Patent US3933983A successfully refreshed from Google Patents.
US3933983A
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Method of increasing the thermal stability of crystalline zeolites
Assignee: WR Grace and Co Conn
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Filing: 1973-11-12
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Granted: 1976-01-20
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Expires: 1993-11-12
Abstract
Abstract Methods of increasing the thermal stability of crystalline zeolites are disclosed. The methods are characterized by the steps of either (i), treating the crystalline zeolite first in at least one step with a dilute solution of a fluorine compound whereby a very small amount of fluoride is incorporated in the zeolite with a subsequent exchange with an ammonium ion, rare earth ion, or other metal ion solution, (ii), first exchanging the zeolite with an ammonium ion, rare earth ion or other metal ion solution followed by a treating with a dilute fluoride solution, or (iii), concurrently treating the zeolite with the fluoride ion and exchanging the zeolite in a simultaneous operation.
Inventors
- 👤 Curtis H. Elliott, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:00
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/08; B01J29/082; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186; B01J29/084; C; C01; C01B; C01B39/00; C01B39/02; C01B39/026; B01J2229/00; B01J2229/30; B01J2229/40; Y; Y10; Y10S; Y10S423/00; Y10S423/21; Y10S423/24; Y10S423/25; Y10S423/28; Y10S423/38
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
167 words
A method of producing highly stable fluorided crystalline aluminosilicate zeolites comprising: a. contacting at least once a crystalline aluminosilicate zeolite in the alkali metal form with a sufficient quantity of a solution of a soluble fluorine compound which in solution yields available fluoride ions to provide from about 2 to 22 grams of available fluoride per 10,000 grams (dry basis) of zeolite, and a slurry pH of about 3 to 11 for a sufficient length of time to allow said solution to thoroughly contact and diffuse into said zeolite; b. separating and washing the fluoride treated crystalline aluminosilicate zeolite; c. exchanging the alkali ions in said fluoride treated crystalline aluminosilicate zeolite with an aqueous solution selected from the group consisting of ammonium salt solutions, rare earth salt solutions, alkaline earth salt solutions and transition metal salt solutions and mixtures thereof, to a final alkali content of less than about 6 percent by weight calculated as the alkali oxide; and d. recovering said highly stable crystalline aluminosilicate zeolite.
Claim 2
Independent Claim
167 words
A method of producing highly stable fluorided crystalline aluminosilicate zeolites comprising: a. contacting at least once a crystalline aluminosilicate zeolite in the alkali metal form with a sufficient quantity of a solution of a soluble fluorine compound which in solution yields available fluoride ions to provide from about 2 to 22 grams of available fluoride per 10,000 grams (dry basis) of zeolite, and a slurry pH of about 3 to 11 for a sufficient length of time to allow said solution to thoroughly contact and diffuse into said zeolite; b. separating and washing the fluoride treated crystalline aluminosilicate zeolite; c. exchanging the alkali ions in said fluoride treated crystalline aluminosilicate zeolite with an aqueous solution selected from the group consisting of ammonium salt solutions, rare earth salt solutions, alkaline earth salt solutions and transition metal salt solutions and mixtures thereof, to a final alkali content of less than about 6 percent by weight calculated as the alkali oxide; and d. recovering said highly stable crystalline aluminosilicate zeolite.
Claim 3
Dependent Claim
19 words
A method as in claim 1 wherein said contacting with a soluble fluorine compound is at 60° to 130°F.
Claim 4
Dependent Claim
33 words
A method as in claim 1 wherein said soluble flourine compound is selected from the group consisting of ammonium fluosilicate, fluosilicic acid, sodium fluosilicate, ammonium fluoride, sodium fluoride, potassium fluoride and mixtures thereof.
Claim 5
Dependent Claim
20 words
A method as in claim 1 wherein in step (c) there are multiple contacting steps for exchanging said alkali ions.
Claim 6
Dependent Claim
28 words
A method as in claim 4 wherein interspersed between at least two of said contacting steps is a heat treating of said zeolite at about 200° to 1500°F.
Claim 7
Dependent Claim
53 words
A method as in claim 1 wherein said exchanging comprises contacting said fluoride treated crystalline aluminosilicate zeolite with an aqueous salt solution containing an excess of the exchanging ions required to replace zeolite alkali ions for a period of from 15 minutes to 5 hours at a temperature of about 25° to 95°C.
Claim 8
Dependent Claim
42 words
A method as in claim 6 wherein there are multiple contacting steps in step (c) with at least one step of washing and heat treating of said zeolite at about 200° to 1500°F. interspersed between at least two of the contacting steps.
Claim 9
Dependent Claim
27 words
A method as in claim 7 wherein said aqueous salt solution is selected from the group consisting of ammonium salt solutions and rare earth metal salt solutions.
Claim 10
Dependent Claim
17 words
A method as in claim 7 wherein said aqueous salt solution is a transition metal salt solution.
Claim 11
Independent Claim
110 words
A method of producing highly stable fluorided crystalline aluminosilicate zeolites comprising: a. forming an admixture of a soluble fluorine compound in an amount which in solution is capable of yielding from about 2 to 22 grams of available fluoride per 10,000 gm. of zeolite and a compatible salt of a cation selected from the group consisting of ammonium, rare earth metals, transition metals and mixtures thereof; b. contacting a crystalline aluminosilicate zeolite in the alkali metal form at least once with said admixture to form a slurry having a pH of about 3 to 11 whereby said zeolite is concurrently fluorided and exchanged; and c. washing and drying said zeolite.
Claim 12
Independent Claim
110 words
A method of producing highly stable fluorided crystalline aluminosilicate zeolites comprising: a. forming an admixture of a soluble fluorine compound in an amount which in solution is capable of yielding from about 2 to 22 grams of available fluoride per 10,000 gm. of zeolite and a compatible salt of a cation selected from the group consisting of ammonium, rare earth metals, transition metals and mixtures thereof; b. contacting a crystalline aluminosilicate zeolite in the alkali metal form at least once with said admixture to form a slurry having a pH of about 3 to 11 whereby said zeolite is concurrently fluorided and exchanged; and c. washing and drying said zeolite.
Claim 13
Dependent Claim
35 words
A method as in claim 10 wherein said soluble fluorine compound is selected from the group consisting of ammonium fluosilicate, fluosilicic acid, sodium fluosilicate, ammonium fluoride, sodium fluoride, potassium fluosilicate, potassium fluoride and mixtures thereof.
Claim 14
Dependent Claim
21 words
A method as in claim 10 wherein said zeolite is selected from the group consisting of Zeolite X and Zeolite Y.
Claim 15
Dependent Claim
26 words
A method as in claim 10 wherein there are multiple contactings of said zeolite with said admixture, each contacting being for 15 minutes to 5 hours.
Claim 16
Dependent Claim
27 words
A method as in claim 13 wherein said contacting is at a temperature of 25° to 95°C, the pH of said admixture being about 3 to 11.
Claim 17
Dependent Claim
26 words
A method as in claim 14 wherein between at least one contacting step and another, said zeolite is washed and calcined at about 200° to 1500°F.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |