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Application of chelating weak base resin Dowex M4195 to the recovery of uranium from mixed sulfate/chloride media
journal contribution
posted on 2017-06-01, 00:00 authored by M D Ogden, Ellen MoonEllen Moon, A Wilson, S E PepperThe use of untreated seawater or bore water in uranium mineral processing circuits may represent a cheaper and more sustainable water resource for Australia's mining operations. Using present technologies, the increased salinity from these water sources results in decreased uranium extraction and increased extraction of impurities. There is incentive to overcome these challenges, either through new technologies, or repurposing existing technologies. The ion exchange behaviour of U from sulfate media on the weakly basic chelating resin Dowex M4195 (bis-picolylamine functionality) and the effect of competing chloride and impurity metal ions (Th, Fe, Al, Cu, Ni) has been studied. Experiments to determine acid, and sulfate media behaviour, and extraction thermodynamics including the effect of increasing chloride concentration upon extraction behaviour were carried out. Dowex M4195 was found to have pK 1 and pK 2 values at 4.13 ± 0.04 and 2.1 ± 0.1 determined at 1.0 M NaCl. Dowex M4195 shows affinity for U(VI) over Fe 3+ and Al 3+ in sulfuric acid media with a U(VI) pH 50 a full pH unit below that of Fe 3+ at 0.17 and 1.82 respectively. With increasing chloride concentrations U and Th extraction is suppressed but Fe extraction increases. At the highest chloride concentrations explored Fe is preferentially extracted over U, and Th is not extracted at all. As chloride concentration increases the extraction of U passes through a minimum (40%) before increasing to around 60% for 4.0 M chloride at pH 1.80. Al 3+ is not extracted by M4195 under any conditions explored. Dowex M4195 does show high selectivity for Cu and Ni over everything else.
History
Journal
Chemical Engineering JournalVolume
317Pagination
80 - 89Publisher
Elsevier BVLocation
Amsterdam, The NetherlandsPublisher DOI
ISSN
1385-8947Language
engPublication classification
C Journal article; C1.1 Refereed article in a scholarly journalCopyright notice
2017, ElsevierUsage metrics
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