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.