REDUCTION OF URANIUM TRIOXIDE WITH AMMONIA
Kinetics of uranium trioxide reduction by nitrogenhydrogen mixture at 350 to 500 un. Concent 85% C and 25 to 600 mm Hg was investigated. The activation energy of the process was 26.5 to 31.7 kcal/mole. The data were compared with the uranium trioxide reduction by pure hydrogen and ammonia. (tr- auth)
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Theoretical investigation of the structure and spectroscopy of uranium …
Understanding the chemistry of gas-phase uranium oxide species is of great interest, especially in environmental monitoring and material analysis. In the present work, theoretical investigation of structural and electronic properties of the diatomic and polyatomic systems: UO, UO+, UO++, UO2, UO2+, UO2++, UO3, UO3+, and UO3++ …
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Reduction Kinetics of Uranium Trioxide to Uranium Dioxide …
The conversion process consists in the reduction reaction of uranium trioxide to uranium dioxide according to Equation (1): [5] [6] UO32+= H UO 22 + H O (1) Figure 3 shows the uranium Pourbaix diagram: According to Figure 3, before the uranium trioxide is reduced to uranium dioxide, it will show up a third oxide species, U3O8.
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PHYSICAL REVIEW B104, 174103 (2021)
Pressure-induced structural and electronic phase transitions of uranium trioxide. The crystal structures, phonon spectra, and electronic properties of uranium trioxide (UO3) under high pressure have been systematically explored using a particle swarm optimization structure prediction method in conjunction with first-principles calculations.
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(PDF) Reduction Kinetics of Uranium Trioxide to Uranium Dioxide …
The conversion process consists in the reduction reaction of uranium trioxide to uranium dioxide according to Equation (1): [5] [6] UO3 + H 2 = UO 2 + H 2 O (1) Figure 3 shows the uranium Pourbaix diagram: According to Figure 3, before the uranium trioxide is reduced to uranium dioxide, it will show up a third oxide species, U3O8.
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Uranium_trioxide
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Images of Uranium trioxide
bing/imagespubchem.ncbi.nlm.nih.govUranium trioxide | UO3 | CID 74013WEBUranium trioxide (UO 3) is a stable chemical form of uranium oxide with multiple polymorphs found throughout the nuclear fuel cycle. The pressure-induced changes in …
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Localized orbitals of the T-shape of UO 3
Investigations of the interactions of uranium trioxide (UO3) with other species are expected to provide a new perspective on its reaction and bonding behaviors. Herein, we present a combined ...
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Oxygen Isotopic Composition of U3O8 Synthesized From …
, produced from uranium metal, uranyl nitrate hydrate, and uranium trioxide as starting materials. The results showed that δ18Oof U 3 O 8 is independent of the above-listed starting materials. δ 18O values of 10 synthetic U 3 O 8 were similar (9.35 ± 0.46‰) and did not change as a function of calcination time or calcination temperature. We ...
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Density Functional Theory Study of the Thermodynamic and …
Gamma uranium trioxide, γ-UO3, is one of the most important polymorphs in uranium trioxide system, which is common throughout the nuclear fuel cycle and used industrially in the reprocessing of nuclear fuel and uranium enrichment. In this work, a detailed theoretical solid-state density functional theory study of this material was carried …
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The uranium-oxygen system: U3O8-UO3
Uranium trioxide (UO 3) is a stable chemical form of uranium oxide with multiple polymorphs found throughout the nuclear fuel cycle.The pressure-induced changes in the structure and lattice dynamics of four of these polymorphs are simulated with density functional perturbation theory and analyzed.
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uranium trioxide
uranium trioxide. Formula: O 3 U; Molecular weight: 286.0271; CAS Registry Number: ; Information on this page: Notes; Other data available: Condensed phase thermochemistry data; Gas phase ion energetics data; Vibrational and/or electronic energy levels; Data at other public NIST sites: X-ray Photoelectron Spectroscopy Database, …
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THE REDUCTION OF HIGH SURFACE AREA URANIUM TRIOXIDE …
THE REDUCTION OF HIGH SURFACE AREA URANIUM TRIOXIDE 1. R. E. DeMarco; and ; M. G. Mendel; Cite this: J. Phys. Chem. 1960, 64, 1, 132–133. Publication Date (Print): January 1 ... Thermoanalytical study on the oxidation of uranium dioxides derived from uranyl nitrate, uranyl acetate and ammonium diuranate. Thermochimica Acta 1979, 33, …
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Pressure-induced structural and electronic phase transitions of uranium
Pressure-induced structural and electronic phase transitions of uranium ...
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Reduction of uranium oxide U3O8 to UO2 by hydrogen
Keywords: uranium trioxide reduction; Kinetic rate; Rate-limiting step Materials: U,0,,; UO, 1. Introduction The reduction by hydrogen of uranium trioxide to uranium dioxide is a gas-solid transformation which occurs during the elaboration of nuclear fuel. In this transformation, the uranium trioxide is first con- verted into the L^Og …
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Unexpected features in the optical vibrational …
The diverse crystal chemistry and resulting variety of optical vibrational (Raman and IR) spectroscopic features of members of the uranium trioxide polymorph system have been of interest to researchers for …
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Investigation of the polymorphs and hydrolysis of …
uranium trioxide species, UO 3, is then reduced to UO 2 and subsequently converted to UF 4 (and ultimately to UF 6)by fluorination prior to isotopic enrichment. The structural phase of UO 3 that is formed as a result of these different production routes is characteristic of the process. With an understanding of the polymorphic nature of UO 3 ...
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Study on Preparation Technology of UCL4 From CCl4
In this study, uranium tetrachloride was prepared by reacting carbon tetrachloride (CCl 4) liquid with uranium trioxide (UO 3) solid powder, The reaction needs to be carried out in the temperature range of 673 ~ 773 K, while the boiling point of CCl 4 is about 349 K. Obviously, the real process is the reaction between CCl 4 vapor and UO 3 …
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Ab Initio Investigation of the UO3 Polymorphs: Structural …
Uranium trioxide (UO 3) is known to adopt a variety of crystalline and amorphous phases.Here we applied the Perdew–Burke–Ernzerhof functional + U formalism to predict structural, electronic, and elastic properties of five experimentally determined UO 3 polymorphs, in addition to their relative stability. The simulations reveal that the …
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Uranium trioxide hydrate | H2O4U | CID 129672010
Uranium trioxide hydrate | H2O4U | CID 129672010 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological ...
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Uranium trioxide and the UO3 hydrates
Uranium trioxide and the UO3 hydrates 1845 Precipitation occurs when polymerization has proceeded to a point where the species is no longer soluble. A UQ hydrate is deposited from aqueous solution and one may envisage this as an hydrated polymer, i.e. a polymer containing double hydroxyl bridges, uo.,/[ "uo., / n The somewhat variable ...
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Accurate and precise measurement of uranium content in uranium trioxide …
1. Introduction. Nuclear material, such as uranium (U) and plutonium (Pu), accountancy is essential for safeguards purposes in nuclear fuel cycle facility (Magara et al., 2000; Alvarez et al., 2000; Donohue, 1998).Tokai Reprocessing Plant (TRP) is the first spent nuclear fuel reprocessing plant in Japan, which adopted Pu and U recovery by …
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The kinetics of hydrogen reduction of UO3 and U3O8 …
The kinetics of the hydrogen reduction of uranium trioxide of surface area below 1.2m/sup 2//g were investigated. An increase in surface area and pore volume occurred during the reaction and an … Expand. 9. Save. THE REDUCTION OF HIGH SURFACE AREA URANIUM TRIOXIDE1. R. DeMarco M. Mendel.
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WebElements Periodic Table » Uranium » uranium …
Formula: UO 3. Hill system formula: O 3 U 1. CAS registry number: [] Formula weight: 286.027. Class: oxide. Colour: orange-yellow. Appearance: crystalline solid. Melting point: (decomposes to U 3 O 8) …
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Oxygen Isotopic Composition of U
Triuranium octoxide (U 3 O 8) is one of the main compounds in the nuclear fuel cycle. As such, identifying its processing parameters that control the oxygen isotopic …
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Uranium oxides structural transformation in human …
Using a combination of methods, a complex examination of structural changes of uranium oxides in the range from UO 2 to U 4 O 9, U 3 O 8 and UO 3 as …
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Uranium Trioxide SDS | IBILABS
Name: Uranium trioxide (UO 3), . Synonyms: Uranium(VI) oxide, Uranus oxide. Formula: UO3. Supplier. IBI Labs. 3495 N. Dixie Hwy. Unit # 8. ... Uranium entering the bloodstream will become stored in the bone marrow, but the majority will become lodged in the kidney, which is the major site of toxicity. More than a year and a half are ...
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uranium trioxide
uranium trioxide. Formula: O 3 U; Molecular weight: 286.0271; CAS Registry Number: ; Information on this page: Gas phase ion energetics data; References; Notes; Other data available: Condensed phase thermochemistry data; Vibrational and/or electronic energy levels; Data at other public NIST sites: X-ray Photoelectron Spectroscopy ...
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Cameco U101
Cameco's Blind River refinery receives drums of uranium concentrates, or yellowcake as it's commonly known, from mines around the world.. Here, the uranium is separated from impurities using a series of chemical processes including digestion, solvent extraction, denitration and other processes. These refinement methods produce high-purity …
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Ab Initio Investigation of the UO3 Polymorphs: …
Uranium trioxide (UO 3) is known to adopt a variety of crystalline and amorphous phases. Here we applied the Perdew–Burke–Ernzerhof functional + U formalism to predict …
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Uranium trioxide | UO3 | CID 74013
Uranium trioxide | UO3 or O3U | CID 74013 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and …
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