Obtaining Nitric Acid Solutions of Uranyl at Deficiency of NO3– Anions

The dissolution of uranium oxides of various chemical compositions at different nitric acid solution concentrations and flow rates with obtaining uranyl nitrate solutions with a deficiency of NO3– anions was studied. The dependences of the solubility of uranyl hydroxonitrates on the nitric acid deficiency relative to stoichiometry and temperature were determined. It was shown that the solubility of hydroxonitrates in these solutions is higher than the solubility of uranyl nitrates obtained with stoichiometric or excess nitric acid content. In addition, the solubility of hydroxonitrates increases with temperature. The kinetics of uranium oxide dissolution in various temperature regimes with the formation of solutions with nitric acid deficiency relative to stoichiometry were studied. The initial dissolution rate of U3O8 in uranyl nitrate solution was determined in the temperature range from 40 to 104°C.