US4399113A
Expired / Lapsed
US
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Process for treating a gas containing a fluorine compound
Assignee: Mitsubishi Light Metal Industries Ltd
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Filing: 1981-11-16
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Granted: 1983-08-16
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Expires: 2001-11-16
Abstract
Abstract A process for treating a gas containing a fluorine compound which comprises the steps of contacting said gas with an aqueous solution as an absorbent containing aluminum fluoride and sulfate radical at a concentration of 3 to 30 g/l to absorb the fluorine compound, producing a solid phase including aluminum fluoride hydrate and/or basic aluminum fluoride by adding aluminum hydroxide and/or alumina to the resultant aqueous solution obtained in the absorbing step, and separating said solid phase from a slurry containing said solid phase obtained in the producing step.
Inventors
- 👤 Susumu Tosaka
- 👤 Tadamichi Abe
- 👤 Hozumi Endo
- 👤 Kiyohiro Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:46
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/48; C01F7/50; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/68
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
A process for treating a gas containing a fluorine compound which comprises the steps of: contacting said gas with an aqueous solution as an absorbent containing aluminum fluoride and sulfate radical at a concentration of 3 to 30 g/l to absorb the fluorine compound, producing a solid phase including aluminum fluoride hydrate and/or basic aluminum fluoride by adding aluminum hydroxide and/or alumina to the resultant aqueous solution obtained in the absorbing step, and separating said solid phase from a slurry containing said solid phase obtained in the producing step.
Claim 2
Dependent Claim
89 words
A process for treating a gas containing a fluorine compound which comprises the steps of: contacting said gas with an aqueous solution as an absorbent containing aluminum fluoride and sulfate radical at a concentration of 3 to 30 g/l to absorb the fluorine compound, producing a solid phase including aluminum fluoride hydrate and/or basic aluminum fluoride by adding aluminum hydroxide and/or alumina to the resultant aqueous solution obtained in the absorbing step, and separating said solid phase from a slurry containing said solid phase obtained in the producing step.
Claim 3
Dependent Claim
41 words
The process according to claim 1, wherein the concentration of the sulfate radical contained in the aqueous solution as an absorbent is maintained at a predetermined value by adding a substance containing sulfate radical in the absorbent in the absorbing step.
Claim 4
Dependent Claim
18 words
The process according to claim 2, wherein the substance containing sulfate radical is sulfuric acid or aluminum sulfate.
Claim 5
Dependent Claim
19 words
The process according to claim 2, wherein the substance containing sulfate radical is amorphous aluminum hydroxide containing sulfate radical.
Claim 6
Dependent Claim
86 words
The process according to claim 1, wherein the absorbing step comprises a former absorbing step wherein the gas containing a fluorine compound is treated with an aqueous solution as a former absorbent containing aluminum fluoride and sulfate radical at a concentration of 3 to 30 g/l, and a latter absorbing step wherein the once treated gas containing the fluorine compound discharged from the former absorbing step is further treated with an aqueous solution as a latter absorbent of pH 1 to 4 containing amorphous aluminum hydroxide.
Claim 7
Dependent Claim
20 words
The process according to claim 5, wherein amorphous aluminum hydroxide to be added to the latter absorbent contains sulfate radical.
Claim 8
Dependent Claim
28 words
The process according to claim 5 or 6, wherein a part of the latter absorbent is withdrawn and the withdrawn part thereof is combined with the former absorbent.
References Cited (Backward Citations)
US4041137A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |