US3943064A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High strength alumina-silica catalyst substrates having high surface area
Assignee: Alcoa Corp
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Filing: 1974-07-11
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Granted: 1976-03-09
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Expires: 1994-07-11
Abstract
Abstract Catalyst substrates characterized by superior structural properties and a subsequent high degree of catalytic activity are produced by using a blend of colloidal silica and specially activated alumina which blend is subsequently rehydrated and activated under certain specified conditions. In a preferred embodiment the substrate is activated at a temperature of 1200°-1400°C to provide a substrate characterized by the absence of free silica.
Inventors
- 👤 Marlyn D. Ballain
- 👤 Leroy D. Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:16
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/06; B01J21/08; Y; Y10; Y10S; Y10S502/00; Y10S502/50; Y10S502/503; Y10S502/504
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
90 words
An alumina-silica catalyst support characterized by a high relative surface area, a minimum compressive strength of 6.9 mPa and an abrasive resistance under 5% weight loss, said support comprising initially a mixture of 10-28% by weight colloidal silica and 72-90% by weight of an activated alumina made by exposure to a temperature of at least 400° C for a period not exceeding 4 minutes and which mixture has been subsequently rehydrated and then fired at a temperature of not less than about 600° C nor more than about 1400° C.
Claim 2
Dependent Claim
90 words
An alumina-silica catalyst support characterized by a high relative surface area, a minimum compressive strength of 6.9 mPa and an abrasive resistance under 5% weight loss, said support comprising initially a mixture of 10-28% by weight colloidal silica and 72-90% by weight of an activated alumina made by exposure to a temperature of at least 400° C for a period not exceeding 4 minutes and which mixture has been subsequently rehydrated and then fired at a temperature of not less than about 600° C nor more than about 1400° C.
Claim 3
Dependent Claim
18 words
The support of claim 1 wherein said colloidal silica, when suspended in a liquid, has a basic pH.
Claim 4
Dependent Claim
22 words
The support of claim 1 wherein said mixture is extruded as pellets and subsequently rehydrated at a temperature of from 50°-120° C.
Claim 5
Dependent Claim
28 words
The support of claim 1 wherein said initial mixture also contains 0.02-8% by total weight of the mixture of a plasticizer to aid in extrusion of the mixture.
Claim 6
Dependent Claim
29 words
The support of claim 1 wherein said mixture is extruded into a thin wall object and rehydrated in the presence of moisture at a temperature of from 50°-90° C.
Claim 7
Dependent Claim
17 words
The support of claim 1 wherein said support is fired for a period of from 3-16 hours.
Claim 8
Dependent Claim
22 words
The support of claim 1 further characterized by a substantial absence of free silica by firing at a temperature above 1200° C.
Claim 9
Dependent Claim
108 words
An alumina-silica catalyst support firable to a surface area of about 100 m 2 /g at 1000° C and exhibiting a minimum compressive strength of 6.9 mPa and an abrasive resistance under 5% weight loss comprising initially 10-28% by weight colloidal silica and 72-90% by weight of an activated alumina made by exposure to a temperature of at least 400° C for a period not exceeding 4 minutes, which mixture has been subsequently rehydrated at a temperature of at least 50° C and then fired for a period of from 3-16 hours at a temperature of not less than about 600° C nor more than about 1400° C.
Claim 10
Dependent Claim
108 words
An alumina-silica catalyst support firable to a surface area of about 100 m 2 /g at 1000° C and exhibiting a minimum compressive strength of 6.9 mPa and an abrasive resistance under 5% weight loss comprising initially 10-28% by weight colloidal silica and 72-90% by weight of an activated alumina made by exposure to a temperature of at least 400° C for a period not exceeding 4 minutes, which mixture has been subsequently rehydrated at a temperature of at least 50° C and then fired for a period of from 3-16 hours at a temperature of not less than about 600° C nor more than about 1400° C.
References Cited (Backward Citations)
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 |