On the use of ion exchange resins for adsorption of gold from ammoniacal thiosulfate solutions

"The paper point out about on the use of ion exchange resins for adsorption of gold from ammoniacal thiosulfate solutions. In this sense, the gold can be recovered from ammonium thiosulfate solutions with strong base resins. The amount of gold loaded onto the resin in a batch process is a function of gold concentration in solution, amount of resin, volume of solution, copper and competing ions concentration in solution. Thiosulfate concentration in leaching solution has influence on gold loadings onto resins; in contrast, ammonia concentration in solutions has no influence on gold loadings. Gold seems to be loaded onto the resin preferentially over copper - thiosulfatecomplexes and also over thiosulfate ions. Polythionate ions strongly compete with gold and copper thiosulfate complexes for resin sites. This causes reduction on gold and copper recoveries from the leaching solutions. Even more, polythionates are produced in leaching solutions when thiosulfate is oxidized by the action of both copper and oxygen. "