Patent US5055019A successfully refreshed from Google Patents.
US5055019A
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US
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Process for the production of boehmitic aluminas
Assignee: Sasol Germany GmbH
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Filing: 1989-06-02
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Granted: 1991-10-08
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Expires: 2009-06-02
Abstract
Abstract A process for the preparation of boehmitic alumina compounds having a purity of, at least, 99.95% Al2O3. The compounds produced according to the invention have a pore radii in the range of 3 to 100 nm. The preparation of such compounds is carried out by, first, obtaining an alumina suspension from a neutral aluminum alkoxide hydrolysis and, then, aging the alumina suspension in an autoclave, preferably, at a steam pressure of 1 to 30 bar, corresponding to a temperature of 100 DEG C. to 235 DEG C., for between 0.5 and 20 hours. The aging step of the invention is preferably carried out with stirring at a peripheral speed of 1 to 6 m/s.
Inventors
- 👤 Arnold Meyer
- 👤 Klaus Noweck
- 👤 Ansgar Reichenauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:52
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/44; C01F7/447; C01F7/448; C01P; C01P2006/00; C01P2006/10; C01P2006/12; C01P2006/14; C01P2006/16; C01P2006/22; C01P2006/80
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
A process for the preparation of a boehmitic alumina compound, comprising the steps of: hydrolysizing a mixture consisting essentially of neutral aluminum alkoxide and alcohol and water to obtain an alumina suspension; and aging the alumina suspension obtained from the neutral aluminum alkoxide hydrolysis in an autoclave having a steam pressure of 1 to 30 bar, at a temperature of 100°-235° C., for between 0.5-20 hours; said aging step being carried out with stirring at a peripheral speed of 1-6 m/s; controlling the stirrer speed until the surface area of said boehmitic alumina compound is between 170 m 2 /g and 78 m 2 /g, as determined on the dried alumina suspension; and said alumina compound having a purity of at least 99.95% Al 2 O 3 and a generally increasing pore volume at pore radii measured in a range of 2 to 300 nm.
Claim 2
Dependent Claim
145 words
A process for the preparation of a boehmitic alumina compound, comprising the steps of: hydrolysizing a mixture consisting essentially of neutral aluminum alkoxide and alcohol and water to obtain an alumina suspension; and aging the alumina suspension obtained from the neutral aluminum alkoxide hydrolysis in an autoclave having a steam pressure of 1 to 30 bar, at a temperature of 100°-235° C., for between 0.5-20 hours; said aging step being carried out with stirring at a peripheral speed of 1-6 m/s; controlling the stirrer speed until the surface area of said boehmitic alumina compound is between 170 m 2 /g and 78 m 2 /g, as determined on the dried alumina suspension; and said alumina compound having a purity of at least 99.95% Al 2 O 3 and a generally increasing pore volume at pore radii measured in a range of 2 to 300 nm.
Claim 3
Dependent Claim
24 words
The process according to claim 1, wherein the alumina suspension obtained in said hydrolysizing step is 5-15%, by weight, Al 2 O 3 .
Claim 4
Dependent Claim
32 words
The process according to claim 1, wherein the alumina suspension obtained is aged in said aging step at a steam pressure of 5-30 bar, accompanied by stirring for 1 to 4 hours.
Claim 5
Dependent Claim
24 words
The process according to claim 1, wherein the aging step is carried out with stirring at a peripheral speed of 1.15 to 5.2 m/s.
Claim 6
Dependent Claim
24 words
The process according to claim 1, wherein the aging step is carried out with stirring at a peripheral speed of 1.55 to 4.03 m/s.
Claim 7
Dependent Claim
17 words
The process according to claim 1, further comprising spray drying the alumina suspension after said aging step.
Claim 8
Dependent Claim
182 words
A process for the preparation of a boehmitic alumina compound comprising the steps of: hydrolysizing a mixture consisting essentially of neutral aluminum alkoxide and alcohol and water to obtain an alumina suspension; and aging the alumina suspension obtained from the neutral aluminum alkoxide hydrolysis in an autoclave having a steam pressure of 1 to 30 bar, at to a temperature of 100°-235° C., for between 0.5-20 hours; said aging step being carried out with stirring at a peripheral speed of 1-6 m/s; controlling the stirrer speed until the surface area of said boehmitic alumina compound is between 170 m 2 /g and 78 m 2 /g, as determined on the dried alumina suspension; and said alumina compound having a purity of at least 99.95% Al 2 O 3 and a controlled maximum of pore radius and a generally increasing pore volume at pore radii measured in a range of 2 to 300 nm; and said suspension obtained in said hydrolyzing step is continuously aged in a cascade reactor with a two to ten stage stirrer at said peripheral speed of 1-6 m/s.
Claim 9
Dependent Claim
182 words
A process for the preparation of a boehmitic alumina compound comprising the steps of: hydrolysizing a mixture consisting essentially of neutral aluminum alkoxide and alcohol and water to obtain an alumina suspension; and aging the alumina suspension obtained from the neutral aluminum alkoxide hydrolysis in an autoclave having a steam pressure of 1 to 30 bar, at to a temperature of 100°-235° C., for between 0.5-20 hours; said aging step being carried out with stirring at a peripheral speed of 1-6 m/s; controlling the stirrer speed until the surface area of said boehmitic alumina compound is between 170 m 2 /g and 78 m 2 /g, as determined on the dried alumina suspension; and said alumina compound having a purity of at least 99.95% Al 2 O 3 and a controlled maximum of pore radius and a generally increasing pore volume at pore radii measured in a range of 2 to 300 nm; and said suspension obtained in said hydrolyzing step is continuously aged in a cascade reactor with a two to ten stage stirrer at said peripheral speed of 1-6 m/s.
Claim 10
Dependent Claim
152 words
A process for the preparation of a boehmitic alumina compound, comprising the steps of: hydrolysizing a mixture consisting essentially of neutral aluminum alkoxide and alcohol and water to obtain an alumina suspension; and aging the alumina suspension obtained from the neutral aluminum alkoxide hydrolysis in an autoclave having a steam pressure of 1 to 30 bar, at a temperature of 100°-235° C., for between 0.5-20 hours; said aging step being carried out with stirring at a peripheral speed of 1-6 m/s; controlling the stirrer speed until the surface area of said boehmitic alumina compound is between 170 m 2 /g and 78 m 2 /g, as determined on the dried alumina suspension; and said alumina compound having a purity of at least 99.95% Al 2 O 3 and a controlled maximum of pore radius and a generally increasing pore volume at pore radii measured in a range of 2 to 300 nm.
Claim 11
Dependent Claim
152 words
A process for the preparation of a boehmitic alumina compound, comprising the steps of: hydrolysizing a mixture consisting essentially of neutral aluminum alkoxide and alcohol and water to obtain an alumina suspension; and aging the alumina suspension obtained from the neutral aluminum alkoxide hydrolysis in an autoclave having a steam pressure of 1 to 30 bar, at a temperature of 100°-235° C., for between 0.5-20 hours; said aging step being carried out with stirring at a peripheral speed of 1-6 m/s; controlling the stirrer speed until the surface area of said boehmitic alumina compound is between 170 m 2 /g and 78 m 2 /g, as determined on the dried alumina suspension; and said alumina compound having a purity of at least 99.95% Al 2 O 3 and a controlled maximum of pore radius and a generally increasing pore volume at pore radii measured in a range of 2 to 300 nm.
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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) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-07 | 1999-04-08 | 1999-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-07 | 2003-04-08 | 2003-10-08 | $7700.00 | Window Closed / Lapsed |