A METHOD OF PREPARING FLUORIDE-FREE URANIUM DIOXIDE
Fluoride-free UO/sub 2/ with less than l00 ppm fluoride may be prepared from fluoride-containing ammonium diuranate without prior purification by thermally decomposing the diuranate at 400 to 850 deg C in a stream of steam and hydrogen in a closed reactor made of a nickel alloy and continuing the heating until the U/sub 3/O/sub 8/ is reduced to UO/sub 2/. The fluorides are volatilized as HF and NH/sub 4/F during the thermal decomposition, and hydrogen in the atmosphere is necessary to prevent corrosion of the nickel alloy and subsequent contamination of the UC/sub 2/ with nickel oxides. The volume proportion of hydrogen to steam is preferably 1 to 10. though hydrogen may be supplied in the form of NH/sub 3/, which decomposes. With 850"C as the operating temperature, the thermal decomposition and reduction are complete in 3 and 2 hr, respectively. Ammonium diuranate prepared from NH/sub 3/ and UF/sub 6/ can be converted into UO/sub 2/ in this way without prior washing. This is an advantage because UO/sub 2/ from unwashed diuranate is more dense than UO/sub 2/ from thoroughly washed diuranate. Six examples of this method are given. (D.L.C.)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-15-001457
- OSTI ID:
- 4159764
- Report Number(s):
- GB 850957
- Country of Publication:
- United Kingdom
- Language:
- English
Similar Records
A laboratory-scale process for producing dilithium beryllium tetrafluoride (FLiBe) with dissolved uranium tetrafluoride
Reaction of zirconium fluoride monohydrate and ammonium bifluoride; Its effect on fluoride glass preparation and quality