Pandelus Samantha B, Kennedy Brendan J, Murphy Gabriel, Brand Helen E, Keegan Elizabeth, Pring Allan, Popelka-Filcoff Rachel S
College of Science and Engineering, Flinders University, Adelaide, South Australia 5001, Australia.
School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia.
Inorg Chem. 2021 Aug 2;60(15):11569-11578. doi: 10.1021/acs.inorgchem.1c01562. Epub 2021 Jul 22.
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-UO(OH), together with metaschoepite (UO)O(OH)·5HO, in the aged UO samples, and it is speculated that this forms as a consequence of the corrosion of UO in the presence of metaschoepite. The third sample, from the Beverley uranium mine, contains the peroxide [UO(η-O)(HO)] (metastudtite) together with α-UO(OH) and metaschoepite. A core-shell model is proposed to account for the broadening of the diffraction peaks of the UO evident in the samples.
铀氧化物的化学形态对样品的来源及其储存条件很敏感。在此，我们使用衍射方法来表征在三种不同来源的老化（超过10年）铀矿浓缩物中发现的相，以及对这些材料的热诱导结构转变进行原位分析。利用高分辨率同步加速器X射线衍射数据，对在三个样品中发现的晶相结构进行了精修。对奥林匹克坝和兰杰铀矿样品的Rietveld分析表明，在老化的UO样品中存在结晶α-UO(OH)以及变水铀矿（UO）O(OH)·5H₂O，据推测，这是UO在变水铀矿存在下腐蚀的结果。来自贝弗利铀矿的第三个样品含有过氧化物[UO₂(η-O₂)(H₂O₂)]（变水铀矿）以及α-UO(OH)和变水铀矿。提出了一个核壳模型来解释样品中UO衍射峰的展宽。
