The solubility and phase diagram of the CsCl–MgCl₂–H₂O ternary system, at a relatively wide temperature range, are significantly important for the extraction of the cesium resources from salt lakes. The isothermal dissolve equilibrium (IDE) method was used to determine the solubility of this ternary system at T = 273.15, 308.15, and 348.15 K, which have not been reported yet. The measured results indicated that the equilibrium solid phases in this ternary system from T = 273.15 to 348.15 K are CsCl, double salt CsCl·MgCl₂·6H₂O, and MgCl₂·6H₂O, and correspondingly there are three crystal regions and two cosaturated points for these solid phases. The solubility of the salt increased with the increase of the temperature, and the double salt CsCl·MgCl₂·6H₂O and CsCl crystal regions also became larger with the increasing temperature. However, the crystal regions of the MgCl₂·6H₂O solid phase are not enlarged obviously. Based on the solubility and phase diagram of CsCl–MgCl₂–H₂O at different temperatures, the separation process of CsCl resources has been proposed.

中文翻译：

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三元体系CsCl–MgCl ₂ –H ₂ O在T = 273.15、308.15和348.15 K时的溶解度和相平衡研究

在相对宽的温度范围内，CsCl–MgCl ₂ –H ₂ O三元系统的溶解度和相图对于从盐湖中萃取铯资源非常重要。等温溶解平衡（IDE）方法用于确定该三元体系在T = 273.15、308.15和348.15 K时的溶解度，但尚未见报道。测量结果表明，该三元体系中从T = 273.15至348.15 K的平衡固相为CsCl，复盐CsCl·MgCl ₂ ·6H ₂ O和MgCl ₂ ·6H ₂O，并且对于这些固相相应地存在三个晶体区域和两个同饱和点。盐的溶解度随温度的升高而增加，CsCl·MgCl ₂ ·6H ₂ O和CsCl的复盐晶体区也随温度的升高而增大。但是，MgCl ₂ ·6H ₂ O固相的晶体区域没有明显扩大。根据CsCl–MgCl ₂ –H ₂ O在不同温度下的溶解度和相图，提出了CsCl资源的分离过程。