Phase analysis of Australian uranium ore concentrates determined by variable temperature synchrotron powder x-ray diffraction
No Thumbnail Available
Date
2021-07-22
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Abstract
The chemical speciation of uranium oxides is sensitive to the provenance of the samples and their storage conditions. Here, we use diffraction methods to characterize the phases found in three aged (>10 years) uranium ore concentrates of different origins as well as in situ analysis of the thermally induced structural transitions of these materials. The structures of the crystalline phases found in the three samples have been refined, using high-resolution synchrotron X-ray diffraction data. Rietveld analysis of the samples from the Olympic Dam and Ranger uranium mines has revealed the presence of crystalline α-UO2(OH)2, together with metaschoepite (UO2)4O(OH)6·5H2O, in the aged U3O8 samples, and it is speculated that this forms as a consequence of the corrosion of U3O8 in the presence of metaschoepite. The third sample, from the Beverley uranium mine, contains the peroxide [UO2(η2-O2)(H2O)2] (metastudtite) together with α-UO2(OH)2 and metaschoepite. A core–shell model is proposed to account for the broadening of the diffraction peaks of the U3O8 evident in the samples. © 2021 American Chemical Society
Description
Keywords
Oxides, Uranium ores, X-ray diffraction, Synchrotrons, Molecular structure, Phase transformations
Citation
Pandelus, S. B., Kennedy, B. J., Murphy, G., Brand, H. E., Keegan, E., Pring, A., & Popelka-Filcoff, R. S. (2021). Phase analysis of Australian uranium ore concentrates determined by variable temperature synchrotron powder x-ray diffraction. Inorganic Chemistry, 60(15), 11569-11578. doi:10.1021/acs.inorgchem.1c01562