磷石膏化工利用的工艺分析

磷石膏是湿法生产磷酸排放的工业废渣,主要成分为CaSO4.2H2O,我国磷石膏的年排放量超过1000万t,但利用率不足10%。磷石膏的大规模露天堆放对生态环境造成难以恢复的危害,已成为磷化工企业在环保达标方面面临的重大难题。本文分析了我国开发利用磷石膏生产硫酸铵、硫酸钾、硫酸、硫脲等产品的工艺流程、技术特点和存在的问题。

Process Analysis for Chemical Utilizing of Phosphogypsum

Phosphogypsum was the industrial waste discharged during the preparation of phosphoric acid by wet methods and was mainly composed of CaSO4·2H2O.In China,more than ten million tons of phosphogypsum was annually dischared,but only less than 10% thereof was utilized.Irremediable damage to environment caused by open dumping of phosphogypsum in large scale had become a significant difficulty to be solved by a phosphorous-related chemical enterprise in order to meet the requirements on environmental protection.In this paper,preparation of ammonium sulfate,potassium sulfate,sulfuric acid,thiourea and the like from phosphogypsum in China was analyzed in terms of preparing process,technical attributes and existing problems.