US4471070A
Expired / Lapsed
US
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Preparative process for alkaline earth metal, aluminum-containing spinels
Assignee: WR Grace and Co Conn
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Filing: 1982-11-29
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Granted: 1984-09-11
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Expires: 2002-11-29
Abstract
Abstract An improved process for the production of alkaline earth, aluminum-containing spinel compositions, preferably magnesium, aluminum-containing spinel compositions and preferably further comprising at least one additional metal component, comprises adding a basic aqueous solution containing at least one aluminum component to an aqueous solution containing at least one alkaline earth metal component to form a precipitate at defined pH conditions and calcining the precipitate to form a spinel composition. The product spinel composition, preferably with included additional metal components, is particularly suited for use to reduce the amount of sulfur oxides emitted from a catalyst regeneration zone, e.g., a catalytic cracking unit regeneration zone.
Inventors
- 👤 Kristine S. Siefert
- 👤 Jin S. Yoo
- 👤 Emmett H. Burk, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:48
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/16; C01F7/162; C01P; C01P2002/00; C01P2002/70; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/584; Y10; Y10S; Y10S502/00; Y10S502/524
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
98 words
A process for the production of an alkaline earth metal, aluminum-containing spinel composition comprising: (a) adding a basic aqueous solution containing at least one aluminum component in which the aluminum is present as an anion to an aqueous solution containing at least one alkaline earth metal component and forming an alkaline earth metal, aluminum-containing precipitate, provided that the pH of the liquid phase present with said precipitate at the time said addition is concluded is in the range of about 8.5 to about 10.5; and (b) calcining said precipitate to form said alkaline earth metal, aluminum-containing spinel composition.
Claim 2
Dependent Claim
98 words
A process for the production of an alkaline earth metal, aluminum-containing spinel composition comprising: (a) adding a basic aqueous solution containing at least one aluminum component in which the aluminum is present as an anion to an aqueous solution containing at least one alkaline earth metal component and forming an alkaline earth metal, aluminum-containing precipitate, provided that the pH of the liquid phase present with said precipitate at the time said addition is concluded is in the range of about 8.5 to about 10.5; and (b) calcining said precipitate to form said alkaline earth metal, aluminum-containing spinel composition.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the pH of the liquid phase present with said precipitate at the time said addition is concluded is in the range of about 9 to about 10.
Claim 4
Dependent Claim
24 words
The process of claim 1 wherein said aqueous solution containing at least one alkaline earth metal component includes at least one added acidic material.
Claim 5
Dependent Claim
33 words
The process of claim 3 wherein the pH of the liquid phase present with said precipitate at the time said addition is concluded is in the range of about 9 to about 10.
Claim 6
Dependent Claim
29 words
The process of claim 1 wherein the atomic ratio of alkaline earth metal to aluminum in said spinel composition is in the range of about 0.17 to about 1.
Claim 7
Dependent Claim
29 words
The process of claim 1 wherein the atomic ratio of alkaline earth metal to aluminum in said spinel composition is in the range of about 0.25 to about 0.75.
Claim 8
Dependent Claim
29 words
The process of claim 1 wherein the atomic ratio of alkaline earth metal to aluminum in said spinel composition is in the range of about 0.35 to about 0.65.
Claim 9
Dependent Claim
15 words
The process of claim 1 wherein said alkaline earth metal component is a magnesium component.
Claim 10
Dependent Claim
24 words
The process of claim 1 wherein said calcining takes place at a temperature in the range of about 1000° F. to about 1800° F.
Claim 11
Dependent Claim
24 words
The process of claim 1 wherein said calcining takes place at a temperature in the range of about 1100° F. to about 1400° F.
Claim 12
Dependent Claim
24 words
The process of claim 1 wherein said precipitate is dried to remove at least a portion of said liquid phase prior to being calcined.
Claim 13
Dependent Claim
61 words
The process of claim 1 which further comprises contacting said precipitate or said spinel compositions with at least one additional metal component to obtain a final spinel composition which includes a minor amount of at least one component of said additional metal in an amount effective to promote the oxidation of SO 2 to SO 3 at SO 2 oxidation conditions.
Claim 14
Dependent Claim
30 words
The process of claim 12 wherein said additional metal is selected from the group consisting of bismuth, rare earth metals, antimony, chromium, copper, iron, manganese, vanadium, tin and mixtures thereof.
Claim 15
Dependent Claim
22 words
The process of claim 1 wherein said alkaline earth metal component is magnesium nitrate and said aluminum component is alkali metal aluminate.
Claim 16
Dependent Claim
22 words
The process of claim 2 wherein said alkaline earth metal component is magnesium nitrate and said aluminum component is alkali metal aluminate.
Claim 17
Dependent Claim
22 words
The process of claim 4 wherein said alkaline earth metal component is magnesium nitrate and said aluminum component is alkali metal aluminate.
Claim 18
Dependent Claim
33 words
The process of claim 11 wherein said precipitate is spray dried and said spinel composition is in the form of particles having diameters in the range of about 10 to about 250 microns.
Claim 19
Dependent Claim
33 words
The process of claim 11 wherein said precipitate is maintained in contact with at least a portion of said liquid phase for a period of up to about 24 hours before being dried.
Claim 20
Dependent Claim
30 words
The process of claim 12 wherein said final spinel composition includes up to about 20% by weight, calculated as elemental metal, of at least one of said additional metal component.
Claim 21
Dependent Claim
29 words
The process of claim 13 wherein said spinel composition includes up to about 20% by weight, calculated as elemental metal, of a least one of said additional metal component.
References Cited (Backward Citations)
US2992191A
Cited
US3791992A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |