无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (3): 30-35.doi: 10.19964/j.issn.1006-4990.2024-0304

• 研究与开发 • 上一篇    下一篇

Li+,K+,Ca2+//Cl--H2O四元体系298.2 K固液相平衡研究

于旭东1,3(), 黎静1, 任思颖1,2, 罗军1,2, 曾英1,3   

  1. 1.成都理工大学材料与化学化工学院,四川 成都 610059
    2.青海盐湖工业股份有限公司,青海格尔木 816000
    3.天府永兴实验室,四川 成都 610213
  • 收稿日期:2024-05-29 出版日期:2025-03-10 发布日期:2024-07-11
  • 作者简介:于旭东(1985— ),男,博士,教授,研究方向为相平衡与分离技术;E-mail:xwdlyxd@126.com
  • 基金资助:
    四川省科技计划资助项目(2023ZYD0036);天府永兴实验室有组织科研项目(2023KJGG13)

Study on solid-liquid phase equilibrium of Li+,K+,Ca2+//Cl--H2O quaternary system at 298.2 K

YU Xudong1,3(), LI Jing1, REN Siying1,2, LUO Jun1,2, ZENG Ying1,3   

  1. 1. College of Materials and Chemistry & Chemical Engineering,Chengdu University of Technology,Chengdu 610059,China
    2. Qinghai Salt Lake Industrial Co. ,Ltd. ,Golmud 816000,China
    3. Tianfu Yongxing Laboratory,Chengdu 610213,China
  • Received:2024-05-29 Published:2025-03-10 Online:2024-07-11

摘要:

四川盆地深藏卤水蕴含丰富的锂、钾资源,极具开发利用价值,但共存离子作用关系复杂。为获取深藏卤水中锂钾钙共存氯化物体系在298.2 K时各盐的结晶规律,采用等温溶解平衡法开展了四元体系Li+,K+,Ca2+//Cl--H2O 298.2 K固液相平衡研究,测定了溶解度、平衡液相密度,采用X射线粉晶衍射法分析了平衡固相组成,并绘制了相应的相图。结果表明:298.2 K时,该四元体系有锂钙复盐(LiCl·CaCl2·5H2O)生成,为复杂四元体系;氯化钙结晶形式受共存氯化锂的影响同时存在CaCl2·6H2O和CaCl2·4H2O。对应的固液平衡相图由3个四元共饱点(E1和E2为不相称共饱点、E3为相称共饱点)、7条单变量曲线和5个结晶区组成(结晶区面积由大到小为KCl、LiCl·H2O、CaCl2·4H2O、LiCl·CaCl2·5H2O、CaCl2·6H2O)。

关键词: 相平衡, 相图, 溶解度, 深藏卤水, 复盐

Abstract:

Deep brine in Sichuan basin is abundant in lithium and potassium resources,which has significant development potential,however,the interactions among the coexisting ions are complex.To obtain the crystallization law of each salt in the coexistence chloride system of lithium,potassium,and calcium,the solid-liquid phase equilibria of Li+,K+,Ca2+//Cl--H2O quaternary system at 298.2 K was investigated by using isothermal dissolution method.The solubilities and densities of the solution were determined,meanwhile the solid phase of the quaternary invariant point was identified by X-ray diffraction.The phase diagram was constructed by using the measured data.The results showed that the system was a complex quaternary system with the double salt LiCl·CaCl2·5H2O formed,and the crystalline form of calcium chloride was influenced by the coexisting lithium chloride,with both CaCl2·6H2O and CaCl2·4H2O forms present simultaneously.The corresponding solid-liquid phase diagram consisted of 3 quaternary invariant points(points E1 and E2 were incommensurate type,E3 belonged to commensurate type),7 univariate curves and 5 crystallization regions,the area of crystallization regions was decreased in the order of KCl,LiCl·H2O,CaCl2·4H2O,LiCl·CaCl2·5H2O,CaCl2·6H2O.

Key words: phase equilibria, phase diagram, solubility, deep brine, double salt

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