Abstract
This paper presents results derived from carbothermic reduction of tellurium from a tellurium-containing condensate obtained during the oxidative-distillation roasting of a tellurium-containing middling. It is shown that the tellurium-containing condensate contains TeO2 and Te2O3(SO4) phases. A regression model and a generalized equation were constructed using mathematical planning methods. This model and equation describe the dependence of tellurium recovery from the tellurium-containing condensate on the main process parameters. The developed models demonstrated a high degree of adequacy and made it possible to calculate the optimal parameters for the carbothermic reduction of tellurium. Experimental verification confirmed the possibility of obtaining elemental tellurium with a purity of 99.5%. The obtained data indicate the feasibility of producing crude tellurium by means of a two-stage pyrometallurgical process performed at low pressure. Organization of the process via the use of sealed equipment for the capture of tellurium-containing compounds through condensation significantly reduces the environmental risks associated with the toxicity of tellurium and its compounds.