Patent US3048576A successfully refreshed from Google Patents.
US3048576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous acidulation and coagulation of lignin in black liquor
Assignee: West Virginia Pulp and Paper Co
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Filing: 1958-11-04
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Granted: 1962-08-07
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Expires: 1978-11-04
Abstract
No abstract record available.
Inventors
- 👤 Frank J Ball
- 👤 William G Vardell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:06
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/0007
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
IN THE METHOD OF RECOVERING SODIUM LIGNATE FROM BLACK LIQUOR HAVING A SOLIDS CONTENT IN EXCESS OF 30% AND A PH IN EXCESS OF 10.4, THE STEPS WHICH CONSIST IN: (A) CONTINOUSLY ADDING CONCENTRATED SULFURIC ACID TO BLACK LIQUOR WHICH HAS A TEMPERATURE SUFFICIENT TO YIELD A PRECIPATION TEMPERATURE IN EXCESS OF THE TEMPERATURE OF LIGNIN COAGULATION OF AROUND 180*F., SAID ACID BEING ADDED IN AN AMOUNT TO EFFECT A SUBSTANTIAL PRECIPITATION OF SODIUM LIGNATE, (B) THROUGHLY AND CONTINOUSLY MIXING SAID HEATED BLACK LIQUOR AND SAID ACID TO BRING ABOUT THE PRECIPITATION OF SODIUM WITH COMMENCEMENT OF SUBSTANTIALLY SIMULTANEOUS COAGULATION THEREOF, (C) MAINTAINING THE COAGULATING BLACK LIQUOR IN A DWELL STAGE AT THE PRECIPITATION TEMPERATURE FOR A PEROID OF FROM 20 SECONDS TO 10 MINUTES TO COMPLETE THE COAGULATION THEREOF, AND, (D) CONTINOUSLY SEPARATING THE COAGULATED LIGNATE FROM THE MOTHER LIQUOR.
Claim 2
Dependent Claim
141 words
IN THE METHOD OF RECOVERING SODIUM LIGNATE FROM BLACK LIQUOR HAVING A SOLIDS CONTENT IN EXCESS OF 30% AND A PH IN EXCESS OF 10.4, THE STEPS WHICH CONSIST IN: (A) CONTINOUSLY ADDING CONCENTRATED SULFURIC ACID TO BLACK LIQUOR WHICH HAS A TEMPERATURE SUFFICIENT TO YIELD A PRECIPATION TEMPERATURE IN EXCESS OF THE TEMPERATURE OF LIGNIN COAGULATION OF AROUND 180*F., SAID ACID BEING ADDED IN AN AMOUNT TO EFFECT A SUBSTANTIAL PRECIPITATION OF SODIUM LIGNATE, (B) THROUGHLY AND CONTINOUSLY MIXING SAID HEATED BLACK LIQUOR AND SAID ACID TO BRING ABOUT THE PRECIPITATION OF SODIUM WITH COMMENCEMENT OF SUBSTANTIALLY SIMULTANEOUS COAGULATION THEREOF, (C) MAINTAINING THE COAGULATING BLACK LIQUOR IN A DWELL STAGE AT THE PRECIPITATION TEMPERATURE FOR A PEROID OF FROM 20 SECONDS TO 10 MINUTES TO COMPLETE THE COAGULATION THEREOF, AND, (D) CONTINOUSLY SEPARATING THE COAGULATED LIGNATE FROM THE MOTHER LIQUOR.
References Cited (Backward Citations)
US2623040A
Cited
US2640052A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-08-06 | 1966-02-05 | 1966-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-08-06 | 1970-02-05 | 1970-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-08-06 | 1974-02-05 | 1974-08-07 | $7700.00 | Window Closed / Lapsed |