铝酸钠溶液碳分母液深度碳分制备片钠铝石  

Dawsonite preparation by deep carbonation decomposition of spent liquor from carbonation of sodium aluminate solutions

作　　者：李小斌[1] 刘楠[1] 周秋生[1] 齐天贵[1] 刘桂华[1] 彭志宏[1] 

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2016年第1期20-32,共13页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51274243)~~

摘　　要：对铝酸钠溶液碳酸化分解制备冶金级氢氧化铝后所得碳分母液进行深度碳分制备片钠铝石纤维,研究深度碳分过程中铝和硅的析出行为;通过FTIR,XRD和SEM等分析手段,研究深度碳分所得最终产物物相及其形貌的主要影响因素。研究结果表明:在深度碳分过程中,溶液中铝的析出存在一临界pH,即随着CO_2气体的通入,当溶液pH降低到11.8以下时,溶液中铝迅速析出;溶液中硅的析出趋势与铝的析出趋势基本相同;控制深度碳分终点pH为10.5左右,所得最终产物均为片钠铝石;随着深度碳分温度升高,最终产物由颗粒状向纤维状转变;随着初始Al_2O_3质量浓度的增加,所得片钠铝石纤维的直径变小,长径比增大,且其均匀性提高。Fibrous dawsonite was prepared by deep carbonation decomposition of spent liquor from carbonation of sodium aluminate solutions for producing metallurgical aluminum trioxide. The precipitation behavior of aluminum and silicon was studied in the deep carbonation decomposition process, and the main factors influencing the morphology of final dawsonite was determined by FTIR, XRD and SEM analyses. The results show that there is a critical pH for the aluminum precipitation from the spent liquor. Dawsonite precipitates rapidly when p H is lower than 11.8 with the continuous ventilation of CO2. The precipitation behavior of silicon species is similar to that of aluminum species. The final product of deep carbonation decomposition is fibrous dawsonite when the final p H of spent liquor is 10.5. The morphology of final product changes from particles to fibers with the increase of carbonation temperature, and the fiber diameter becomes small with the increase of initial alumina concentration for deep carbonation decomposition.

关 键 词：铝酸钠溶液 深度碳分 片钠铝石 

分 类 号：TF802[冶金工程—有色金属冶金]