Mg^(2+),K^+//Cl^-,B_4O_7^(2-)-H_2O四元体系288K固液相平衡

Solid-Liquid Phase Equilibrium of the Quaternary System Mg～(2+), K～+//Cl～-, B_4O_7～(2-)-H_2O at 288 K

采用等温溶解平衡法研究了288K时Mg2+,K+//Cl-,B4O27--H2O四元体系的相平衡关系,测定该体系在288K时平衡液相的溶解度和密度.依据实验测定的平衡溶解度数据及对应的平衡固相,绘制了该四元体系的平衡相图以及其密度-组成图.研究结果表明,四元体系Mg2+,K+//Cl-,B4O27--H2O288K时的固液相平衡实验中,有复盐KCl·MgCl2·6H2O生成,平衡相图中有3个共饱点,7条单变量曲线,5个结晶区,对应的平衡固相分别为MgB4O7·9H2O,K2B4O7·4H2O,KCl,MgCl2·6H2O,KCl·MgCl2·6H2O.简要讨论了实验结果.

Phase equilibria of the reciprocal quaternary system Mg^2＋, K＋//Cl%-, B4O7^2--H2O at 288 K were studied by the isothermal solution equilibrium method. Solubilities and densities in solution of the system were determined experimentally. The equilibrium phase diagram and the density-composition diagram of the quaternary system were plotted using experimental data. Experimental results also showed that the double salt KCl·MgCl2·6H2O formed in the quaternary system Mg^2＋, K＋//Cl%-, B4O7^2--H2O at 288 K. The quaternary system at 288 K had three invariant points （F1, F2, and F3）, seven univariant curves, and five fields of crystallization [MgB4O7·9H2O, K2B4O7·4H2O, KCl, MgCl2·6H2O, and KCl·MgCl2·6H2O]. The results are discussed simply.