Studies On Adsorption And Desorption Of Gold On Activated Carbon

Two main behaviors, adsorption and desorption, of the interaction between gold and activated carbon have been studied in present work.We studied the adsorption of gold cyanide on activated carbon through changes of various factors affecting adsorption. We also studied the existing forms of gold cyanide on activated carbon by the way of investigating of the desorpting behavior of gold. We presented some presumptions of the adsorption mechanism of gold on carbon on the base of experiments. The results indicated that the first step of adsorption process of gold onto activated carbon was the adsorption of gold cyanide species in the form of HAu (CN) 2 or Na+[Au (CN) 2]-, then oxidation-deoxidation reaction took place partly.The desorption of gold from activated carbon was also researched. The addition adding in reductive could promote the desorption of gold and technical conditions in industrial application in the presence of reductive were improved. The optimum efficiency was achieved with the redox potential of -0.2v. At the same time, ultrasound was introduced to the desorpting system. The results showed that ultrsonic could promote the generation and transportation of radicals so that the dynamics of the desorption of gold was improved and relative desorpting rate was accelerated. A optimum desorpting conditions in the presence of ultrasound was gained as well which is likely to be applied in the industry.