磷石膏一步法制硫酸钾肥工艺研究

对磷石膏和氯化钾制取硫酸钾溶剂法工艺进行了研究。考察了在氨水及乙醇-氨溶液体系中影响硫酸钾收率的主要因素。实验得到较优的工艺条件：乙醇质量分数为25%、氨水初始质量分数为25%、反应温度为5 ℃、反应时间为60 min、液固体积质量比为10∶1 mL/g。在此最优条件下，氧化钾收率达70%左右，所得硫酸钾产品质量达到农用一级品。该工艺流程简单，生产条件温和，溶剂经回收后循环使用，有利于经济效益的提高。

Study on one-stage process of producing potassium sulfate fertilizer from phosphogypsum

The technology that producing potassium with phosphogypsum and potassium chloride by adding proper solvent was studied.Main variables affecting the yield of potassium sulfate in ammonium or ethyl alcohol-ammonium solution were researched.The optimized reaction conditions were obtained as follows：mass fraction of ethyl alcohol was 25%，initial mass fraction of ammonia was 25%，reaction temperature was 5 ℃，reaction time was 60 min，and ratio of liquid volume  to solid mass was 10∶1 mL/g. Under those optimum conditions the yield of potassiumoxide was about 70%.The quality of the obtained potassiumsulfateproduct also reached the standard of agricultural first-grade products.The producing process was simpler and the operational conditions were milder than others. Additionally，the solvent can be recycled and reused，which was better for increasing the economic benefit.