Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape

dc.contributor.advisorWillis, Jamesen_ZA
dc.contributor.authorGlendinning, John Edwarden_ZA
dc.date.accessioned2016-08-18T13:52:51Z
dc.date.available2016-08-18T13:52:51Z
dc.date.issued1997en_ZA
dc.description.abstractIt is well known that the release of long-lived radionuclides to the water path is probably the most relevant radiological risk originating from an underground repository. Transuranic elements (ie. all elements with an atomic number greater than 92 (U)) do not have any non-radioactive isotopes and are very rare in natural materials. The long term geochemical behaviour of these elements must thus be derived from chemical analogues such as the rare earth elements (REE), Th and U. Steenkampskraal monazite mine, situated 350 km north of Cape Town, has been found to be an excellent locality for the study of these elements, due to the high concentration of these elements in the ore as well as the ideal geology, which consists of low permeability rocks with groundwater flow governed by fractures. The ore body consists of a monazite [(REE, Th, U)P04], apatite [Ca₃P0₄)₂], chalcopyrite [CuFeS] and magnetite [FeP₄] veindeposit. Water was sampled from six boreholes in the vicinity of the mine and five wi.ndpumps on the surrounding farm Nabeep and Brandewynskraal. Surface water samples were taken from the slimes dam, an ephemeral stream on the western side of the mine, as well as from the surface of a road shortly after rain, below the tailings. Four water samples were taken from within the underground mine workings (Mainshaft, Main shaft extension, Sump on level 3 and Inclined shaft). Colloids were sampled from three of the boreholes and a precipitate was taken from the surface of the main shaft water. Soils were sampled along two transects away from the mine on the eastern and western side of the ore body. Due to the topography of the area, surface contamination could only occur on these two sides. Stable isotopes of oxygen (8 180) and hydrogen ((8 180) indicated the presence of two distinct groups of waters within the vicinity of the mine. One group is composed of unevaporated waters and includes all borehole sand the water sampled in the inclined shaft. The water moving through the inclined shaft is in contact with the ground water. A second group of highly evaporated waters was present in the slin1es dam samples as well as the underground water samples not directly in contact with groundwater. Groundwater contamination by REE-bearing phosphate minerals has resulted in measurable concentrations of U, Th and REE in all mine waters and boreholes in the near vicinity of the mine. The chondritenormalized REE patterns of the water samples are sin1ilar to those displayed by monazite, with a distinctive Eu depletion and an obvious enrichment in LREE with respect to HREE. Monazite-normalized REE patterns for the selected borehole waters show a marked fractionation between LREE and HREE, with the HREE strongly enriched in the aqueous phase. Heavy REE have been shown to have a greater tendency for complexatioi1 and a greater affinity for mineral surfaces. In the present study, the three boreholes in which colloids were found had high concentrations of U, Th and REE. It is likely that colloidal transport of these elements is the dominant mechanism of transport.en_ZA
dc.identifier.apacitationGlendinning, J. E. (1997). <i>Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Geological Sciences. Retrieved from http://hdl.handle.net/11427/21332en_ZA
dc.identifier.chicagocitationGlendinning, John Edward. <i>"Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Geological Sciences, 1997. http://hdl.handle.net/11427/21332en_ZA
dc.identifier.citationGlendinning, J. 1997. Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Glendinning, John Edward AB - It is well known that the release of long-lived radionuclides to the water path is probably the most relevant radiological risk originating from an underground repository. Transuranic elements (ie. all elements with an atomic number greater than 92 (U)) do not have any non-radioactive isotopes and are very rare in natural materials. The long term geochemical behaviour of these elements must thus be derived from chemical analogues such as the rare earth elements (REE), Th and U. Steenkampskraal monazite mine, situated 350 km north of Cape Town, has been found to be an excellent locality for the study of these elements, due to the high concentration of these elements in the ore as well as the ideal geology, which consists of low permeability rocks with groundwater flow governed by fractures. The ore body consists of a monazite [(REE, Th, U)P04], apatite [Ca₃P0₄)₂], chalcopyrite [CuFeS] and magnetite [FeP₄] veindeposit. Water was sampled from six boreholes in the vicinity of the mine and five wi.ndpumps on the surrounding farm Nabeep and Brandewynskraal. Surface water samples were taken from the slimes dam, an ephemeral stream on the western side of the mine, as well as from the surface of a road shortly after rain, below the tailings. Four water samples were taken from within the underground mine workings (Mainshaft, Main shaft extension, Sump on level 3 and Inclined shaft). Colloids were sampled from three of the boreholes and a precipitate was taken from the surface of the main shaft water. Soils were sampled along two transects away from the mine on the eastern and western side of the ore body. Due to the topography of the area, surface contamination could only occur on these two sides. Stable isotopes of oxygen (8 180) and hydrogen ((8 180) indicated the presence of two distinct groups of waters within the vicinity of the mine. One group is composed of unevaporated waters and includes all borehole sand the water sampled in the inclined shaft. The water moving through the inclined shaft is in contact with the ground water. A second group of highly evaporated waters was present in the slin1es dam samples as well as the underground water samples not directly in contact with groundwater. Groundwater contamination by REE-bearing phosphate minerals has resulted in measurable concentrations of U, Th and REE in all mine waters and boreholes in the near vicinity of the mine. The chondritenormalized REE patterns of the water samples are sin1ilar to those displayed by monazite, with a distinctive Eu depletion and an obvious enrichment in LREE with respect to HREE. Monazite-normalized REE patterns for the selected borehole waters show a marked fractionation between LREE and HREE, with the HREE strongly enriched in the aqueous phase. Heavy REE have been shown to have a greater tendency for complexatioi1 and a greater affinity for mineral surfaces. In the present study, the three boreholes in which colloids were found had high concentrations of U, Th and REE. It is likely that colloidal transport of these elements is the dominant mechanism of transport. DA - 1997 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1997 T1 - Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape TI - Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape UR - http://hdl.handle.net/11427/21332 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21332
dc.identifier.vancouvercitationGlendinning JE. Factors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Cape. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Geological Sciences, 1997 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/21332en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Geological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherGeological Sciencesen_ZA
dc.subject.otherGeochemistryen_ZA
dc.titleFactors influencing the mobility of uranium, thorium and rare earth elements at the Steenkampskraal monazite, North Western Capeen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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