COMPETITIVE ADSORPTION OF GOLD CYANIDE AND ORGANIC-COMPOUNDS ONTO POROUS ADSORBENTS

Activated carbon has had a tremendous impact on the technology of gold recovery from leached liquors. Ion-exchange resins have been proposed as possible alternatives to carbon, while ion-exchange fibers and mem branes were investigated recently as adsorbents for metal recovery in view of their fast rate of uptake. This paper deals with the competiti ve adsorption of organic compounds and gold cyanide onto activated car bon, ion-exchange resin, ion-exchange fiber, and membrane. Loadings of organic compounds were measured on gold equilibrated adsorbents and c ompared to loadings on virgin adsorbents. Both the kinetic and equilib rium parameters in a film/surface diffusion model were affected, which indicated a competitive type of mechanism between gold cyanide and or ganic compounds. A two-component Freundlich-type isotherm fitted the e quilibrium for adsorption on carbon, membrane, and fiber. Furthermore, low molecular mass organic substances revealed a smaller inhibiting e ffect on gold adsorption than long-chain or high molecular mass organi c compounds.