Recovery of [Au(CN)2]− from gold cyanidation with graphene oxide as adsorbent

The recovery of gold cyanide complex Au(CN)2− from gold cyanidation with graphene oxide (GO) and GO hydrogel have been studied to explore the possibility of the application of GO or GO hydrogel in gold cyanidation process for extracting gold. The study was performed on the adsorption of artificial Au(CN)2− aqueous solution on GO and GO hydrogel. The adsorption results, as well as the SEM-EDS, AFM and XPS, demonstrated that GO was a better adsorbent for the recovery of Au(CN)2− from aqueous solution than conventional activated carbon because of its higher adsorption capacity and adsorption rate. It has been also found that the adsorption of Au(CN)2− on GO followed the Langmuir isotherm and fitted well with both the pseudo-first-order and pseudo-second-order kinetics models. The recovery of Au(CN)2− with GO might be attributed to the interaction between Au(CN)2− and oxygenous function groups on GO surface. GO hydrogel exhibited excellent Au(CN)2− adsorption property and easy separation, which enabled it a potential adsorbent in gold cyanidation.