In this work, the activities and activity coefficients of binary precious metal alloys (Ag-Pb, Ag-Sb, Ag-Bi, Au-Pb, Pd-Pb, Pt-Pb and Cu-Pb) were predicted using molecular interaction volume model (MIVM), modified MIVM (M-MIVM), Wilson equation and nonrandom two-liquid (NRTL) model. The average standard deviation and average relative deviations of these models were also calculated. The results show that the prediction deviations of the M-MIVM were smallest among the four thermodynamic models, indicating that the M-MIVM is reliable. On this premise, the separation coefficient and vapor-liquid equilibrium (VLE) data of Ag-Pb, Au-Pb, Pd-Pb and Pt-Pb were calculated based on the M-MIVM. The results show that the separation coefficients were much larger than one, indicating that these alloys can be easily separated by vacuum distillation. There is good agreement between the predicted and experiment VLE data, indicating that M-MIVM is reliable for the VLE calculation in vacuum distillation. The VLE phase diagrams procured in this work can afford theoretical guidance for experimental design and industrial production in vacuum distillation.

在这项工作中，使用分子相互作用体积模型预测二元贵金属合金（Ag-Pb、Ag-Sb、Ag-Bi、Au-Pb、Pd-Pb、Pt-Pb 和 Cu-Pb）的活度和活度系数(MIVM)、修正 MIVM (M-MIVM)、Wilson 方程和非随机两液体 (NRTL) 模型。还计算了这些模型的平均标准偏差和平均相对偏差。结果表明，在四种热力学模型中，M-MIVM的预测偏差最小，表明M-MIVM是可靠的。在此前提下，基于M-MIVM计算了Ag-Pb、Au-Pb、Pd-Pb和Pt-Pb的分离系数和汽液平衡（VLE）数据。结果表明，分离系数远大于1，表明这些合金可以很容易地通过真空蒸馏进行分离。预测和实验 VLE 数据之间有很好的一致性，表明 M-MIVM 对真空蒸馏中的 VLE 计算是可靠的。在这项工作中获得的 VLE 相图可以为真空蒸馏的实验设计和工业生产提供理论指导。