Patent US3575884A successfully refreshed from Google Patents.
US3575884A
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US
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Method for the production of active charcoal from sawdust treated with sulphuric acid
Assignee: Individual
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Filing: 1968-06-25
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Granted: 1971-04-20
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Expires: 1988-06-25
Abstract
Abstract AN IMPROVED METHOD FOR PRODUCING ADSORBEND CHARCOAL IS DISCLOSED, SAID METHOD INVOLVING THE DISTILLATION OF SAWDUST FROM RESINOUS WOODS IN THE PRESENCE OF A PREDETERMINED AMOUNT OF DILUTED SULPHURIC ACID AS A TWOFOLDACTION CATALYST. A MODIFICATION OF THE METHOD INVOLVES THE ADDITIONAL STEP OF REHEATING UPON COOLING, AT A TEMPERATURE EXCEEDING BY 50*C. THE DISTILLATION TEMPERATURE. THE ADDITION OF PORE-FILLING, COKE-FORMING COMPONENTS IS ALSO CONTEMPLATED. THE CHARCOAL SO PRODUCED IS PARTICULARLY ADVANTAGEOUS FOR VARIOUS PHYSICO-CHEMICAL PROCESSES, SUCH AS PURIFICATION OF WASTE AND SEWAGE WATERS AND OTHERS.
Inventors
- 👤 Rene-Rodolphe Seiler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:23
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/30; C01B32/312; C01B32/342; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/917
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |