Oxidation Process of Cadmium Sulfide

Abstract

Complicated thermogravimetric curve was observed on oxidation process of cadmium sulfide precipitate in air. Phases of various oxidation stage were identified by X-ray diffraction method. Cadmium sulfide was first oxidized to cadmium oxide at 400°C, while the successive reaction with sulfur dioxide and oxygen gases gave rise to cadmium sulfate. The phases such as 2CdS, CdSO₄, Cd₃SO₆ and β-CdSO₄ appeared during the oxidation process up to 1100°C, at which all the particles were converted into cadmium oxide at 1100°C. Cadmium sulfide kept in nitrogen gas above 700°C was directly converted into cadmium oxide when oxygen as was introduced into the furnace.