Abstract

It is a great challenge to highly recover gold from the E-waste leaching solution due to the low concentration and the resultant slow ion diffusion. In this research, COMSOL Multiphysics was employed for the first time to give a graphical display of the mass transfer behavior of Au(S2O3)23– under an electric field. An enhanced strategy for gold recovery from the leaching solution by utilizing porous activated carbon (AC) coated electrode was proposed as well. The recovery rate of gold with low concentration was limited by the slow ion diffusion from the solution to the interface of electrode, which had been confirmed through COMSOL Multiphysics. While, both the simulations and experiments demonstrated that the Ti cathode coated with AC could make a great facilitation for the ion diffusion to the electrode interface benefited from the rich pore network of AC. As a result, 96.9 % Au was efficiently recovered from the WPCBs leaching solution with AC electrode at 1.2 V. This study not only gives a new understanding on the reduction kinetics of Au(S2O3)23– under electric field, but also a valuable strategy for the efficient recovery of precious metal from electronic waste. © 2024 Elsevier B.V.