CaCl_(2)和MgCl_(2)及其复合溶液制备α-半水石膏  

Preparation ofα-hemihydrous gypsum from CaCl_(2)and MgCl_(2)and their composite solution

作　　者：胡成[1,2] 刘梦 向玮衡 陈平 王能[2,3] 卢冠举 周金兰 HU Cheng;LIU Meng;XIANG Weiheng;CHEN Ping;WANG Neng;LU Guanju;ZHOU Jinlan(GuangXi Key Laboratory of Green Building Materials and Construction Industrialization,Guilin University of Technology,Guilin 541004,China;Guangxi Engineering and Technology Center for Utilization of Industrial Waste Residue in Building Materials,Guilin University of Technology,Guilin 541004,China;College of Civil and Architectural Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学,广西绿色建材与建筑工业化重点实验室,广西桂林541004 [2]桂林理工大学,土木与建筑工程学院,广西桂林541004 [3]桂林理工大学,广西工业废渣建材资源利用工程技术研究中心,广西桂林541004

出　　处：《无机盐工业》2024年第7期112-117,共6页Inorganic Chemicals Industry

基　　金：广西重点研发计划项目(桂科AB22035064);国家自然科学基金项目(52368029);广西绿色建材与建筑工业化重点实验室开发基金项目(桂科能22-J-21-19)。

摘　　要：为提高磷石膏的利用率和附加值,采用常压水热合成法以磷石膏为主要原材料制备α-半水石膏材料,主要研究不同质量分数的CaCl_(2)、MgCl_(2)及其复合溶液对磷石膏常压水热制备α-半水石膏脱水速率、物相组成和微晶形貌的影响。研究发现,磷石膏在95℃的CaCl_(2)溶液、MgCl_(2)溶液及CaCl_(2)-MgCl_(2)复合溶液中均可脱水转晶生成α-半水石膏。在CaCl_(2)溶液和MgCl_(2)溶液中,随着盐溶液浓度的增加,α-半水石膏的生成速率加快,其中经质量分数为35%的CaCl_(2)溶液反应4 h后或质量分数为25%的MgCl_(2)溶液反应1 h后,磷石膏可完全反应成α-半水石膏。在CaCl_(2)-MgCl_(2)复合溶液中,随着MgCl_(2)溶液浓度的增加,磷石膏的脱水转化速率逐渐加快,当CaCl_(2)质量分数≤19%和MgCl_(2)质量分数≥11%时,磷石膏水热反应1 h即可形成颗粒分布较为完整的α-半水石膏。In order to improve the utilization rate and added value of phosphogypsum,α-hemihydrate gypsum was prepared from phosphogypsum by atmospheric hydrothermal synthesis method.The effects of CaCl_(2),MgCl_(2)and their composite solutions on the dehydration rate,phase composition and microcrystal morphology ofα-hemihydrate gypsum prepared by atmospheric hydrothermal preparation of phosphogypsum were studied.It was found that phosphogypsum could be dehydrated and recrystallized to formα-hemihydrate gypsum in CaCl_(2)solution,MgCl_(2)solution and CaCl_(2)-MgCl_(2)composite solution at 95℃.In CaCl_(2)solution and MgCl_(2)solution,the formation rate ofα-hemihydrate gypsum accelerated with the increase of salt solution concentration,in which phosphogypsum could be completely reacted intoα-hemihydrate gypsum after reaction of 35%CaCl_(2)solution for 4 h or 25%MgCl_(2)solution for 1 h.In the CaCl_(2)-MgCl_(2)composite solution,the dehydration and conversion rate of phosphogypsum gradually accelerated with the increase of the concentration of MgCl_(2)solution.When the mass fraction of CaCl_(2)was≤19%and the mass fraction of MgCl_(2)was≥11%,the hydrothermal reaction of phosphogypsum for 1 h could formα-hemihydrate gypsum with relatively complete particle distribution.

关 键 词：磷石膏 CaCl_(2) MgCl_(2) 复合溶液 Α-半水石膏 

分 类 号：TQ177.373[化学工程—硅酸盐工业]