THE REACTION OF URANIUM TRIOXIDE WITH THE DECOMPOSITION PRODUCTS OF AMMONIA IN THE PRESENCE OF A NUMBER OF EXTRANEOUS OXIDE ADDITIVES

Journal Article · Wed Dec 11 04:00:00 EST 1963 · Doklady Akademii Nauk SSSR (U.S.S.R.) English translation currently published in a number of subject-oriented journals

OSTI ID:4119429

Zhukovskii, V M; Vlasov, V G

The initial UO/sub 3/ had a density of 6.5 g/cm/sup 3/ and a surface area of 15 m/sup 2//g. A total of 5 mole% of ZnO, TiO/sub 2/, or UO/sub 2 .04/ was used as the oxide additive. The reduction was carried out in a circulating, fluidized-bed reactor at a temperature of 350 to 500 deg C, and a pressure P(3H/ sub 2/ + N/sub 2/) = 200 mg Hg std. The ZnO addition had the greatest effect in accelerating the reduction of UO/sub 3/ to UO/sub 2/. The addition of TiO/sub 2/ had a lesser effect in accelerating the reduction, and the addftion of UO/sub 2.04/ slowed down the reduction somewhat. The apparent activation energy increased with increasing conversion of UO/sub 3/ to UO/sub 2/, because the presence of UO/sub 2/ slowed down the reduction process. The following phase conversions can be expected in the reduction of UO/sub 3/: UO/sub 3/ yields U/ sub 3/O/sub 8/ yields U/sub 3/O/sub 8-x/ yields UO/sub 2+x/ yields UO/sub 2/. Mixtures o f these phases were detected hy x-ray analysis. The oxides ZnO and TiO/sub 2/ are n-type semiconductors with an electrical conductivity significantly higher than that of UO/sub 3/. Electron transfer takes place from the ZnO or TiO/sub 2/ to the UO/sub 3/ with an increase in the reduction rate of UO/sub 3/. The emf of a UO/sub 3/--ZnO couple at 400 deg C was found to be 240 mv. The oxide UO/sub 2.04/ is a hole conductor which favors the recombination of free electrons, and thus, the reduction of UO/sub 3/ to U/sub 3/O/sub 8/ is slowed down. (TTT)

• Research Organization: Urals Polytechnical Inst., USSR
• NSA Number: NSA-18-012056
• OSTI ID: 4119429
• Journal Information: Doklady Akademii Nauk SSSR (U.S.S.R.) English translation currently published in a number of subject-oriented journals, Journal Name: Doklady Akademii Nauk SSSR (U.S.S.R.) English translation currently published in a number of subject-oriented journals Vol. Vol: 153; ISSN DANKA
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

AMMONIA
ATOMS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DENSITY
DETECTION
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRON TRANSFER
ELECTRONS
ENERGY
MIXING
PRESSURE
QUALITATIVE ANALYSIS
REDUCTION
SEMICONDUCTORS
SURFACES
TEMPERATURE
TITANIUM OXIDES
U3O8
URANIUM DIOXIDE
URANIUM OXIDES
URANIUM TRIOXIDE
USES
X RADIATION
ZINC OXIDES