Aerobic processes for bioleaching manganese and silver using microorganisms indigenous to mine tailings.

Mining wastes containing appreciable concentrations of silver are considered alternative sources for metal extraction, although these wastes are often refractory due to the presence of manganese oxides. The high cost and/or environmental impact of the hydrometallurgical and pyrometallurgical extraction processes make it necessary to search for biotechnological processes for the solubilization of manganese compounds. This paper describes the characterization of chemoorganotrophic microorganisms indigenous to the tailings of a silver mine located in Coahuila, México, regarding their capability to remove manganese and silver present in these residues by lixiviation.