Studies to determine the optimal parameters of direct vacuum distillation of selenium from selenium-containing dusts

Abstract

The urgency of the problem is due to the fact that the development of electronic technology in the world is growing demand for high purity selenium. This work is aimed at solving the applied technical problem solved by specialists in the field of processing of selenium-containing industrial product of metallurgical production by vacuum distillation, the introduction of which will solve the problem of waste generation and accumulation, increase the extraction of precious metals, and reduce the negative impact on the environment. The chemical, phase compositions and structure of the investigated selenium-containing industrial product –dusts
of Balkhash Copper Smelting Plant of the metallurgical complex of «Kazakhmys Smelting» LLP are studied. It was found that the dust is an extremely heterogeneous material, the average content of selenium in them is more than 30 %, in addition they contain significant amounts of precious metals, gold — more than 100 g/t, silver — more than 2 %, tellurium — more than 2 %. The studies of the dependence of the degree of direct vacuum distillation of selenium from selenium-containing dusts on temperature, on the duration of the process, on the pressure in the system. The optimal parameters of direct vacuum sublimation of selenium from the dusts of bag filters of refining production at which the maximum degree of distillation of selenium is achieved is the temperature of 400–450 ºC, the duration of the process is 20–30 minutes and the pressure in the system is 0.13÷0.65 kPa.