Influence of different 3-D electrodes towards the performance of gold recovery by using an electrogenerative process

Abstract

In this study, gold was recovered by using an electrogenerative process employing a batch cell. This system is based on Galvanic cell which it does not require any external power supply but it produces an electrical energy by a spontaneous chemical reaction in which gold is reduced at cathode and zinc is oxidized at anode. The performances of three-dimensional electrodes, reticulated vitreous carbon (RVC) and porous graphite sheet (PG) were used as cathodes and investigated based on the time and percentage of gold recovery. In batch cell system, RVC served as the best cathode material, having the highest recovery rate with >99% of gold being recovered in 1 h operation for gold concentration of 100 mg L−1. Cyclic voltammetry and mass transfer studies were conducted to study the characteristics of these cathodes for gold deposition. Based on the cyclic voltammograms, RVC and PG undergoes redox reaction within range 1200 mV to −600 mV. Finally, based on the cyclic voltammograms, it was found that gold reduction was observed at 0.2–0.1 V of potential range while oxidation peak was occurred at a potential range between 0.8 and 1.0 V. Keywords: Electrogenerative system, Three-dimensional electrodes, Gold recovery, Mass transfer, Cyclic voltammetry