Microbial consortium treatment of refractory precious metal ores

摘要

A method is provided for the recovery of precious metals, such as gold and silver, from refractory carbonaceous sulfidic material. The carbonaceous sulfidic material is ground and placed in heaps or piles or pulped or slurried and bioleached to oxidize the sulfide minerals using bacteria at temperatures from about 15 DEG C. and up to about 40 DEG C. The biooxidized residue is then treated using a specific microbial consortium, or a product of the microbial consortium, at temperature from about 5 DEG C. to 40 DEG C. to deactivate the carbonaceous component of the material to prevent binding of the precious metal to the carbonaceous component. The precious metal liberated in the residue remaining from the biological oxidation of sulfide and deactivation of carbon are recovered by dissolution.