Galvanic Biomining: A Low-Carbon Hydrometallurgical Process for Efficient Resource Recovery and Power Generation

Abstract

Biomining/bioleaching has been widely considered as an alternative to traditional technologies in processing ores and solid wastes mainly due to its environmental and economic advantages, but the low leaching rate and adverse microorganism–environment interactions cause the severe restriction of industrial application. Here, we first report galvanic biomining that achieves both efficient resource recovery and power generation based on the Fe2+/Fe3+ redox couple of indirect/noncontact bioleaching. Ore oxidation, oxidant regeneration, and power generation are achieved in the oxidation leaching section, the bio-oxidation section, and the galvanic biomining reactor, respectively. At various temperatures and in the presence of toxic ions, leaching rates are approximately 10 times higher than those of conventional bioleaching, which represents a breakthrough of the above bottleneck. The power generation, bacterial carbon sequestration, and total carbon sequestration are 23.5 kW h, 34.4, and 2510 kg, respectively, per ton of copper produced. The galvanic biomining effectively regenerates oxidants at room temperature and significantly reduces power consumption and the carbon footprint.