Patent ID: 7837760

Claim:
A process to increase the bioleaching speed of ores or concentrates in an ore bed which is in the form of heaps, tailing dams, dumps, and other on-site bioleaching operations of sulfide metal species, the process comprising: inoculating the ore or concentrate to be bioleached with an inoculating solution containing isolated microorganisms of the Acidithiobacillus thiooxidans type, or together with isolated microorganisms of the Acidithiobacillus ferrooxidans type, with a total concentration of isolated microorganisms of about 1×10 7 cells/ml up to about 5×10 9 cells/ml, and wherein the bioleaching is carried out with or without the presence of native microorganisms that grow in the inoculating solution or of oxidizing ions; and carrying out the inoculation of the ore or concentrate until self-sustaining conditions of bacterial activity in the ore are reached, wherein self-sustaining conditions are reached when the bacterial count and iron-oxidizing activity of the bacteria in an effluent solution collected from the ore bed is similar in magnitude and composition to the bacterial count and iron-oxidizing activity of the bacteria in the inoculating solution.