Patent US2589252A successfully refreshed from Google Patents.
US2589252A
Expired / Lapsed
US
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Process for metal recovery
Assignee: Weyerhaeuser Timber Co
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Filing: 1946-12-07
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Granted: 1952-03-18
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Expires: 1966-12-07
Abstract
No abstract record available.
Inventors
- 👤 Clark C Heritage
- 👤 William G Van Beckum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:30
CPC Classifications
C; C08; C08H; C08H6/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
THE PROCESS COMPRISING SUBJECTING LIGNOCELLULOSE MATERIAL IN A DEFIBERED STATE TO THE ACTION OF A DILUTE AQUEOUS SOLUTION OF A BASIC-ACTING COMPOUND OF AN ALKALI METAL AND THEREBY DISSOLVING FROM SAID LIGNOCELLULOSE MATERIAL A LIGNIN CONSISTING OF CARBON, HYDROGEN AND OXYGEN, SAID LIGNIN BEING INSOLUBLE IN DIOXANE AND INCAPABLE OF BEING PRECIPITATED FROM AN ALKALINE SOLUTION BY REACTION WITH CARBON DIOXIDE, CONCENTRATING THE SO-PRODUCED LIGNIN SOLUTION, ACIDIFYING THE LATTER TO A PH OF ABOUT 1.5 WHEREUPON A LIGNIN PRODUCT IS PRECIPITATED LEAVING A RESIDUAL SOLUTION, SEPARATING SAID LIGNIN PRECIPITATE FROM SAID RESIDUAL SOLUTION, FORMING AN AQUEOUS SOLUTION FROM SAID LIGNIN PRECIPITATE, SAID AQUEOUS SOLUTION CONTAINING A LIGNIN MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE LIGNIC ACID AND WATERSOLUBLE SALTS OF LIGNIC ACID, REACTING SAID AQUEOUS SOLUTION WITH A SOLUTION OF A SALT OF A METAL WHICH FORMS A WATER-INSOLUBLE METAL LIGNATE WHEREUPON A METAL LIGNATE IS PRECIPITATED, AND RECOVERING SAID PRECIPITATE.
Claim 2
Dependent Claim
152 words
THE PROCESS COMPRISING SUBJECTING LIGNOCELLULOSE MATERIAL IN A DEFIBERED STATE TO THE ACTION OF A DILUTE AQUEOUS SOLUTION OF A BASIC-ACTING COMPOUND OF AN ALKALI METAL AND THEREBY DISSOLVING FROM SAID LIGNOCELLULOSE MATERIAL A LIGNIN CONSISTING OF CARBON, HYDROGEN AND OXYGEN, SAID LIGNIN BEING INSOLUBLE IN DIOXANE AND INCAPABLE OF BEING PRECIPITATED FROM AN ALKALINE SOLUTION BY REACTION WITH CARBON DIOXIDE, CONCENTRATING THE SO-PRODUCED LIGNIN SOLUTION, ACIDIFYING THE LATTER TO A PH OF ABOUT 1.5 WHEREUPON A LIGNIN PRODUCT IS PRECIPITATED LEAVING A RESIDUAL SOLUTION, SEPARATING SAID LIGNIN PRECIPITATE FROM SAID RESIDUAL SOLUTION, FORMING AN AQUEOUS SOLUTION FROM SAID LIGNIN PRECIPITATE, SAID AQUEOUS SOLUTION CONTAINING A LIGNIN MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE LIGNIC ACID AND WATERSOLUBLE SALTS OF LIGNIC ACID, REACTING SAID AQUEOUS SOLUTION WITH A SOLUTION OF A SALT OF A METAL WHICH FORMS A WATER-INSOLUBLE METAL LIGNATE WHEREUPON A METAL LIGNATE IS PRECIPITATED, AND RECOVERING SAID PRECIPITATE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-03-18 | 1955-09-17 | 1956-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-03-18 | 1959-09-17 | 1960-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-03-18 | 1963-09-17 | 1964-03-18 | $7700.00 | Window Closed / Lapsed |