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Full-Text Articles in Physical Sciences and Mathematics
Trace Element Geochemistry And Nd-Sr Isotope Systematics Of Scheelite From The Thunder Creek And 144 Gap Deposits, Timmins, Ontario: Implications For Timing And Genesis Of Gold, Annika Van Kessel
Electronic Thesis and Dissertation Repository
The age of the youngest gold event at the Timmins West Mine is unknown. Scheelite geochemistry and geochronology at the TWM were constrained using WDS and EDS mapping, LA-ICPMS and MC-ICPMS analytical techniques. Trace element analyses by LA-ICPMS revealed scheelites mineralized from a common and oxidized fluid. Samarium-Neodymium isotopic analyses of 15 scheelite grains yielded a linear regression isochron with a corresponding age of 2587 +/- 49 Ma (MSWD = 2.5) and εNdi, calculated from CHUR, of 1.01 ± 0.11 (2SD). A second internal isochron from a single scheelite grain yielded an age of 2516 +/- 88 Ma (MSWD = …
Coinage Metal Chalcogenide Clusters With N-Heterocyclic Carbene Ancillary Ligands, Alex Polgar
Coinage Metal Chalcogenide Clusters With N-Heterocyclic Carbene Ancillary Ligands, Alex Polgar
Electronic Thesis and Dissertation Repository
This thesis describes the synthesis and characterization of homo- and heterometallic group 11 – group 16 clusters with N-heterocyclic carbene (NHC) ligands. The clusters were prepared from reactive group 11 trimethylsilylchalcogenolate reagents (NHC-M-ESiMe3; M = Cu, Au; E = S, Se, Te) by silane deprotection reactions with phosphine- or phosphite-solubilized group 11 acetates (R3P-M-OAc; M = Cu, Ag, Au). Clusters were characterized by combustion analysis and spectroscopic methods in solution and the solid state. The clusters were phosphorescent at low temperatures with emission energies that depend on the metal/chalcogen composition, ancillary NHC ligand, cluster geometry and nuclearity, and local environment. …
Study On The Surface Features Of Preg-Robbing Carbonaceous Matter During Oxidation Treatment, Mana Pourdasht
Study On The Surface Features Of Preg-Robbing Carbonaceous Matter During Oxidation Treatment, Mana Pourdasht
Electronic Thesis and Dissertation Repository
Carbonaceous gold ores have the ability to adsorb gold (I) cyanide from leach solutions during processing. This phenomenon, known as preg-robbing, is responsible for poor recoveries as the carbonaceous materials of the ore compete with activated carbon used during the leaching and adsorption phase of processing. Chemical oxidation of carbonaceous materials by different reagents has been utilized to investigate and compare the mechanism of Au (CN)2 adsorption onto carbonaceous materials prior to and following the treatment.
The procedure for characterization of the carbonaceous materials (plain and modified) in the sample combines the use of several analytical techniques and test …