Patent US4673558A successfully refreshed from Google Patents.
US4673558A
Expired / Lapsed
US
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Method for treating a waste gas
Assignee: AGC Inc
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Filing: 1985-09-04
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Granted: 1987-06-16
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Expires: 2005-09-04
Abstract
Abstract A method for treating a waste gas containing a fluorine component and/or a chlorine component, which comprises contacting the waste gas with magnesium oxide particles having a specific surface area of from 100 to 200 m 2 /g.
Inventors
- 👤 Makoto Senoue
- 👤 Kunihiko Terase
- 👤 Keiichi Nakaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:46
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8659
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
48 words
A method for treating a waste-gas containing a fluorine component and/or a chlorine component, which comprises: contacting the waste gas with magnesium oxide particles which have a specific surface area of from 100 to 200 m 2 /g and a particle size ranging from 0.5 to 10 mm.
Claim 2
Independent Claim
48 words
A method for treating a waste-gas containing a fluorine component and/or a chlorine component, which comprises: contacting the waste gas with magnesium oxide particles which have a specific surface area of from 100 to 200 m 2 /g and a particle size ranging from 0.5 to 10 mm.
Claim 3
Dependent Claim
15 words
The method according to claim 1, wherein the fluorine component is SiF 4 or HF.
Claim 4
Dependent Claim
18 words
The method according to claim 1, wherein the chlorine component is BCl 3 , SiCl 4 or HCl.
Claim 5
Dependent Claim
19 words
The method according to claim 1, wherein the waste gas is a waste gas discharged from dry etching treatment.
Claim 6
Dependent Claim
23 words
The method according to claim 1, wherein the specific surface area of said magnesium oxide particles ranges 110 to 190 m 2 /g.
Claim 7
Independent Claim
52 words
A method for treating a waste-gas containing a fluorine component and/or a chlorine component, which comprises: contacting the waste gas with a fixed bed of magnesium oxide particles which have a specific surface area of from 100 to 200 m 2 /g and a particle size ranging from 0.5 to 10 mm.
Claim 8
Independent Claim
52 words
A method for treating a waste-gas containing a fluorine component and/or a chlorine component, which comprises: contacting the waste gas with a fixed bed of magnesium oxide particles which have a specific surface area of from 100 to 200 m 2 /g and a particle size ranging from 0.5 to 10 mm.
References Cited (Backward Citations)
US2919174A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-15 | 1998-12-15 | 1999-06-16 | $7700.00 | Window Closed / Lapsed |