THE PREPARATION, STABILISATION AND ANALYSIS OF URANIUM (IV) NITRATE SOLUTIONS
Hydrazine and urea are considered as alternatives to sulfamic acid to stabilize uranium(IV) nitrate solutions. All three stabilizers act as nitrite destroyers in reactions which involve evolution of nitrogen gas. A comparison of the rates of the nitrite-stabilizer reactions shows that urea is greatly inferior to either hydrazine or sulfamic acid. Sulfamic acid has the important disadvantage of introducing sulfate into the plant effluents, so hydrazine is the stabilizer to be preferred. In liquid-liquid extraction, the nitrite may occur chiefly in the organic phase and the stabilizer chiefly in the aqueous; reaction then occurs mainly in the vicinity of the interface. Hydrazine may also be used as a nitrite destroyer in the production of uranium(IV) nitrate by electrolysis of uranyl nitrate solution at a mercury cathode. 80% conversion is readily achieved. Small quantities of the solutions so obtained re-oxidize slowly at a rate not greater than 5% per week. Of three analytical methods tested for uranium(IV), an absorptiometric method based on reduction of iron(III) and complexing of iron(II) with o-phenanthroline at pH 3 to 5 was shown to be the best for either aqueous or organic samples. (auth)
- Research Organization:
- United Kingdom Atomic Energy Authority. Research Group. Atomic Energy Research Establishment, Harwell, Berks, England (United Kingdom)
- NSA Number:
- NSA-16-011574
- OSTI ID:
- 4808448
- Report Number(s):
- AERE-R-3938
- Country of Publication:
- United Kingdom
- Language:
- English
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