ABSTRACT-The objectives of this study were to address uncertainties in the solubility product of (UO2)3(PO4)2?4H2O(c) and in the phosphate complexes of U(VI), and more importantly to develop needed thermodynamic data for the Pu(VI)-phosphate system in order to ascertain the extent to which U(VI) and Pu(VI) behave in an analogous fashion. Thus studies were conducted on (UO2)3(PO4)2?4H2O(c) and (PuO2)3(PO4)2?4H2O(lc) solubilities for long equilibration periods (up to 870 days) in a wide range of pH values (2.5 to 10.5) at fixed phosphate concentrations of 0.001 and 0.01 M, and in a range of phosphate concentrations (0.0001 to 1.0 M) at fixed pH values of about 3.5. A combination of techniques (XRD, DTA/TG, XAS, and thermodynamic analyses) was used to characterize the reaction products...
Revised: June 23, 2011 |
Published: April 30, 2005
Citation
Rai D., Y. Xia, L. Rao, N.J. Hess, A.R. Felmy, D.A. Moore, and D.E. McCready. 2005.Solubility of (UO2)3(PO4)2.4H2O in H+-Na+-OH--H2PO-4-HPO2-4-PO3-4-H2O and its Comparison to the Analogous PuO2+2 System.Journal of Solution Chemistry 34, no. 4:469-498.PNNL-SA-43126.