2026 Yepsen Sunlight assisted chalcopyrite leaching

This research investigates the fundamental impact of the photochemical effect of sunlight on the oxidative dissolution of chalcopyrite (CuFeS2) in sulfate-oxidizing media under mild conditions and circumneutral pH. Beyond its traditional role as a thermal or electrical energy source, this study explores solar light (UV-Vis-NIR) as a photochemical reagent capable of driving the in situ generation of reactive sulfur species to assist the conventional oxidative dissolution pathway. The interaction at the mineral–solution interface under UV-Vis radiation was investigated using a laboratory-scale solar-assisted PS/TiO2/UV-Vis-NIR system, employing persulfate (S2O82−) as a radical precursor and TiO2 (Aeroxide® TiO2 P25) as a photocatalyst. The findings demonstrate that solar exposure increases the system’s electrochemical potential and induces pH changes, which are critical for overcoming the inherent refractoriness of CuFeS2 at near-neutral pH. This study demonstrates that integrating UV-Vis-NIR radiation serves as a synergistic catalyst in oxidative hydrometallurgical processes, enhancing Cu extraction yields to 14%–19% within 5 h of exposure at the laboratory scale. The use of natural light could offer a synergistic pathway to augment the efficiency of cleaner leaching technologies. These findings suggest that solar radiation could serve as a promising assistant to address kinetic limitations during the oxidative dissolution of complex sulfide ores under ambient conditions.