Gold Adsorption by Activated Carbon and Resin

Activated carbon and resins readily adsorb gold from cyanide leach solutions. The main advantages of carbon are its high selectivity towards gold, its ease of elution and its large particle size. On the other hand, resins do not suffer from the problems of pore blocking by fine particles in the slurry and show superior adsorption kinetics and higher loading capacity for gold. In addition, when resins are used in the form of fibre-reinforced sheets, many of the problems associated with beads are overcome. The experimental results are shown to fit the homogeneous surface diffusion model with certain modifications when pore blocking occurs. The Fritz and Schluender isotherm is used to describe the equilibrium behaviour of adsorbed species. This reduces to the well-known Freunlich isotherm when only one component (eg. Gold) need be considered.