UBC Theses and Dissertations
Combustion of particles of copper concentrate in a stagnant gas furnace Thomas, Anabel
Two copper concentrates, "La Escondida" and "La Caridad", were oxidized in a stagnant gasflow reactor to examine and compare their combustion behavior. "La Escondida" concentrate is a high grade copper (49 % Cu) concentrate based on chalcocite (CU2S) and pyrite (FeS2), while "La Caridad" contains pyrite (FeS2), chalcopyrite (CuFeS2), chalcocite (CU2S) and covellite (CuS) with 29.5 % Cu. The effects of oxygen partial pressure, temperature, and particle size on the reaction behaviour of each concentrate were studied. The reaction products were analyzed for copper, iron, and sulfur to determine the fraction of original sulfur remaining as a measure of the extent of reaction and the Cu/Fe ratio as a measure of copper volatilization. X-Ray Diffraction was employed to identify the phases present and Scanning Electron Microscopy (SEM-EDX) and Optical Microscopy were used to determine the particle morphology and chemical analysis of the individual particles. The results show that although La Escondida does not contain chalcopyrite, in the individual particles both pyrite and chalcocite are present and form chalcopyrite before ignition, leading to oxidation behaviour similar to that of La Caridad concentrate. The extent of reaction was found to increase with increasing oxygen concentration, temperature and particle size.
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