Stabilization of Hydrogen Peroxide used as Oxidizing Agent in the In-situ Leaching of Uranium from Arkosic Sandstone

Abstract

H2O2 was used as oxidizing agent of the insoluble tetravalent uranium into the soluble hexavalent state along with NH4HCO3 as complexing agent in tap water solvent. The study was conducted to look at the possibility of commercial scale insitu leaching of uranium from an underground arkosic sandstone ore deposit. It was found that the peroxide was unstable in the basic tap water solvent as well as in the lixiviants to be used for uranium leaching, especially, in the presence of Ca ions and NH4HCO3. The rate of dissipation of the oxidizing agent was studied in different media at room temperature for 192 hours with distilled water as a reference medium. The material was stabilized by complexing the different ions / metal catalysts in the lixiviant by EDTA. In the presence of EDTA the stability behaviour of the peroxide became almost identical in the distilled water and tap water lixiviants.