磷石膏一步法制硫酸钾肥工艺研究

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

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。

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 fractionofammoniawas25%,reaetiontemperaturewas 5℃,reaction timewas 60min,andratio ofliquidvolume to solid mass was 10：1 mug. Under those optimum conditions the yield of potassium oxide was about 70%.The quality of the obtained potassium sulfate product also reached the standard of agricultural first-grade products.The producing process was simpler and the oper- ational conditions were milder than others. Additionally, the solvent can be recycled and reused, which was better for increas- ing the economic benefit.