“…The definition of refractory applies to gold ores when the conventional cyanidation recovers around 80% of gold after fine grinding . Refractory materials include the submicroscopic or occlusion of fine-grained gold, presence of tellurides, carbonaceous matter, clays, arsenic, iron and base-metal sulfides, silica encapsulation, and incomplete oxidation of elemental sulfur. − Most refractory ores are composed of sulfide and carbonaceous matter combined with gangue materials, which prevents effective leaching from lixiviants due to preg-robbing and the occlusion of gold. , Further, carbonaceous matter adsorbs the aurocyanide complex behaving like activated carbon . These factors result in lower lixiviant leaching efficiencies, higher lixiviant consumption, and boosting operating costs.…”