五元体系KCl-KBr-K_2SO_4-K_2B_4O_7-H_2O 323K和348K的相平衡  

Phase equilibrium in quinary system KCl-KBr-K_2SO_4-K_2B_4O_7-H_2O at 323 K and 348 K

作　　者：崔瑞芝[1] 桑世华[1,2] 李婷[1] 张勇刚[1] 

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]矿产资源化学四川省高校重点实验室,四川成都610059

出　　处：《化工学报》2013年第3期827-833,共7页CIESC Journal

基　　金：国家自然科学基金项目(40973047);四川省杰出青年学科带头人培养计划项目(08ZQ026-017)~~

摘　　要：用等温溶解平衡法研究了五元体系KCl-KBr-K2SO4-K2B4O7-H2O在323K和348K时的相平衡关系,测定了该五元体系在相应温度条件下平衡溶液的溶解度和密度,根据相平衡实验数据绘制相应的相图(K2SO4饱和)。研究结果表明:该五元体系在323K和348K条件下均属于固溶体型,相图中均有2个平衡固相结晶区,其平衡固相分别为固溶体K(Cl,Br)和K2B4O7.4H2O,1条单变量曲线。该五元体系323K和348K的相图相比,348K时K2B4O7.4H2O结晶区变小,而固溶体K(Cl,Br)结晶区变大。Phase equilibria in the quinary system KC1-KBr-K2SO4-K2B407-H2O at 323 K and 348 K were studied by isothermal solution saturation method. The solubilities and densities of the solution in this system were determined experimentally. Using the experimental data, the phase diagrams of the quinary system were obtained （saturated with K2SO4）. The quinary system is a solid solution. It comprises one univariant curve and two crystallization fields （saturated with K2SO4）, i.e. , solid solution K （C1, Br） and K2B407 · 4H20, and does not have invariant point. K2B407 · 4H20 has larger crystallization fields, while solid solution K （C1, Br） has smaller crystallization fields. It is also found that KBr has the salting- out effect on KC1. The density of the solution increases with the increase of KBr concentration anc decreases with the increase of KC1 concentration. Compared with the stable phase diagrams at 323 K and 348 K, the crystallization fields of K2B407 · 4H20 is small at 348 K, whereas the crystallization field ot solid solution K （C1, Br） is large.

关 键 词：水盐体系 相平衡 钾盐 固溶体 

分 类 号：O642[理学—物理化学]