文献类型：期刊文献

英文题名：Measurement and model prediction of solid-liquid equilibrium in the ternary system KCl-MgCl2-H2O at 293.15, 298.15, 303.15, and 308.15 K

作者：Wang, Congying[1];Luo, Mengjie[1];Chen, Hang[1];Zhang, Shengtai[2];Zhong, Dingyong[2];Song, Xingfu[1,2]

机构：[1]East China Univ Sci & Technol, Natl Engn Res Ctr Integrated Utilizat Salt Lake Re, Joint Int Lab Potassium & Lithium Strateg Resource, Shanghai 200237, Peoples R China;[2]Qinghai Salt Lake Ind Co Ltd, Golmud 816000, Peoples R China

年份：2024

卷号：576

外文期刊名：FLUID PHASE EQUILIBRIA

收录：;EI(收录号：20234014839711);WOS:【SCI-EXPANDED(收录号:WOS:001092007800001)】；

基金：Acknowledgements The work was supported by the Special Project of Qinghai Province on Enterprise Research Transformation and Industrialization (2022-GX-C14) and Kunlun Talent Program of Qinghai Province for High-end Innovative Talents.

语种：英文

外文关键词：Model prediction; Density functional theory; Pitzer model; Phase diagram; KCl-MgCl2-H2O system

摘要：The stable phase equilibrium of the ternary system K+, Mg2+//Cl--H2O at 293.15, 298.15, 303.15, and 308.15 K were determined by isothermal dissolution equilibrium method. A kind of incongruent double salt, KClMgCl26H(2)O, is found in this ternary system. Therefore, phase diagrams at each temperature all consist of two invariant points, three univariant curves and three crystallization regions for KClMgCl26H(2)O, MgCl26H(2)O, and KCl, respectively. Strong salting out effect of MgCl2 on KCl leads to the order of crystallization areas, KCl > KClMgCl26H(2)O > MgCl26H(2)O. Meanwhile, with temperature decreasing, crystallization region of KCl becomes larger. Thus, the high MgCl2 concentration and low temperature are beneficial to KCl preparation from carnallite ores. Furthermore, an approach combing density functional theory (DFT) and Pitzer model was proposed, which can predict solubility data in complex systems containing incongruent double salts. The calculated solubilities have a good agreement with experimental values. All the results involved in this paper provide basic thermodynamic data and theoretical guidance to fully utilize potassium resource stored in carnallite ores.