HPLC in gold processing

The predominant method for gold extraction involves cyanidation of ore under aerated conditions to form aurocyanide ([Au(CN)2]-). Since the major reagent cost in this process is that of sodium cyanide, any components ("cyanicides") apart from gold that consume cyanide increase the cost of gold recovery. The two most important cyanicides are sulfide- and copper-bearing minerals. The major products of these secondary cyanidation reactions are thiocyanate, the Cu1-cyanide complexes, cyanate (from the oxidation of cyanide, especially during the reduction of soluble Cu11 minerals), [Fe(CN)6l4- and other metal-cyanide complexes.