Production of nuclear grade uranium trioxide by a non-conventional method

A non - conventional method to produce nuclear grade uranium trioxide (orange oxide) from crude yellow cake has been proposed. The method depends on selective leaching of uranium from the yellow cake using ammonium carbonate and selective precipitation of ion from the obtained leach solution using hydrogen peroxide. In carrying out the optimization of the leaching of uranium, it was found that 130 g/L of ammonium carbonate will be required for complete dissolution of uranium from the present yellow cake at a solid/;liquid ratio of 1/10, a reaction temperature of 50 degree C and 6 h mixing time. Nitric acid is added to the leach solution to convert uranyl carbonate solution (ph = 8) to uranyl nitrate (ph-2.7). Afterwards, uranium peroxide is precipitated from the uranyl nitrate solution by adding hydrogen peroxide and ammonia solution in presence of 5% (W/V) EDTA solution for masking impurities. Finally, uranium trioxide dihydrate (UO3.2 H2 O) is obtained by reducing the precipitated uranium peroxide with 2 M sodium thiosulphate solution at ambient temperature. Nuclear purity of the product has been confirmed by determination of trace impurities using inductively coupled plasma--mass spectrometer (ICP-MS) instrument