How is yellow cake refined into purified uranyl nitrate?

To obtain nuclear-grade uranium from yellow cake, the material undergoes a solvent-extraction process to produce purified uranyl nitrate, ${\text{UO}}_2({\text{NO}}_3{)}_2$.1

The refining process involves the following steps:

• Dissolution: The yellow cake is first dissolved in nitric acid to create a feed solution.1
• Selective Extraction: Uranium is selectively extracted from this acidic feed using tributyl phosphate, which is typically diluted with kerosene or another suitable hydrocarbon mixture.1
• Stripping: Finally, the uranium is stripped from the tributyl phosphate extract into acidified water, resulting in highly purified uranyl nitrate.1

Once produced, this uranyl nitrate serves as a primary starting material for further conversion into uranium metal or for the enrichment of the uranium-235 isotope.2