Abstract:Co-intensification was researched to accelerate gold leaching with regards to its electrochemical nature by using anodic intensifiers of heavy metal ions (Pb²⁺, Bi³⁺, Tl⁺, Hg²⁺ and Ag⁺) on the basis of hydrogen peroxide assistant leaching on three different types of materials which were classified as a refractory sulphide gold concentrate, an easily leachable sulphide gold concentrate, and a low grade oxide gold ore according to their leaching characteristics. The results showed that, favorable co-intensification effects on the three materials were obtained and leaching time of gold was effectively shortened to no longer than 12 h from 16 to 24 h for hydrogen peroxide assistant leaching. For the five tested heavy metal ions, Bi³⁺and Tl⁺ presented co-intensifying effect on all the three materials, and Hg²⁺ caused co-intensifying effect on both refractory and easily leachable sulphide gold concentrates, and Pb²⁺ and Ag⁺ only had co-intensifying effect on the easily leachable sulphide gold concentrate.

Key words: gold leaching; co-intensification; cyanidation; heavy metals; hydrogen peroxide