To provide theoretical data for the hydrometallurgical process of lead–zinc ores and the separation process of secondary lead recovery, the quaternary system MgCl₂–PbCl₂–ZnCl₂–H₂O at 323 K was investigated using the isothermal dissolution equilibrium method. The isothermal solubility data were obtained, based on which the corresponding dry salt phase diagram and the water content diagram were constructed. The double salts MgZnCl₄·6H₂O and 3MgCl₂·2PbCl₂·18H₂O were found in the equilibrium solid phases as its ternary subsystems. The dry salt phase diagram contains three invariant points, seven isothermal solubility curves, and five crystallization fields (the crystal salts are PbCl₂, 3MgCl₂·2PbCl₂·18H₂O, ZnCl₂, MgZnCl₄·6H₂O, and MgCl₂·6H₂O(Bis), respectively), and the crystallization region of PbCl₂ is the largest. At the same time, the invariant data of this quaternary system and its ternary subsystems at different temperatures were compared and discussed.

中文翻译：

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323 K时四元体系MgCl ₂ -PbCl ₂ -ZnCl ₂ -H ₂ O的固液平衡

以提供用于铅-锌矿石的湿法冶金工艺理论数据和次级铅回收的分离过程中，四元体系的MgCl ₂ -PbCl ₂ -ZnCl ₂ -H ₂ O不连到323 K，采用等温溶解平衡法研究。获得了等温溶解度数据，在此基础上构建了相应的干盐相图和水含量图。复盐MgZnCl ₄ ·6H ₂ O和3MgCl ₂ ·2PbCl ₂ ·18H ₂O在平衡固相中作为其三元子系统被发现。将干燥的盐的相图包含三个不变点，七条温溶解度曲线，和五个结晶区（晶体盐是PBCL ₂，3MgCl ₂ ·2PbCl ₂ ·18H ₂ O，氯化锌₂，MgZnCl ₄ ·6H ₂ O，和氯化镁₂ ·6H ₂ O（Bis），并且PbCl ₂的结晶区域最大。同时，比较并讨论了该四元系统及其三元子系统在不同温度下的不变数据。