Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 25 for “"metal sulfides"”.
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Investigating the role of dithiophosphate in the flotation of base metal sulfides
… to the Platinum Group Mineral (PGM) and Base Metal Sulphide (BMS) industry. Operationally, SEDTP has proved to be a point of contention as there are conflicting views regarding the role of collector with regard to its behaviour at the air-water and solid-water interface in the flotation …
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Synthesis of binary, ternary, and alloyed metal sulfides by a solvent-less route
… by reacting with an aqueous solution of the metal nitrate. The second section involves the melt (solvent less) method. This is as follows, a stoichiometric amount of xanthate complexes of the corresponding metal was mixed and crushed to obtain a homogenous mixture. The mixture was then placed …
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Non-hydrolytic Sol-gel (NHSG) Synthesis of Transition Metal Sulfides and Theoretical Investigations
… is explored for the synthesis of binary metal sulfides.Sulfides, some of which are thermally unstable and highly oxygen sensitive, have applications in many areas, such as solar cells, catalysts, sensors, lubricants, semiconductors etc.<sup>2</sup> Despite the widespread use of sulfides, …
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Roussin's Red Salt Revisited: Synthesis and Characterization of Metal Nitrosyl Dimers and Clusters (Cubanes, Heterobimetallic, Metal Sulfides)
… prompted us to investigate the synthesis of metal nitrosyl dimers in general, later evolving into a study of metal nitrosyl clusters.
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An Investigation of Metal Sulfides as the Source of the Low Emissivity Anomaly on the Highlands of Venus
<p>Since its detection in the 1960s the source of the unusual radar emissivity signal seen on several highlands on Venus has long eluded researchers. Researchers have determined that a mineral with a high dielectric constant could explain the signal. Using a Venus simulation chamber, we …
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Waste to an Asset, H2S to Hydrogen: A DFT Study
… H2S oxidation reaction (H2SOR) over various metal oxides and metal sulfides using Density Functional Theory (DFT) calculations. We demonstrate why RuO2 has been widely reported as an active H2SOR catalyst. We also show that metal oxides are susceptible to sulfur poisoning, which makes their …
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Synthesis and Reactivity of Dichalcogenide and Substituted Dichalcogenide Ligands in Molecular and Nonmolecular Compounds
… reactivity studies were extended to solid-state metal sulfides, particularly pyrite (FeS(,2)).
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Tetrathiometallates in Synthesis and Catalysis
… cycloaddition has not been observed before for metal sulfides.
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Depression of pyrite in polymetallic sulfide flotation using chitosan-grafted-polyacrylamide polymers
… depressants of pyrite in the flotation of base metal sulfides. Fundamental studies of the adsorption behavior of Chi-g-PAM on model sulfide minerals indicated that Chi-g-PAM was more selective to pyrite’s surfaces as compared to base metal sulfides. Results suggested that the adsorption of …
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Petrology and geochemistry of precious and base metal mineralization, North Amethyst vein system Mineral County, Colorado
Gold, silver and base metal-rich minerals of the North Amethyst vein occupy fractures in 26 Ma volcanic rocks near the southern margin of the San Luis caldera, at the northern edge of the Creede district, San Juan Mountains, Colorado. The veins contain two associations of mineral assemblages that …
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Effects of intermittent irrigation on the extraction of copper from heap bioleaching systems.
… ores is finding increasing application as a hydrometallurgical unit operation applicable to the treatment of the increasing low grade ores. These same microorganisms contribute to the formation of acid rock drainage (ARD) through the oxidation of base metal sulfides, particularly pyrite. In this …
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Entwicklung einer Technologie zur langzeitstabilen Biologischen Reinigung schwermetallbelasteter Bergbauwässer
… waters with both high concentrations of heavy metals and sulphate was developed. The technology is based on the technical coupling of microbially mediated hydrolysis, fermentation and microbial sulphate reduction in a self-stabilising process. Electron donor for sulphate reduction is supplied …
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Gold-silver mineralization at the London-Virginia Mine, Buckingham County, Virginia
… limonite, and pyrite with minor calcite, base metal sulfides and is believed to have formed as a result of exhalative processes analogous to those currently active in the Atlantis II Deep of the Red Sea. Silica-rich, hypersaline brines discharging through fractures in the sea floor ponded in a …
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Methodology for determining electronic transference numbers in molten sulfide melts
… [1]. The allure of an electrolysis process for metals extraction can be enhanced by increasing its faradaic efficiency, through, for example, decreasing the electronic transference number of the electrolyte. This thesis compares two methods of determining the electronic transference number in …
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Inferences on the influences of age & porosity on oxidative weathering of seafloor massive sulfide deposits at the endeavour segment of the Juan de Fuca Ridge
… mineral deposits comprised mainly of inorganic metal sulfides that precipitate from mixtures of seawater and high-temperature, sulfide-rich, oxygen-poor vent fluid. These mineral aggregates are known as seafloor massive sulfide deposits and occupy unique biogeochemical niches that remain largely …
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Direct Templating of Semiconductor Nanostructures With Lyotropic Liquid Crystals
… structure and water content. Several other metal sulfides such as PbS, Ag2S. CuS and HgS were produced only as nonfeatured solids using identical synthetic methodologies. The sensitivity of the methodologies to the chemistry of precursors has allowed us to develop a model that takes into …
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Inferences on the Influences of Age & Porosity on Oxidative Weathering of Massive Sulfides at the Endeavour Segment of Juan de Fuca Ridge
… mineral deposits comprised mainly of inorganic metal sulfides that precipitate from mixtures of seawater and high-temperature, sulfide-rich, oxygen-poor vent fluid. These mineral aggregates are known as seafloor massive sulfide deposits and occupy unique biogeochemical niches that remain largely …
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Evaluation of sorbents for the cleanup of coal-derived synthesis gas at elevated temperatures
… only carbon dioxide, but also sulfur and trace metals such as lead or mercury. One potential method to improve the efficiency for IGCC is through the use of solid sorbents that operate at elevated temperatures. Because many of these technologies are in their infancy and have yet to be …
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Synthesis and characterisation of CdS and PbS nanoparticles in an imidazolium based ionic liquid
Semiconductor metal sulfides nanoparticles have been prepared using the imidazolium based ionic liquid surfactant as both the stabilizer and growth modifier. The structural and morphological properties of the as-prepared nanoparticles were characterized by X-ray diffraction (XRD), transmission …
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The geochemistry of carbonate-hosted Pb-Zn-Ag mineralization in the Lavrion District, Attica, Greece: fluid inclusion, stable isotope, and rare earth element studies
… deposits is dominated by base metal sulfides and sulfosalts of Ag, Bi, Sn, Sb, As, and Pb, particularly at Plaka and Kamariza. Carbonates are intergrown with earlier sulfide and sulfosalt mineralization, but are more abundant late in the paragenetic sequence with fluorite and …
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