Case study: bacterial cyanide detoxification during closure.
Biohydrometallurgical technologies: fossil energy materials, bioremediation, microbial physiology: Proceedings of an International Biohydrometallurgy Symposium, August 22-25, 1993, Jackson Hole, Wyoming, USA. Torma AE, Apel ML, Brierley CL, eds. Warrendale, PA: Minerals, Metals and Materials Society, 1993 Sep; 2:219-227
The U.S. Bureau of Mines, U.S. Department of the Interior, demonstrated the viability of using bacterial cyanide oxidation for decommissioning a heap leach operation. The field demonstration was conducted under a CRADA with USMX during the decommissioning of USMX's Green Springs gold operation near Ely, NV. The test objective was to bacterially oxidize the cyanide in the process solution using the carbon adsorption tanks as bioreactors and then to rinse residual cyanide from the spent heaps using the biotreated process solution. Results are presented from the initial laboratory tests designed to (1) determine the effectiveness of cyanide-oxidizing bacteria, previously isolated and tested at the SLRC, in Green Springs solutions, (2) determine the cyanide oxidizing potential of the indigenous bacteria, (3) determine the most cost effective nutrient, and (4) simulate actual operating conditions at the site. Results from the field test are presented showing that the bacteria destroyed a portion of the cyanide using the carbon tanks as bioreactors at flow rates of 50 and 300 gal /min. Data indicated that bacterial cyanide oxidation is a function of retention time and nutrient concentration. A flowsheet is presented depicting the circuit.
Waste treatment; Mining industry; Metals; Bacteria
U.S. Bureau of Mines, Salt Lake City Research Center, 729 Arapeen Drive, Salt Lake City, Utah 84108
Torma-AE; Apel-ML; Brierley-CL
Biohydrometallurgical technologies: fossil energy materials, bioremediation, microbial physiology: Proceedings of an International Biohydrometallurgy Symposium, August 22-25, 1993, Jackson Hole, Wyoming, USA