的工艺条件
(1. 武汉理工大学 化学工程学院，武汉 430070;
2. 汉江集团郧县丰源电化制造有限公司，郧县 442500)
摘 要: 以硫酸铝和尿素水热均相沉淀合成的低密度一水软铝石为晶种，研究分解条件对溶液分解率和分解产物性质的影响，还对从铝酸钠溶液析出低密度一水软铝石的过程进行了初步分析。结果表明：适当延长分解时间，降低分解温度，或采用Al2O3浓度和分子比较低的铝酸钠原液都可以得到较高的分解率；该晶种具有较好的水热稳定性，连续使用3次对溶液分解率、分解产物的堆密度和比表面积影响不大。推荐工艺条件为：分子比1.30~1.45、Al2O3浓度为140 g/L左右的铝酸钠溶液在种子比1.0和180 ℃左右下分解3 h。
关键字: 水热均相沉淀；铝酸钠溶液；水热种分；低密度一水软铝石
precipitation from sodium aluminate solution
（1. School of Chemical Engineering, Wuhan University of Technology,Wuhan 430070, China;
2. Fengyuan Electrochemical Manufacture Co. Ltd, Hanjiang Group,Yunxian 442500, China）
Abstract:Effect of decomposition conditions on the ratio of seeded decomposition and properties of precipitation products from sodium aluminate (SA) solutions with the very light boehmite seed prepared from the hydrothermal homogeneous precipitation between aluminum sulfate and urea, was studied. Mechanism of the very light boehmite precipitation process was also analyzed. The results show that with the appropriate increase of precipitation time and decrease of temperature, the initial alumina concentration and molar ratio of Na2O/Al2O3 (MR) can obtain higher ratio of seeded decomposition. The seed has better hydrothermal stability. Ratio of seeded decomposition, tape density and specific surface area of the product almost keep constant after three precipitation cycles. Process conditions are recommended as follows: the SA solutions with MR of 1.30−1.45 and alumina concentration about 140 g/L are decomposed for 3 h at approximate 180 ℃ with a low seed ratio of 1.0.
Key words: hydrothermal homogeneous precipitation; sodium aluminate solution; hydrothermal seed precipitation; very light boehmite
