Thermodynamics of the MgCl2-MgSO4 and CaCl2-CaSO4 systems

IF 1.9 3区材料科学 Q4 CHEMISTRY, PHYSICAL

Calphad-computer Coupling of Phase Diagrams and Thermochemistry Pub Date : 2025-10-10 DOI:10.1016/j.calphad.2025.102888

Amedeo Morsa , Elena Yazhenskikh , Rhys Dominic Jacob , Michael Müller , Dmitry Sergeev

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引用次数: 0

Abstract

Thermodynamic properties of MgCl₂-MgSO₄ and CaCl₂-CaSO₄ binary systems hold significant importance in the exploration of potential phase change materials for thermal energy storage applications. This study aims to elucidate the phase diagrams and thermodynamic properties of the eutectic mixtures within these systems, employing experimental techniques such as Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). Through comprehensive experimental investigations, the phase diagrams of the MgCl₂-MgSO₄ and CaCl₂-CaSO₄ systems were meticulously delineated, revealing the eutectic compositions and transition temperatures. Specifically, the eutectic composition for MgCl₂-MgSO₄ was proposed to be 28.0 mol% MgSO₄ with a melting temperature of 663 ± 5 °C, while for the CaCl₂-CaSO₄ system it was found to be at 14.0 mol% CaSO₄ and 722 ± 5 °C. Additionally, the enthalpy of fusion of these eutectic mixtures was for the first time determined, providing crucial insights into their thermal behaviour. They are 38.2 ± 1.0 kJ/mol for the Mg-containing system and 30.2 ± 0.4 kJ/mol for the Ca-containing system, respectively. The experimental data obtained in this study served as the foundation for the development of a new Gibbs energy dataset, which is essential for conducting thermodynamic calculations. The utilisation of this dataset enables accurate predictions of thermodynamic properties across the entire composition and temperature ranges of the systems under investigation.

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MgCl2-MgSO4和CaCl2-CaSO4体系的热力学

MgCl2-MgSO4和CaCl2-CaSO4二元体系的热力学性质对探索潜在的相变储能材料具有重要意义。本研究旨在阐明这些体系中共晶混合物的相图和热力学性质，采用差热分析（DTA）和差示扫描量热法（DSC）等实验技术。通过全面的实验研究，绘制了MgCl2-MgSO4和CaCl2-CaSO4体系的相图，揭示了共晶成分和转变温度。具体来说，MgCl2-MgSO4体系的共晶组成为28.0 mol% MgSO4，熔融温度为663±5°C，而CaCl2-CaSO4体系的共晶组成为14.0 mol% CaSO4，熔融温度为722±5°C。此外，首次确定了这些共晶混合物的熔合焓，为其热行为提供了重要的见解。含mg体系为38.2±1.0 kJ/mol，含ca体系为30.2±0.4 kJ/mol。本研究获得的实验数据为建立新的Gibbs能量数据集奠定了基础，该数据集对进行热力学计算至关重要。利用该数据集可以准确预测所研究系统的整个组成和温度范围的热力学性质。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Calphad-computer Coupling of Phase Diagrams and Thermochemistry 化学-热力学

CiteScore

4.00

自引率

16.70%

发文量

审稿时长

2.5 months

期刊介绍： The design of industrial processes requires reliable thermodynamic data. CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) aims to promote computational thermodynamics through development of models to represent thermodynamic properties for various phases which permit prediction of properties of multicomponent systems from those of binary and ternary subsystems, critical assessment of data and their incorporation into self-consistent databases, development of software to optimize and derive thermodynamic parameters and the development and use of databanks for calculations to improve understanding of various industrial and technological processes. This work is disseminated through the CALPHAD journal and its annual conference.