Numerical Analysis and Experimental Validation of Distillation Process for Purification of Tellurium

Abstract

Numerical analysis was performed on a vacuum distillation process for Te purification. The effects of temperature gradient and Ar gas flow rate and vacuum level on the evaporation behavior of Te were investigated through a series of simulations with a diffusion-coupled convection model. An overall yield of up to 95% of 4N pure Te was achieved at an average distillation rate of approximate to 5.6 x 10(-4) g center dot cm(-2) (center dot) s(-1) from 2N pure indigenous Te. The diffusion and condensation factors of impurities were investigated under different distillation conditions such as vacuum degree, temperature and argon flow rate. It was found that the numerical model could be used to predict impurity level during vacuum distillation process of Te and designing and optimization of a larger-scale distillation process also could be possible with a sufficient reliability.