Mine tailings, fine-grained residues from ore beneficiation, contain substantial unrecovered metals such as lead(Pb) and zinc(Zn). These metals are vital for industry, and Pb is listed among Korea’s ten strategic critical minerals. This study aimed to maximize the leaching of Pb and Zn and developed a fuel cell-based leaching system to simultaneously recover metals and generate electricity using Pb-Zn mine tailings as the anode active material. The single-chamber fuel cell, composed mainly of quartz, pyrite, dolomite, and chlorite-serpentine, served as both an electron source and a leaching substrate. The physical separation of anodic oxidation and cathodic oxygen reduction enabled sustained oxidation of tailings in the anode, suppressing surface passivation and promoting electron transfer. The system achieved a maximum power density of 5.4 mW/m² at 43.8 mA/m² and 0.11 V. Under a 300 Ω external load, the closed-circuit voltage remained at about 8.5 mV for ten days. During operation, 37.3 mg-Pb/kg and 84.2 mg-Zn/kg were leached, corresponding to efficiencies of 1.4% and 0.6%, equivalent to annual leaching rates of approximately 50%/yr and 20%/yr, respectively. These results indicate that galvanic interactions between pyrite and base-metal sulfides, combined with the lower rest potential of PbS, enhanced Pb dissolution. When scaled up to a 1 m² module (20 × 20 unit cells), the system produced 6.0 mW (2 V), and application to a 20,900 m² tailings dam was estimated to yield 125 W total output. The proposed self-sustaining system enables continuous electricity generation and metal recovery through sulfide oxidation, providing a sustainable approach to mitigate environmental risks and promote resource circularity in mine waste management.

Keywords: Fuel cell, Metal recovery, Electricity generation, Sulfidic mine tailings, Galvanic leaching