Patent US2694897A successfully refreshed from Google Patents.
Patent US3248169A successfully refreshed from Google Patents.
US3248169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of regenerating sodium sulfite waste liquors
Assignee: —
•
Filing: —
•
Granted: 1966-04-26
•
Expires: 1983-04-26
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:51
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/02; Y; Y10; Y10S; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
139 words
A METHOD OF TREATING SPENT SULFITE LIQUOR OBTAINED FROM COOKING CELLULOSE MATERIALS WITH A SULFITE COOKING LIQUOR WHICH COMPRISES THE STEPS OF: EVAPORATING WATER FROM SAID SPENT LIQUOR TO FORM A CONCENTRATING LIQUOR; BURNING THE CONCENTRATED LIQUOR IN A COMBUSTION FURNACE TO FORM A SULFUR DIOXIDE CONTAINING COMBUSTION GAS AND A SMELT CONTAINING SODIUM AND SULFUR; DISSOLVING THE SMELT TO OBTAIN A SOLUTION CONTAINING SODIUM SULFIDE AND SODIUM CARBONATE; PRECIPITATING THE SODIUM CARBONATE AND SEPARATING THE SODIUM CARABONATE FROM THE SOLUTION OF SODIUM SULFIDE; PASSING THE SULFIDE SULFUR CONTENT OF SAID SOLUTION TO THE COMBUSTION FURNACE WITHOUT APPRECIABLE REACTION OF SAID SULFUR CONTENT WITH THE SULFUR IN THE SPENT LIQUOR WHEREIN A PORTION OF THE SULFUR SO PASSED IS CONVERTED TO SULFUR DIOXIDE; AND ABSORBING THE SULFUR DIOXIDE SO PRODUCED IN A SOLUTION PREPARED FROM THE PRECIPITATED SODIUM CARBONATE.
Claim 2
Independent Claim
139 words
A METHOD OF TREATING SPENT SULFITE LIQUOR OBTAINED FROM COOKING CELLULOSE MATERIALS WITH A SULFITE COOKING LIQUOR WHICH COMPRISES THE STEPS OF: EVAPORATING WATER FROM SAID SPENT LIQUOR TO FORM A CONCENTRATING LIQUOR; BURNING THE CONCENTRATED LIQUOR IN A COMBUSTION FURNACE TO FORM A SULFUR DIOXIDE CONTAINING COMBUSTION GAS AND A SMELT CONTAINING SODIUM AND SULFUR; DISSOLVING THE SMELT TO OBTAIN A SOLUTION CONTAINING SODIUM SULFIDE AND SODIUM CARBONATE; PRECIPITATING THE SODIUM CARBONATE AND SEPARATING THE SODIUM CARABONATE FROM THE SOLUTION OF SODIUM SULFIDE; PASSING THE SULFIDE SULFUR CONTENT OF SAID SOLUTION TO THE COMBUSTION FURNACE WITHOUT APPRECIABLE REACTION OF SAID SULFUR CONTENT WITH THE SULFUR IN THE SPENT LIQUOR WHEREIN A PORTION OF THE SULFUR SO PASSED IS CONVERTED TO SULFUR DIOXIDE; AND ABSORBING THE SULFUR DIOXIDE SO PRODUCED IN A SOLUTION PREPARED FROM THE PRECIPITATED SODIUM CARBONATE.
References Cited (Backward Citations)
CA504057A
Cited
US1689534A
Cited
US2320294A
Cited
US2351780A
Cited
US2730445A
Cited
US2789883A
Cited
US2824071A
Cited
US2849292A
Cited
US2792350A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-04-25 | 1969-10-25 | 1970-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-25 | 1973-10-25 | 1974-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-25 | 1977-10-25 | 1978-04-26 | $7700.00 | Window Closed / Lapsed |