US4622166A
Expired / Lapsed
US
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Process for preparation of zeolite slurry excellent in static stability and dynamic stability
Assignee: Mizusawa Industrial Chemicals Ltd
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Filing: 1984-07-05
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Granted: 1986-11-11
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Expires: 2004-07-05
Abstract
Abstract Disclosed is a process for the preparation of a zeolite slurry being excellent in either the static stability or the dynamic stability and having a good flowability, which comprises neutralizing an aqueous cake or slurry containing water and zeolite in such a state that both are substantially inseparable from each other by filtration, with an inorganic or organic acid or an acid anydride or acidic salt thereof so that the pH value of the zeolite slurry at the time of completion of addition of said acid, acid anhydride or acidic salt is in the range of from 9.5 to 12 and the pH value of the zeolite slurry in the stationary state after addition of said acid, acid anhydride or acidic salt is in the range of from 11.3 to 12.7, adding a water-soluble or water-dispersible organic polymeric dispersant in an amount of at least 0.1% by weight based on the anhydrous zeolite to the neutralized zeolite slurry, and subjecting the resulting slurry to highly shearing stirring.
Inventors
- 👤 Tadahisa Nakazawa
- 👤 Koichi Usui
- 👤 Masahide Ogawa
- 👤 Kiyoshi Abe
- 👤 Takashi Tokita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:33
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/02; C11D3/12; C11D3/124; C11D3/1246; C11D3/128; C11D3/1286
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
203 words
A process for the preparation of a zeolite slurry being excellent in both its staic stability and its dynamic stability and having a good flowability, which comprises stirring a wet cake containing water and zeolite in such a state that both are substantially inseparable from each other by filtration and further containing 0.1 to 1.0% by weight of free alkali to form a slurry of zeolite, blowing carbon dioxide gas into the zeolite slurry to neutralize the slurry so that the pH value (P 1 ) of the zeolite slurry at the time of completion of addition of said gas is in the range of from 10 to 11.5 and the pH value (P 2 ) of the zeolite slurry in the stationary state when 4 hours have passed from at time of completion of addition of said gas is in the range of from 11.5 to 12.5 and that the value of (P 2 -P 1 ) is in the range of from 0.7 to 1.3, adding a water-soluble or water-dispersible organic polymeric dispersant in an amount of at least 0.1% by weight based on the anhydrous zeolite to the neutralized zeolite slurry, and subjecting the resulting slurry to highly shearing stirring.
Claim 2
Dependent Claim
203 words
A process for the preparation of a zeolite slurry being excellent in both its staic stability and its dynamic stability and having a good flowability, which comprises stirring a wet cake containing water and zeolite in such a state that both are substantially inseparable from each other by filtration and further containing 0.1 to 1.0% by weight of free alkali to form a slurry of zeolite, blowing carbon dioxide gas into the zeolite slurry to neutralize the slurry so that the pH value (P 1 ) of the zeolite slurry at the time of completion of addition of said gas is in the range of from 10 to 11.5 and the pH value (P 2 ) of the zeolite slurry in the stationary state when 4 hours have passed from at time of completion of addition of said gas is in the range of from 11.5 to 12.5 and that the value of (P 2 -P 1 ) is in the range of from 0.7 to 1.3, adding a water-soluble or water-dispersible organic polymeric dispersant in an amount of at least 0.1% by weight based on the anhydrous zeolite to the neutralized zeolite slurry, and subjecting the resulting slurry to highly shearing stirring.
Claim 3
Dependent Claim
34 words
A process according to claim 1, wherein said starting aqueous cake or slurry has such a concentration that the concentration of anhydrous zeolite solids in the final slurry is 30 to 50% by weight.
Claim 4
Dependent Claim
19 words
A process according to claim 1, wherein the zeolite has a CaO binding capacity of 120 to 180 mg/g.
Claim 5
Dependent Claim
14 words
A process according to claim 1, wherein the zeolite is a type A zeolite.
Claim 6
Dependent Claim
18 words
A process according to claim 13, wherein the zeolite has a primary particle size smaller than 1 μm.
Claim 7
Dependent Claim
31 words
A process according to claim 1, wherein the carbon dioxide gas is added to the slurry in an amount of 7 to 45 milliequivalents per 100 g of the anhydrous zeolite.
Claim 8
Dependent Claim
22 words
A process according to claim 1, wherein the water-soluble or water-dispersible organic polymeric dispersant is a dispersant containing carboxyl and hydroxyl groups.
Claim 9
Dependent Claim
12 words
A process according to claim 7, wherein th dispersant is carboxymethyl cellulose.
Claim 10
Dependent Claim
19 words
The process of claim 1 wherein the carbon dioxide is blown into the zeolite slurry while stirring the slurry.
Claim 11
Dependent Claim
279 words
A process for the preparation of a zeolite slurry being excellent in static stability and dynamic stability and having a good flowability, which comprises neutralizing an aqueous cake or slurry containing water and zeolite in such a state that both are substantially inseparable from each other by filtration, said aqueous cake or slurry containing an alkali ion in the following three states: (a) the alkali ion dissolved in the aqueous phase, (b) the alkali ion built in the crystal structure of zeolite particles and (c) the alkali ion present in the interface between the zeolite particles and the aqueous phase, with an inorganic or organic acid or an acid anhydride or acidic salt thereof so that the pH value (P 1 ) of the zeolite slurry at the time of completion of addition of said acid, acid anhydride or acidic salt is in the range of from 9.5 to 12 and the pH value (P 2 ) of the zeolite slurry in the stationary state when 4 hours have passed from the time of completion of addition of said acid, acid anhydride or acidic salt is in the range of from b 11.3 to 12.7, and that the value of (P 2 -P 1 ) is in the range of from 0.7 to 1.3, thereby to neutralize all of the free alkali ion (a) and at least a part of the alkali ion (c) while the alkali ion (b) is not substantially neutralized, adding a water-soluble or water-dispersible organic polymeric dispersant in an amount of at least 0.1% by weight based on the anhydrous zeolite to the neutralized zeolite slurry, and subjecting the resulting slurry to highly shearing stirring.
Claim 12
Dependent Claim
279 words
A process for the preparation of a zeolite slurry being excellent in static stability and dynamic stability and having a good flowability, which comprises neutralizing an aqueous cake or slurry containing water and zeolite in such a state that both are substantially inseparable from each other by filtration, said aqueous cake or slurry containing an alkali ion in the following three states: (a) the alkali ion dissolved in the aqueous phase, (b) the alkali ion built in the crystal structure of zeolite particles and (c) the alkali ion present in the interface between the zeolite particles and the aqueous phase, with an inorganic or organic acid or an acid anhydride or acidic salt thereof so that the pH value (P 1 ) of the zeolite slurry at the time of completion of addition of said acid, acid anhydride or acidic salt is in the range of from 9.5 to 12 and the pH value (P 2 ) of the zeolite slurry in the stationary state when 4 hours have passed from the time of completion of addition of said acid, acid anhydride or acidic salt is in the range of from b 11.3 to 12.7, and that the value of (P 2 -P 1 ) is in the range of from 0.7 to 1.3, thereby to neutralize all of the free alkali ion (a) and at least a part of the alkali ion (c) while the alkali ion (b) is not substantially neutralized, adding a water-soluble or water-dispersible organic polymeric dispersant in an amount of at least 0.1% by weight based on the anhydrous zeolite to the neutralized zeolite slurry, and subjecting the resulting slurry to highly shearing stirring.
Claim 13
Dependent Claim
52 words
The process of claim 10 wherein the step of neutralizing the aqueous cake or slurry containing water and zeolite with the inorganic or organic acid or acid anhydride or synthetic salt thereof comprises gradually adding an aqueous solution of the acid, acid anhydride or acidic salt to the zeolite slurry with stirring.
Claim 14
Dependent Claim
34 words
The process of claim 10 wherein the acid, acid anhydride or acidic salt is added to the slurry in an amount of from 7 to 45 milliequivalents per 100 g of the anhydrous zeolite.
Claim 15
Dependent Claim
46 words
The process of claim 11 wherein the aqueous cake or slurry is neutralized with an inorganic acid selected from the group consisting of sulfuric acid, sulfurous acid, hydrochloric acid, hydrobromic acid, hypochlorous acid, chloric acid, boric acid, nitric acid, phosphoric acid, phosphorous acid and metaphosphoric acid.
Claim 16
Dependent Claim
58 words
The process of claim 11 wherein the aqueous cake or slurry is neutralized with an organic acid selected from the group consisting of acetic acid, propionic acid, oxalic acid, citric acid, tartaric acid, succinic acid, maleic acid, malic acid, gluconic acid, itaconic acid, thioglycolic acid, ethylenediamine-tetraacetic acid, nitrilotriacetic acid, diglycolic acid, sulfoitaconic acid, trimellitic acid and pyromellitic acid.
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) | 1989-11-10 | 1990-05-12 | 1990-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-10 | 1994-05-12 | 1994-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-10 | 1998-05-12 | 1998-11-11 | $7700.00 | Window Closed / Lapsed |