常压水热Ca-Na-Cl溶液中用磷石膏制备α-半水石膏  

Preparation of α-calcium sulfate hemihydrate from phosphogypsum in Ca-Na-Cl solutions under atmospheric pressure

作　　者：马保国[1] 茹晓红[1] 邹开波[1] 卢斯文[1] 付浩兵[1] 

机构地区：[1]武汉理工大学硅酸盐材料与工程国家重点实验室,湖北武汉430070

出　　处：《化工学报》2013年第7期2701-2707,共7页CIESC Journal

基　　金：'十二五'国家科技支撑计划项目(2011BAJ03B03);湖北省科技计划重大专项项目(DZS0005)

摘　　要：引言常压水热电解质溶液中,二水石膏（calcium sulfate dihydrate,DH）、α-半水石膏（α-calcium sulfate hemihydrate,α-HH）、无水石膏（calcium sulfate anhydrate,AH）三相之间的转化对于无机盐工业、Preparation of α-calcium sulfate hemihydrate from phosphogypsum in hydrothermal electrolyte solutions under atmospheric pressure has been a promising way of effective utilization of phosphogypsum.In this paper preparation of α-calcium sulfate hemihydrate from phosphogypsum in Ca-Na-Cl solutions at 95℃was studied.Reaction time and solid products identification in 18.8% NaCl solution,24% CaCl2 and CaCl2＋NaCl solutions were investigated through morphologic observation,water of crystalization determination and phase analysis methods.The results showed that NaCl solution was not favorable as the dehydration reaction medium of phosphogypsum though reaction time was only 20 min,because the dehydration product was α-calcium sulfate hemihydrate containing omangwaite（Na2Ca5（SO4）6·3H2O）which had no hydration property of gypsum.In 24% CaCl2 solution α-calcium sulfate hemihydrate phase could be obtained at reaction time of 240 min,reaction time was reduced obviously with increasing NaCl content in Ca-Na-Cl solution,but it was accompanied by increase of Na2O content and irregular uncompleted crystal shapes in the reaction product.Therefore,Ca-Na-Cl solution could be a suitable medium for dehydration reaction of phosphogypsum to form α-calcium sulfate hemihydrate in hydrothermal electrolyte solution under atmospheric pressure.Meanwhile NaCl content should be limited to 2%.

关 键 词：磷石膏 Α-半水石膏 CACL2溶液 NACL溶液 

分 类 号：TU526[建筑科学—建筑技术科学] TQ177.3[化学工程—硅酸盐工业]