Abstract: Increased efficiency of extraction of silver and gold from ore materials thereof containing active carbonaceous material is obtained by conducting the extraction in two stages. In a first stage a portion of the silver and of the gold when present is extracted in a cyanide leach solution. The leached solids residue is contacted with activated carbon so that the silver and the gold when present are adsorbed on the activated carbon at elevated temperature (most preferably at about 35.degree. C. to about 100.degree. C.). In a modification, a slurry of the ore material is treated with cyanide and the precious metal adsorbed directly from the cyanided slurry with activated carbon at elevated temperature up to about 70.degree. C.

Abstract: Refractory sulfidic silver ore which is not amenable to cyanide leaching is formed into an aqueous slurry and oxidized at elevated temperature, usually about 150.degree. to 250.degree. C., in the presence of an oxidizing agent, usually oxygen, and in the presence of about 30 to about 160 g/L zinc. Zinc present in the above range results in increased extractability of silver from the oxidized residue by cyanide leaching.