Uranium stripping from tri-n-butyl phosphate by hydrofluoric acid solutions with hydrazine addition

The process of uranium stripping from tri-n-butyl phosphate by hydrofluoric acid solutions with the addition of hydrazine was investigated in the temperature range of 20 to 60 °C. Uranium was selectively precipitated in the form of a hydrazine uranyl fluoride complex when stripped from TBP by HF solutions with the addition of hydrazine. The uranium precipitation increased with increasing N2H4/U molar ratio in the range of 1 to 3 and with increasing holding time. Uranium tetrafluoride was obtained by the thermal decomposition of the hydrazine uranyl fluoride complex in a hydrogen stream. The uranium content in UF4 is 76%. The obtained uranium tetrafluoride is a high-purity product and meets all requirements imposed on UF4 at conversion plants. Thus, the stripping method provides a reduction of uranium processing operations to uranium tetrafluoride.