Measurements and Calculations of Solid-liquid Equilibria in Quaternary System Li2SO4-Na2SO4-K2SO4-H2O at 288 K

• Published in: Chemical research in Chinese universities 2017-06, Vol.33 (3), p.460-465
• Main Authors: Cui, Ruizhi, Yang, Lei, Wang, Wei, Sang, Shihua
• Format: Article
• Language: English
• Subjects: Alloys; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Crystallization; Inorganic Chemistry; K2SO4; Mechanical properties; Na2SO4; Organic Chemistry; Physical Chemistry; Potassium sulfate; Solubility; 固-液平衡; 实验测量; 溶解度数据; 第四系; 等温溶解平衡法; 计算结果
• ISSN: 1005-9040; 2210-3171
• DOI: 10.1007/s40242-017-6275-y

The isothermal dissolution equilibrium method has been used to investigate the solid and liquid equilibria of quatemary system Li2SO4-Na2SO4-K2SO4-H2O at 288 K. The phase diagram and water diagram were plotted according to the experiment results. It was found that LizSO4-Na2SO4-K2SO4-H2O quaternary system contains four double salts at 288 K. There are six invariant points, twelve univariant curves and seven areas of crystallization： Li2SO4·H2O, Na2SO4·10H2O, K2SO4,LiESO4·3Na2SO4-12H2O, Li2SO4K2SO4, Na2SO4·3K2SO4, 2Li2SO4·Na2SO4- K2SO4. Using the equilibrium solubility data of the quaternary system at 288 K, the solubility product（lnKsp） of solid phase 2LiESO4-Na2SO4.KESO4, which is not reported was acquired. Based on the chemical model of Pitzer＇s electrolyte solution theory, the solubilities for the quaternary system Li2SO4-Na2SO4-K2SO4-H2O at 288 K were calculated with corresponding parameters. Compared the results of experimental measurement with those of calculation, it was shown that the calculated values had a good agreement with the experimental ones.