Gold recovery from finely disseminated ore by use of cyanidation and thioureation

The aim of this investigation was to compare the influence of the main process variables of cyanidation and thioureation on gold recovery. The investigation was carried out on a finely disseminated gold-bearing ore (5 g/t Au). The main parameters utilised in the leaching tests have been: oxidizing agent (O2, Fe3+), leaching agent (NaCN, CS(NH2)2), pH, temperature, pulp density and leaching time. The optimisation of the parameters permitted to obtain about 85% Au recovery in both the processes.