三元体系LiCl+KCl+H_2O 323 K介稳相平衡研究  

Metastable Phase Equilibrium in the Ternary System LiCl+KCl+H_2O at 323 K

作　　者：常文华[1] 曾英[1,2] 闫书一[1,2] 张志翔[1] 

机构地区：[1]成都理工大学材料与化学化工学院 [2]矿产资源化学四川省高校重点实验室,四川成都610059

出　　处：《盐业与化工》2012年第4期26-28,共3页Jounral of Salt and Chemical Industry

基　　金：中国地质调查局地质调查工作项目(1212011085523);国家自然基金项目(41173071)资助

摘　　要：采用等温蒸发平衡法,研究了三元体系LiCl+KCl+H2O 323 K时的介稳相关系,同时测定了平衡液相的密度和pH值。根据实验数据,绘制了该三元体系的相图和密度、pH值组成图。研究结果表明:该三元体系为简单三元体系,无复盐或固溶体生成。该体系介稳相图含有1个共饱点,2条单变量曲线和2个单盐结晶相区。两个结晶区分别对应单盐LiCl.H2O和KCl。LiCl对KCl有较强的盐析作用。平衡液相的密度随着LiCl质量分数的增加而增大,pH值随着LiCl质量分数的增加而呈现规律性变化。对比三元体系LiCl+KCl+H2O 298 K介稳相关系研究结果可知,323 K下,LiCl结晶相区增大,KCl结晶相区减小。To aim at the composition characteristics of the underground brines in the west of Si- chuan Basin, the solubility, density and pH value of the equilibrated solution in the ternary system LiC1 ＋ KC1 ＋ I-I20 were studied at 323 K using an isothermal evaporation method. Based on the experimental data, the metastable phase diagram, the density vs composition diagram, and pH vs composition diagram were plotted. Results show that the ternary system is of a simple euteetic type, no double salt or solid solution formed at 323 K. The phase diagram consists of one invariant point, two uninvariant curves, and two crystallization regions. The crystallization regions correspond to single salts potassium chloride（KC1） and lithium chloride monohydrate（ LiC1 ~ H20）, respectively. Salt LiC1 has strong salting- out effect on salt KC1. The density increases with the increase of the mass fraction of LiC1, while the pH value de- creases with the increase of the mass fraction of LiC1. Comparisons between the metastable phase dia- grams at 298 K and at 323 K show that the crystallization forms have not changed, whereas the crystalli- zation zones have slight changes. The crystallization field of salt LiC1 is larger at 323 K, while the crys- tallization region of salt KC1 is smaller at 323 K.

关 键 词：介稳相平衡 氯化锂 氯化钾 等温蒸发 

分 类 号：O642[理学—物理化学]