Adsorption of colloidal gold on colloidal iron oxides

Lateritic gold enrichment can be associated with the formation of colloidal gold and its interaction with the iron-oxide-rich medium. Adsorption of colloidal gold on synthetic goethite and hematite was measured at 25°C. The observed high affinity between the oppositely charged particles depends on the medium composition. The presence of citrate anions can inhibit mutual coagulation, while inert electrolytes enhance this effect.