Rates of evaporation of Bismuth and Selenium from Bi-Se alloy under vacuum condition

Abstract

Vacuum distillation has obvious advantages, including a short flow, short production cycle, high direct metal, and low cost. The evaporation rates of bismuth and selenium from Bi-Se alloy were investigated at 953, 963, 973, 983, 993 K, and 1 Pa. The element's evaporation rate is required for selecting the best experimental conditions in vacuum distillation. SEM and EDS were used to describe and analyze the residue and volatile. The activity coefficients of components for the Bi-Se system were determined using the Non-random two liquid (NRTL) equation and agree with the literature. The activities of components bismuth and selenium for the Bi-Se system are proportional to their evaporation rates during vacuum distillation. The influence of compound Bi2Se3 formation on the evaporation rate of elements in Bi-Se alloy at 973 K was discussed in detail. The activation energies of pure bismuth and Bi in Bi-Se alloy were also presented.