US4292287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for directly recovering fluorine from gas streams
Assignee: United States Department of Energy
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Filing: 1980-04-24
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Granted: 1981-09-29
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Expires: 2000-04-24
Abstract
Abstract This invention is a process for the direct recovery of gaseous fluorine from waste-gas streams or the like. The process comprises passing the gas stream through a bed of anhydrous K 3 NiF 6 pellets to fluorinate the same to K 3 NiF 7 and subsequently desorbing the fluorine by heating the K 3 NiF 7 pellets to a temperature re-converting them to K 3 NiF 6 . The efficiency of the fluorine-absorption step is maximized by operating in a selected and conveniently low temperature. The desorbed fluorine is highly pure and is at a pressure of several atmospheres. Preferably, the K 3 NiF 6 pellets are prepared by a method including the steps of forming agglomerates of hydrated K 3 NiF 5 , sintering the agglomerates to form K 3 NiF 5 pellets of enhanced reactivity with respect to fluorine, and fluorinating the sintered pellets to K 3 NiF 6 .
Inventors
- 👤 Michael J. Orlett
- 👤 Anthony J. Saraceno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:59
CPC Classifications
C; C01; C01G; C01G53/00; C01G53/80; C01G53/82; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/68; C01B; C01B7/00; C01B7/19; C01B7/191; C01B7/195; C01P; C01P2002/00; C01P2002/80; C01P2002/88
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
46 words
A process for the removal of gaseous fluorine from a gas stream containing the same, said process comprising: directing said stream through a bed of sintered anhydrous K 3 NiF 6 pellets at a temperature effecting fluorination of said pellets to K 3 NiF 7 .
Claim 2
Dependent Claim
46 words
A process for the removal of gaseous fluorine from a gas stream containing the same, said process comprising: directing said stream through a bed of sintered anhydrous K 3 NiF 6 pellets at a temperature effecting fluorination of said pellets to K 3 NiF 7 .
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said temperature is in the range of from 225°-250° C.
Claim 4
Dependent Claim
18 words
The process of claim 2 wherein said temperature is maintained in the range of from about 240°-246° C.
Claim 5
Dependent Claim
35 words
The process of claim 1 further characterized by the step of heating the fluorinated pellets to a temperature effecting evolution of gaseous fluorine therefrom and re-conversion of said pellets to K 3 NiF 6 .
Claim 6
Dependent Claim
98 words
A method for the production of K 3 NiF 6 pellets for use in the process of claim 1, comprising: providing a 3:1 mole-ratio mixture of powdered potassium fluoride and nickel fluoride hydrate, contacting said mixture with finely divided water at a temperature effecting formation of agglomerates of K 3 NiF 5 hydrate, heating said agglomerates to a temperature effecting sintering but not fusion thereof to form sintered pellets of anhydrous K 3 NiF 5 , and contacting said pellets with gaseous fluorine at a temperature effecting their conversion to unfused pellets of K 3 NiF 6 .
Claim 7
Dependent Claim
115 words
A process for the removal of gaseous fluorine from a gas stream containing the same, comprising: contacting said stream with anhydrous K 3 NiF 6 pellets, said pellets having been prepared by the steps of: (a) providing a 3:1 mole-ratio powder mixture of potassium fluoride and hydrated nickel fluoride, (b) contacting said mixture with finely divided water at a temperature effecting conversion of said mixture to agglomerates of hydrated K 3 NiF 5 , (c) heating the agglomerates to a temperature effecting sintering but not fusion thereof to form sintered pellets of anhydrous K 3 NiF 5 , and (d) reacting said pellets with gaseous fluorine to convert them to K 3 NiF 6 .
Claim 8
Dependent Claim
115 words
A process for the removal of gaseous fluorine from a gas stream containing the same, comprising: contacting said stream with anhydrous K 3 NiF 6 pellets, said pellets having been prepared by the steps of: (a) providing a 3:1 mole-ratio powder mixture of potassium fluoride and hydrated nickel fluoride, (b) contacting said mixture with finely divided water at a temperature effecting conversion of said mixture to agglomerates of hydrated K 3 NiF 5 , (c) heating the agglomerates to a temperature effecting sintering but not fusion thereof to form sintered pellets of anhydrous K 3 NiF 5 , and (d) reacting said pellets with gaseous fluorine to convert them to K 3 NiF 6 .
Claim 9
Dependent Claim
21 words
The process of claim 6 wherein said stream and pellets are contacted at a temperature in the range from 225°-250° C.
Claim 10
Dependent Claim
13 words
The process of claim 7 wherein said range is from about 240°-246° C.
Claim 11
Dependent Claim
13 words
Anhydrous K 3 NiF 6 pellets prepared by steps (a)-(d) of claim 6.
Claim 12
Dependent Claim
80 words
A process for the direct recovery of fluorine from a gas stream containing the same, comprising: directing said stream through a bed of anhydrous K 3 NiF 6 pellets at a temperature in the range of from 225° C. to 250° C. to fluorinate said pellets to K 3 NiF 7 , and heating the resulting K 3 NiF 7 pellets to a temperature effecting evolution of fluorine therefrom and re-conversion of said pellets to K 3 NiF 6 .
Claim 13
Dependent Claim
80 words
A process for the direct recovery of fluorine from a gas stream containing the same, comprising: directing said stream through a bed of anhydrous K 3 NiF 6 pellets at a temperature in the range of from 225° C. to 250° C. to fluorinate said pellets to K 3 NiF 7 , and heating the resulting K 3 NiF 7 pellets to a temperature effecting evolution of fluorine therefrom and re-conversion of said pellets to K 3 NiF 6 .
Claim 14
Dependent Claim
24 words
The process of claim 10 wherein the superficial bed-residence time of said stream is in the range of from about 100 to 1000 seconds.
Claim 15
Dependent Claim
19 words
The method of claim 5 wherein said mixture is contacted with one of a water aerosol and saturated steam.
Claim 16
Dependent Claim
87 words
A process for preferentially recovering fluorine from a gas stream containing fluorine and at least one non-fluorinating gas selected from the group consisting of inert gases, nitrogen, oxygen, and fluorocarbons, said process comprising: directing said stream through a bed of sintered anhydrous K 3 NiF 6 pellets at a temperature in the range of from 240°-246° C., the residence time of said stream in said bed being in the range of 100 to 1000 seconds, to effect fluorination of said pellets to K 3 NiF 7 .
Claim 17
Dependent Claim
87 words
A process for preferentially recovering fluorine from a gas stream containing fluorine and at least one non-fluorinating gas selected from the group consisting of inert gases, nitrogen, oxygen, and fluorocarbons, said process comprising: directing said stream through a bed of sintered anhydrous K 3 NiF 6 pellets at a temperature in the range of from 240°-246° C., the residence time of said stream in said bed being in the range of 100 to 1000 seconds, to effect fluorination of said pellets to K 3 NiF 7 .
References Cited (Backward Citations)
US3372004A
Cited
US3989808A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |