US4584183A
Expired / Lapsed
US
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Process for separating zirconium isotopes
Assignee: Westinghouse Electric Corp
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Filing: 1983-12-21
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Granted: 1986-04-22
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Expires: 2003-12-21
Abstract
Abstract A solvent extraction-exchange process for the enrichment of either the zirconium 90 isotope component or the zirconium 91-96 isotope component of an aqueous feed stream containing both components is described. An aqueous feed stream of zirconium complexes such as that from a thiocyanate separation process is contacted with an organic solvent to preferentially extract one of the isotope components, resulting in an aqueous raffinate enriched in the other isotope component. The organic phase is further contacted with an aqueous phase enriched in said one isotope component to exchange the other isotope component from the organic phase with the one isotope component in the aqueous phase and produce a further enriched organic phase. The one isotope component in the further enriched organic phase is then stripped with an aqueous acidic strip medium, and zirconium enriched in said one isotope component separated therefrom.
Inventors
- 👤 Peter T. Chiang
- 👤 Edward J. Lahoda
- 👤 Herbert A. Burgman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:57
CPC Classifications
B; B01; B01D; B01D59/00; B01D59/28; B01D59/32
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
194 words
A method of separating a feed stream consisting essentially of an aqueous solution of a mixture of 90 Zr and 91 to 96 Zr salts selected from group consisting of thiocyanate, nitrate, sulfate, chloride, perchlorate, and mixtures thereof, into two aqueous product streams, each containing both a 90 Zr isotopic portion and a 91 to 96 Zr isotopic portion, but in different ratios, comprising (A) contacting said feed stream with methylisobutyl ketone or an organic water-immiscible solvent containing an extractant medium selected from the group consisting of quaternary ammonium salts, organic phosphonates, organic phosphinates, organic phosphates, organic sulfonates, primary amines, tertiary amines, polyethers, beta-diketones, and mixtures thereof, that preferentially extracts one of said isotopic portions, leaving an aqueous raffinate depleted in that isotopic portions and enriched in the other isotopic portion; (B) stripping said organic solvent of its zirconium with an aqueous acidic strip medium to produce a first aqueous product stream; (C) recycling said stripped organic solvent to step (A); (D) evaporating water from a portion of said aqueous raffinate to produce a concentrated aqueous raffinate and a second aqueous product stream; and (E) recycling said concentrated aqueous raffinate to said feed stream.
Claim 2
Independent Claim
194 words
A method of separating a feed stream consisting essentially of an aqueous solution of a mixture of 90 Zr and 91 to 96 Zr salts selected from group consisting of thiocyanate, nitrate, sulfate, chloride, perchlorate, and mixtures thereof, into two aqueous product streams, each containing both a 90 Zr isotopic portion and a 91 to 96 Zr isotopic portion, but in different ratios, comprising (A) contacting said feed stream with methylisobutyl ketone or an organic water-immiscible solvent containing an extractant medium selected from the group consisting of quaternary ammonium salts, organic phosphonates, organic phosphinates, organic phosphates, organic sulfonates, primary amines, tertiary amines, polyethers, beta-diketones, and mixtures thereof, that preferentially extracts one of said isotopic portions, leaving an aqueous raffinate depleted in that isotopic portions and enriched in the other isotopic portion; (B) stripping said organic solvent of its zirconium with an aqueous acidic strip medium to produce a first aqueous product stream; (C) recycling said stripped organic solvent to step (A); (D) evaporating water from a portion of said aqueous raffinate to produce a concentrated aqueous raffinate and a second aqueous product stream; and (E) recycling said concentrated aqueous raffinate to said feed stream.
Claim 3
Dependent Claim
26 words
The process as defined in claim 1 wherein a portion of said aqueous acidic strip medium, after said stripping, is transferred for use in said contacting.
Claim 4
Dependent Claim
28 words
The process as defined in claim 1 wherein said organic, water-immiscible solvent is selected from the group consisting of an alkyl hydrocarbon, an aryl hydrocarbon, or mixtures thereof.
Claim 5
Dependent Claim
26 words
The process as defined in claim 3 wherein said organic, water-immiscible solvent contains between 3-20 percent by volume of an alkyl alcohol containing 6-8 carbon atoms.
Claim 6
Dependent Claim
46 words
The process as defined in claim 1 wherein said organic, water-immiscible solvent contains said extractant medium in an amount of between 4:1 to 1:4 mole ratio relative to the zirconium present in the aqueous feed stream, based on an organic to aqueous volume ratio of 1:1.
Claim 7
Dependent Claim
31 words
The process as defined in claim 1 wherein said aqueous strip medium contains an inorganic acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid and perchloric acid.
Claim 8
Dependent Claim
25 words
The process as defined in claim 1 wherein said acid present in said aqueous strip medium is in an amount of 1-10 moles per liter.
Claim 9
Dependent Claim
14 words
The process as defined in claim 1 wherein said organic solvent is methylisobutyl ketone.
Claim 10
Dependent Claim
16 words
The process as defined in claim 8 wherein said methylisobutyl ketone contains an additional extractant medium.
Claim 11
Dependent Claim
16 words
The process as defined in claim 1 wherein said aqueous acidic strip medium contains hydrochloric acid.
Claim 12
Dependent Claim
17 words
A method according to claim 1 wherein a portion of said first aqueous product stream is recycled.
Claim 13
Dependent Claim
27 words
A method according to claim 1 wherein said contacting and stripping steps are performed in a plurality of stages to further increase the difference between said ratios.
Claim 14
Dependent Claim
17 words
A method according to claim 12 wherein the time for each stage is 2 to 120 minutes.
Claim 15
Dependent Claim
20 words
A method according to claim 1 wherein said feed stream is the aqueous raffinate stream from a zirconium-hafnium separation process.
Claim 16
Dependent Claim
18 words
A method according to claim 8 wherein said solvent is methylisobutyl ketone and said salt is a thiocyanate.
Claim 17
Dependent Claim
20 words
A method according to claim 1 wherein said 91-96 Zr portion is preferentially extracted into the water-immiscible organic contacting liquid.
Claim 18
Dependent Claim
18 words
A method according to claim 1 wherein said organic solvent is methylisobutyl ketone and said extractant is di(2,4,4'-trimethylpentyl)phosphinate.
Claim 19
Dependent Claim
33 words
A method according to claim 5 wherein said organic water-immiscible solvent is selected from the group consisting of methylisobutyl ketone, heptane, cyclohexane, C 8 to C 10 alkanol, kerosene, benzene, and mixtures thereof.
Claim 20
Dependent Claim
13 words
A method according to claim 3 wherein said solvent is an aryl hydrocarbon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |