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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Sandstone provenance and diagenesis of arc-related basins : James Ross Island and Alexander Island, Antarctica

Browne, Joanna Rae January 1995 (has links)
No description available.
52

Genesis of Cu-PGE-rich footwall-type mineralization in the Morrison deposit, Sudbury

Nelles, Edward William 21 May 2014 (has links)
The Morrison deposit, located at the Levack mine in the City of Greater Sudbury, is a footwall-type Cu-Ni-platinum-group-element (PGE) deposit hosted within a zone of Sudbury Breccia in the Archean Levack Gneiss Complex beneath the North Range of the Sudbury Igneous Complex. It consists of sharp-walled, sulfide-rich veins that are enriched in Cu-Pt-Pd-Au relative to contact-type mineralization and can be subdivided based on vein geochemistry, mineralogy, texture, and morphology into a pyrrhotite-rich upper domain, a chalcopyrite-rich lower domain, and a pyrrhotite equal to chalcopyrite middle domain. All domains contain steeply to vertically dipping first-order sulfide veins, irregular and discontinuous second-order sulfide veins, and disseminated sulfides in country rocks. First- and second-order veins can be further subdivided into inclusion-free veins typically within Sudbury breccia matrix or along clast-matrix boundaries, and very irregular and inclusion-rich veins associated with leucosomes in mafic gneiss clasts and granophyric-textured dikes. First-order veins consist of pyrrhotite > chalcopyrite = pentlandite > magnetite in the upper domain, pyrrhotite = chalcopyrite > pentlandite > cubanite > magnetite in the middle domain, and chalcopyrite >> pentlandite > pyrrhotite = cubanite > magnetite in the lower domain. Second-order veins consist of pyrrhotite = chalcopyrite > pentlandite > magnetite and chalcopyrite = millerite = pentlandite in the middle domain, and chalcopyrite >> millerite, millerite > chalcopyrite, bornite >> chalcopyrite, and millerite > bornite > chalcopyrite in the lower domain. Second order veins are adjacent to and in contact with epidote, amphibole, chlorite, carbonate, quartz, and magnetite alteration minerals. Sulfide mineralization in the Morrison deposit is similar to other footwall mineralization associated with the SIC. The veins appear to have been emplaced preferentially into zones of Sudbury Breccia that were within ~400m of the basal contact of the SIC, because that lithology is more permeable and because those zones are within the thermal aureole of the cooling SIC permitting penetration of sulfide melts. The mineralogical, textural, and geochemical zoning in the chalcopyrite-pentlandite-pyrrhotite-rich parts of the Morrison deposit are best explained by partial fractional and/or equilibrium crystallization of MSS and ISS. Bornite ± millerite-rich mineralization are interpreted to have formed by reaction of residual sulfide melts with wall rocks, consuming Fe and S to form actinolitemagnetite- epidote-chlorite-sulfide reaction zones and driving the sulfide melt across the thermal divide in that part of the Fe-Cu-Ni-S system to crystallize borniteSS ± milleriteSS. Gold-Pt-Pd appear to have been more mobile than other metals, forming localized zones of enrichment, although it is not clear yet whether they were mobile as Au-Pt-Pd-Bi-Te-Sb-rich melts or aqueous fluids.
53

Copper minerals under the microscope

Hjeltström, Anna January 2015 (has links)
From many perspectives copper is a very important metal for the modern society. It can be found in everything from jewellery to electronics. For this reason it is very important for geologists to be able to develop efficient methods for identification, characterisation, extraction and processing of copper. One method for the identification of copper bearing minerals is ore microscopy which has been used in this paper along with a general introduction. Samples from the study collection of the Department of Earth Sciences and the area of Långban and Månhöjden have been examined, documented and described in detail. The thesis begins with an introduction to the history and geochemistry of copper along with some ore forming processes.
54

Electronic structures of the sulfide minerals sphalerite, wurtzite, pyrite, marcasite, and chalcopyrite

Jones, Robert T. Unknown Date (has links)
The electronic spectra of sulfide minerals can be complex, and their features difficult to assign. Often, therefore, they are interpreted using electronic-structure models obtained from quantum-chemical calculations. The aim of this study is to provide such models for the minerals sphalerite, wurtzite, pyrite, marcasite, and chalcopyrite. All are important minerals within a mining context, either as a source for their component metals or as a gangue mineral. They are also semiconductors. Each is the structural archetype for a particular class of semiconductors, and so a knowledge of their electronic structures has wider applicability. / Thesis (PhDAppliedScience)--University of South Australia, 2006.
55

Electronic structures of the sulfide minerals sphalerite, wurtzite, pyrite, marcasite, and chalcopyrite /

Jones, Robert T. Unknown Date (has links)
The electronic spectra of sulfide minerals can be complex, and their features difficult to assign. Often, therefore, they are interpreted using electronic-structure models obtained from quantum-chemical calculations. The aim of this study is to provide such models for the minerals sphalerite, wurtzite, pyrite, marcasite, and chalcopyrite. All are important minerals within a mining context, either as a source for their component metals or as a gangue mineral. They are also semiconductors. Each is the structural archetype for a particular class of semiconductors, and so a knowledge of their electronic structures has wider applicability. / Thesis (PhDAppliedScience)--University of South Australia, 2006.
56

Selective aggregation and flotation of lead sulphide /

Wightman, Elaine Unknown Date (has links)
Thesis (PhD)--University of South Australia, 2000
57

Quantum chemical and experiental studies of reactions of sulfide mineral surfaces /

O'Dea, Anthony R. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 2000
58

The interaction of thionocarbamate and thiourea collectors with sulfide mineral surfaces /

Fairthorne, Gillian A. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 1996
59

Application of surface science to sulfide mineral processing

Goh, Siew Wei, Chemistry, Faculty of Science, UNSW January 2006 (has links)
Surface spectroscopic techniques have been applied to facets of the flotation beneficiation and hydrometallurgical extraction of sulfide minerals to enhance the fundamental understanding of these industrially important processes. As a precursor to the determination of surface chemical composition, the sub-surface properties of some sulfide minerals that have not previously been fully characterised were also investigated. The electronic properties of ??-NiS and ??-NiS (millerite), Ni3S2 (heazlewoodite), (Ni,Fe)9S8 (pentlandite), CuFe2S3 (cubanite), CuFeS2 (chalcopyrite), Cu5FeS4 (bornite) and CuS (covellite) were investigated by conventional and synchrotron X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy augmented by ab initio density of state calculations and NEXAFS spectral simulations. Particular aspects studied included the relationship between sulfur coordination number and core electron binding energies, the higher than expected core electron binding energies for the sulfur in the metal-excess nickel sulfides, and the formal oxidation states of the Cu and Fe in Cu-Fe sulfides. It was concluded that the binding energy dependence on coordination number was less than previously believed, that Ni-Ni bonding was the most likely explanation for the unusual properties of the Ni sulfides, and that there was no convincing evidence for Cu(II) in sulfides as had been claimed. Most of the NEXAFS spectra simulated by the FEFF8 and WIEN2k ab initio codes agreed well with experimental spectra, and the calculated densities of states were useful in rationalising the observed properties. XPS, static secondary ion mass spectrometry (SIMS) and NEXAFS spectroscopy were used to investigate thiol flotation collector adsorption on several sulfides in order to determine the way in which the collector chemisorbs to the mineral surface, to differentiate monolayer from multilayer coverage, and to characterise the multilayer species. It was found that static SIMS alone was able to differentiate monolayer from multilayer coverage, and together with angle-resolved NEXAFS spectroscopy, was also able to confirm that 2-mercaptobenzothiazole interacted through both its N and exocyclic S atoms. The altered layers formed on chalcopyrite and heazlewoodite during acid leaching were examined primarily by means of threshold S KLL Auger electron spectroscopy, but no evidence for buried interfacial species was obtained.
60

Application of surface science to sulfide mineral processing

Goh, Siew Wei, Chemistry, Faculty of Science, UNSW January 2006 (has links)
Surface spectroscopic techniques have been applied to facets of the flotation beneficiation and hydrometallurgical extraction of sulfide minerals to enhance the fundamental understanding of these industrially important processes. As a precursor to the determination of surface chemical composition, the sub-surface properties of some sulfide minerals that have not previously been fully characterised were also investigated. The electronic properties of ??-NiS and ??-NiS (millerite), Ni3S2 (heazlewoodite), (Ni,Fe)9S8 (pentlandite), CuFe2S3 (cubanite), CuFeS2 (chalcopyrite), Cu5FeS4 (bornite) and CuS (covellite) were investigated by conventional and synchrotron X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy augmented by ab initio density of state calculations and NEXAFS spectral simulations. Particular aspects studied included the relationship between sulfur coordination number and core electron binding energies, the higher than expected core electron binding energies for the sulfur in the metal-excess nickel sulfides, and the formal oxidation states of the Cu and Fe in Cu-Fe sulfides. It was concluded that the binding energy dependence on coordination number was less than previously believed, that Ni-Ni bonding was the most likely explanation for the unusual properties of the Ni sulfides, and that there was no convincing evidence for Cu(II) in sulfides as had been claimed. Most of the NEXAFS spectra simulated by the FEFF8 and WIEN2k ab initio codes agreed well with experimental spectra, and the calculated densities of states were useful in rationalising the observed properties. XPS, static secondary ion mass spectrometry (SIMS) and NEXAFS spectroscopy were used to investigate thiol flotation collector adsorption on several sulfides in order to determine the way in which the collector chemisorbs to the mineral surface, to differentiate monolayer from multilayer coverage, and to characterise the multilayer species. It was found that static SIMS alone was able to differentiate monolayer from multilayer coverage, and together with angle-resolved NEXAFS spectroscopy, was also able to confirm that 2-mercaptobenzothiazole interacted through both its N and exocyclic S atoms. The altered layers formed on chalcopyrite and heazlewoodite during acid leaching were examined primarily by means of threshold S KLL Auger electron spectroscopy, but no evidence for buried interfacial species was obtained.

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