Evaporation Trends for Elemental Tellurium Recovery in a Te–Cu₂S System Produced from a Sustainable Sulfidation-Vacuum Distillation Process

Sulfidation-vacuum distillation is a sustainable approach for extracting elemental tellurium from industrial copper telluride slag, but the volatilization law of tellurium in the Te–Cu₂S system is unclear, which hinders the development of tellurium recovery methods. In this paper, vacuum differential gravimetric mathematical statistical analysis was conducted to determine the evaporation rate of tellurium in the Te–Cu₂S system under the conditions of 773 K to 923 K and 10–10,000 Pa. The experimental results showed that the relationship model between the evaporation rate and the pressure was ω = A₂ + (A₁ − A₂)/(1 + (P/P₀)^m) at a constant distillation temperature. The evaporation rate satisfied the linear Eq. lg ω = A + B/T at the 95 pct confidence level under a constant system pressure. The experiments verified that the accuracy of the model was about 95 pct. The qualitative and quantitative relationship between the evaporation rate, time, and evaporation of tellurium in the Te–Cu₂S system was discussed through experimental research and data analysis. The evaporation dynamics were summarized and used to predict the vacuum separation process in the Te–Cu₂S system. This research is oriented by practical problems and aims to quantitatively determine the conceptual relationship among time, so as to provide practical reference for the production process and save time and cost.