半水石膏转晶二水石膏工艺研究

A Study into the Conversion of Gypsum Hemihydrate to Dihydrate

在湿法磷酸净化中副产的半水硫酸钙晶型不稳定,易水化,残磷高,若直接排放,不仅磷损失量大,且增加环保压力。为了提高磷石膏品质和磷回收率,试验研究了半水石膏转晶二水石膏的较优工艺条件,提高了磷石膏品质,减少了环境污染,并具有良好的经济效益和社会效益。

The crystal form of calcium sulfate hemihydrate produced by wet phosphoric acid purification is unstable,easy to hydrate,and has high residual phosphorus.If it is directly discharged,it will not only cause a large loss of phosphorus,but also increase the pressure on environmental protection.In order to improve the quality of phosphogypsum and the recovery rate of phosphorus,the optimal process conditions for converting hemihydrate gypsum to crystallized dihydrate gypsum are studied,which improves the quality of phosphogypsum,reduced environmental pollution,and offers good economic and social benefits.