Discussion on the kinetics of the elution of gold from activated carbon

The validity of a steady state assumption made by Adams and Nicol (1986) in the modelling of the elution of gold from activated carbon was investigated. It is shown that the accuracy of the steady state approximation is dependent, not only on the magnitudes of the solution flow rate and reactor volume, but also on the lumped elution rate constant. Under the experimental conditions used by Adams and Nicol (1986) the steady state assumption was inaccurate, This could be circumvented in this instance by applying a rigorous general model which accounts for unsteady state behaviour in the solution and in the activated carbon to the experimental data.