五元体系NaCl+KCl+MgCl_(2)+SrCl 2+H_(2)O(NaCl饱和)在288 K时相平衡研究  

Studies on the Phase Equilibria in the Quinary System NaCl+KCl+MgCl_(2)+SrCl 2+H_(2)O(Saturated with NaCl)at 288 K

作　　者：桑世华[1] 岑雨秋 高云云 崔瑞芝[2] SANG Shi-hua;CEN Yu-qiu;GAO Yun-yun;CUI Rui-Zhi(College of Materials,Chemistry&Chemical Engineering,Chengdu University of Technology,Chengdu,610059,China;Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province,Xining,810008,China)

机构地区：[1]成都理工大学材料与化学化工学院,四川成都610059 [2]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

出　　处：《盐湖研究》2022年第4期30-40,共11页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(41873071);青海省盐湖资源化学重点实验室创新平台建设项目(2022-ZJ-Y06)。

摘　　要：合理开发利用四川盆地地下卤水资源,对卤水体系开展多温相平衡与相图的研究具有重要意义。本文通过等温溶解平衡法对在288 K时五元体系NaCl+KCl+MgCl_(2)+SrCl_(2)+H_(2)O(NaCl饱和)进行了相平衡实验研究,运用化学分析法以及X-ray粉晶衍射法分别确定了在288 K温度条件下该体系的平衡液相和平衡固相组成。通过固液相平衡实验数据,绘制了该五元体系以NaCl为饱和区域的干盐相图、水含量图以及氯化钠含量变化图。研究结果表明在288 K且NaCl饱和条件下,该五元体系干盐相图含有2个五元共饱和点、5条等温溶解度曲线和4个固相结晶区(KCl、MgCl_(2)·6H_(2)O、KCl·MgCl_(2)·6H_(2)O和SrCl_(2)·6H_(2)O)。固相结晶区KCl在该干盐相图中面积最大,其次是SrCl_(2)·6H_(2)O,而MgCl_(2)·6H_(2)O的结晶区面积最小,说明KCl在饱和溶液中的溶解度较小,易析出而得到分离,而MgCl_(2)的溶解度最大,难以从饱和溶液中结晶析出,且MgCl_(2)·6H_(2)O对KCl和SrCl_(2)·6H_(2)O有强烈盐析作用。通过对本体系热力学相平衡实验研究和多温相平衡的对比讨论,揭示了钾锶镁等含氯化物卤水体系在多温相平衡与相图条件下的结晶析盐规律,为液态矿产资源开发利用提供理论指导。In order to rationally develop and utilize the underground brine resources in Sichuan Basin,it is of great significance to conduct the research of multi-temperature phase equilibrium and phase diagram of the brine system.In this paper,the isothermal dissolution equilibrium method was adopted to determine the phase equilibrium experiment of NaCl+KCl+MgCl_(2)+SrCl_(2)+H_(2)O(saturated with NaCl)system at 288 K.The equilibrium liquid phase and the equilibrium solid phase composition at 288 K were analyzed by the chemical analysis method and the X-ray powder crystal diffraction method,respectively.Through the obtained solid-liquid phase equilibrium experimental data,the corresponding dry salt phase diagram,water content diagram and sodium chloride content diagram of the quinary system with NaCl as the saturated region were drawn.The results show that at 288 K and with NaCl saturation condition,the phase diagram of the quinary system has two invariant points,five isothermal solubility curves and four solid-phase crystallization zones(KCl,MgCl_(2)·6H_(2)O,KCl·MgCl_(2)·6H_(2)O and SrCl_(2)·6H_(2)O crystallization zones).KCl has the largest crystallization area in the dry salt phase diagram,followed by SrCl_(2)·6H_(2)O,while MgCl_(2)·6H_(2)O has the smallest crystallization area.The results show that KCl has the low solubility in the saturated solution and is most likely to separate out,while MgCl_(2)has the large solubility and is difficult to separate out from the saturated solution,which indicates that KCl and SrCl_(2)·6H_(2)O will be affected by the strong salting-out effect of MgCl_(2)·6H_(2)O.Through the thermodynamic phase equilibrium experiment study of this system and comparative discussion of phase equilibria at multi-temperatures,the crystallization rule and salt evolution of chloride brine systems containing potassium,strontium,magnesium in phase equilibrium condition at multi-temperatures were revealed accordingly.The obtained results can be provided guidance for the development and utilization of li

关 键 词：地下卤水 等温溶解平衡法 相平衡 溶解度 氯化物 

分 类 号：O642.542[理学—物理化学]