MODELING OF THE AARL ELUTION PROCESS

The influence of temperature on the equilibrium adsorption of gold and hydroxide ion at elution conditions was examined. Experiments were co nducted for both single and multiple solute adsorption of gold and OH- ion at the temperatures between 80 and 120-degrees-C. Two models were employed to model the equilibrium adsorption of each solute at the si ngle solute level. These consist of the Freundlich isotherm (FI) and t he Modified Freundlich isotherm (MFI). In the case of the multiple sol ute adsorption, the Freundlich-type isotherm and a General multi-compo nent isotherm were used for the modelling. Elution kinetic data was al so generated. Models depending upon surface diffusion and film transfe r were also developed. A plug flow model was developed and simplified using the method of characteristics. These models were solved simultan eously with the Modified Freundlich isotherm to simulate the experimen tal data obtained. It was observed that the model was less sensitive t o the diffusion coefficient. The model was modified to be film transfe r dependent and this modification was found to represent the experimen tal data very well.