ADSORPTION-DESORPTION OF GOLD ONTO ACTIVATED CARBON FROM CYANIDE-GLYCINE LEACH SOLUTION OF COMPLEX GOLD ORE

Abstract

This research investigated the adsorption of gold on activated carbon from a cyanide-glycine leach solution and their desorption. The pH value varied between 9 and 11, and at each pH value, the concentration of activated carbon was changed between 5 and 20 g L^-1. The results showed that both pH and carbon concentration did not have a significant effect on gold adsorption. In all experiments, a high adsorption value of gold (above 98 %) was obtained. In all carbon concentrations, except for 5 g L^-1, the maximum gold adsorption was obtained at a pH of 10.5. The reduction of gold adsorption on activated carbon with the increase of pH to 11 can be related to the decrease of active points on the carbon surface due to the increase in the concentration of hydroxide ions. When the concentration of activated carbon was 5 g L^-1, more than 98 % of gold was adsorbed. So, a further increase in carbon concentration is not required. Elution experiments were carried out after different leaching methods; carbon in pulp (CIP) and carbon in leach (CIL). The results showed that for both leaching methods, most of the gold was dissolved in the first 6 h of the elution process and the final gold desorption for CIP and CIL were 82.89 % and 72.64 % respectively.