Westinghouse Electric Corporation

Parameshwaran S Sundar

Ward L Lyon

Leonard Elikan

The precipitation of an iron complex is reduced during the stripping of uranium with ferrous ion, where the uranium was oxidized with nitric acid then extracted with an organic solvent. The reduction is accomplished by pre-stripping with sufficient ferrous ion to reduce nitrates and nitrites formed during the nitric acid oxidation. The amount of ferrous ion used in pre-stripping, however, is insufficient to precipitate uranium.

Reduction of iron precipitation in uranium extraction process

Uranium is separated from analytical Group II and Group III metal ions in an aqueous liquor containing uranyl ions. The liquor is extracted with a non-interfering, water-immiscible, organic solvent containing a reagent which will react with the uranyl ions to form a complex soluble in the solvent. If the liquor is acidic, the solvent is washed with water. Then to the solvent is added an aqueous solution containing about 0.5 to 1.0 mole per liter of (NH.sub.4).sub.2 CO.sub.3 or NH.sub.4 HCO.sub.3 ions and sufficient sulfide ions to precipitate the metal ions as sulfides. The solvent and the aqueous solution are separated and the sulfides filtered from the aqueous solution. The ammonium-uranyl-tricarbonate in the aqueous solution can then be precipitated by increasing the concentration of (NH.sub.4).sub.2 CO.sub.3 or NH.sub.4 HCO.sub.3 ions to about 1.5 to 2.5 moles per liter. The precipitate is filtered and calcined to obtain U.sub.3 O.sub.8 or UO.sub.2.

Sulfide precipitation method of separating uranium from  group II and

Uranium is separated from contaminating metal ions in an aqueous feed liquor containing the uranyl ion. The liquor is extracted with a first, non-interfering, waterimmiscible, organic solvent containing a reagent which reacts with the uranyl ion to form a complex soluble in the organic solvent. The organic solvent is scrubbed with water if necessary, then stripped with a stripping liquor of an aqueous sulfuric acid liquor having a pH of about 0.5 to about 6 containing a reducing ion or an aqueous carbonate solution having a pH of about 8 to about 9. If the sulfuric acid liquor is used the stripped uranous ion is oxidized and the sulfuric acid liquor is diluted to prevent the precipitation of a uranium complex. The stripping liquor is extracted with an amine liquor comprising a second, noninterfering, water-immiscible, organic solvent and a tertiary or quaternary amine. The amine liquor is stripped with an ammonium carbonate solution to precipitate a uranium complex. The uranium complex is filtered off and may be calcined to produce U.sub.3 O.sub.8 or UO.sub.2.

Coupled cationic and anionic method of separating uranium

Uranium is separated from contaminating cations in an aqueous liquor containing uranyl ions. The liquor is mixed with sufficient recycled uranium complex to raise the weight ratio of uranium to said cations preferably to at least about three. The liquor is then extracted with at least enough non-interfering, water-immiscible, organic solvent to theoretically extract about all of the uranium in the liquor. The oganic solvent contains a reagent which reacts with the uranyl ions to form a complex soluble in the solvent. If the aqueous liquor is acidic, the organic solvent is then scrubbed with water. The organic solvent is stripped with a solution containing at least enough ammonium carbonate to pecipitate the uranium complex. A portion of the uranium complex is recycled and the remainder can be collected and calcined to produce U.sub.3 O.sub.8 or UO.sub.2.

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Pittsburgh, PA, United States of America

Parameshwaran S Sundar