298K四元体系LiCl-MgCl2-CaCl2-H2O相平衡实验及溶解度计算  

Measurements and calculations of solid-liquid equilibria in quaternary system LiCl-MgCl_2-CaCl_2-H_2O at 298 K

作　　者：崔瑞芝[1] 李武[1,2] 董亚萍 桑世华[4] CUI Ruizhi;LI Wu;DONG Yaping;SANG Shihua(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,Qinghai,China;Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Xining 810008,Qinghai,China;Qinghai Engineering and Technology Research Center of Comprehensive Utilization of Salt Lake Resources,Xining 810008,Qinghai,China;College of Materials and Chemistry&Chemical Engineering, Chengdu University of Technology,Chengdu 610059,Sichuan,China)

机构地区：[1]中国科学院青海盐湖研究所,中国科学院盐湖资源综合高效利用重点实验室,青海西宁810008 [2]青海省盐湖资源化学重点实验室,青海西宁810008 [3]青海省盐湖资源综合利用工程技术中心,青海西宁810008 [4]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《化工学报》2018年第10期4148-4155,共8页CIESC Journal

基　　金：国家自然科学基金项目(41472078,41273032)。

摘　　要：采用等温溶解平衡法测定了四元体系LiCl-MgCl_2-CaCl_2-H_2O在298 K下的溶解度,由此绘制了相应的相图和水含量图。实验结果表明,该体系在298 K时有三种复盐生成,无固溶体生成。其相图中含有五个共饱点,十一条单变量曲线以及七个平衡固相结晶区,分别为四个单盐结晶区(Ca Cl2·6H_2O、CaCl_2·4H_2O、Mg Cl2·6H_2O和LiCl·H_2O)以及三个复盐结晶区(LiCl·Mg Cl2·7H_2O、LiCl·CaCl_2·5H_2O和2Mg Cl2·CaCl_2·12H_2O)。运用Pitzer模型,采用文献中报道的参数对该四元体系进行了298 K条件下的溶解度计算。对比发现,计算结果与实验数据基本吻合。Solid-liquid equilibria in the quaternary system LiCl-MgCl2-CaCl2-H2O at 298 K were studied by the method of isothermal solution saturation method.Using the experimental data,the phase diagram and the relevant water diagram of the quaternary system were obtained.The results show that the phase diagram of the quaternary system consists of seven crystallization fields,eleven univariant curves,and five invariant points.In addition to four simple salts CaCl2·6H2O,CaCl2·4H2O,MgCl2·6H2O and LiCl·H2O,the three double salts LiCl·MgCl2·7H2O,LiCl·CaCl2·5H2O and 2MgCl2·CaCl2·12H2O also crystallizes from the saturated solutions.The crystallized area of single salt MgCl2·6H2O is the largest because of its smallest solubility.The solubility of the quaternary system at 298 K was calculated by Pitzer model using the parameters reported in the literature.The calculated results are basically consistent with the experimental data.

关 键 词：热力学性质 相平衡 水溶液 溶解度 Pizter电解质溶液模型 

分 类 号：O642[理学—物理化学]