Patent US2633240A successfully refreshed from Google Patents.
US2633240A
Expired / Lapsed
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Beneficiation of coal by flotation
Assignee: Hercules Powder Co
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Filing: 1950-11-16
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Granted: 1953-03-31
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Expires: 1970-11-16
Abstract
No abstract record available.
Inventors
- 👤 William T Bishop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:46
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
78 words
A METHOD OF REDUCING THE ASH CONTENT OF COAL CONTAINING SILICEOUS IMPURITIES WHICH COMPRISES SUBJECTING SAID COAL TO FROTH FLOTATION IN AN AQUEOUS FLOTATION SYSTEM CONTAINING A DEPRESSANT FOR THE COAL IN AN AMOUNT UP TO ABOUT 0.25 WEIGHT PER CENT ON THE DRY COAL BASIS AND A ROSIN AMINE IN THE FORM OF A WATER-DISPERSIBLE SALT THEREOF, SAID DEPRESSANT BEING SELECTED FROM THE GROUP CONSISTING OF HIGH MOLECULAR WEIGHT CARBOHYDRATES HAVING HYDROPHILIC PROPERTIES, PROTEINS, TANNINS, AND GLUCOSIDES.
Claim 2
Independent Claim
78 words
A METHOD OF REDUCING THE ASH CONTENT OF COAL CONTAINING SILICEOUS IMPURITIES WHICH COMPRISES SUBJECTING SAID COAL TO FROTH FLOTATION IN AN AQUEOUS FLOTATION SYSTEM CONTAINING A DEPRESSANT FOR THE COAL IN AN AMOUNT UP TO ABOUT 0.25 WEIGHT PER CENT ON THE DRY COAL BASIS AND A ROSIN AMINE IN THE FORM OF A WATER-DISPERSIBLE SALT THEREOF, SAID DEPRESSANT BEING SELECTED FROM THE GROUP CONSISTING OF HIGH MOLECULAR WEIGHT CARBOHYDRATES HAVING HYDROPHILIC PROPERTIES, PROTEINS, TANNINS, AND GLUCOSIDES.
References Cited (Backward Citations)
GB186143A
Cited
US2132902A
Cited
US2337118A
Cited
US2341046A
Cited
US2327408A
Cited
US2381662A
Cited
US2483890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-03-30 | 1956-09-29 | 1957-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-03-30 | 1960-09-29 | 1961-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-03-30 | 1964-09-29 | 1965-03-31 | $7700.00 | Window Closed / Lapsed |