Carbothermic Reduction of Metals in the FeS–Cu1.96S–CaO System

Abstract

The conditions for the direct carbothermic reduction of metals from mixtures of sulfides Cu_1.96S and FeS with calcium oxide are studied using thermogravimetric and thermal analyses combined with mass spectrometry of the formed gases. The metal reduction in a mixture of FeS and CaO on heating to 1250°C is shown to occur with the formation of intermediate oxysulfide phases almost without the evolution of sulfur-containing gases. The formation of SO₂ is observed in a mixture of Cu_1.96S and CaO at temperatures higher than 550°C. The introduction of FeS into the reaction mixture of Cu_1.96S and CaO enhances the completeness of metal reduction by carbon, decreases the temperatures of the intense processes, and suppresses sulfur dioxide evolution.