MINERALOGICAL AND GEOCHEMICAL CHARACTERISATION OF CORES FROM AN IN SITU RECOVERY URANIUM MINE
| dc.contributor.advisor | MCBETH, JOYCE DR. | |
| dc.contributor.advisor | HENDRY, JAMES DR | |
| dc.contributor.committeeMember | LINDSAY, MATHEW | |
| dc.contributor.committeeMember | GROSVENOR, ANDREW | |
| dc.creator | Sumaila, Samira 1986- | |
| dc.creator.orcid | 0000-0002-8679-7086 | |
| dc.date.accessioned | 2018-01-15T17:21:20Z | |
| dc.date.available | 2018-01-15T17:21:20Z | |
| dc.date.created | 2017-12 | |
| dc.date.issued | 2018-01-15 | |
| dc.date.submitted | December 2017 | |
| dc.date.updated | 2018-01-15T17:21:20Z | |
| dc.description.abstract | This study investigates the mineralogy and geochemistry of natural aquifer materials associated with a uranium (U) ore deposit at the Smith Ranch-Highlands Mine, Wyoming, USA. The ore occurs in a roll front deposit and is mined via in situ recovery (ISR). This method of mining is used to recover U from low-grade deposits while producing no tailings or waste rock. This method of mining can, however, contaminate adjacent aquifers with residual U and other elements. The objective of this project is to characterize core taken down-gradient of a mined unit to provide information on the capacity of down-gradient aquifer solids to attenuate U. Core samples were obtained from hydraulically down-gradient of the mine unit B at two locations. Powder X-ray diffraction analyses showed the presence of quartz, clays, feldspar, goethite and pyrite. Electron microprobe analysis, scanning electron microscopy and physical examination confirmed that the core is a heterogeneous mixture of grain sizes with different shapes and composed of clays, sandy materials and coal lenses. Synchrotron X-ray fluorescence mapping revealed the close association of U with Fe, V, Ca and coal lenses in the sediments. Uranium X-ray absorption spectroscopy (XANES) showed the presence of both U(IV) and U(VI) in samples containing coal lenses. Carbon (C) XANES indicated the presence of several C functional groups representative of organic C; however, inorganic C was not identified in the C-K-edge XANES analysis. Iron and S XANES also confirmed the presence of reduced and oxidised Fe and S species. Clays, coal lenses, Fe- oxides and pyrite observed in the core samples may control U concentrations and mobility in groundwater. Geochemical modelling using PHREEQC software showed that primary and secondary U minerals may not control U mobility in these materials but the presence of carbonate, Fe oxides and clays may control U concentrations and mobility through sorption, reduction and precipitation processes. Information from this work can contribute to the quantification and estimation of the risk of downstream/down-gradient human exposure in fate-and-transport models. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | http://hdl.handle.net/10388/8342 | |
| dc.subject | uranium, in-situ recovery mining, reclamation, geochemistry, XANES, PXRD | |
| dc.title | MINERALOGICAL AND GEOCHEMICAL CHARACTERISATION OF CORES FROM AN IN SITU RECOVERY URANIUM MINE | |
| dc.type | Thesis | |
| dc.type.material | text | |
| thesis.degree.department | Geological Sciences | |
| thesis.degree.discipline | Geology | |
| thesis.degree.grantor | University of Saskatchewan | |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science (M.Sc.) |