نتایج جستجو برای: reduction of hematite

تعداد نتایج: 21188099  

Journal: :Minerals 2021

Magnetization roasting followed by magnetic separation is considered an effective method for recovering iron minerals. As hematite and magnetite are the main concomitant constituents in ores, index after magnetization will be more optimized than with only hematite. In this research, mechanism of original improving ore reduction during process was explored using fines lump samples. Under optimum...

پایان نامه :دانشگاه تربیت معلم - سبزوار - دانشکده علوم انسانی و پایه 1393

burnout is a response to the chronic work stress which is prevalent mostly among the people who do people job, like teaching. the purpose of this study was to develop a valid and reliable instrument that can measure burnout in foreign language teachers. although some widely used instruments were developed before which measured burnout in teachers, a specific instrument which include specific sy...

Journal: :Environmental science & technology 2007
Je-Hun Jang Brian A Dempsey William D Burgos

Measured pH and dissolved ferric iron concentration ([Fe(III)diss]) in contact with well-characterized hematite indicated an equilibrium with hematite immediately after synthesis, but [Fe(III)diss] increased with hydration time to be consistent with the predicted solubility of goethite or hydrous ferric oxide (HFO), hydrated analogues of hematite. X-ray diffraction did not detect structural mod...

Journal: :The Journal of chemical physics 2014
Manh-Thuong Nguyen Nicola Seriani Simone Piccinin Ralph Gebauer

Adopting the theoretical scheme developed by the Nørskov group [see, for example, Nørskov et al., J. Phys. Chem. B 108, 17886 (2004)], we conducted a density functional theory study of photo-driven oxidation processes of water on various terminations of the clean hematite (α-Fe2O3) (0001) surface, explicitly taking into account the strong correlation among the 3d states of iron through the Hubb...

Journal: :Journal of colloid and interface science 2004
Andrew G Stack Kevin M Rosso Dayle M A Smith Carrick M Eggleston

The rate of reaction of hematite with quinones and the quinone moieties of larger molecules may be an important factor in limiting the rate of reductive dissolution of hematite, especially by iron-reducing bacteria. It is possible that the rate of reductive dissolution of hematite in the presence of excess hydroquinone at pH 2.5 may be limited by the electron-transfer rate. Here, a reductive di...

2016
David W. Jenkins Alexis K. Ault James P. Evans

This project serves as a literature review on the transformation and synthesis of magnetite from hematite under hydrothermal conditions as well as with Pulsed Laser Deposition (PLD) and milling. Magnetite forms over a similar range of elevated temperatures regardless the method that is used to synthesize it, including nonheterogeneous, loosely controlled environments such as a ceramics kiln. Ba...

2003
DEREK R. LOVLEY ELIZABETH J. P. PHILLIPS

The potential for ferric iron reduction with fermentable substrates, fermentation products, and complex organic matter as electron donors was investigated with sediments from freshwater and brackish water sites in the Potomac River Estuary. In enrichments with glucose and hematite, iron reduction was a minor pathway for electron flow, and fermentation products accumulated. The substitution of a...

2005
K. Piotrowski T. Wiltowski K. Mondal D. Dasgupta

The kinetics of Fe2O3→FeO reaction was investigated. The thermogravimetric (TGA) data covered the reduction of hematite both by pure species (nitrogen diluted CO or H2) and by their mixture. The conventional analysis has indicated that initially the reduction of hematite is a complex, surface controlled process, however once a thin layer of lower oxidation state iron oxides (magnetite, wüstite)...

Journal: :Transactions of the Iron and Steel Institute of Japan 1978

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