Patent US2696424A successfully refreshed from Google Patents.
US2696424A
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Preparation of calcium bisulfite cooking acid from waste sulfite liquor
Assignee: STWB Inc
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Filing: 1951-06-16
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Granted: 1954-12-07
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Expires: 1971-06-16
Abstract
No abstract record available.
Inventors
- 👤 Eugene W Schoeffel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:00
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/02; Y; Y02; Y02P; Y02P40/00; Y02P40/40; Y10; Y10S; Y10S423/00; Y10S423/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
IN A PROCESS FOR REGENERATING WASTE CALCIUM BISULFITE COOKING ACID TO BE USED FOR DIGESTING WOOD TO YIELD PULP AND WASTE SULFITE LIQUOR, THE STEPS WHICH INCLUDE: SUBSTANTIALLY COMPLETELY OXIDIZING, IN THE LIQUID PHASE, WITH FREE OXYGEN AT A TEMPERATURE ABOVE ABOUT 160 DEGREES CENTIGRADE A WASTE SULFITE LIQUOR NEUTRALIZED WITH LIME TO PRODUCE CALCIUM SULFATE AND CALCIUM CARBONATE TOGETHER WITH GASEOUS OXIDATION PRODUCTS AND A LIQUID EFFLUENT; SEPARATING AND ROASTING THE CALCIUM SULFATE AND CALCIUM CARBONATE TO OBTAIN PRIMARILY SULFUR DIOXIDE AS AN EVOLVED GAS AND CALCIUM OXIDE AS A SOLID RESIDUE; CONTACTING WATER AND THE SAID CALCIUM OXIDE TO FORM A SUSPENSION THEREOF; AND, INTRODUCING INTO SAID SUSPENSION THE SULFUR DIOXIDE FROM THE ROASTING STEP TO FORM CALCIUM BISULFITE COOKING ACID.
Claim 2
Dependent Claim
123 words
IN A PROCESS FOR REGENERATING WASTE CALCIUM BISULFITE COOKING ACID TO BE USED FOR DIGESTING WOOD TO YIELD PULP AND WASTE SULFITE LIQUOR, THE STEPS WHICH INCLUDE: SUBSTANTIALLY COMPLETELY OXIDIZING, IN THE LIQUID PHASE, WITH FREE OXYGEN AT A TEMPERATURE ABOVE ABOUT 160 DEGREES CENTIGRADE A WASTE SULFITE LIQUOR NEUTRALIZED WITH LIME TO PRODUCE CALCIUM SULFATE AND CALCIUM CARBONATE TOGETHER WITH GASEOUS OXIDATION PRODUCTS AND A LIQUID EFFLUENT; SEPARATING AND ROASTING THE CALCIUM SULFATE AND CALCIUM CARBONATE TO OBTAIN PRIMARILY SULFUR DIOXIDE AS AN EVOLVED GAS AND CALCIUM OXIDE AS A SOLID RESIDUE; CONTACTING WATER AND THE SAID CALCIUM OXIDE TO FORM A SUSPENSION THEREOF; AND, INTRODUCING INTO SAID SUSPENSION THE SULFUR DIOXIDE FROM THE ROASTING STEP TO FORM CALCIUM BISULFITE COOKING ACID.
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) | 1957-12-06 | 1958-06-07 | 1958-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-12-06 | 1962-06-07 | 1962-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-12-06 | 1966-06-07 | 1966-12-07 | $7700.00 | Window Closed / Lapsed |