Pyrolysis of copper telluride in a water vapour atmosphere

This paper presents the results of exploratory studies on the feasibility of extracting tellurium from synthetic copper telluride and industrial tellurium–containing middlings using a vacuum-thermal method conducted in a water vapour atmosphere. It was determined that the thermal behavior of synthetic copper telluride follows an oxidation mechanism involving oxygen in a dry environment. The phase transformations occurring in the tellurium–containing industrial middlings are also comparable to those observed during oxidative-distillation roasting and vacuum-thermal processing in an inert atmosphere. The achieved degrees of extraction of copper telluride and tellurium-containing industrial middlings at a temperature of 1100 °C and a pressure of 1.3-2 kPa were 57.83 % and 94.89 %, respectively. The obtained residues are represented by copper oxide phases. At the same time, tellurium evaporates from the material and deposits on the walls of the condenser in the cold part of the reactor at temperatures below 400 °C. According to X-ray phase analysis, the condensate is represented by tellurium in the form of oxide.