title: Speciation and leachability of copper in mine tailings from porphyry copper mining: influence of particle size.
abstract: Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150 mg kg (-1) dry matter. This tailing was segmented into fractions of different size intervals: 0-38, 38-45, 45-53, 53-75, 75-106, 106-150, 150-212, and >212 microm, respectively. Copper content determination, sequential chemical extraction, and desorption experiments were carried out for each size interval in order to evaluate the speciation of copper. It was found that the particles of smallest size contained 50-60% weak acid leachable copper, whereas only 32% of the copper found in largest particles could be leached in weak acid. Copper oxides and carbonates were the dominating species in the smaller particles, and the larger particles contained considerable amounts of sulphides.
authors.affiliation: Departamento de Procesos Químicos, Biotecnológicos y Ambientales, Universidad Técnica Federico Santa Maria, Avenida España 1680, Valparaíso, Chile. henrik.hansen@usm.cl
authors.forename: Henrik K
authors.initials: HK
authors.lastname: Hansen
authors.forename: Juan B
authors.initials: JB
authors.lastname: Yianatos
authors.forename: Lisbeth M
authors.initials: LM
authors.lastname: Ottosen
mesh_terms: D000327:Adsorption; D005591:Chemical Fractionation; D019343:Citric Acid / Q000737:chemistry; D003300:Copper / Q000032:analysis / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008906:Mining; D017942:Nitric Acid / Q000737:chemistry; D010316:Particle Size; D013440:Sulfides; D013464:Sulfuric Acids / Q000737:chemistry; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D007220:Industrial Waste; D013440:Sulfides; D013464:Sulfuric Acids; D014874:Water Pollutants, Chemical; D019343:Citric Acid; C099343:cuprous sulfide; D017942:Nitric Acid; D003300:Copper; C033158:sulfuric acid; D006851:Hydrochloric Acid