Secondary extraction properties of actinide and zirconium solvates with tributyl phosphate

The nitrate groups of tributyl phosphate solvates of polyvalent metal salts can be substituted by other anions (TcO4-, MnO4-, Cl-, ClO4-) during extraction from mixtures of mineral acids by the anion-exchange reaction, e.g., UO2(TBP)(2)(NO3)(2) + A(-) = UO2(TBP)(2)NO(3)A + NO3-, where A(-) is the anion. This capability of solvates to substitute or add anions can be considered as their own extraction activity of the anion-exchange type. In the case of organic layer separation into two phases, the ion pair with the composition [Me(NO3)(3)(TBP)(4)](+)...[UO2(NO3)(3)](-), where Me = Th or Zr, is probably formed in the heavy organic phase.