This paper presents the solid–liquid equilibria phase diagrams of two ternary systems KCl–ZnCl2–H2O and MgCl2–ZnCl2–H2O at 278 K using the method of isothermal dissolution equilibrium. Integrated with the determined equilibrated liquid phase and humid residue composition, the phase diagrams of the two systems were generated. At the same time, the invariant points, the univariant solubility curves and the solid crystalline phase regions are displayed and discussed. The results of the experiment show that the two ternary systems are classified as complex owing to the formation of double salt. The phase diagram of the ternary system KCl–ZnCl2–H2O at 278 K is comprised of two invariant points, three univariant solubility curves and three solid crystalline phase regions corresponding to KCl, ZnCl2·2H2O and 2KCl·ZnCl2·2H2O. The phase diagram of the ternary system MgCl2–ZnCl2–H2O at 278 K includes two invariant points, three univariant solubility curves and three solid crystalline phase regions corresponding to MgCl2·6H2O, MgCl2·ZnCl2·6H2O and ZnCl2·2H2O. The densities of ternary mixtures at 278 K were measured. The possibility of Laliberte model to predict densities of investigated ternary saturated solution was checked. The results show that this model is allowed to offer fundamental description for densities of ternary mixtures and calculated results are in good agreement with the experimental values.

中文翻译：

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三元系统 KCl-ZnCl2-H2O 和 MgCl2-ZnCl2-H2O 在 278 K 中的固液相平衡

本文采用等温溶解平衡法，给出了 KCl-ZnCl2-H2O 和 MgCl2-ZnCl2-H2O 两种三元体系在 278 K 下的固液平衡相图。结合确定的平衡液相和潮湿残留物组成，生成两个系统的相图。同时，对不变点、单变溶解度曲线和固晶相区进行了展示和讨论。实验结果表明，由于形成了复盐，这两个三元体系被归类为复合物。三元体系 KCl-ZnCl2-H2O 在 278 K 的相图由两个不变点、三个单变溶解度曲线和三个对应于 KCl、ZnCl2·2H2O 和 2KCl·ZnCl2·2H2O 的固晶相区组成。三元体系 MgCl2-ZnCl2-H2O 在 278 K 的相图包括两个不变点、三个单变溶解度曲线和三个固晶相区，分别对应于 MgCl2·6H2O、MgCl2·ZnCl2·6H2O 和 ZnCl2·2H2O。测量了 278 K 下三元混合物的密度。检查了 Laliberte 模型预测所研究的三元饱和溶液密度的可能性。结果表明，该模型可以为三元混合物的密度提供基本描述，计算结果与实验值吻合较好。检查了 Laliberte 模型预测所研究的三元饱和溶液密度的可能性。结果表明，该模型可以为三元混合物的密度提供基本描述，计算结果与实验值吻合较好。检查了 Laliberte 模型预测所研究的三元饱和溶液密度的可能性。结果表明，该模型可以为三元混合物的密度提供基本描述，计算结果与实验值吻合较好。