(1. 中南大学 冶金科学与工程学院, 长沙 410083;
2. 中国铝业股份有限公司 山西分公司技术中心，
河津 043300)
摘 要: 对高浓度铝酸钠溶液碳酸化分解过程中Na2O的析出行为和产品中Na2O的存在形式进行了实验研究。 结果表明： 溶液中NaAl(OH)4的过饱和度是高浓度铝酸钠溶液碳酸化分解的主要动力，并直接影响产品中吸附碱和晶间碱含量水平； 提高分解温度、 添加晶种或钾碱均可以明显降低产品的Na2O含量；表面吸附和晶间夹杂存在的可洗碱一般占氢氧化铝产品中Na2O含量的20%~30%， 而晶格碱和含碱化合物杂质等不可洗碱是产品中Na2O的主要存在形式。
关键字: 碳酸化分解; Na2O; 析出行为
（1. School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China;
2. The Technological Center of Shanxi Branch,
China Aluminum Ltd, Hejin 043300, China）
Abstract:Nowadays the Al2O3 content in the sodium aluminate solution is generally not more than 110g/L in the industrial production, which has become one of the primary factors restricting the equipment productivity, while soda is still one of the primary impurities influencing the quality of the product in sintering process and Bayer-sintering combining process. The experimental research on the carbonization precipitation of sodium aluminate solution with high content Al2O3 (170~190g/L) is carried out. It is demonstrated that the soda pick-up behavior is mainly determined by the liquor super-saturation and the experimental result indicates that the Na2O content in Al(OH)3 can be reduced by increasing precipitation temperature or adding seeds. Finally the existence formation of Na2O in aluminum trihydroxide is also investigated.
Key words: carbonization precipitation; soda; pick-up behavior
