US3943070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of spheroidal alumina particles
Assignee: Universal Oil Products Co
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Filing: 1974-10-15
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Granted: 1976-03-09
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Expires: 1994-10-15
Abstract
Abstract A method of manufacturing high surface area spheroidal alumina particles. A finely divided eta alumina is admixed and suspended in an alumina hydrosol and the mixture thereafter converted to spheroidal particles comprising eta and gamma alumina by the oil-drop method. The alumina spheres are particularly useful as a high surface area support or carrier material for catalytic components, and as a high surface area adsorbent.
Inventors
- 👤 Roy T. Mitsche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:44
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/06; B01J20/08; B01J2/00; B01J2/02; B01J2/06; B01J2/08; B01J21/00; B01J21/02; B01J21/04
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A method of manufacturing mixed eta and gamma alumina particles which comprises: a. admixing and suspending a finely divided eta alumina in an acid anion-containing alumina sol having an aluminum/acid anion ratio of from about 1:1 to about 1.5:1, said alumina being admixed with said sol in an amount to provide from about 20 to about 50 wt. % of the final alumina product; b. commingling the resulting sol with an ammonia precursor at below gelation temperature, said ammonia precursor being decomposable to ammonia with increasing temperature; c. dispersing the mixture as droplets in a hot oil bath effecting decomposition of said ammonia precursor and formation of hydrogel spheres therein; d. aging the spheres at an elevated temperature effecting decomposition of the residual ammonia precursor contained therein, and washing, drying and calcining the aged hydrogel spheres.
Claim 2
Independent Claim
136 words
A method of manufacturing mixed eta and gamma alumina particles which comprises: a. admixing and suspending a finely divided eta alumina in an acid anion-containing alumina sol having an aluminum/acid anion ratio of from about 1:1 to about 1.5:1, said alumina being admixed with said sol in an amount to provide from about 20 to about 50 wt. % of the final alumina product; b. commingling the resulting sol with an ammonia precursor at below gelation temperature, said ammonia precursor being decomposable to ammonia with increasing temperature; c. dispersing the mixture as droplets in a hot oil bath effecting decomposition of said ammonia precursor and formation of hydrogel spheres therein; d. aging the spheres at an elevated temperature effecting decomposition of the residual ammonia precursor contained therein, and washing, drying and calcining the aged hydrogel spheres.
Claim 3
Dependent Claim
18 words
The method of claim 1 further characterized in that said acid anion-containing alumina sol is aluminum chloride sol.
Claim 4
Dependent Claim
14 words
The method of claim 1 further characterized in that said ammonia precursor is hexamethylenetetramine.
Claim 5
Dependent Claim
32 words
The method of claim 1 further characterized in that said ammonia precursor is hexamethylenetetramine and utilized in an amount to effect substantially complete neutralization of the acid anion contained in said mixture.
Claim 6
Dependent Claim
30 words
The method of claim 1 further characterized in that said ammonia precursor is hexamethylenetetramine and utilized in from about a 1:4 to about 1.25:4 mole ratio with said acid anion.
Claim 7
Dependent Claim
25 words
The method of claim 1 further characterized in that said oil bath is maintained at a temperature of from about 120° to about 220° F.
Claim 8
Dependent Claim
40 words
The method of claim 1 further characterized in that said hydrogel spheres are aged at a temperature of from about 120° to about 500° F. and at a pressure to maintain the water content thereof in a substantially liquid phase.
Claim 9
Dependent Claim
36 words
The method of claim 1 further characterized in that said hydrogel spheres are aged at a temperature of from about 120° to about 350° F. and a pressure of from about 40 to about 150 psig.
Claim 10
Dependent Claim
27 words
The method of claim 1 further characterized in that said aged hydrogel spheres are dried and calcined at a temperature of from about 800° to about 1400°F.
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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) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |