338.15 K时四元体系CaCl_(2)-SrCl_(2)-BaCl_(2)-H_(2)O相平衡测定及溶解度计算  

Phase equilibria determination and solubility calculation of the quaternary system CaCl_(2)-SrCl_(2)-BaCl_(2)-H_(2)O at 338.15 K

作　　者：曹大群 金艳 陈杭[1] 于建国[1] CAO Daqun;JIN Yan;CHEN Hang;YU Jianguo(Engineering Research Center of Resource Process Engineering,Ministry of Education,East China University of Science and Technology,Shanghai 200237,China;Suzhou Juzhi Tongchuang Environmental Technology Co.Ltd.,Changshu 215513,Jiangsu,China)

机构地区：[1]华东理工大学资源过程工程教育部工程研究中心,上海200237 [2]苏州聚智同创环保科技有限公司,江苏常熟215513

出　　处：《化工学报》2021年第10期5028-5039,共12页CIESC Journal

基　　金：国家自然科学基金重点项目(U20A20142)。

摘　　要：采用等温溶解平衡法研究338.15 K时三元体系CaCl_(2)-Sr Cl_(2)-H_(2)O、CaCl_(2)-BaCl_(2)-H_(2)O和Sr Cl_(2)-BaCl_(2)-H_(2)O的稳定相平衡,进一步研究四元体系CaCl_(2)-Sr Cl_(2)-BaCl_(2)-H_(2)O的相平衡。根据实验数据,分别绘制了三元体系的相图和密度-组成图,四元体系空间立体图、相图、水图和密度-组成图。研究结果表明:CaCl_(2)-Sr Cl_(2)-BaCl_(2)-H_(2)O四元体系在338.15 K时没有复盐和固溶体生成,稳定平衡相图由1个共饱点、3条单变量溶解度曲线,3个结晶区组成,分别对应BaCl_(2)·2H_(2)O结晶区、Sr Cl_(2)·m H_(2)O (m=2,6)结晶区和CaCl_(2)·2H_(2)O结晶区。采用DFT模型进行338.15 K三元体系CaCl_(2)-Sr Cl_(2)-H_(2)O、CaCl_(2)-BaCl_(2)-H_(2)O和Sr Cl_(2)-BaCl_(2)-H_(2)O的溶解度计算,计算结果与实验结果基本吻合。针对CaCl_(2)-Sr Cl_(2)-BaCl_(2)-H_(2)O四元体系及三元子体系的稳定相平衡研究,可为综合开发利用油田卤水中的钙-锶-钡资源提供数据基础。The stable phase equilibria of ternary system CaCl_(2)-SrCl_(2)-H_(2)O,CaCl_(2)-BaCl_(2)-H_(2)O and SrCl_(2)-BaCl_(2)-H_(2)O at 338.15 K were studied by isothermal dissolution equilibrium method,and then the quaternary system CaCl_(2)-SrCl_(2)-BaCl_(2)-H_(2)O was studied.According to the experimental data,the phase diagram and density composition diagram of ternary system,the space diagram,phase diagram,water diagram and density composition diagram of quaternary system were drawn respectively.The results show that there is no double salt or solid solution in the quaternary system CaCl_(2)-SrCl_(2)-BaCl_(2)-H_(2)O.The stable phase diagram of the quaternary system consists of one invariant saturation point,three univariate solubility curves and three salt crystallization regions at 338.15 K,corresponding to the crystallization regions of BaCl_(2)·2 H_(2)O,SrCl_(2)·m H_(2)O(m=2,6)and CaCl_(2)·2 H_(2)O respectively.The solubility of the ternary system CaCl_(2)-SrCl_(2)-H_(2)O,CaCl_(2)-BaCl_(2)-H_(2)O and SrCl_(2)-BaCl_(2)-H_(2)O at 338.15 K were calculated by DFT model.The calculated results are basically consistent with the experimental data.The study of stable phase equilibria of quaternary and ternary systems of CaCl_(2)-SrCl_(2)-BaCl_(2)-H_(2)O can provide data basis for comprehensive development and utilization of calcium-strontium-barium resources in oilfield brine.

关 键 词：水盐体系 相平衡 溶解性 热力学性质 DFT模型 

分 类 号：O642.4[理学—物理化学]