摘要
为探索地下卤水中锂盐的盐析规律,采用等温溶解平衡法研究三元体系LiBr-Li_(2)SO_(4)-H_(2)O在288 K和323 K时的稳定相平衡,测定该三元体系的溶解度及密度,根据溶解度和密度数据绘制该三元体系相图及液相密度-组成图。结果表明:该体系在288 K和323 K时的相图均为简单共饱和型相图,没有固溶体以及复盐生成。288 K和323 K时的稳定相图均包含1个共饱点,2条单变量曲线,2个固相结晶区。288 K时2个结晶区的固相为Li_(2)SO_(4)·H_(2)O和LiBr·2H_(2)O,323 K时2个结晶区的固相为Li_(2)SO_(4)·H_(2)O和LiBr·H_(2)O。Li_(2)SO_(4)·H_(2)O的结晶区远大于LiBr·2H_(2)O和LiBr·H_(2)O的结晶区,表明Li_(2)SO_(4)·H_(2)O更容易从该体系饱和溶液中析出。LiBr对Li_(2)SO_(4)有明显的盐析作用。
The stable phase equilibria in the ternary system LiBr-Li_(2)SO_(4)-H_(2)O at 288 K and 323 K were studied by using an isothermal dissolution equilibrium method in order to explore the salting-out rules of lithium salt in underground brine.The solubilities and densities of the ternary system were measured at two temperatures.According to the data,the corresponding phase diagrams and liquid phase density diagrams were plotted.The results show that the ternary system is the simple co-saturated type at 288 K and 323 K,and there is neither a double salt nor a solid solution in the system.Both of the phase diagrams include one invariant point,two univariate curves and two crystallization regions.The solids of the two crystallization regions at 288 K are Li_(2)SO_(4)·H_(2)O and LiBr·2H_(2)O.The solids of the two crystallization regions at 323 K are Li_(2)SO_(4)·H_(2)O and LiBr·H_(2)O.The crystallization region of Li_(2)SO_(4)·H_(2)O is much larger than that of LiBr·2H_(2)O and LiBr·H_(2)O,indicating that Li_(2)SO_(4)·H_(2)O is easier to crystallize from saturated solution in the ternary system.LiBr has an obvious salting-out effect on Li_(2)SO_(4).
作者
陈国蓬
李斌
雷鸣
刘子龙
袁俊生
CHEN Guo-peng;LI Bin;LEI Ming;LIU Zi-long;YUAN Jun-sheng(College of Chemical Engineering,Hebei University of Technology,Tianjin 300130,China;Engineering Research Center of Seawater Utilization of Ministry of Education,Tianjin 300130,China;School of Chemical Engineering and Material,Quanzhou Normal University,Quanzhou 362000,Fujian Province,China)
出处
《化学工程》
CAS
CSCD
北大核心
2022年第4期30-34,共5页
Chemical Engineering(China)
基金
国家重点研究发展计划(2016YFB0600504)
教育部创新团队发展计划(IRT14R14)
河北省自然科学基金项目(B2017202246,E2020202020)
河北省重点研发计划项目(18394008D)
河北省高等学校科学技术研究项目(QN2019048)
河北省现代海洋化工技术协同创新中心(冀教科[2013]37号)
泉州市科技计划项目(2019C109)。
关键词
相平衡
溶解度
溴化锂
稳定相图
phase equilibrium
solubility
lithium bromide
stable phase diagram
