An Innovative Bioleaching Approach for the Extraction of Valuable and Hazardous Metals from Mining Waste

The global demand for various metals has greatly increased over the past few years and this demand is envisaged to double over the next coming decades. The extractive waste residue (tailings) by the EU mining industries is a large waste stream and could constitute various environmental hazards such as acid mine drainage, especially when poorly managed. Reprocessing of these tailings could be a significant source of valuable metals and could alleviate environmental risks. This calls for a cost-effective metal mining technology with minimal damaging effect to the environment. We hereby propose the use of (halo)alkaliphilic and/or marine sulfur-oxidizing bacteria that live at neutral to alkaline conditions for the bioleaching of elements from these tailings. This will prevent the acidification of the environment, which is the case when bioleaching with acidophilic bacteria. In addition, this bioleaching approach which could be applicable in seawater is beneficial as fresh water could be saved.