Application of molecular interaction volume model in vacuum distillation of Pb-based alloys

A method is presented for calculating the separation coefficients of Pb–Au and Pb–Sn alloys in vacuum distillation based on molecular interaction volume model (MIVM). A significant advantage of the model lies in its ability to predict the thermodynamic properties of liquid alloys using only binary infinite activity coefficients. The calculated results of Pb–Ag, Pb–Au, Pb–Sb, Pb–Sn and Sb–Sn show good agreement with experimental data in literature. It shows that the prediction effect of the proposed method is of better stability and reliability because the MIVM has a good physical basis.

► We calculated activities of components of Pb-based alloys by the molecular interaction volume model.
► We predicted the separation coefficients of Pb–Au and Pb–Sn alloys in vacuum distillation.
► It can be used to evaluate the possibility and extent of distilling separation of a crude metal and an alloy before experiment.