US4284611A
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Aqueous phosphate-stabilized polyaluminum sulfate solutions and preparation thereof
Assignee: Hmc Patents Holding Co Inc
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Filing: 1979-07-25
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Granted: 1981-08-18
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Expires: 1999-07-25
Abstract
Abstract A physically and functionally stable solution for water treatment comprises an about 1.2-2.7 molar aqueous phosphate-stabilized polyaluminum sulfate solution of a composition having the formula Al(OH)x(SO4)y(H2PO4)z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19 with the proviso that the sum of x+2y+z is 3. The aqueous phosphate-stabilized polyaluminum sulfate solution can be prepared by reacting alumina hydrate with phosphoric acid and contacting the reacted alumina hydrate with an aqueous polyaluminum sulfate solution. Alternatively, the aqueous phosphate-stabilized polyaluminum sulfate solution can be prepared by reacting an aqueous overbasified polyaluminum sulfate phosphate solution with an aqueous aluminum sulfate solution.
Inventors
- 👤 Alan B. Gancy
- 👤 Christian A. Wamser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:55
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/78; C01F7/786; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/5245
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
50 words
An aqueous chloride-free, phosphate-stabilized polyaluminum sulfate solution, useful as a coagulant in water treatment, having the formula: Al(OH.sub.x)(SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19, with the proviso that the sum of x+2y+z is 3.
Claim 2
Dependent Claim
50 words
An aqueous chloride-free, phosphate-stabilized polyaluminum sulfate solution, useful as a coagulant in water treatment, having the formula: Al(OH.sub.x)(SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19, with the proviso that the sum of x+2y+z is 3.
Claim 3
Dependent Claim
17 words
The solution as set forth in claim 1 wherein the solution is about 1.2 to 2.7 molar.
Claim 4
Dependent Claim
15 words
The solution as set forth in claim 1 wherein x is about 1.3 to 1.34.
Claim 5
Dependent Claim
15 words
The solution as set forth in claim 1 wherein y is about 0.76 to 0.8.
Claim 6
Dependent Claim
15 words
The solution as set forth in claim 1 wherein z is about 0.10 to 0.14.
Claim 7
Dependent Claim
27 words
The solution as set forth in claim 1 with a turbidity after seeding of less than about 3 Formazin turbidity units for over at least seven days.
Claim 8
Dependent Claim
19 words
The solution as set forth in claim 1 having a composition of the formula Al(OH).sub.1.3-1.34 (SO.sub.4).sub.0.76-0.8 [H.sub.2 PO.sub.4 ].sub.0.1-0.14.
Claim 9
Dependent Claim
71 words
A process for preparing an aqueous chloride-free, phosphate stabilized polyaluminum sulfate solution, useful as a coagulant in water treatment, having the formula: Al(OH.sub.x)(SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19, comprising blending an overbasified aqueous chloride-free phosphate-stabilized polyaluminum sulfate solution with an aqueous chloride-free, alum solution, with the proviso that the sum of x+2y+z is 3.
Claim 10
Dependent Claim
71 words
A process for preparing an aqueous chloride-free, phosphate stabilized polyaluminum sulfate solution, useful as a coagulant in water treatment, having the formula: Al(OH.sub.x)(SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19, comprising blending an overbasified aqueous chloride-free phosphate-stabilized polyaluminum sulfate solution with an aqueous chloride-free, alum solution, with the proviso that the sum of x+2y+z is 3.
Claim 11
Dependent Claim
27 words
The process as set forth in claim 8 comprising the additional step of heating the solution to a temperature of from about 30° to about 70° C.
Claim 12
Dependent Claim
25 words
The process as set forth in claim 8 wherein the solution is allowed to stand for at least 1 day before use as a coagulant.
Claim 13
Dependent Claim
28 words
The process as set forth in claim 8 wherein x is about 1.3 to 1.34; y is about 0.76 to 0.8; and z is about 0.1 to 0.14.
Claim 14
Dependent Claim
23 words
The process as set forth in claim 8 wherein the aqueous phosphate-stabilized polyaluminum sulfate solution is from about 1.6 to about 2.7 molar.
Claim 15
Dependent Claim
115 words
A process for preparing an aqueous chloride-free, phosphate-stabilized polyaluminum sulfate solution, useful as a coagulant in water treatment, of a composition having the formula: Al(OH).sub.x (SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19 which comprises: reacting Al 2 O 3 .nH 2 O, wherein n is at least 3, with chloride-free phosphoric acid, in a ratio of about 3 to 10 moles of H 3 PO 4 per mole of Al 2 O 3 .nH 2 O; and mixing the resultant reaction product with an aqueous chloride-free polyaluminum sulfate solution, with the proviso that the sum of x+2y+Z is 3.
Claim 16
Dependent Claim
115 words
A process for preparing an aqueous chloride-free, phosphate-stabilized polyaluminum sulfate solution, useful as a coagulant in water treatment, of a composition having the formula: Al(OH).sub.x (SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.z wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19 which comprises: reacting Al 2 O 3 .nH 2 O, wherein n is at least 3, with chloride-free phosphoric acid, in a ratio of about 3 to 10 moles of H 3 PO 4 per mole of Al 2 O 3 .nH 2 O; and mixing the resultant reaction product with an aqueous chloride-free polyaluminum sulfate solution, with the proviso that the sum of x+2y+Z is 3.
Claim 17
Dependent Claim
23 words
The process as set forth in claim 8 wherein the aqueous phosphate-stabilized polyaluminum sulfate solution is from about 1.2 to about 2.7 molar.
Claim 18
Dependent Claim
71 words
A process for preparing aqueous phosphate-stabilized polyaluminum sulfate/chloride solutions, useful as a coagulant in water treatment, comprising blending an aqueous chloride-free phosphate-stabilized polyaluminum sulfate solution of a composition having the formula Al(OH).sub.x (SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.2 wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19 with the proviso that the sum x+2y+7 is 3, with an aqueous aluminum trichloride solution .
Claim 19
Dependent Claim
71 words
A process for preparing aqueous phosphate-stabilized polyaluminum sulfate/chloride solutions, useful as a coagulant in water treatment, comprising blending an aqueous chloride-free phosphate-stabilized polyaluminum sulfate solution of a composition having the formula Al(OH).sub.x (SO.sub.4).sub.y (H.sub.2 PO.sub.4).sub.2 wherein x is about 1.2 to 1.62; y is about 0.595 to 0.87; and z is about 0.06 to 0.19 with the proviso that the sum x+2y+7 is 3, with an aqueous aluminum trichloride solution .
References Cited (Backward Citations)
DE372246C
Cited
US4131545A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-17 | 1985-02-16 | 1985-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-17 | 1989-02-16 | 1989-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-17 | 1993-02-16 | 1993-08-18 | $7700.00 | Window Closed / Lapsed |