In order to investigate the reaction behavior of associated thallium sulfide in zinc concentrate during fluidized roasting, thermodynamic calculation and verification experiments were conducted for the oxidation process of thallium sulfide. Firstly, the volatilization of thallium chloride, thallium oxide, metallic thallium and thallium sulfide were analyzed based on data retrieval and calculation, and the volatilization of those four matters was determined in the following descending order: Tl₂O>TlCl>Tl₂S>Tl. Then, the equilibrium analysis and the calculation of Gibbs free energy change of the Tl₂S-O₂ system were conducted. It is shown that Tl₂S volatilizes violently in an inert atmosphere as temperature rises, and decomposes into Tl and sulfur vapor after temperature is above 1 000 ℃. However, in an oxidizing atmosphere, Tl₂S begins to generate a large quantities of Tl₂SO₄ after the temperature reaches 100 ℃, and a few of Tl₂S begins to decompose into SO₂ and Tl₂O after temperature is above 1 000 ℃. No interaction occurs between Tl₂S and ZnO. In the practical roasting process, Tl₂S is completely converted into Tl₂SO₄ and remains stable in the calcine at the temperature above 800 ℃, which can be intensively removed in the subsequent open-circuit of leaching and purification process.

thallium  /  oxidation  /  equilibriumsimulation  /  phaseanalysis  /  thalliumsulfide  /  thalliumoxide  /  thermodynamic calculation  /  zinc smelting  /  fluidized roasting