Percolation bioleaching of copper and zinc and gold recovery from flotation tailings of the sulfide complex ores of the Ural region, Russia

Laboratory experiments in percolators have demonstrated effective bioleaching of copper and zinc, as well as recovery of precious metals from flotation tailings of the Svyatogor concentrator. The defined culture constructed from strains of acidophilic chemolithotrophic microorganisms exhibited higher rates of bioleaching than the indigenous culture obtained from the acid mine drainage. Treatment of the substrate with sulfuric acid (pH 1.24) resulted in recovery of 48.6% of zinc, 28.2% of copper, and 2.8% the total iron. Acidic percolation leaching and biooxidation for 134 days with the indigenous and defined cultures resulted in solubilization of 59.5 and 87.0% zinc, 46.0 and 54.5% copper, and recovery of 56.4 and 57.8% gold and 50.5 and 50.9% silver, respectively.