In the leaching step, catalysts can facilitate the dissolution of metal ores into the aqueous solution. For example, in the pressure leaching of copper ores, iron-based catalysts can increase the rate of copper dissolution by promoting the oxidation of sulfide minerals. Similarly, in the cyanidation process for gold extraction, catalysts like activated carbon can improve the efficiency of gold recovery by enhancing the adsorption of gold-cyanide complexes.
