Leaching and Adsorption of Gold from Lape-Sumbawa Rocks (Indonesia) by Hypochlorite-Chloride

In this study, leaching and activated carbon adsorption of gold from Lape-Sumbawa rocks (Indonesia) by hypochlorite-chloride solution have been investigated. The application of hypochlorite-chloride solution may offer an alternative on replacing cyanide for gold extraction. XRD and XRF analysis indicated that the Lape-Sumbawa rock is carbonate sediment. Several variables for gold leaching such as the concentration of HCl and NaOCl as well as solid-liquid ratio have been optimized. The optimum conditions for gold leaching were 1:12 mL of HCl 37% solution (v/v), 1:12 of NaOCl 12% solution (v/v), and 1:20 of solid-liquid ratio (w/v). The gold extraction yield was about 89%. Gold recovery by activated carbon adsorption was about 49.852%.