Patent US2864669A successfully refreshed from Google Patents.
US2864669A
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Method for recovering sulfur and alkali from waste liquors
Assignee: Stora Enso Oyj
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Filing: 1954-11-01
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Granted: 1958-12-16
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Expires: 1974-11-01
Abstract
No abstract record available.
Inventors
- 👤 Ahlborg Knut
- 👤 Cederquist Karl Nicolaus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:53
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/62; Y; Y10; Y10S; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
171 words
A METHOD FOR RECOVERING SULFUR AND ALKALI FROM WASTE LIQUORS DERIVED FROM THE DIGESTION OF LIGNOCELLULOSIC MATERIALS WITH A COOKING LIQUOR CONTAINING A SULFUR COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKALI SULFITES AND BISULFITES SUBSEQUENT TO EVAPORATING AND BURNING THE LIQUORS TO SMELT SODA WITHOUT ANY APRECIABLE FORMATION OF THIOSULFATE, IN WHICH A SOLUTION OF SAID SMELT SODA IS CARBONATED IN A FIRST STAGE AT A PRESSURE OF AT LEAST ABOUT ATMOSPHERIC PRESSURE BY MEANS OF AT LEAST SUBSTANTIALLY PURE OXYGEN-FREE CARBON DIOXIDE TO CONVERT THE SODA AND THE ALKALI METAL SULFIDE OF THE SOLUTION AT LEAST SUBSTANTIALLY COMPLETELY INTO BICARBONATE, THE CARBONATED SOLUTION IS FREED FROM THE MAIN PORTION OF THE SULFIDE SULFUR BY STRIPPING BY MEANS OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF STEAM UNDER VACUUM, AIR AND FLUE GAS, THE SOLUTION IS RECARBONATED IN A SECOND STAGE BY MEANS OF CARBON DIOXIDE AT A PRESSURE OF AT LEAST ABOUT ATMOSPHERIC PRESSURE, REMAINING SULFIDE SULFUR IS STRIPPED BY MEANS OF AT LEAST SUBSTANTIALLY PURE OXYGEN-FREE CAR-
Claim 2
Independent Claim
171 words
A METHOD FOR RECOVERING SULFUR AND ALKALI FROM WASTE LIQUORS DERIVED FROM THE DIGESTION OF LIGNOCELLULOSIC MATERIALS WITH A COOKING LIQUOR CONTAINING A SULFUR COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKALI SULFITES AND BISULFITES SUBSEQUENT TO EVAPORATING AND BURNING THE LIQUORS TO SMELT SODA WITHOUT ANY APRECIABLE FORMATION OF THIOSULFATE, IN WHICH A SOLUTION OF SAID SMELT SODA IS CARBONATED IN A FIRST STAGE AT A PRESSURE OF AT LEAST ABOUT ATMOSPHERIC PRESSURE BY MEANS OF AT LEAST SUBSTANTIALLY PURE OXYGEN-FREE CARBON DIOXIDE TO CONVERT THE SODA AND THE ALKALI METAL SULFIDE OF THE SOLUTION AT LEAST SUBSTANTIALLY COMPLETELY INTO BICARBONATE, THE CARBONATED SOLUTION IS FREED FROM THE MAIN PORTION OF THE SULFIDE SULFUR BY STRIPPING BY MEANS OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF STEAM UNDER VACUUM, AIR AND FLUE GAS, THE SOLUTION IS RECARBONATED IN A SECOND STAGE BY MEANS OF CARBON DIOXIDE AT A PRESSURE OF AT LEAST ABOUT ATMOSPHERIC PRESSURE, REMAINING SULFIDE SULFUR IS STRIPPED BY MEANS OF AT LEAST SUBSTANTIALLY PURE OXYGEN-FREE CAR-
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) | 1961-12-15 | 1962-06-16 | 1962-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-15 | 1966-06-16 | 1966-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-15 | 1970-06-16 | 1970-12-16 | $7700.00 | Window Closed / Lapsed |