Enhancing ion - Exchange leaching of rare earth elements from Malaysian ion adsorption clay sources by using commercial surfactant

Abstract

Rare earth elements (REE) from ion adsorption clay (IAC) sources are gaining much interest globally due to its simpler extraction process compared to its mineral sources' counterpart. REE are extracted from IAC sources via ion-exchange leaching process by using ammonium sulphate as commonly used lixiviant. In this study, ion exchange leaching process is enhanced by utilizing commercial surfactant, sodium lauryl sulfate (SLS) to mitigate issues such as high lixiviant consumption, high operating period as well as low leaching efficiency associated with current ion exchange leaching process. The effect of surfactant concentration on leaching efficiency, leaching kinetics and permeability coefficient was studied. Experimental works performed indicate that addition of 0.03 wt% of SLS improved total REE leaching efficiency by 15%. Column leaching tests conducted show that addition of 0.03 wt% SLS also reduced the required amount of lixiviant used to achieve optimum total REE recovery by 17%. Ion exchange leaching process improvement via addition of SLS was due to improvement of permeability coefficient of the IAC ore bodies which was proven via permeability coefficient measurement. The results show that addition of 0.03 wt% SLS increased the permeability coefficient of the IAC ore bodies.