Effect of temperature on sorption of metals by silica-supported 2-(aminomethyl)pyridine. Part II: Sorption dynamics

The adsorption rate of sulfuric acid and metal sulfates is controlled by pore diffusion and increasing temperature markedly increases the sorption rate. The experimental batch uptake curves can be well correlated with the proposed diffusion model and with constant diffusion coefficients. The estimated activation energies of pore diffusion are about 9 and 20 kJ/mol for the acid and the metals, respectively. In column separation, increasing temperature substantially improves copper removal from the ZnSO4 process solution. The improvement is predominantly due to enhanced intra-particle mass transport. The effect is further amplified by marked decrease in viscosity of the feed solution.