氧化铝生产中铝酸钠溶液结构的研究

RESEARCH ON STRUCTURE OF SODIUM ALUMINATE SOLUTION IN ALUMINA PRODUCTION

对有关铝酸钠溶液结构方面近几十年的进展进行系统研究表明 :在中等浓度的铝酸钠溶液中 ,铝酸根离子以Al(OH) - 4 形式存在 ;在稀溶液中且温度较低时 ,铝酸根离子以水化离子 [Al(OH) - 4 ] (H2 O) x 形式存在 ;在较浓的溶液中或温度较高时 ,Al(OH) - 4 离子脱水形成 [Al2 O(OH) 6 ] 2 - 二聚离子 ,在 15 0℃以下 。

Understanding the structure of sodium aluminate solution is the prime study about the mechanism of alumina production by alkali, especially the basic research on the procedure of seed precipitation in Bayer liquor To get sandy alumina and achieve high precipitation rate, we must research the mechanism of seed precipitation in Bayer liquor so as to improve the quality of hydroxide aluminum,therefore,exploring the structure of sodium aluminate liquor is required Recent development on the structure of sodium aluminate solution is discussed in this paper,and the results are as fallows:the aluminate ion exists in the form of Al(OH) - 4 in moderate concentration,and hydrous ion as[Al(OH) - 4](H 2O) x in diluted solution at low temperatures,while Al(OH) - 4 dehydrates in high concentration solution at high temperature and exists as polymeric ion of[Al 2O(OH) 6] 2- ,but both of Al(OH) - 4 and [Al 2O(OH) 6] 2- could exist when temperature is lower than 150℃