US4130402A
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US
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Method for producing coarsely crystalline alumina
Assignee: Almatis Chemie GmbH
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Filing: 1977-05-24
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Granted: 1978-12-19
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Expires: 1997-05-24
Abstract
Abstract Coarsely crystalline aluminum oxide is provided which contains the following trace elements: V 2 O 5 > 0.005 percent by weight, P 2 O 5 > 0.005 percent by weight, Na 2 O > 0.8 percent by weight. A method is provided for producing such an aluminum oxide by calcining aluminum hydroxide in the presence of at least one flouride and of vanadium salt.
Inventors
- 👤 Bernhard Schepers
- 👤 Heinz Hellinghausen
- 👤 Alois Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:20
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; C09K3/1409; C09K3/1418; C01; C01F; C01F7/00; C01F7/02; C01F7/44; C01F7/441; C01F7/442; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
60 words
Coarsely crystalline aluminum oxide having a portion in the beta Al 2 O 3 modification, and having the following trace elements: V 2 O 5 > 0.005 percent by weight, P 2 O 5 > 0.005 percent by weight, and Na 2 O > 0.8 percent by weight, and which has an average primary crystal size of more than 6μ.
Claim 2
Dependent Claim
60 words
Coarsely crystalline aluminum oxide having a portion in the beta Al 2 O 3 modification, and having the following trace elements: V 2 O 5 > 0.005 percent by weight, P 2 O 5 > 0.005 percent by weight, and Na 2 O > 0.8 percent by weight, and which has an average primary crystal size of more than 6μ.
Claim 3
Dependent Claim
51 words
Aluminum oxide as defined in claim 1 which contains V 2 O 5 in an amount of 0.005 to 0.05 percent by weight, P 2 O 5 in an amount of 0.005 to 0.05 percent by weight, and Na 2 O in an amount of 0.8 to 3 percent by weight.
Claim 4
Dependent Claim
19 words
Aluminum oxide as defined in claim 1 which has an average primary crystal size of between 6.1 and 25μ.
Claim 5
Dependent Claim
18 words
Aluminum oxide as defined in claim 1 which has an average primary crystal size between 8 and 16μ.
Claim 6
Independent Claim
104 words
A method for producing a coarsely crystalline aluminum oxide having a portion in the beta Al 2 O 3 modification, having an average primary crystal size of more than 6μ and having the following trace elements: V 2 O 5 > 0.005 percent by weight, P 2 O 5 > 0.005 percent by weight, Na 2 O > 0.8 percent by weight, comprising calcining aluminum hydroxide in the presence of vanadium salt and at least one fluoride compound, the amount of vanadium salt being sufficient to provide said weight percentages of V 2 O 5 , P 2 O 5 and Na 2 O.
Claim 7
Independent Claim
104 words
A method for producing a coarsely crystalline aluminum oxide having a portion in the beta Al 2 O 3 modification, having an average primary crystal size of more than 6μ and having the following trace elements: V 2 O 5 > 0.005 percent by weight, P 2 O 5 > 0.005 percent by weight, Na 2 O > 0.8 percent by weight, comprising calcining aluminum hydroxide in the presence of vanadium salt and at least one fluoride compound, the amount of vanadium salt being sufficient to provide said weight percentages of V 2 O 5 , P 2 O 5 and Na 2 O.
Claim 8
Dependent Claim
35 words
Method as defined in claim 5 wherein the fluoride compound is used in an amount of 0.001 to 0.1 percent by weight with respect to the Al 2 O 3 content of the aluminum hydroxide.
Claim 9
Dependent Claim
18 words
Method as defined in claim 5 wherein the calcination is effected at temperatures of 1100° to 1300° C.
Claim 10
Dependent Claim
63 words
Method as defined in claim 5 wherein the vanadium salt is present in an amount such that the aluminum oxide contains V 2 O 5 in an amount of 0.005 to 0.05 percent by weight, P 2 O 5 in an amount of 0.005 to 0.05 percent by weight and Na 2 O in an amount of 0.8 to 3 percent by weight.
Claim 11
Dependent Claim
26 words
Method as defined in claim 5 wherein the fluoride compound is AlF 3 , CaF 2 , Na 3 AlF 6 , or a mixture thereof.
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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) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |