浓氨介质中石膏转化制硫酸钾的工艺条件研究

Study of Process Conditions of Potassium Sulfate Production by Gypsum Conversion in Concentrated Ammonia Medium

实验研究了浓氨介质中石膏与氯化钾直接转化制硫酸钾过程中初始氨浓度、反应温度、液固比及石膏过量比等重要参数的影响规律 ,并通过对实验结果进行线性回归处理 ,对该工艺参数的影响作了动力学分析。适宜的工艺条件为 :反应温度 0～ 5℃ ,初始氨浓度 30 %～ 36 % ,氨水与石膏质量比约 9∶1,KCl与石膏质量比 1.1∶1。在此条件下 ,CaO转化率接近 90 % ,产品纯度高于 70 % ,粗产品可采用结晶法提纯。

An experimental study is made of the regular pattern of the effect of such important parameters as the initial ammonia concentration, reaction temperature, liquid solid ratio and ratio of gypsum in excess in the manufacture of potassium sulfate by direct conversion of gypsum and potassium chloride in concentrated ammonia medium, and through linear regressive treatment of the experimental results a kinetic analysis is made of the effect of these process parameters. The suitable process conditions are:reaction temperature of 0～5 ℃, inital ammonia concentration of 30%～36%, mass ratio of aqua ammonia to gypsum of about 9∶1, and mass ratio of KCl to gypsum of 1.1∶1. Under these conditions the conversion of CaO is close to 90%, product purity higher than 70%, and the crude product may be further purified by crystallization.