磷石膏的净化处理及制备硫酸钙晶须的研究

实验研究磷石膏净化处理方法及化工综合利用新路。在对磷石膏样品进行粒度分布、XRD矿物分析、化学成分分析和SEM形貌分析等物性检测的基础上，利用廉价的碳酸氢铵和氨水及工业副产盐酸，对磷石膏进行净化处理，去除杂质提纯得到硫酸钙，副产氯化铵并回收二氧化碳。以磷石膏提纯得到的硫酸钙为原料，采用水热法制备硫酸钙晶须，提升磷石膏的利用价值。实验得到磷石膏净化处理和水热法制备硫酸钙晶须的最优化工艺条件，并通过POM与SEM对所得硫酸钙样品和硫酸钙晶须进行形貌分析。结果表明，工艺路线在技术上是可行的，工艺设备和操作条件简单、母液可循环使用、无三废污染，既减轻了环境污染，又降低了生产成本，具有较好的经济效益和社会效益。

Research on purification of phosphogypsum and preparation of calcium sulfate whisker

New methods of purification and comprehensive utilization of phosphogypsum were experimentally studied.On the basis of physical testing of phosphogypsum samples,including particle size distribution,XRD mineral analysis,chemical analysis,and SEM morphology analysis,phosphogypsum was treated with low-cost ammonium bicarbonate,ammonia,and industrial by-product hydrochloric acid,and calcium sulfate(CaSO4) was obtained by removing impurities.Meanwhile,by-product ammonium chloride was also got and carbon dioxide could be recovered.Then CaSO4 was applied as raw material to prepare calcium sulfate whisker by hydrothermal method,so as to enhance the application value of phosphogypsum.Optimal conditions of phosphogypsum purification and hydrothermal method of calcium sulfate whisker were obtained by experiments,the morphologies of calcium sulfate and calcium sulfate whisker were analyzed by POM and SEM.Results showed that the experimental process route was technically feasible,the process equipment and operating conditions were simple,the mother liquor could be recycled,no’three waste’ pollution,so it not only reduced environmental pollution,but also cut down the production costs.Therefore,it had good economic and social benefits.