US2909407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method in the recovery of alkali and sulphur by carbonization of melt soda solutions obtained in the manufacture of cellulose
Assignee: Stora Enso Oyj
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Filing: 1956-02-14
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Granted: 1959-10-20
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Expires: 1976-02-14
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
2026-11-01 15:02
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/0064; D21C11/0071; C; C01; C01B; C01B17/00; C01B17/62; C01D; C01D5/00; C01D5/14; Y; Y10; Y10S; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
156 words
A METHOD FOR THE PREPARATION OF ALKALI SULFITE WITH A MINIMUM OF THIOSULFATE FORMATION FROM ALKALI AND SULFIDE SULFUR RECOVERED FROM A MELT SODA SOLUTION CONTAINING THE SAME WHICH COMPRISES THE STEPS OF: (1) EXPELLING SULFIDE SULFUR FROM SAID SOLUTION AS HYDROGEN SULFIDE IN THE FORM OF A SUBSTANTIALLY OXYGEN-FREE GASEOUS MIXTURE CONSISTING ESSENTIALLY OF HYDROGEN SULFIDE AND CARBONIC ACID BY TREATING SAID SOLUTION WITH OXYGEN-FREE, SUBSTANTIALLY PURE CARBONIC ACID WHEREBY A SUBSTANTIALLY SULFIDE-FREE SOLUTION IS OBTAINED; (2) REACTING SAID GASEOUS MIXTURE OF HYDROGEN SULFIDE AND CARABONIC ACID WITH SULFUROUS ACID WHEREBY ELEMENTAL SULFUR AND SUBSTANTIALLY SULFIDE-FREE CARBONIC ACID ARE OBTAINED; (3) DIRECTLY RECYCLING THE THUS OBTAINED SULFIDE-FREE CARBONIC ACID TO STEP (1) FOR THE TREATMENT OF ADDITIONAL METL SODA SOLUTION AND THE EXPULSION OF SULFIDE SULFUR THEREFROM; (4) COMBUSTING SAID ELEMENTAL SULFUR TO SULFUR DIOXIDE; AND (5) UTILIZING SAID SULFUR DIOXIDE AND THE SULFIDEFREE MELT SODA SOLUTION OBTAINED IN STEP (1) TO FORM ALKALI SULFITE.
Claim 2
Independent Claim
156 words
A METHOD FOR THE PREPARATION OF ALKALI SULFITE WITH A MINIMUM OF THIOSULFATE FORMATION FROM ALKALI AND SULFIDE SULFUR RECOVERED FROM A MELT SODA SOLUTION CONTAINING THE SAME WHICH COMPRISES THE STEPS OF: (1) EXPELLING SULFIDE SULFUR FROM SAID SOLUTION AS HYDROGEN SULFIDE IN THE FORM OF A SUBSTANTIALLY OXYGEN-FREE GASEOUS MIXTURE CONSISTING ESSENTIALLY OF HYDROGEN SULFIDE AND CARBONIC ACID BY TREATING SAID SOLUTION WITH OXYGEN-FREE, SUBSTANTIALLY PURE CARBONIC ACID WHEREBY A SUBSTANTIALLY SULFIDE-FREE SOLUTION IS OBTAINED; (2) REACTING SAID GASEOUS MIXTURE OF HYDROGEN SULFIDE AND CARABONIC ACID WITH SULFUROUS ACID WHEREBY ELEMENTAL SULFUR AND SUBSTANTIALLY SULFIDE-FREE CARBONIC ACID ARE OBTAINED; (3) DIRECTLY RECYCLING THE THUS OBTAINED SULFIDE-FREE CARBONIC ACID TO STEP (1) FOR THE TREATMENT OF ADDITIONAL METL SODA SOLUTION AND THE EXPULSION OF SULFIDE SULFUR THEREFROM; (4) COMBUSTING SAID ELEMENTAL SULFUR TO SULFUR DIOXIDE; AND (5) UTILIZING SAID SULFUR DIOXIDE AND THE SULFIDEFREE MELT SODA SOLUTION OBTAINED IN STEP (1) TO FORM ALKALI SULFITE.
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) | 1962-10-19 | 1963-04-20 | 1963-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-10-19 | 1967-04-20 | 1967-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-10-19 | 1971-04-20 | 1971-10-20 | $7700.00 | Window Closed / Lapsed |