Patent US2997466A successfully refreshed from Google Patents.
US2997466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decantation of lignin
Assignee: West Virginia Pulp and Paper Co
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Filing: 1958-11-04
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Granted: 1961-08-22
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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
2026-10-30 13:19
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/0007
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
IN THE METHOD OF RECOVERING LIGNATES FROM LIGNIN BEARING SOLUTIONS, THE STEPS OF COAGULATING COLLOIDALLY PRECIPITATED LIGNATE BY MAINTAINING A SLURRY THEREOF IN WATER IN A ZONE OF QUIESCENCE, WHEREIN THE SLURR IS MAINTAINED UNDER SUPERATMOSPHERIC PRESSURE AND AT A TEMPERATURE ABOVE THE MELTING POINT OF THE LIGNATE UNTIL SAID SLURRY DEPOSITS COAGULATED LIGNATE IN A FUSED LOWER LAYER SEPARATE FROM AN UPPER LAYER OF MOTHER LIQUOR, AND THEREAFTER REMOVING SAID FUSED LAYER BY DECANTATION.
Claim 2
Dependent Claim
75 words
IN THE METHOD OF RECOVERING LIGNATES FROM LIGNIN BEARING SOLUTIONS, THE STEPS OF COAGULATING COLLOIDALLY PRECIPITATED LIGNATE BY MAINTAINING A SLURRY THEREOF IN WATER IN A ZONE OF QUIESCENCE, WHEREIN THE SLURR IS MAINTAINED UNDER SUPERATMOSPHERIC PRESSURE AND AT A TEMPERATURE ABOVE THE MELTING POINT OF THE LIGNATE UNTIL SAID SLURRY DEPOSITS COAGULATED LIGNATE IN A FUSED LOWER LAYER SEPARATE FROM AN UPPER LAYER OF MOTHER LIQUOR, AND THEREAFTER REMOVING SAID FUSED LAYER BY DECANTATION.
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) | 1964-08-21 | 1965-02-20 | 1965-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-21 | 1969-02-20 | 1969-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-21 | 1973-02-20 | 1973-08-22 | $7700.00 | Window Closed / Lapsed |