US3220797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing anhydrous alumina
Assignee: Universal Oil Products Co
•
Filing: 1961-11-29
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Granted: 1965-11-30
•
Expires: 1981-11-29
Abstract
No abstract record available.
Inventors
- 👤 George R Lester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:59
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/30; C07; C07C; C07C51/00; C07C51/41; C07C51/412
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
54 words
A METHOD OF PREPARING ALUMINA WHICH COMPRISES REACTING MELLITIC ACID WITH ALUMINUM HYDROXIDE, DRYING THE RESULTING REACTION PRODUCT AT A TEMPERATURE OF FROM ABOUT 100*F. TO ABOUT 210*F. AND CALCINING THE DRIED PRODUCT AT A TEMPERATURE OF FROM ABOUT 600*F. TO ABOUT 1400*F. IN AN ATMOSPHERE CONTAINING FREE OXYGEN TO FORM SUBSTANTIALLY ANHYDROUS ALUMINA.
Claim 2
Independent Claim
54 words
A METHOD OF PREPARING ALUMINA WHICH COMPRISES REACTING MELLITIC ACID WITH ALUMINUM HYDROXIDE, DRYING THE RESULTING REACTION PRODUCT AT A TEMPERATURE OF FROM ABOUT 100*F. TO ABOUT 210*F. AND CALCINING THE DRIED PRODUCT AT A TEMPERATURE OF FROM ABOUT 600*F. TO ABOUT 1400*F. IN AN ATMOSPHERE CONTAINING FREE OXYGEN TO FORM SUBSTANTIALLY ANHYDROUS ALUMINA.
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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) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |