(General session) Environment / Mineral processing

[2501-08-04] Leachability studies of complex copper oxide ores in Mantoverde mine, Chile

○Diego Mendoza Flores¹, Ikumi Suyama¹, Hajime Kijitani¹, Koichiro Takatsugi¹ (1. Mitsubishi Materials Corporation)

司会：晴山　渉（岩手大学）

Keywords:Black copper ore, Leaching, Mineral Liberation Analysis, Sequential extraction

The Mantoverde mine has been processing copper oxide ores via heap leaching, solvent extraction, and electrowinning (L-SX-EW) since 1995. Based on the current estimations, oxide beneficiation is planned to continue for at least another decade. Mantoverde’s orebody mainly contains common supergene oxides, but some areas report the presence of unusual Cu-mineralization, including the so-called black copper oxides. These mineraloids are colloquially classified as copper pitch/copper wad and described as earthy materials typically with a dark brown to black appearance. Several studies have reported that their composition varies among deposits, so understanding their leachability is crucial for evaluating any impact on their recovery in the heap. Among the characterization techniques, Mineral Liberation Analysis (MLA) and seven-step sequential extraction were used to classify the Cu-bearing minerals and identify their acid-soluble sensitivity. Preliminary results on the composition of the black copper phases suggest Cu is strongly associated with Mn-Co and Fe. Meanwhile, other Cu occurrences appear to be linked to silicate minerals. Further leaching tests are discussed in addition to the necessary operational considerations for their introduction into the processing plant.