PROCESS FOR LEACHING GOLD AND SILVER FROM ORES USING CYANIDE AND HYDROGEN PEROXIDE

摘要

The invention relates to a process for leaching gold and silver from ores and ore concentrates using a cyanide-containing leaching solution and hydrogen peroxide and maintaining an oxygen concentration of 2 to 20 mg O2/l. The leaching is carried out according to the invention in the presence of decomposition catalysts, and the cyano complexes which are formed are preferably separated from the leaching solution during leaching. Decomposition catalysts are manganese compounds - 0.01 to 1 mg calculated as Mn/l barren solution or 1 to 50 mg calculated as Mn/kg ore pulp - or inorganic or organic polymers or carbon. Active carbon is preferably employed in an amount of 1-20 g/l of leaching solution, because this decomposes H2O2 and simultaneously adsorbs noble metal cyano complexes. The process leads to a reduced consumption of H2O2 and, where appropriate, cyanide and maximum yields of gold with shortened leaching times.