A New Method for Calculation of Vapor-Liquid Equilibrium (VLE) of Au-Cu Alloy System

The activities of components of Au-Cu alloy were calculated using the simplified molecular interaction volume model (SMIVM). The calculated average relative deviation Si and average standard deviation S-i* are smaller than +/- 0.5528% and +/- 0.0100, respectively, which indicates that the calculation of the activities of Au-Cu alloy by SMIVM is reliable. The VLE data of Au-Cu alloy were calculated based on theVLEtheory and the SMIVM. TheVLEphase diagrams (i.e., T - x(y) and p - x(y)) of Au-Cu alloywere also established in thiswork. TheVLEphase diagrams offer an intuitive and simple way to analyze the product compositions' dependence of temperature and system pressure in vacuum distillation, which also provide an effective way of determining the optimum technique parameters. This has important guiding significance for efficient separation of alloys by vacuum distillation.