-, CO32-, Cl-溶液的硅量指数分别可达3943, 3545和3221. 在阴离子浓度为0~70 g/L时，SO42-促进溶液深度脱硅，CO32-, Cl-均先促进后抑制脱硅，通过硅渣XRD衍射分析，得到了SO42-, CO32-, Cl-对脱硅影响的变化规律.

关键词: 铝酸钠溶液, 深度脱硅, SO42-, CO32-, Cl-