Investigation of Bioprocesses to Enhance Metal Extraction from Ores and Wastes in Mining Operations

Mine sites are a large source of genetic information that can be studied to explore ways of processing minerals using bacteria. This study investigates the bioleaching potential to extract nickel from ores and wastes at circumneutral pH and denitrifying conditions, and the cyanide biodegradation phenomenon at a gold heap leaching operation by examining naturally growing bacteria at two mine sites. Neutral pH bioleaching of nickel was achieved using nitrate as electron acceptor and oxidant. A mass balance revealed that about 20-30% of the original concentrate was leached over a period of more than 500 days. Faster rates could possibly be achieved by increasing biomass concentration. Thiobacillus was the dominant microbe identified in these microcosms. In gold heap leaching with cyanide, the microbial community was found to be almost entirely composed of a Hydrogenophaga with 16S sequence most similar to other alkaliphilic strains. This strain is presumably growing on the cyanide.M.A.S.2020-11-21 00:00:0