INTERACTION OF URANIUM OXIDES WITH THE OXIDES OF VANADIUM AND NIOBIUM (in Russian)
Journal Article
·
· Doklady Akademii Nauk SSSR (U.S.S.R.) English translation currently published in a number of subject-oriented journals
OSTI ID:4734467
Studies carried out by x-ray diffraction and thermal and chemical analysis revealed the existence of 2 phases resulting from the interaction of the oxides of U with those of V and Nb. The tests involved boiling aqueous suspensions of uranyl hydroxide, UO/sub 2/(OH)/sub 2/, with V/sub 2/O/sub 5/ for perio ds ranging from 85 to 100 hours. Keeping the U: V ratio within 1: 2 to 1: 3 only uranyl vanadate was obtained; changing this ratio to 3: 2 resulted in the formation of a 2-phase system of U pyrovanadate and alpha -UO/sub 2/(OH)/sub 2/. The water-free orthovanadate was obtained by heating the pyrovanadate with uranyl hydroxide to 575 deg C. The (UO/sub 2/)/sub 3/(VO/sub 4/)/sub 2/ melted at 805 to 810 deg C under decomposition. Dehydration of the pyrovanadate, which melted at 790 deg C, was accompanied by the formation of alpha and te at 260 deg C yielded BETA -(UO/sub 2/)/sub 2/V/sub 6/O/sub 17/, changing into its alpha - modificat ion at 550 deg C. At 600 to 1000 deg C in vacuum V pentoxide reacts with UO/sub 2/ and U/sub 2/O/sub 5/ forming UV/sub 3/O/sub 10/ and UVO/sub 5/. N b pentoxide does not react with the aqueous uranyl hydroxide suspension; upon dehydration Nb/sub 2/O/sub 5/ and gamma -UO/sub 3/ is obtained. The latter is decomposed at 675 deg C into lower oxides while the Nb/sub 2/O/sub 5/ is transformed into its high-temperature modification beyond 1000 deg C. Thus, in spite of the structural similarity, the alpha -Nb/sub 2/O/sub 5/ does not react with U/sub 3/O/sub 8/ and U O/sub 3/, although a reaction may teke place at higher temperatures. (TTT)
- Research Organization:
- Moscow State Univ.
- NSA Number:
- NSA-17-014244
- OSTI ID:
- 4734467
- 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: 148; ISSN DANKA
- Country of Publication:
- Country unknown/Code not available
- Language:
- Russian
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