Gold Adsorption from Pregnant Thiocyanate Solution Using Activated Carbon

Abstract

Gold adsorption from dissolution of gold ore concentrate at Tanggamus mine using activated carbon from thiocyanate leached solution was investigated in this research. As the pollution of the environment has been raising accordingly with the increasing of cyanidation, thiocyanate is becoming current alternative and less toxic reagent in terms of gold dissolution. However, the research was still limited. The development and implementation of thiocyanate in gold extraction is the core of this research. Solvent and oxidizer concentrations (KSCN and FeCl3) were used in this study with 0.3 M and 0.1 M of concentration, respectively. Adsorption process was carried out for 4 hours using 100 ml of filtrate with activated carbon addition. Adsorption of thiocyanate complex gold compounds was studied by varying the size of activated carbon, the concentration of activated carbon, and the rotary speed of bottle roll. At-10+20# of activated carbon size, the %-adsorption obtained was 93.65%. Meanwhile, 94.31% of gold adsorption was achieved with the concentration of activated carbon at 1500 mg/l and 93.37% of gold adsorption was reached with the rotary speed of 150 rpm. Pseudo second order was applied to calculate the kinetics of gold adsorption with the R2 value obtained was 0.9999.