三元体系KCl+CaCl_(2)+H_(2)O在278.2 K及308.2 K下的稳定相平衡研究  

Stable Phase Equilibria of Ternary System KCl+CaCl_(2)+H_(2)O at 278.2 K and 308.2 K

作　　者：姚智豪 孟浩 于旭东[1] 陈帅 罗军 YAO Zhihao;MENG Hao;YU Xudong;CHEN Shuai;LUO Jun(College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China;Qinghai Salt Lake Industry Co., Ltd, Golmud 816099, 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]青海盐湖工业股份有限公司,青海格尔木816099

出　　处：《矿产保护与利用》2021年第6期112-116,共5页Conservation and Utilization of Mineral Resources

基　　金：四川省科技计划应用基础研究(2017JY0191)。

摘　　要：采用等温溶解平衡法研究了三元体系KCl+CaCl_(2)+H_(2)O在278.2 K及308.2 K温度条件下的稳定相平衡关系,实验测定了平衡时各组分的溶解度、密度、折光率,联合采用Schreinemaker湿渣法与X-ray粉晶衍射法确定了平衡固相组成。结果表明三元体系在278.2 K及308.2 K温度条件下为简单三元体系,无复盐或固溶体生成,对应的稳定相图包含1个共饱和点,2条单变量曲线和2个单盐结晶区。对比三元体系278.2 K、308.2 K、348.2 K温度条件下的相图发现:308.2 K时,氯化钾结晶区最大,表明此时氯化钾最易析出;随温度进一步升高,氯化钙结晶形式由CaCl_(2)·6H_(2)O转变为CaCl_(2)·2H_(2)O。The stable phase equilibria of the ternary system KCl+CaCl_(2)+H_(2)O at 278.2 K and 308.2 K were investigated by isothermal dissolution equilibrium method.The solubilities,densities,and refractive indices of the aqueous ternary system were determined,the corresponding solid phases were identified by Schreinemakers wet residue method and X-ray diffraction.The results show that the ternary system KCl+CaCl_(2)+H_(2)O at 278.2 K and 308.2 K are both simple types,without double salt or solid solution formed.The stable phase diagram of the ternary system consists of one invariant point,two isothermal dissolution curves,and two crystallization zones corresponding to two single salts CaCl_(2)·6H_(2)O and KCl.By comparison of the stable phase diagrams at 278.2 K,308.2 K,and 348.2 K shows that the crystallization region of KCl is largest at 308.2 K,which means that it is most easily precipitated from the chloride type solution with potassium and calcium.The crystallization form of calcium chloride changes from CaCl_(2)·6H_(2)O to CaCl_(2)·2H_(2)O with temperature increase.

关 键 词：氯化钾 氯化钙 相平衡 水合盐 多温相图 

分 类 号：TD971.1[矿业工程—选矿] TF111.3[冶金工程—冶金物理化学]