工业级磷酸二氢铵生产工艺研究进展

磷酸二氢铵是典型的精细磷酸盐产品,在农业、消防、食品和材料等领域有广阔的应用及市场前景,需求量不断增大,工业级以上磷酸二氢铵的生产技术研究越来越引起人们的重视。制备工业级磷酸二氢铵的技术路线主要有热法磷酸路线、净化湿法磷酸路线。热法磷酸生产路线耗能高、污染大、成本高,该生产技术路线逐渐受限;溶剂萃取法净化湿法磷酸生产工业级磷酸二氢铵路线,产品纯度高、质量好、自动化程度高,但是流程复杂、投资大、成本高。因此近年来探索其他途径制备工业级磷酸二氢铵的研究不断增多。综述了以热法磷酸、净化湿法磷酸、湿法磷酸、萃余酸和磷酸脲母液为原料制备工业级磷酸二氢铵的技术路线,并且评述了各工艺的特点。就目前而言,由廉价易得的湿法磷酸直接制备高附加值的工业级磷酸二氢铵是研究的重点,提高产品纯度和五氧化二磷收率、改善料浆的过滤性能、探索氨化除杂后滤渣的再利用途径是该方法急需解决的问题。

Research progress on production process of industrial grade ammonium dihydrogen phosphate

Ammonium dihydrogen phosphate is a typical fine phosphate product,which has a wide range of applications and excellent market prospects in agriculture,fire protection,food,materials and many other fields.With the ever-increasing demand for ammonium dihydrogen phosphate,research on the producing process of industrial grade ammonium dihydrogen phosphate has attracted more and more attention.The main technical routes for the preparation of industrial grade ammonium dihydrogen phosphate include hot-process phosphoric acid route and wet-process purified phosphoric acid route,the hot-pro-cess phosphoric acid route shows high energy consumption,high pollution and high cost,which is gradually restricted,while the route of purifying wet-process phosphoric acid route by solvent extraction to produce industrial grade ammonium dihydro-gen phosphate has high purity,good quality and high degree of automation,but the process is complex,large investment and high cost.Therefore,in recent years,more and more research has been carried out to explore other ways to prepare industrial grade ammonium dihydrogen phosphate.Herein,the technical routes of preparing industrial grade ammonium dihydrogen phosphate from thermal process phosphoric acid,purified wet-process phosphoric acid,wet-process phosphoric acid,raffinate acid and urea phosphate mother liquid were reviewed.The characteristics of each process were discussed in detail.At present,producing high value-added high purity ammonium dihydrogen phosphate from wet-process phosphoric acid is the focus of research which is cheap and easy to obtain.It is urgent for this method to increase the purity of product and P₂O₅ yield,to improve the filtration performance of the slurry and to explore the appropriate reuse methods of filter residues after removing impurities with ammoniation.