中文摘要：

基于Pitzer模型,提出了计算含盐有机溶液体系固液相平衡的Pitzer扩展模型,把扩展模型中的模型参数表达为Pitzer模型参数和有机溶剂摩尔组成xm的函数。文中利用吉布斯自由能差获得盐在混合溶剂中的溶度积常数,并结合扩展模型计算盐在混合溶剂中的溶解度。以NaCl,KCl,NaBr,NaI 4种盐在甲醇-水混合溶剂体系中的溶解度为例,关联得到了各体系的新模型参数。结果表明：计算结果和文献数据吻合良好,最大绝对误差为0.209mol/kg,验证了该模型的可行性,成功扩展了Pitzer模型的适用范围。因此,Pitzer扩展模型是一种可用于含盐有机溶液体系固液相平衡计算的方法。

英文摘要：

Based on Pitzer model,the extended Pitzer model was applied to study solid-liquid equilibrium in mixedsolvent electrolyte system. The model parameters were represented as a function of Pitzer model parameters and organic solvent composition xm. The solubility product constant was calculated by Gibbs energy difference,and the salt solubility in mixed-solvent electrolyte system was obtained by the extended model. The solubility of four salts NaCl,KCl,NaBr and NaI in methanol-water mixture was calculated,and the corresponding parameters were also correlated. The results show that the extended model can accurately calculate the salt solubility in mixed-solvent electrolyte system,and the maximum absolute deviation is 0. 209 mol / kg. Moreover,the feasibility of the model is confirmed and the extent of Pitzer model is expanded. Therefore the extended model can be widely applied to calculate solid-liquid equilibrium in mixed-solvent electrolyte system.