How to handle gold ores with high copper content

Due to the high solubility of copper minerals associated with gold, except for a few copper minerals such as chalcopyrite and chrysotile, most of them such as malachite, chalcopyrite, and chalcopyrite have high solubility in cyanide solutions. These cyanide soluble copper will compete with gold for cyanide and oxygen during gold cyanide leaching, thereby hindering the dissolution of gold. Therefore, different treatment methods should be adopted according to the amount of copper in the ore.

When the soluble copper content in the ore is low, the increased cyanide consumption can be increased without causing economic irrationality. Attention should be paid to operating at lower temperatures and lower cyanide mass fractions, as the dissolution rate of copper minerals significantly increases with increasing temperature and cyanide mass fraction. The method of segmented (tank) dosing is adopted in production to control the appropriate cyanide mass fraction in each tank, in order to control the dissolution rate of copper minerals and minimize cyanide consumption while recovering the deposit.

When the copper mineral content in the ore is high (such as greater than 0.3%), and the cyanide consumption is too high and economically uneconomical, flotation can be used to select some qualified copper concentrates, and then cyanide gold extraction can be carried out on the tailings. In order to fully utilize mineral resources, different leaching methods can be used in combination for comprehensive recovery when necessary. If copper is first leached with dilute sulfuric acid, the obtained copper sulfate solution is used to obtain sponge copper by iron displacement method, and the copper leaching residue with reduced copper content is then subjected to cyanide gold extraction. This method can also be used to process gold containing copper powder.