US3975231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing concentrated alumina slurries
Assignee: Vista Chemical Co
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Filing: 1975-08-18
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Granted: 1976-08-17
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Expires: 1995-08-18
Abstract
Abstract A method for producing concentrated alumina slurries containing from about 14 to about 20 weight percent Al 2 O 3 by forming a solvent-aqueous alumina mixture and evaporating solent-aqueous vapor from said mixture to produce said concentrated alumina slurries.
Inventors
- 👤 William C. Ziegenhain
- 👤 Bruce E. Leach
- 👤 Dean O. Coleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:35
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/34; C01F7/36; C01P; C01P2006/00; C01P2006/19; C01P2006/22
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
A method for producing free flowing concentrated alumina slurries from aqueous alumina slurries said method consisting of: a. adding a liquid solvent to an aqueous alumina slurry to form a slurry mixture, said solvent being selected from the group consisting of ethanol, propanol, isopropanol, n-butanol, isobutanol and tertiary butanol; and b. azeotropically evaporating solvent-aqueous vapor to produce a concentrated alumina slurry consisting essentially of from about 14 to about 17 weight percent Al 2 O 3 , from about 15 to about 70 weight percent water and from about 70 to about 13 weight percent solvent.
Claim 2
Independent Claim
96 words
A method for producing free flowing concentrated alumina slurries from aqueous alumina slurries said method consisting of: a. adding a liquid solvent to an aqueous alumina slurry to form a slurry mixture, said solvent being selected from the group consisting of ethanol, propanol, isopropanol, n-butanol, isobutanol and tertiary butanol; and b. azeotropically evaporating solvent-aqueous vapor to produce a concentrated alumina slurry consisting essentially of from about 14 to about 17 weight percent Al 2 O 3 , from about 15 to about 70 weight percent water and from about 70 to about 13 weight percent solvent.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein said concentrated alumina slurry contains from about 14.5 to about 16.5 weight percent Al 2 O 3 .
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said solvent is evaporated azeotropically at reduced pressures.
Claim 5
Dependent Claim
52 words
The method of claim 1 wherein said solvent in said solvent-aqueous alumina mixture is n-butanol and said concentrated alumina slurry contains from about 19 to about 55 weight percent water, from about 14.5 to about 16.5 weight percent Al 2 O 3 and from about 66.5 to about 28.5 weight percent n-butanol.
Claim 6
Independent Claim
117 words
A method for producing free flowing concentrated alumina slurries from aqueous alumina slurries said method consisting of: a. adding a liquid solvent to an aqueous alumina slurry to for a slurry mixture, said solvent being selected from the group consisting of ethanol, propanol, isopropanol, n-butanol, isobutanol and tertiary butanol; and b. subjecting the solvent-aqueous alumina mixture to mild shear at rates from about 10 to about 10,000 sec - 1 and simultaneously azeotropically evaporating solvent-aqueous vapor to produce a concentrated alumina slurry consisting essentially of from about 14 to about 20 weight percent Al 2 O 3 , from about 15 to about 70 weight percent water and from about 71 to about 10 weight percent solvent.
Claim 7
Independent Claim
117 words
A method for producing free flowing concentrated alumina slurries from aqueous alumina slurries said method consisting of: a. adding a liquid solvent to an aqueous alumina slurry to for a slurry mixture, said solvent being selected from the group consisting of ethanol, propanol, isopropanol, n-butanol, isobutanol and tertiary butanol; and b. subjecting the solvent-aqueous alumina mixture to mild shear at rates from about 10 to about 10,000 sec - 1 and simultaneously azeotropically evaporating solvent-aqueous vapor to produce a concentrated alumina slurry consisting essentially of from about 14 to about 20 weight percent Al 2 O 3 , from about 15 to about 70 weight percent water and from about 71 to about 10 weight percent solvent.
Claim 8
Dependent Claim
23 words
The method of claim 5 wherein said shear is imparted at a rate from about 100 to about 1000 sec - 1 .
Claim 9
Dependent Claim
30 words
The method of claim 6 wherein said solvent-aqueous vapor is evaporated azeotropically at absolute pressures from about 50 mm Hg to about 760 mm Hg and said solvent is n-butanol.
References Cited (Backward Citations)
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US2970892A
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US3268295A
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US3382040A
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US3343915A
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US3384458A
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US3773691A
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US3907512A
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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) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |