Scaling Bioleaching from Lab to Industry: A Life Cycle Assessment of Cathode Copper Production

The copper industry is under growing pressure to reduce its environmental footprint and address declining ore grades, as global demand rises in parallel with the energy transition. In response, bioleaching has emerged as a promising low-carbon alternative for extracting copper from low-grade sulfide ores. This study presents the first cradle-to-gate life cycle assessment (LCA) of cathode copper production via bioleaching using laboratory-scale data scaled to an industrial context. Results show that bioleaching achieves lower greenhouse gas (GHG) emissions (6.94 kg CO2-eq/kg copper) compared to conventional pyrometallurgy (8.45 kg CO2-eq/kg), with a notable reduction in acidification (85%). Hotspot analysis identifies electricity, steel ball production, diesel consumption, and waste treatment as key contributors to environmental burdens. Moreover, sensitivity analysis reveals that inadequate recovery of AgNO3 (50% recycling rate) could significantly elevate ozone depletion (213%), smog (191%), and fossil fuel depletion (187%). Scenario analysis indicates that integrating solar electricity could reduce GHG emissions by up to 52%. Future improvements in flotation reagent formulation, low-carbon steel production, and advanced waste treatment are recommended to further optimize the environmental performance of bioleaching.