Experimental investigation and modeling of the Cu–Sn system in vacuum distillation

Abstract Vapor-liquid equilibria (VLE) of the Cu–Sn system have been investigated in the temperature range from 1612 to 1650 K and at pressure of 5 Pa. The VLE data of Cu–Sn alloy was calculated by using Wilson equation and compared with experimental values under vacuum condition. The thermodynamic consistency of the experimental data was checked by Van Ness method. The azeotropic and non-azeotropic regions are plotted by correlating the Wilson equation, vapor pressure equation and the enthalpies of vaporization. The calculated results reveal that the Cu–Sn system is located in azeotropic region which the specific composition and temperature of azeotropic point are x C u = 0.71 and T = 1649 K . The agreements between calculated and measured results are good. This work provides an effectively method for predicting whether binary system will form an azeotrope or not and the azeoropic position in vacuum distillation. It can also be used to test the quality of a vapor-liquid equilibrium model and to guide experiments.