中文摘要：

用等温溶解平衡法研究了四元体系K^＋，Na^＋／／Cl^-，Br^- - H2O348K条件下的相平衡关系，测定了该交互四元体系在相应温度条件下平衡溶液的溶解度和密度，并根据相平衡实验数据绘制了相应的相图。研究结果表明：四元体系K^＋，Na^＋／／Cl^-，Br^- - H2O348K条件下属于固溶体型，相图中含有1条单变量曲线，2个平衡固相结晶区，无共饱和点。其平衡固相分别为固溶体K（C1，Br）和Na（C1，Br），其中固溶体K（Cl，Br）结晶区较大，固溶体Na（Cl，Br）结晶区较小。与同体系313K条件下的相图相比，348K时固溶体Na（Cl，Br）·2H2O结晶区消失。

英文摘要：

Phase equilibria in the quaternary system K^＋ ,Na^＋//Cl^- ,Br^- -H2O AT 348 K was studied by isothermal solution saturation method. The solubilities and densities of the solution in this quaternary system were determined experimentally. Using the experimental data,the phase diagram of the quaternary system was obtained,the quaternary system K^＋ ,Na^＋//Cl^- ,Br^- -H2O at 348 K is a solid solution. In the phase diagram,the quaternary system at 348 K has one univari-ant curve and two crystallization fields corresponding to solid solution K （Cl,Br） and solid solu-tion Na （Cl,Br）,and has not invariant point. Solid solution K （Cl,Br） have larger crystallization field,whereas solid solution Na （Cl,Br） have smaller crystallization field. Compared with the sta-ble phase diagram at 313 K,the crystallization fields of solid solution Na （Cl,Br）·2H2O disap-peared at 348 K.