Patent US3630959A successfully refreshed from Google Patents.
US3630959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbonization of bituminous coals
Assignee: Standard Oil Co
•
Filing: 1969-06-04
•
Granted: 1971-12-28
•
Expires: 1989-06-04
Abstract
Abstract CASRBONIZATION OF BITUMINOUS COAL WHEREIN THE COAL IS ACIDIFIED WITH A LIQUID SULFONATING AGENT SUCH AS SULFURIC ACID OR OLEUM AND THEREAFTER CARBONIZED BY HEATING TO A TEMPERATURE IN THE RANGE OF 600*C. TO 900*C., THE HEATING RATE IN THE TEMPERATURE RANGE OF 400*C. TO 600*C. BEING IN EXCESS OF 10*C. PER MINUTE. THE ACIDIFIED COAL IS PREFERABLY DEACIDIFIED PRIOR TO CARBONIZATION BY HEATING AT A TEMPERATURE IN THE RANGE OF 400*F. TO 700*F. WITH OR WITHOUT A SWEEPING AIRSTREAM. ACID TREATMENT OF THE BITUMINOUS COALS PERMITS CARBONIZATION THEREOF AT AN ACCELERATED RATE WITHOUT CAKING DURING HEATING THROUGH THE TEMPERATURE RANGE OF 400*C. TO 600*C.
Inventors
- 👤 Oliver A Kiikka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:48
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/30; C01B32/312; C01B32/342
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |