中文摘要：

系统研究了Na2CO3,Na2SO4和NaCl三种杂质对甲醇强化铝酸钠溶液分解沉淀Al（OH）3过程的影响,考察了不同浓度的Na2CO3,Na2SO4和NaCl对醇解过程分解率和产品粒度、形貌的影响.结果表明,控制分解温度为60℃,Na2O浓度170g/L,Na2O与Al2O3摩尔比1.5～1.6的铝酸钠溶液与等体积的甲醇反应24h时,当Na2CO3,Na2SO4和NaCl浓度（均以Na2O计）分别低于17.6,6.55和7.00g/L时,杂质对醇分过程分解率、产品粒径和形貌影响较小;当其浓度升高时,能加快新核的生成,产品中出现1～10μm形貌不规整的细化颗粒.

英文摘要：

The influences of major impurities,including Na2CO3,Na2SO4 and NaCl,on the precipitation rate,size distributions and morphology of Al（OH）3 particles in the decomposition process of sodium aluminate solution with methanol were studied.The results showed that when the sodium aluminate solution （Na2O concentration 170 g/L,molar ratio of Na2O to Al2O3 1.5～1.6） reacted with methanol in the same volume at 60℃ for 24 h,the impurities had little impacts on the decomposition ratio,particle size distributions and morphology with the concentrations of sodium carbonate,sodium sulfate and sodium chloride （calculated as Na2O） less than 17.55,6.55 and 7.00 g/L.With the impurity concentrations increasing and higher than these values,the generation of nucleus was promoted,and consequently a lot of fine and irregular particles appeared.