title: Leaching of a silicate and carbonate copper ore with heterotrophic fungi and bacteria, producing organic acids.
abstract: Leaching of metals with carbon-heterotrophic microorganisms and organic acids as active agents has been performed with Timna copper ore containing 1.1% copper as carbonates and silicate and with some other metal oxides. Aspergillus niger surface cultures on a 14% sucrose fermentation medium yeilded 87.3% of total copper from 10% suspension within 2 weeks of leaching. On sulfite liquor as an industrial waste product A. niger solubilized 73.8% Cu within 4 weeks. In percolators with 14% sucrose medium up to 1780 ppm copper were found in solution. In leaching experiments with a sea water medium containing 7% sucrose only 684 ppm Cu were soluble. Leaching with lactobacilli containing whey yielded 83.4% of the total copper in 4 weeks.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001234:Aspergillus niger / Q000378:metabolism*; D002254:Carbonates / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D003470:Culture Media; D007778:Lactobacillus / Q000378:metabolism*; D008906:Mining; D012623:Seawater; D012824:Silicic Acid / Q000378:metabolism; D012988:Soil Microbiology; D012995:Solubility; D013395:Sucrose / Q000378:metabolism; D013447:Sulfites / Q000378:metabolism
chemical_list: D002254:Carbonates; D003470:Culture Media; D013447:Sulfites; D012824:Silicic Acid; D013395:Sucrose; D003300:Copper