Metallurgy Commons^™

Voltammetric Investigation Of Xanthate Chemisorption On A Chalcopyrite Surface, Jesse Lynn Bowden

Graduate Theses & Non-Theses

Cyclic Voltammetry experiments have been conducted on copper, iron, and chalcopyrite (CuFeS2) and compared to mass-balanced EH-pH Diagrams. Potassium ethyl xanthate (KEX) was added to solution and additional voltammetry experiments were performed to determine the surface chemistry reactions of flotation collector in solution with these minerals. The ultimate goal of this research was to investigate the possibility of xanthate chemisorption onto the chalcopyrite mineral surface. Results of the copper mineral testing confirm previous literature studies and corroborate published isotherm data. Results of the iron mineral testing showed changes in surface reactions with the addition of potassium ethyl xanthate to solution, …

Thermodynamic Considerations In Molten Salt Electrolysis For Rare Earth Metals, Arwin Gunawan

Graduate Theses & Non-Theses

Many applications utilize rare earths as a part of their essential composition, such as: Ni-MH batteries, glass screen, magnets, fluorescent lightning, etc. These reactive elements are normally found as an oxide compound due to their affinity with oxygen. Their oxide formation exhibits a high standard free energy, which make them really stable. Consequently, extracting rare earths cannot be easily done with a simple acid-base reaction.

It has been known that there are two reduction ways to extract rare earth, metallothermic reduction and molten salt electrolysis process. Metallothermic method is determined by standard free energy formation, melting point, boiling point, vapor …

Thermal Processing And Mechanical Properties Of Beta Phase Titanium Alloys For Biomedical Applications, Ethan Wood

Graduate Theses & Non-Theses

The past few decades have seen an increase in the use of beta titanium alloys as structural biomaterials. Their combination of excellent mechanical properties, corrosion resistance and biocompatibility, along with a lower Young’s modulus than stainless steel, cobalt-chromium and commercially pure titanium make the beta titanium alloys ideal biomaterials. This work evaluates the use of three beta titanium alloys for biomedical applications. Three beta titanium alloys, Ti 15-3-3-3, Ti SP-700 and Ti Beta-C, underwent thermal processing to optimize mechanical properties. The alloys were subjected to tensile testing, hardness testing, fatigue testing, optical microscopy and SEM fracture analysis in order to …

Estimation And Thermodynamic Modeling Of Solid Iron Species In The Berkeley Pit Water, Rajesh Srivastava

Graduate Theses & Non-Theses

Since the cessation of open-pit mining activities from the Berkeley Pit located in Butte, MT in 1982, the pit had gradually filled with metal-laden acidic mine water. The purpose of this investigation was to estimate and apply thermodynamic theory to a group of iron-sulfate solids that might equilibrate with the Berkeley Pit water. Thermodynamic data was incomplete for acid mine affected water, and the effects of Cu cementation on the formation of iron oxide and sulfate solids had not been analyzed. Ferric iron compounds such as Ferrihydrite, Goethite, Schwertmannite, Potassium Jarosite and Potassium Hydronium Jarosite were modelled in Stabcal using …

Optimization Of Rare Earth Leaching From Ores And Concentrates, Grant Wallace

Graduate Theses & Non-Theses

The use of applied chemistry in the production and optimization of leach solutions from Rare Earth Element (REE) ores and concentrates was investigated. Ore and concentrate samples were characterized using scanning electron microscopy/mineral liberation analysis (SEM/MLA), X-ray Diffraction (XRD), and Inductively-coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Multiple leach tests were performed to analyze the effects of temperature, residence time, and reagent concentration on the leaching of REEs. Analysis of leach solutions was carried out using ICP-AES. Modeling and statistical analysis of extraction behavior was carried out using DesignExpert 9. Modeling data for multiple REEs indicate that extraction is strongly influenced …