Abstract

In Chile, a large amount of tailings is generated by copper extraction operations. The final disposal has a negative environmental consequence as chemical and physical instability in underground layers. Recent studies have postulated that the reuse of these wastes could be employed as raw materials to elaborate products to different applications as thermal and acoustic insulation, filtration and catalysis. In this research, a physical, chemical and mineralogical characterization were performed at two tailings deposits, in order to evaluate the technical feasibility of develop ceramic materials to be used in thermal insulation. Tailings samples were supplied by Chancon and Chepica mines. Physical analysis included granulometric analysis through laser diffraction, determination of humidity and density. The chemical composition was determined by X-ray fluorescence (XRF), mineralogy was identified by X-ray diffraction (XRD) and using the automated mineralogy technique. The results of the physical characterization indicated that Chepica mine tailings had a humidity of 21.4%, a p80 of 279 microns and a density of 2,85 g/cm3. In addition, Chancon tailings had a 13.3% humidity, a p80 of 98.3 microns, and a density of 2,65 g/cm3. The most abundant chemical elements were the silicon with 27.1% in Chepica and 36.9% in Chancon and the main differences were presented within iron and sulfur, reaching 16.3% and 17.5% in Chepica respectively, while in Chancon concentrations of 4.5% and 0.88% were found. This result is complemented by the mineralogical characterization where it is observed that pyrite concentration reaches 34.5% in Chepica and only 1.54% in Chancon. According to the results obtained in this study, it is concluded that presence of silicates in the tailings could contribute to serve as raw material for applications as ceramic thermal insulation products; meanwhile, the presence of pyrite and other sulfur need to be removed in order to achieve these types of application.