分子相互作用体积模型在真空蒸馏分离Pb-Sb、Pb-Ag和Sb-Cu合金中的应用

Application of molecular interaction volume model in separation of Pb-Sb,Pb-Ag and Sb-Cu alloys by vacuum distillation

基于分子相互作用体积模型(MIVM),使用牛顿迭代方法结合无限稀活度系数实验数据γ∞计算对势能相互作用参数Bij和Bji;然后使用参数Bij和Bji计算Pb-Sb、Pb-Ag及Sb-Cu二元合金体系的活度α和活度系数γ,并与实验值进行比较分析;最后计算Pb-Sb、Pb-Ag及Sb-Cu二元合金体系的气液相平衡组成。气液相平衡组成计算结果表明:活度计算值和实验值吻合较好;Pb-Ag和Sb-Cu体系中的组元均能通过真空蒸馏实现良好分离,而Pb-Sb体系中的组元不能通过一次真空蒸馏实现完全分离。分子相互作用体积模型用于预测二元合金体系的活度及真空蒸馏分离效果具有很高的可靠性,为真空蒸馏分离二元合金提供良好的理论依据。

Based on the molecular interaction volume model （MIVM）, the pair-potential energy interaction parameters BU and Bji were calculated by using the Newton-Raphson methodology with the aid of experimental data of infinite dilution activity coefficient yoo. Then, the activities and activity coefficients of the components of Pb-Sb, Pb-Ag and Sb-Cu alloys can be obtained from B~ and Bji, a comparison between the calculated and experimentally determined values of activities was also executed. Finally, the vapor-liquid phase equilibrium compositions of components of Pb-Sb, Pb-Ag and Sb-Cu alloys were calculated. The results show that the agreement between the calculated and experimentally determined values of activities is excellent. The vapor-liquid phase equilibrium composition indicates that the components of Pb-Ag and Sb-Cu alloys can be separated from each other thoroughly by vacuum distillation, the components of Pb-Sb alloy cannot be separated by vacuum distillation one time. The above analysis results indicate that the validity and reliability of the MIVM in the activities calculation of the components of these alloys and the prediction of the separating effect in vacuum distillation are good. This research provides a good theoretical principle for the separation of binary alloys by vacuum distillation.