US3948809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorbent and the process for producing it
Assignee: Unisearch Ltd
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Filing: 1973-01-18
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Granted: 1976-04-06
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Expires: 1993-01-18
Abstract
Abstract This invention relates to absorbents which are particularly useful for the treatment of sulphur-containing oxides. These absorbents are made from materials containing aluminium oxide by steps including leaching an oxide-containing material, such as bauxite, with an alkaline solution; separating the resultant leach liquor; and drying the liquor. If desired alkali metal carbonate may be added to the liquor between the steps of separation and drying.
Inventors
- 👤 Joseph Rangott Norman
- 👤 David Graham Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:33
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/48; C01B17/50; C01B17/60; B; B01; B01J; B01J20/00; B01J20/02; B01J20/04; B01J20/041; B01J20/06; B01J20/08; B01J20/30; B01J20/3071; B01J20/3078
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
98 words
A process for producing an absorbent, capable of absorbing sulphur-containing oxides from industrial gases, from materials containing aluminum oxide consisting essentially of naturally occurring bauxite or red mud waste product from aluminum plants comprising the steps of leaching said material with an alkaline solution; separating the resultant leach liquor from the undissolved material; adding up to about 30% by weight of an alkali metal carbonate to the separated leach liquor, said weight being based on the weight of the original alkaline solution; drying the liquor so as to produce the absorbent in solid form; and calcining said absorbent.
Claim 2
Dependent Claim
98 words
A process for producing an absorbent, capable of absorbing sulphur-containing oxides from industrial gases, from materials containing aluminum oxide consisting essentially of naturally occurring bauxite or red mud waste product from aluminum plants comprising the steps of leaching said material with an alkaline solution; separating the resultant leach liquor from the undissolved material; adding up to about 30% by weight of an alkali metal carbonate to the separated leach liquor, said weight being based on the weight of the original alkaline solution; drying the liquor so as to produce the absorbent in solid form; and calcining said absorbent.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 1 wherein the alkali metal carbonate is, sodium carbonate.
Claim 4
Dependent Claim
17 words
A process as claimed in claim 1 wherein the alkaline solution is a solution of sodium hydroxide.
Claim 5
Dependent Claim
25 words
A process as claimed in claim 1 wherein the leaching is carried out at atmospheric pressure at a temperature within the range 50° to 100°C.
Claim 6
Dependent Claim
21 words
A process as claimed in claim 1 wherein the calcination is performed at a temperature within the range 600° to 700°C.
Claim 7
Dependent Claim
9 words
An absorbent product produced in accordance with claim 1.
References Cited (Backward Citations)
US2378155A
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US2992884A
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US3268295A
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US3228891A
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US3557025A
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US3551093A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |