半水-二水稀磷酸工艺流程探讨  

Discussion on the process of hemihydrate dihydrate dilute phosphoric acid

作　　者：马思全 李成伟 蒲中云 MA Siquan;LI Chengwei;PU Zhongyun(Phosphate Laboratory,Sichuan Hongda Co.,Ltd.,Deyang 618400,China)

机构地区：[1]四川宏达股份有限公司磷酸盐实验室,四川德阳618400

出　　处：《磷肥与复肥》2021年第7期30-33,共4页Phosphate & Compound Fertilizer

摘　　要：阐述磷酸萃取工艺现状,分析各工艺特点。简单介绍半水-二水稀磷酸工艺流程并探讨工艺条件。半水-二水稀磷酸工艺流程可以在与二水流程接近的工艺条件下,通过控制w(SO_(4)^(2-))2%~3%、温度80~90℃、磷酸w(P_(2)O^(5))30%~35%,在单槽多室萃取槽内实现半水结晶;根据半水石膏和二水石膏在转化槽内的溶解度差,实现半水石膏到二水石膏的快速转化,半水石膏溶解重结晶,最终形成结晶粗大、易于过滤、w(P_(2)O_(5总))≤0.3%的二水磷石膏。The present situation of phosphoric acid extraction processes are described and the characteristics of each process are analyzed.The process flow of hemihydrate dihydrate dilute phosphoric acid is briefly introduced and the process conditions are discussed.Under the similar process parameters of dihydrate dilute phosphoric acid process,for the process flow of hemihydrate dihydrate dilute phosphoric acid,hemihydrate crystallization can be realized in single tank multi chamber extraction tank by controlling the process parameters of w(SO_(4)^(2-))2%-3%,temperature 80-90℃,phosphoric acid w(P_(2)O_(5))30%-35%;According to the solubility difference of hemihydrate gypsum and dihydrate gypsum in the conversion tank,the rapid conversion from hemihydrate gypsum to dihydrate gypsum is realized.Hemihydrate gypsum dissolves and recrystallizes,and finally forms dihydrate phosphogypsum with coarse crystal,easy filtration,and w(total P_(2)O_(5))≤0.3%.

关 键 词：半水-二水稀磷酸流程 工艺条件 结晶动力学 磷石膏 

分 类 号：TQ126.35[化学工程—无机化工]