The Solubility of Th(IV) and U(IV) Hydrous Oxides in Concentrated Nahco3 and Na2Co3 Solutions
Authors:
- 1 January 1994
- journal article
- Published by Springer Nature in MRS Proceedings
- Vol. 353
Abstract
The solubility of Th(IV) and U(IV) hydrous oxide was studied in the aqueous HCO3−-CO32−-OH−-H2O system extending to high concentration. The solubility of the Th(IV) and U(IV) hydrous oxides increases dramatically in both high bicarbonate and carbonate solutions and decreases with the increase in hydroxide at a fixed carbonate concentration. In general, the observed solubility of Th(IV) hydrous oxide at a given total carbonate concentration was three to four orders of magnitude higher than the solubility of U(IV) hydrous oxide. In the studies of the U(IV) system, extreme caution was used to ensure that the dissolved U was present as U(IV). Oxidation state analyses and systematic trends in the U(IV) solubility data similar to those for Th(IV), which is not redox sensitive, indicated that the dissolved U was present as U(IV).Keywords
This publication has 8 references indexed in Scilit:
- On the influence of carbonate on mineral dissolution: III. The solubility of microcrystalline ThO2 in CO2-H2O mediaGeochimica et Cosmochimica Acta, 1994
- Uranium(IV) hydrolysis constants and solubility product of UO2.cntdot.xH2O(am)Inorganic Chemistry, 1990
- Studies of metal carbonate equilibria. 20. Formation of tetra(carbonato)uranium(IV) ion, U(CO3)44−, in hydrogen carbonate solutionsInorganica Chimica Acta, 1989
- Thorium(IV) hydrous oxide solubilityInorganic Chemistry, 1987
- Solubility of NpO2 • xH2O(am) in the Presence of Cu(I)/Cu(II) Redox BufferRadiochimica Acta, 1987
- Neptunium(IV) hydrous oxide solubility under reducing and carbonate conditionsInorganic Chemistry, 1985
- Solubility Product of Pu(IV) Hydrous Oxide and Equilibrium Constants of Pu(IV)/Pu(V), Pu(IV)/Pu(VI), and Pu(V)/Pu(VI) CouplesRadiochimica Acta, 1984
- Electrochemical and spectroscopic studies of uranium(IV), -(V), and -(VI) in carbonate-bicarbonate buffersInorganic Chemistry, 1980