Preferential association of adsorbed uranium with mineral surfaces: a study using analytical electron microscopy
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Date
1999-08-01
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Cambridge University Press/Springer Nature Limited
Abstract
Analytical electron microscopy (AEM) has been employed to characterize the distribution of U(VI) on several mineral substrates, including standard kaolinite samples and weathered rock samples from Koongarra, Australia. Results of this study reveal that pre-existing impurity phases play a significant role in the uptake of U(VI) on standard kaolinite samples. Using a natural sample from the weathered zone of the Koongarra uranium deposit, we have also demonstrated that U(VI) sorption is controlled by iron oxyhydroxides (predominantly goethite) which constitute a small fraction of the sample. Limited sorption of U(VI) was observed on the clay minerals of this substrate. Uptake of U(VI) by goethite increases with total uranium content up to the point of uranium precipitation, after which it decreases dramatically. Uranium precipitation is indicated by the appearance of a uranyl oxyhydroxide phase. © 1999 Materials Research Society
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MRS Proceedings Online were formerly published by Cambridge University Press and are currently published by Springer Nature.
Keywords
Adsorption, Clays, Goethite, Kaolinite, Natural analogue, Phase studies, Radioactive waste disposal, Sorptive properties, Uranyl compounds, Koongarra deposit, Australia, Electron microscopy, Northern Territory, Uranium
Citation
Lumpkin, G., Payne, T., Fenton, B., & Waite, T. (1999). Preferential association of adsorbed uranium with mineral surfaces: a study using analytical electron microscopy. Paper presented to the 1998 Materials Research Society Fall Meeting, Boston, MA (United States), 30 Nov - 4 Dec 1998. In Lee, J. H. & Wronkiewicz, D. J., (Eds), MRS Proceedings, 556, 1067-1074. doi:10.1557/PROC-556-1067