Optimization of the bacterial oxidation of an arsenical gold sulphide concentrate from Olympias, Greece

In this study the optimization of the bacterial oxidation of an extremely refractory arsenical gold sulphide concentrate, from Olympias, Greece, is examined. Leaching tests were conducted in air-stirred pachuca reactors in order to determine the effect of the variation of the particle size of the concentrate during bacterial leaching tests on the degree of pyrite and arsenopyrite oxidation for a pulp density range varying between 5 and 30% w/v. Cyanidation tests were conducted in order to determine the degree of gold and silver liberation in relation to the degree of each sulphide phase oxidised and the cyanide consumed.