Patent US2497790A successfully refreshed from Google Patents.
US2497790A
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Sink and float process for the separation of coal from its impurities
Assignee: VALENCIENNOISE DE GESTION SOC
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Filing: 1948-02-25
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Granted: 1950-02-14
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Expires: 1968-02-25
Abstract
No abstract record available.
Inventors
- 👤 Robert L P Pauvrasseau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:02
CPC Classifications
B; B03; B03B; B03B5/00; B03B5/28; B03B5/30; B03B5/44; B03B5/442
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
A FLOAT-AND-SINK PROCESS FOR THE SEPARATION OF IMPURITIES FROM COAL, SAID COAL HAVING A MINIMUM SIZE OF APPROXIMATELY 5 MM., COMPRISING THE STEPS OF INTRODUCING SAID MATERIALS INTO A SUSPENSION CONTAINING PARTICLES OF COAL SHALE AND COAL FINES IN WATER, THE AVERAGE SPECIFIC GRAVITY OF SAID SHALE PARTICLES AND SAID COAL FINES BEING APPROXIMATELY 2.34, THE MAXIMUM PROPORTION BY WEIGHT OF COAL FINES TO THE TOTAL WEIGHT OF SOLID MATERIALS BEING APPROXIMATELY 24 PER CENT, THE PARTICLES OF SHALE AND COAL FINES TOGETHER HAVING NO PARTICLES TO EXCEED 1 MM, IN SIZE, WITH A MAXIMUM PERCENTAGE OF 10 PER CENT BY WEIGHT FOR PARTICLES OF SIZES BETWEEN 0.2 MM. AND 1 MM., A MAXIMUM PERCENTAGE OF 20 PER CENT BY WEIGHT FOR PARTICLES OF SIZES BETWEEN 0.1 MM. AND 0.2 MM., A
Claim 2
Dependent Claim
132 words
A FLOAT-AND-SINK PROCESS FOR THE SEPARATION OF IMPURITIES FROM COAL, SAID COAL HAVING A MINIMUM SIZE OF APPROXIMATELY 5 MM., COMPRISING THE STEPS OF INTRODUCING SAID MATERIALS INTO A SUSPENSION CONTAINING PARTICLES OF COAL SHALE AND COAL FINES IN WATER, THE AVERAGE SPECIFIC GRAVITY OF SAID SHALE PARTICLES AND SAID COAL FINES BEING APPROXIMATELY 2.34, THE MAXIMUM PROPORTION BY WEIGHT OF COAL FINES TO THE TOTAL WEIGHT OF SOLID MATERIALS BEING APPROXIMATELY 24 PER CENT, THE PARTICLES OF SHALE AND COAL FINES TOGETHER HAVING NO PARTICLES TO EXCEED 1 MM, IN SIZE, WITH A MAXIMUM PERCENTAGE OF 10 PER CENT BY WEIGHT FOR PARTICLES OF SIZES BETWEEN 0.2 MM. AND 1 MM., A MAXIMUM PERCENTAGE OF 20 PER CENT BY WEIGHT FOR PARTICLES OF SIZES BETWEEN 0.1 MM. AND 0.2 MM., A
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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) | 1953-02-13 | 1953-08-15 | 1954-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-02-13 | 1957-08-15 | 1958-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-02-13 | 1961-08-15 | 1962-02-14 | $7700.00 | Window Closed / Lapsed |