KINETIC MODELS FOR THE ADSORPTION OF GOLD ONTO ACTIVATED CARBON.
A kinetic model for the adsorption of gold onto activated carbon is a valuable tool in the design and prediction of the performance of an operating adsorption plant. This paper compares and evaluates the existing kinetic models for batch adsorption. A dual-rate model is proposed to simulate the slow approach to equilibrium revealed by certain carbons. In this model, the carbon is divided into two interconnected regions with different kinetic characteristics. Equilibrium is assumed to exist between the liquid phase surrounding a carbon particle and the gold adsorbed on the external carbon surface. Batch kinetic experiments have been run for longer than 30 hours, with pure potassium aurocyanide used as the adsorbate. Different initial gold concentrations, carbon-to-solution ratios, and stirring rates have been used.