Year: 2025
Type: article
Abstract: This study presents the results of oxidative leaching of chalcopyrite (CuFeS2) and pyrite (FeS2) in a sulfuric acid medium at low temperature in the presence of copper (Cu2+) and iron (Fe3+) ions. Using orthogonal experimental design, the optimal conditions were identified to maximize sulfide matrix decomposition and valuable metal recovery. Experiments were conducted at a constant temperature of 100 °C. The parameters investigated included partial oxygen pressure (0.2–0.75 MPa), concentrations of sulfuric acid (10–50 g/dm3), Fe3+ ions (2–10 g/dm3), Cu2+ ions (1–3 g/dm3), and leaching time (60–240 min). The composition of the feed minerals and leach products was analyzed by X-ray fluorescence (XRF) analysis, X-ray diffraction (XRD) analysis, and atomic absorption spectrometry (AAS). Maximum copper recovery from chalcopyrite (55 %) was achieved under the following conditions: O2 partial pressure of 0.25 MPa, initial concentrations of H2SO4 – 50 g/dm3, Cu2+ – 1 g/dm3, Fe3+ – 2.5 g/dm3, and leaching time – 240 min. The maximum degree of pyrite oxidation (56 %) was obtained at an O2 partial pressure of 0.75 MPa, initial concentrations of H2SO4 – 50 g/dm3, Cu2+ – 2 g/dm3, and Fe3+ – 10 g/dm3. The results showed that leaching time and oxygen pressure have the greatest effect on chalcopyrite and pyrite decomposition (p < 0.05). The interaction between Fe3+ and Cu2+ ions was also established: excess Fe3+ (>10 g/dm3) leads to hydrolysis and decreases chalcopyrite leaching efficiency, whereas Cu2+ promotes partial formation of secondary copper sulfides. Regression equations (R2 = 0.98 for chalcopyrite and R2 = 0.96 for pyrite) were derived, providing an adequate description of the process.
Source: Izvestiya Non-Ferrous Metallurgy
Institution: Ural Federal University
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Funder: Russian Science Foundation
OpenAlex ID: W4414987016