Preparation of High Concentrations of Trivalent Uranium by Acid Control and Studying It’s Stability

Abstract

High aqueous trivalent uranium concentrations ( ≥2.0 M) in hydrochloric acid medium have been prepared , using zinc amalgam and by controlling the acid concentration during preparation .Stabilities of 1.5M U(III) in different HCl concentrations(3, 4, 5 and 7)M were studied. It was found that U (III) is more stable in low acid concentration, due to the formation of chloro-complex compound with U (III) at high concentrations.The half oxidation time was calculated from experimental data. It was found that the half oxidation time of U(III) is (6 - 211) days and it decreased with increase of acid concentration.Addition of low concentrations (2mmole) of Cu+2, Cr+3, Ni+2 and Fe+2 ions (impurities) to 1.5M aqueous solution of U(III) in 3M HCl , decreased the U(III) half oxidation time dramatically (2-6 hours).It was concluded that the presence of impurities in U(III) solution act as a catalyst for oxidation of U (III).