Industrial water Gold and Silver - Water and Wastewater - Water Filtration and Separation
Cyanidation is still the most widely used method to leach gold, using sodium or calcium cyanide as lixiviant. An anionic gold-cyanide complex is formed that is extractable by basic resins. Other metals present in the ore, such as silver and base metals ( copper, nickel, cobalt, zinc, iron, etc. ) are also leached in cyanide media. Selective ion exchange resins are designed to preferentially adsorb the mono-valent gold-cyanide species.
- Ion exchange resins are stripped at low temperatures and do not require energy-intensive thermal regeneration.
- Ion exchange resins show high adsorption efficiencies, even in the presence of naturally occurring carbonaceous matter.
- Complexes can be stripped from the columns with sodium cyanide and salts of metal cyanide compexes.