US4292206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of hollow glass spheres in conjunction with rehydratable alumina for making low density catalyst support beads
Assignee: Wyeth Holdings LLC
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Filing: 1980-08-22
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Granted: 1981-09-29
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Expires: 2000-08-22
Abstract
Abstract For making low density alumina or silica-alumina beads as catalyst support particles for auto-exhaust catalysts, hollow glass spheres of very small diameter are incorporated in the alumina powder mix before it is formed into beads and calcined. The beads may be finished with a surface coat of alumina without the microspheres to improve resistance to abrasion. Preferred beads are made with rehydratable alumina powder.
Inventors
- 👤 Robert E. Barnes, Jr.
- 👤 Venkatrao Pai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:11
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01J; B01J21/00; B01J21/02; B01J21/04; B01J35/00; B01J35/50; B01J35/51
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
35 words
Spherical alumina particles having macroporous structure prepared by forming a mixture of alumina powder and hollow glass spheres with water into wet spherical beads of said mixture, drying the beads and calcining the dried beads.
Claim 2
Dependent Claim
35 words
Spherical alumina particles having macroporous structure prepared by forming a mixture of alumina powder and hollow glass spheres with water into wet spherical beads of said mixture, drying the beads and calcining the dried beads.
Claim 3
Dependent Claim
18 words
Spherical alumina particles defined by claim 1 wherein the wet spherical beads are formed on a pan granulator.
Claim 4
Dependent Claim
30 words
Spherical alumina particles defined by claim 1 wherein the alumina powder is rehydratable alumina hemihydrate and the wet spherical beads are cured by steaming before they are dried and calcined.
Claim 5
Dependent Claim
37 words
Spherical alumina particles defined by claim 1 wherein the mixture comprises about 0.5 to 5% by wt. based on the alumina weight of hollow glass spheres of mean diameter in the range from 50 to 175 microns.
Claim 6
Dependent Claim
17 words
Auto exhaust catalyst comprising spherical alumina support particles defined by claim 1 with catalytic metals deposited thereon.
References Cited (Backward Citations)
US3923688A
Cited
US4179408A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |