Abstract A process for the recovery of uranium as ammonium diuranate from aqueous solutions having uranyl and fluoride ions such as produced by hydrolyzing UF6, and for reducing soluble uranium losses in the liquid waste stream, by forming a first neutralized solution of uranyl fluoride (UO2F2), with concentrated ammonium hydroxide, at a pH of about 4.5 to 6.0, and then by precipitating essentially all of the uranium, as ammonium diuranate, ((NH4)2U2O7), (ADU), from the solution by adding concentrated ammonium hydroxide under controlled conditions preventing formation of any soluble fluoride complexes that would otherwise be ordinarily formed during the precipitation of the ammonium diuranate, to produce an ADU slurry which is calcinable to UO2 having good ceramic pelletizing properties.
Inventors
👤 L Gerrald
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-08 01:12
CPC Classifications
C; C01; C01G; C01G43/00; C01G43/01; C01G43/025
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
282 words
The process of converting uranium hexafluoride to uranium dioxide powder having good ceramic pelletizing properties, comprising the steps of: a. contacting water with the uranium hexafluoride to produce an acidic aqueous hydrolysis solution containing uranyl fluoride and hydrogen fluoride, b. adding aqueous ammonium hydroxide of a concentration of at least 6 molar to the acidic aqueous hydrolysis solution to produce a first neutralized solution having a pH of from 4.5 to 6.0, the added ammonium hydroxide being sufficient to react with only from about 85 to 95 percent of the hydrogen fluoride in he acidic solution and with substantially none of the uranyl fluoride, c. thereafter rapidly admixing the first neutralized solution while it is at a temperature of from 125*F to 175*F with aqueous ammonium hydroxide at a temperature below 100*F and of a molarity of at least 3 in an amount to provide at least two times the stoichiometric quantity needed to convert all of the uranium in the first neutralized solution to ammonium diurante, the resulting solution having a pH of at least 9.5, and the ammonium diuranate so produced precipitating rapidly as a fine precipitate to form a slurry, d. digesting the slurry at a temperature of about 40*C to 70*C for a period of about 5 to 30 minutes, e. separating a major portion of the liquid from the digested ammonium diuranate particles, only sufficient liquid being present to produce a flowable or pumpable ammonium diuranate slurry end product, and f. calcining the ammonium diuranate slurry at temperatures up to about 1,000*C whereby to evaporate all the liquid, and decompose the ammonium diuranate in the presence of a reducing atmosphere to produce a pure uranium dioxide powder.