INOR 187 |
| Differences in the solubility of transition metals (TM), lanthanides (Ln), and uranium(VI) compounds in alkaline carbonate media can be used to develop a new alkaline-based separation process for spent nuclear fuel reprocessing. Hydrogen peroxide, used to dissolve UO2 in carbonate media, readily forms multiple mixed-ligand U(VI)-peroxo-carbonato complexes in solution. These complexes exhibit significantly higher solubility than the limiting binary UO2(CO3)34- species. The solubility of Ln(III) and TM is altered significantly upon the addition of H2O2 due to the formation of insoluble mixed peroxo-carbonato complexes. Mixtures of U(VI)-Ln(III) or U(VI)-TM in carbonate solutions show surprising behavior: Ln(III) and TM solubility increases in the presence of U(VI), with and without H2O2 , and H2O2 preferentially complexes U(VI) over Ln(III). We will present the complex and dynamic chemistry of U(VI), TM, and Ln(III) in H2O2 containing carbonate solutions , including structural characterization, thermodynamic parameters, solution speciation, and synergistic phenomena in multi-metal systems. |
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Chemistry of Lanthanides and Actinides
7:00 PM-10:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Sci-Mix
Division of Inorganic Chemistry |