ABSTRACT
Depletion of direct leaching gold ores and the discovery of ores that are not amenable to direct cyanide leaching has required development of new treatment methods for these refractory ores. While there are many causes of refractory ores, the two most common and economically significant causes are encapsulation of gold by sulfide minerals (Monroy et al., 1993) and adsorption of the gold cyanide complex formed during leaching by organic carbon present in the ore (Vassilou, 1988). Both of these causes may be encountered in the same ore.
