US2800388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of alkali and sulphur from waste lyes in the manufacture of cellulose with alkali sulphite and alkali bisulphite
Assignee: Stora Enso Oyj
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Filing: 1955-09-06
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Granted: 1957-07-23
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Expires: 1975-09-06
Abstract
No abstract record available.
Inventors
- 👤 Ahlborg Nils Knut Gabriel
- 👤 Cederquist Karl Nicolaus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:50
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/0064; D21C11/0071; Y; Y10; Y10S; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
181 words
A METHOD OF RECOVERING SULPHUR AND ALKALI FROM THE SULPHITE WASTE LYE OBSTINED IN DIGESTION CELLULOSE WITH A MEMBER OF THE GROUP CONSISTING OF ALKALI SULPHITES AND BISULPHIITES WHICH COMPRISES EVAPORATING SAID LYE ANDD COMBUSTING SAME TO OBTAIN A MELT SODA CONTAINING SODA AND SULHIDE SULPHUR, CARBONATING AN AQUEOUS SOLUTION OF SAID MELT SODA WITH SUBSTANTIALLY PURE, OXYGEN-FREE CARBON DIOXIDE, AND REMOVING FROM SAID MELT SODA SOLUTION THE MAIN PART OF THE SULPIDE SULPHUR THEREIN AS HYDROGEN SULPHIDE, THEREAFTER FURTHER CARBONATING THE MELT SODA SOLUTION FOM WHICH THE MAIN PART OF SAID SULPHIDE SULPHUSR HAS BEEN REMOVED BY BLOWING SUBSTANTIALLY PURE, OXYGEN-FREE CARBON DIOXIDE THERETHROUGH AND EXPELLING THE RESIDUAL SULPHIDE SULPHUR IN SAID MELT SODA SOLUTION AS HYDROGEN SULPHIDE IN THE FORM OF A GASEOUS MIXTURE WITH CARBON DIOXIDE, RELIEVEING SAID GASEOUS MIXTURE OF HYDROGEN SULPHIDE BY TREATING SAID MIXTURE WITH AN AQUEOUS SOLUTION OF A MEMBER OF THE GROUP CONSISTING OF ALKALI SULPHITES AND BISULPHITES WHEREUPON SAID HYDROGEN SULPHIDE IS CONVERTED TO THIOSULPHATE AND OTHER SULPHUR COMPOUNDS IN AQUEOUS SOLUTION AND THE CARBON DIOXIDE GAS IS RENDERED SUBSTANTIALLY PURE, THERE-
Claim 2
Independent Claim
181 words
A METHOD OF RECOVERING SULPHUR AND ALKALI FROM THE SULPHITE WASTE LYE OBSTINED IN DIGESTION CELLULOSE WITH A MEMBER OF THE GROUP CONSISTING OF ALKALI SULPHITES AND BISULPHIITES WHICH COMPRISES EVAPORATING SAID LYE ANDD COMBUSTING SAME TO OBTAIN A MELT SODA CONTAINING SODA AND SULHIDE SULPHUR, CARBONATING AN AQUEOUS SOLUTION OF SAID MELT SODA WITH SUBSTANTIALLY PURE, OXYGEN-FREE CARBON DIOXIDE, AND REMOVING FROM SAID MELT SODA SOLUTION THE MAIN PART OF THE SULPIDE SULPHUR THEREIN AS HYDROGEN SULPHIDE, THEREAFTER FURTHER CARBONATING THE MELT SODA SOLUTION FOM WHICH THE MAIN PART OF SAID SULPHIDE SULPHUSR HAS BEEN REMOVED BY BLOWING SUBSTANTIALLY PURE, OXYGEN-FREE CARBON DIOXIDE THERETHROUGH AND EXPELLING THE RESIDUAL SULPHIDE SULPHUR IN SAID MELT SODA SOLUTION AS HYDROGEN SULPHIDE IN THE FORM OF A GASEOUS MIXTURE WITH CARBON DIOXIDE, RELIEVEING SAID GASEOUS MIXTURE OF HYDROGEN SULPHIDE BY TREATING SAID MIXTURE WITH AN AQUEOUS SOLUTION OF A MEMBER OF THE GROUP CONSISTING OF ALKALI SULPHITES AND BISULPHITES WHEREUPON SAID HYDROGEN SULPHIDE IS CONVERTED TO THIOSULPHATE AND OTHER SULPHUR COMPOUNDS IN AQUEOUS SOLUTION AND THE CARBON DIOXIDE GAS IS RENDERED SUBSTANTIALLY PURE, THERE-
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) | 1960-07-22 | 1961-01-21 | 1961-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-22 | 1965-01-21 | 1965-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-22 | 1969-01-21 | 1969-07-23 | $7700.00 | Window Closed / Lapsed |