Cyanide regeneration by AVR process using ion exchange polymeric resins

This work presents laboratory bench scale results for cyanide regeneration from pure alkaline aqueous solutions of gold, copper and iron cyanocomplexes using an innovative option of the AVR process associated to the ion exchange polymeric resins Imac HP555s® ((Room&Haas––USA) and Amberlite IRA-420® (Room&Haas Brasil Ltda.) in columns. The resin Imac HP555s® adsorbed 64.5% CN from the alkaline solution containing metal cyanocomplexes. Meanwhile, the elution stage with H2SO4 and thiourea reached 31.2% CN, 86.2% Au, 86.4% Cu and 41.5% Fe. The resin IRA-420® adsorbed 53.4% CN under the same experimental conditions adopted for the resin Imac HP555s®. The resin Amberlite IRA-420® eluted 48% CN, 96.8% Au, 9.1% Cu and 76% Fe.