Method for biological processing of metal-containing ores

A continuous process for leaching gold, silver and platinum from sulfide containing ore solids, said process comprising:

• providing a first slurry retaining vessel and a second slurry retaining vessel;
• placing within said first vessel a slurry comprised of gold, silver or platinum bearing, sulfide-containing solids, water, a culture of sulfide oxidizing thiobacillus bacteria, capable of oxidizing said solids and obtaining energy for growth from said oxidation, oxygen carbon dioxide and nutrients for said sulfide-oxidizing, thiobacillus bacteria;
• said bacteria operating to oxidize said sulfide containing solids, within said slurry;
• withdrawing at intervals a first quantity of said slurry from said first vessel;
• processing said first quantity of slurry thereby separating those sulfide containing solids which are not oxidized from a remainder of said first quantity of slurry
• recycling said non-oxidized solids to said first vessel;
• placing said remainder of said first quantity of slurry in said second vessel;
• said remainder of said slurry containing oxidized solids;
• wherein liquor, containing dissolved by-products of said oxidation, is removed from both said first and said second vessels while conserving said thiobacillus bacteria within said vessels.

A continuous process for treating gold, silver and platinum bearing sulfide containing solids, said continuous process comprising:

• providing a first slurry vessel and a second slurry vessel;
• placing within said first slurry retaining vessel a slurry comprised of a quantity of gold, silver or platinum bearing sulfide containing solids, water, a quantity of thiobacillus bacteria able to oxidize sulfides;
• providing oxygen and carbon dioxide-containing gas to said bacteria within said slurry;
• said bacteria operating to oxidize said sulfide containing solids, within said slurry;
• withdrawing a quantity of said slurry from said first vessel;
• said bacteria operating to oxidize said sulfide containing solids within said slurry, said bacteria's operation yielding a slurry containing oxidized solids, less than completely oxidized solids, and non-oxidized solids;
• separating said non-oxidized solids from said oxidized and less than completely oxidized solids within said quantity of slurry;
• recycling said non-oxidized solids to said first vessel;
• channeling said less than completely oxidized solids to said second vessel for further treatment.