Abstract
A stepwise thermal treatment process for the recovery of uranium phosphate from uranium-dissolved spent TBP was demonstrated. The pathway of the reactions involved in the thermal decomposition and oxidation processes of uranium-bearing spent TBP was established based on the results of thermogravimetric analyses. Relatively low-temperature pyrolysis is required to avoid the condensation of corrosive phosphoric acid via vaporization. Low-temperature pyrolysis residue was analyzed and found to be composed of pyrocarbon, phosphorus oxide (P2O5) and two types of uranium phosphate (UP2O7 and UP4O12). Uranium pyrophosphate (UP2O7) was recovered from the burning out of pyrocarbon in the pyrolysis residue after the dissolution removal of phosphorus oxide in water. A substantial recovery of uranium by the proposed stepwise thermal treatment method was successfully demonstrated by a treatment of pyrolysis residue from a bench-scale low-temperature pyrolysis process.
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Acknowledgments
This work was supported by the National Research Foundation of Korea (NRF) Grant funded by Korea government (MSIP) (No. NRF-2012M2A8A5025658).
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Yang, HC., Kim, HJ., Yang, IH. et al. Recovery of uranium phosphate by a stepwise thermal treatment of uranium-bearing spent TBP. J Mater Cycles Waste Manag 18, 437–444 (2016). https://doi.org/10.1007/s10163-016-0467-2
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DOI: https://doi.org/10.1007/s10163-016-0467-2