# Structure and Phase Composition of the Products Derived from Vacuum–Thermal Treatment of a Tellurium-Containing Middling

## TL;DR

This study explores the products formed when copper telluride is processed under vacuum and high temperature, aiming to develop eco-friendly methods for tellurium recovery.

## Contribution

The paper presents novel phase composition data from vacuum-thermal treatment of copper telluride middling, supporting eco-friendly processing methods.

## Key findings

- The residue after processing mainly contained copper(I) oxide.
- The condensate included phases like CuTe2O5, CuO·CuTeO3, TeO2, SiO2, and CuTe2Cl.
- Tellurium oxide monophase was identified in the condensate at 150 to 270 °C.

## Abstract

In this paper, the results from a study of the products obtained by vacuum–thermal processing of industrial copper telluride in an inert atmosphere at a pressure of 66 Pa and a temperature of 1100 °C are presented. The residue obtained mainly consisted of the copper(I) oxide phase. The condensate was represented by the phases CuTe2O5, CuO·CuTeO3, TeO2, SiO2, and CuTe2Cl. The vapor phase condensed in four temperature zones, each represented by a different phase composition. A monophase of tellurium oxide was identified in the condensate at temperatures of 150 to 270 °C. The obtained data contribute to expanding scientific knowledge and form the basis for developing a new, environmentally safe method of processing tellurium-containing middling. The creation of new technologies promotes increased efficiency of tellurium recovery and reduces environmental risks.