Patent US4676928A successfully refreshed from Google Patents.
US4676928A
Expired / Lapsed
US
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Process for producing water dispersible alumina
Assignee: Sasol North America Inc
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Filing: 1986-01-30
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Granted: 1987-06-30
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Expires: 2006-01-30
Abstract
Abstract A process of producing a water dispersible alumina comprising forming an aqueous alumina slurry, acidifying the slurry to a pH range of from about 5 to about 8, aging the acidified slurry at elevated temperatures and for a sufficient amount of time to convert the greater portion of the alumina to a colloidal sol, recovering the sol and drying the sol to produce a highly water dispersible alumina.
Inventors
- 👤 Bruce E. Leach
- 👤 Lewis B. Decker, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:41
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/021; C01P; C01P2002/00; C01P2002/60; C01P2006/00; C01P2006/12; C01P2006/14; C01P2006/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
92 words
A process of producing a water dispersible alumina comprising: forming an aqueous alumina slurry from an uncalcined alumina obtained from the hydrolysis of an aluminum alkoxide; admixing a monovalent acid with said alumina slurry to produce an alumina slurry-acid composition having a pH of from about 5.0 to about 9.0; aging said alumina slurry-acid composition at an elevated temperature of above about 70° C. and for a period of time sufficient to convert the greater portion of said alumina to a colloidal sol; recovering said colloidal sol; and drying said colloidal sol.
Claim 2
Dependent Claim
92 words
A process of producing a water dispersible alumina comprising: forming an aqueous alumina slurry from an uncalcined alumina obtained from the hydrolysis of an aluminum alkoxide; admixing a monovalent acid with said alumina slurry to produce an alumina slurry-acid composition having a pH of from about 5.0 to about 9.0; aging said alumina slurry-acid composition at an elevated temperature of above about 70° C. and for a period of time sufficient to convert the greater portion of said alumina to a colloidal sol; recovering said colloidal sol; and drying said colloidal sol.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said alumina slurry has an alumina content of from about 9 to about 15% by weight.
Claim 4
Dependent Claim
23 words
The process of claim 1 wherein the pH of said alumina slurry prior to addition of said acid is about 9 or greater.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein said acid comprises nitric acid.
Claim 6
Dependent Claim
14 words
The process of claim 1 including concentrating said colloidal sol by removing water therefrom.
Claim 7
Dependent Claim
84 words
A process for producing a pumpable, alumina sol comprising: forming an aqueous alumina slurry from an uncalcined alumina obtained from the hydrolysis of an aluminum alkoxide; admixing a monovalent acid with said alumina slurry to produce an alumina slurry-acid composition having a pH of from about 5.0 to about 9.0; and aging said alumina slurry-acid composition at an elevated temperature of above about 70° C. and for a period of time sufficient to convert the greater portion of said alumina to a colloidal sol.
Claim 8
Dependent Claim
84 words
A process for producing a pumpable, alumina sol comprising: forming an aqueous alumina slurry from an uncalcined alumina obtained from the hydrolysis of an aluminum alkoxide; admixing a monovalent acid with said alumina slurry to produce an alumina slurry-acid composition having a pH of from about 5.0 to about 9.0; and aging said alumina slurry-acid composition at an elevated temperature of above about 70° C. and for a period of time sufficient to convert the greater portion of said alumina to a colloidal sol.
Claim 9
Dependent Claim
10 words
The process of claim 6 including recovering said colloidal sol.
Claim 10
Dependent Claim
22 words
The process of claim 6 wherein said alumina slurry has an alumina content of from about 9 to about 15% by weight.
Claim 11
Dependent Claim
23 words
The process of claim 1 wherein the pH of said alumina slurry prior to addition of said acid is about 9 or greater.
Claim 12
Dependent Claim
11 words
The process of claim 6 wherein said acid comprises nitric acid.
Claim 13
Dependent Claim
14 words
The process of claim 6 including concentrating said colloidal sol by removing water therefrom.
References Cited (Backward Citations)
US3268295A
Cited
US3411877A
Cited
US3411876A
Cited
US3997476A
Cited
US4211667A
Cited
US4532072A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |