Experimental and Thermodynamic Model Study on Solid and Liquid Equilibrium of Ternary System MgBr2–MgSO4–H2O at 333.15 K

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• 作者：Rongjian Ying ; Dan Li ; Lingzong Meng ; Tianlong Deng ; Yafei Guo
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2016
• 出版时间：July 14, 2016
• 年：2016
• 卷：61
• 期：7
• 页码：2624-2628
• 全文大小：255K
• 年卷期：0
• ISSN：1520-5134

文摘

The solubilities and the refractive indices of the MgBr₂–MgSO₄–H₂O system at 333.15 K were studied with the isothermal equilibrium solubility method. The phase diagram and refractive index diagram were plotted for this system at 333.15 K. The system belongs to hydrate II type. The phase diagram is constituted of three invariant points cosaturated with two salts, four univariant solubility isotherms saturated with one salt, and four stable crystallization fields in the ternary system corresponding to MgSO₄·6H₂O (Hex), MgSO₄·4H₂O (Tet), MgSO₄·H₂O (Kie), and MgBr₂·6H₂O (Mb). The calculated refractive index data agree well with the experimental results. Combining the experimental solubility data of the ternary system, the Pitzer binary parameters for MgBr₂ and MgSO₄, and the Pitzer mixing ion-interaction parameter θ_Br,SO4, the Pitzer parameter ψ_Mg,Br,SO4 and the solubility equilibrium constants K_sp of solid phases in the ternary system at 333.15 K were fitted using the Pitzer and Harvie–Weare (HW) model. Then the solubilities for the ternary system at 333.15 K were calculated. A comparison between the experimental and calculated solubilities illustrates that the predicted data obtained with the model are in accordance with experimental results.