Adsorption of Uranium on Clay Minerals

Abstract

IN the conventional sulphuric acid leaching of low-grade uranium ores, using 50–200 1b. acid per ton of ore, considerable amounts of uranium may remain in the leach residues, especially with secondary ores where the uranium is in the hexavalent form and should be readily soluble. We have recently been studying the absorption of uranium on clay-like minerals (for example, montmorillonite, vermiculite and halloysite) to investigate the possibility that dissolved uranium may be reabsorbed by an ion exchange mechanism on the clay minerals in an ore, thereby leaving a residue relatively high in uranium despite the usual nitration and washing procedures.