US3650989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of silica-alumina catalyst
Assignee: Engelhard Minerals and Chemicals Corp
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Filing: 1969-12-09
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Granted: 1972-03-21
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Expires: 1989-12-09
Abstract
Abstract A HIGHLY ACIDIC SILICA-ALUMINA CATALYST, CONTAINING A RELATIVELY LARGE AMOUNT OF ALKALI METAL, E.G. UP TO ABOUT 1%, IS PREPARED BY A PROCESS COMPRISING ACIDIFYING AN ALKALI METAL SILICATE TO A PH OF LESS THAN ABOUT 5.0 TO FORM A SILICA HYDROGEL, WASHING THE HYDROGEL WITH WATER, SLURRYING THE HYDROGEL IN SOLUTION OF AN ALUMINUM SALT, ADDING TO THE SLURRY AN AMMONIACAL BASE IN EXCESS OF THE AMOUNT REQUIRED FOR NEUTRALIZATION OF THE ALUMINUM SALT, AND SEPARATING, DRYING AND CALCINING THE RESULTANT SILICAALUMINA COMPOSITE.
Inventors
- 👤 Saul G Hindin
- 👤 Joseph C Dettling
- 👤 William R Larsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:55
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/12; B01J23/00; B01J23/02; B01J23/04; B44; B44D; B44D3/00; B44D3/02; C; C10; C10G; C10G35/00; C10G35/04; C10G35/06
Claims Analysis
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References Cited (Backward Citations)
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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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |