Lanxess Lewatit® AF 5 and activated carbon catalysis of enargite leaching in chloride media; a parameters study

Enargite leaching is investigated in chloride media with and without Activated Carbon (AC), and Lanxess Lewatit (R) AF 5 (abbreviated as AF 5), a novel carbon based catalyst. Moreover, single and synergistic effects of different parameters on copper dissolution rate are studied. Both catalysts were found to be very effective in facilitating the enargite leaching process and improved the copper recovery rate from 65% to 92% (AC) and 96% (AF 5) after 96 h. The best leaching condition was found to be: ferric and cupric concentrations greater than 5 g/L, concentrate to catalyst ratio of 1:2, at 90 degrees C working temperature. Most of the dissolved copper was oxidized to cupric by the AC or AF 5 in the solution. An elemental sulfur coating was not observed on the surface of the partially leached mineral particles with catalysts, which is known to cover the surface of the minerals during leaching in acidic solutions without the catalysts.