Novel valence regulation-vacuum gasification method for separation of selenium and tellurium

Abstract

It is a general challenge to separate similar elements in material and non-ferrous metallurgical industries. Due to their unique semiconductor properties, selenium and tellurium as well as their separation have been increasingly drawing the attention of worldwide research. Currently, they are mainly extracted and recycled from copper anode slime. The conventional methods used for separating selenium and tellurium have several drawbacks, including low separation efficiency, lengthy processes, and significant environmental pollution. To address these issues, in this paper, the gas-liquid equilibrium (VLE) phase diagram of selenium-base binary alloy at full concentration was drawn according to the theory of gas-liquid equilibrium, the limitation of single vacuum distillation separation technique is theoretically interpreted, and a novel valence regulation-vacuum gasification method is proposed, which shows a superior selenium/tellurium separation rate of 99.98 % and a high material volatilization rate around 90 % achieved with hydrogen peroxide addition. The optimal amount of hydrogen peroxide for the separation process is determined as 1.1 L/kg. The promising results suggest potential of the new method for effectively separating other similar elements.