锂盐水溶液的热力学性质研究

Study on thermodynamic propertiesof aqueous lithium salts

用Ｍｅｉｓｎｅｒ公式、Ｂｒｏｍｌｅｙ公式、Ｃｈｅｎ公式、Ｐｉｔｚｅｒ公式及经作者改进的平均球近似（ＭＳＡ）方法对锂盐水溶液（最大质量摩尔浓度达２０ｍｏｌ／ｋｇ）的离子平均活度系数进行了计算和比较，结果表明改进后的ＭＳＡ方法的计算精度最高。另外，还应用改进的ＭＳＡ法，使用由单一电解质水溶液离子平均活度系数数据得到的参数，在不用任何混合参数的情况下，预测了２９８．１５Ｋ时ＬｉＣｌ＋Ｌｉ２ＳＯ４和ＬｉＣｌ＋ＫＣｌ水溶液的等温溶解度图，其结果与文献实验值基本一致。

The mean ionic activity coefficients of aqueous lithium salts, the concentrations of which were up to 20mol/kg, were calculated by the Meissner equation, Bromley equation, Chen equation, Pitzer equation and the mean spherical approximation (MSA) method modified by the authors. The results show that among the above equations the accuracy of the modified MSA is the highest. Meanwhile, using the parameters obtained from the activity coefficients of single electrolyte solutions, the isothermal solubility diagrams of aqueous LiCl+Li2SO4 and LiCl+KCl were predicted by the modified MSA. The calculated results are coincident with the experimental data.