Electrochemical investigation of microbially and galvanically leached chalcopyrite

• Published in: Hydrometallurgy Vol. 202; p. 105603
• Main Authors: Tanne, C., Schippers, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-06-2021
• Subjects: Bioleaching; Chalcopyrite; Electrochemistry; Galvanic corrosion; Pyrite; Galvanic corrosion; Electrochemistry; Bioleaching; Chalcopyrite; Pyrite
• ISSN: 0304-386X; 1879-1158
• DOI: 10.1016/j.hydromet.2021.105603

The effect of the galvanic interaction between anodic chalcopyrite and cathodic pyrite was investigated by long-term electrochemical measurements of the galvanic coupling current and verified by chemical leaching and bioleaching. For the first time galvanic corrosion measurements (in the absence and in the presence of microorganisms) over days are reported. Combined microbial and galvanic leaching of chalcopyrite showed increased Cu recovery in the presence of pyrite. Corrosion resulted in mineral dissolution depending on multiple parameters (like metal corrosion). However, maximal chalcopyrite dissolution via bioleaching occurred in the presence of a large cathodic pyrite surface. Highest copper recovery was observed in case of high rest potential differences between galvanically coupled minerals (pyrite coupled with copper concentrate). A comparison of electrochemical data of this study with scientific literature revealed a wide range of rest potential data for a single metal sulfide. Fundamental research on galvanic interaction of mixed mineral systems need to focus on unified experimental parameters to allow a comparison.
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•The galvanic interaction between anodic chalcopyrite and cathodic pyrite was investigated.•Galvanic corrosion studies were conducted for long-term electrochemical measurements.•Galvanic corrosion measurements were performed in the absence and presence of leaching microorganisms.•Corrosion potential and corrosion currents of leaching residues were recorded.•Combined microbial and galvanic leaching showed maximal Cu recovery.