US4371513A
Expired / Lapsed
US
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Alumina compositions
Assignee: WR Grace and Co Conn
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Filing: 1981-02-19
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Granted: 1983-02-01
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Expires: 2001-02-19
Abstract
Abstract An alumina composition comprising a microcrystalline boehmite-pseudoboehmite intermediate having from about 70 to about 85 weight percent of the total amount of Al2O3 present in crystalline form. The composition is prepared by adding aluminum sulfate and sodium aluminate solutions to a mixture of water and aluminum sulfate solution to precipitate alumina and adjusting the pH to a pH higher than the precipitation pH. The reactant concentrations, and rates of addition, temperatures, and pH's in the precipitation are specifically controlled to form the boehmite-pseudoboehmite intermediate.
Inventors
- 👤 Moises G. Sanchez
- 👤 Norman R. Laine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:26
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/44; B01J21/00; B01J21/02; B01J21/04; B01J23/42; B01J35/00; B01J35/60; C; C01; C01F; C01F7/00; C01F7/02; C01F7/34; B01J35/61; B01J35/615; B01J35/63; B01J35/635; B01J35/64; B01J35/647; C01P; C01P2002/00; C01P2002/60; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/11; C01P2006/12; C01P2006/14; C01P2006/16; C01P2006/17; C01P2006/21; C01P2006/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
99 words
An alumina composition comprising a microcrystalline boehmite-pseudoboehmite intermediate, said composition having a calcium content expressed as CaO that does not exceed 0.15 weight percent, a [020] d spacing of from about 6.2 to about 6.5 A., and a nitrogen pore volume of about 0.60 to about 0.75 cm. 3 /g., said pore volume determined after a thermal treatment for about 1 hour at about 1850° F., and requiring from about 130 to about 180 milliequivalents of sulfuric acid per mole of alumina to change the pH of a water slurry of the composition from about 8.3 to about 4.0.
Claim 2
Dependent Claim
99 words
An alumina composition comprising a microcrystalline boehmite-pseudoboehmite intermediate, said composition having a calcium content expressed as CaO that does not exceed 0.15 weight percent, a [020] d spacing of from about 6.2 to about 6.5 A., and a nitrogen pore volume of about 0.60 to about 0.75 cm. 3 /g., said pore volume determined after a thermal treatment for about 1 hour at about 1850° F., and requiring from about 130 to about 180 milliequivalents of sulfuric acid per mole of alumina to change the pH of a water slurry of the composition from about 8.3 to about 4.0.
Claim 3
Dependent Claim
22 words
The composition of claim 1 having a mid-point width of the X-ray diffraction peak [020] of about 1.65 to about 1.85 A.
Claim 4
Dependent Claim
30 words
The composition of claim 1 having a surface area of about 100 to about 150 m. 2 /g. after a thermal treatment for about 1 hour at about 1850° F.
Claim 5
Dependent Claim
37 words
The composition of claim 1 requiring from about 140 to about 160 milliequivalents of sulfuric acid per mole of alumina to change the pH of a water slurry of the composition from about 8.3 to about 4.0.
Claim 6
Dependent Claim
17 words
The composition of claim 1 having a [020] d-spacing of from about 6.3 to about 6.4 A.
Claim 7
Dependent Claim
25 words
The composition of claim 1 having a half maximum intensity width of the [020] X-ray diffraction peak of from about 1.75 to about 1.80 A.
Claim 8
Dependent Claim
31 words
The composition of claim 1 having a nitrogen pore volume of about 0.64 to about 0.72 cm. 3 /g. after a thermal treatment for about 1 hour at about 1850° F.
Claim 9
Dependent Claim
30 words
The composition of claim 1 having a surface area of about 110 to about 140 m. 2 /g. after a thermal treatment for about 1 hour at about 1850° F.
Claim 10
Dependent Claim
27 words
The composition of claim 1 having from about 70 to about 85 weight percent of the total amount of Al 2 O 3 present in crystalline form.
Claim 11
Dependent Claim
13 words
The composition of claim 1 in which the boehmite-pseudoboehmite intermediate is substantially pure.
Claim 12
Dependent Claim
69 words
An alumina composition comprising a substantially pure, microcrystalline boehmite-pseudoboehmite intermediate, said composition having a [020] d spacing of about 6.3 to about 6.4 A, a nitrogen pore volume of about 0.64 to about 0.72 cm. 3 /g., and a surface area of about 110 to about 140 m. 2 /g., said pore volume and surface area determined after a thermal treatment for about 1 hour at about 1850° F.
Claim 13
Dependent Claim
69 words
An alumina composition comprising a substantially pure, microcrystalline boehmite-pseudoboehmite intermediate, said composition having a [020] d spacing of about 6.3 to about 6.4 A, a nitrogen pore volume of about 0.64 to about 0.72 cm. 3 /g., and a surface area of about 110 to about 140 m. 2 /g., said pore volume and surface area determined after a thermal treatment for about 1 hour at about 1850° F.
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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) | 1986-01-31 | 1986-08-02 | 1987-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-31 | 1990-08-02 | 1991-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-31 | 1994-08-02 | 1995-02-01 | $7700.00 | Window Closed / Lapsed |