Recovery of gold from hydrochloric acid by using lemon peel gel

Recovery of Au(III) in aqueous hydrochloric acid medium using lemon peel was studied. The adsorption gel prepared from lemon peel was found to adsorb Au(III) highly selectively showing negligible affinity for other precious metals and some base metal ions studied so far. The adsorption isotherm study gives the maximum loading capacity of the gel as 6.5mol per kg dry weight of gel. XRD analysis and the digital micrograph of the gel taken after adsorption reveal the formation of gold particles during the adsorption process which is associated with the high selectivity and capacity of the gel for Au(III). Kinetic and electrochemical studies were performed at various temperatures. An endothermic adsorption process following pseudo-first order kinetics was established.