Selective liquid‐liquid extraction of uranium by phosphoramidate‐group bearing ionic liquid

Extraction of pure uranium (U) from its ore or spent nuclear fuel and separation of U for trace impurities characterization of nuclear fuels are the processes resulting into the accumulation of large amounts of low boiling and volatile organic waste. The limited reusability and degradation (chemical and radiation induced) of these waste solutions turning out to be an environmental threat. The authors have addressed this issue by developing an eco‐friendly, simple and selective liquid‐liquid extraction (LLE) procedure for U employing a phosphoramidate group bearing task specific ionic liquid (TSIL). Optimization of various LLE parameters resulted in high distribution ratio (D) value of 174±5 for U when extracted from 5 mol L${}^{-1}$ HNO${}_3$ medium. A detailed study on the infrared and extended X‐ray absorption fine structure spectroscopy of U loaded ionic liquid phase reveals the extraction mechanism. Such high D${}_U$ value resulted in high separation factors for U with respect to the elements which are commonly present in the ore, processed nuclear fuel and spent nuclear fuel. The structural integrity and metal ion extractability of the TSIL is found to remain unaffected when irradiated up to an absorbed dose of 400 kilogray (kGy). Sodium carbonate solution is found to back‐extract ≥ 95% of U from the ionic liquid phase and regenerate it for further usage. (© 2019 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)