During the past fifteen years significant progress has been made on carbon-in-pulp (CIP) technology for the extraction of gold. Most research on the mechanisms and kinetics of CIP subprocesses has focused on the adsorption step only; auxiliary unit operations such as elution have received less attention. Mathematical models have been developed for the elution of gold and can be used for design and process optimization. The adverse effect of high loadings of a base metal such as copper on carbon during the desorption of gold is known, but not yet fully understood. A multicomponent Freundlich equilibrium model was used fbr the simulation and evaluation of the elution of gold and base metals from activated carbon. This model was incorporated in a material balance for a series of well-mixed reactors simulating the effects of an elution column, and was related to the elution of spectator cations such as potassium via an empirical expression. The model successfully simulated the elution profiles, but it was found that base metals, and especially copper(I), complicate the modeling of the base metals due to the consumption of cyanide and the possible formation of polymeric gold-copper species on the carbon surface. The competition coefficients are parameters which indicate the extent to which the base metals affect the elution of gold. At high copper loadings the desorption behavior of copper and gold changed, and an increased adsorptivity was detected. It was postulated that this was mainly due to the formation of copper-gold polymeric chains.