US3637491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Clarification of water
Assignee: Monsanto Co
•
Filing: 1969-11-03
•
Granted: 1972-01-25
•
Expires: 1989-11-03
Abstract
Abstract Aqueous suspensions of inorganic particles are clarified by addition of a polyacrylamide.
Inventors
- 👤 Ross M Hedrick
- 👤 David T Mowry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:44
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
18 words
The method of claim 1 in which the amount is sufficient to flocculate and precipitate the suspended particles.
Claim 2
Dependent Claim
13 words
The method of claim 1 in which the suspension is of clay particles.
Claim 3
Dependent Claim
27 words
The method of claim 1 in which the polyacrylamide is in an amount such as to provide a concentration not in excess of 0.1 percent by weight.
Claim 4
Independent Claim
43 words
The method of treating a stable suspension of inorganic particles in an aqueous medium, which comprises adding to said medium a linear water-soluble polymer of acrylamide having a molecular weight of at least 5,000 in an amount sufficient to flocculate the suspended particles.
Claim 5
Dependent Claim
18 words
The method of claim 5 in which the amount is sufficient to flocculate and precipitate the suspended particles.
Claim 6
Dependent Claim
13 words
The method of claim 5 in which the suspension is of clay particles.
Claim 7
Independent Claim
48 words
The method of clarifying water containing solid inorganic particles in stable suspension, which comprises adding to said water a linear water-soluble polymer of acrylamide having a molecular weight of at least 5,000 in an amount sufficient to flocculate the suspended particles, and allowing the flocculated particles to settle.
Claim 8
Dependent Claim
20 words
The method of claim 8 in which the polymer is present in an amount not exceeding 0.1 percent by weight.
Claim 9
Independent Claim
39 words
The method of clarifying water containing solid inorganic particles in stable suspension, which comprises adding to said water a linear water-soluble polyacrylamide having a molecular weight of at least 5,000 in an amount sufficient to flocculate the suspended particles.
Claim 10
Dependent Claim
20 words
The method of claim 10 in which the polymer is present in a concentration not exceeding 0.1 percent by weight.
Claim 11
Independent Claim
49 words
The method of clarifying a flocculated suspension of solid inorganic particles in an aqueous medium which comprises adding sufficient polymer of acrylamide to further flocculate and to reinforce the bonds between the flocculated particles but not in excess of 0.1 percent by weight and allowing the aggregates to settle.
Claim 12
Dependent Claim
12 words
The method of claim 12 in which the suspension is of clay.
Claim 13
Dependent Claim
54 words
A process of settling mineral suspensions containing finely divided mineral solids which comprises treating said mineral suspensions with a water-soluble polymer of acrylamide having an average molecular weight of at least 10,000, said polymer being employed in an amount sufficient to flocculate the suspended mineral solids, and allowing the flocculated mineral solids to settle.
Claim 14
Dependent Claim
25 words
The method of claim 1 further defined in that electrolytes selected from the group consisting of alum, ferric chloride and ferric sulfate are not present.
Claim 15
Dependent Claim
13 words
The method of claim 1 further defined in that alum is not present.
Claim 16
Dependent Claim
27 words
The method of claim 1 in which the polyacrylamide combines with particles of the suspension causing a bonding together into flocs and an increased rate of settling.
Claim 17
Dependent Claim
14 words
The method of claim 15 in which the molecular weight is at least 30,000.
Claim 18
Dependent Claim
22 words
The method of claim 15 in which the polymer of acrylamide had undergone some hydrolysis prior to its addition to the suspension.
Claim 19
Independent Claim
58 words
The method of treating a suspension of inorganic particles in an aqueous medium, which comprises adding to said medium a linear water-soluble polymer of acrylamide having a molecular weight of at least 5,000 in an amount such as to provide a concentration of polymer sufficient to aggregate said particles but not in excess of 0.1 percent by weight.
Claim 20
Dependent Claim
21 words
The method of claim 20 in which the polyacrylamide contains some ammonium salt and imide groups as well as acrylamide units.
Claim 21
Dependent Claim
16 words
The method of claim 20 in which the polymer is a copolymer of acrylamide and acrylonitrile.
Claim 22
Independent Claim
52 words
The method of treating a suspension of inorganic particles in an aqueous medium which comprises adding to said medium a linear polymer having as its repeating unit in an amount sufficient to aggregate said particles but not in excess of 0.1 percent by wEight thereby causing the particles to aggregate and settle.
References Cited (Backward Citations)
GB475671A
Cited
US2351259A
Cited
US2552775A
Cited
US2616818A
Cited
US2995512A
Cited
US2718497A
Cited
US2728724A
Cited
US2981630A
Cited
US2687374A
Cited
US2625529A
Cited
US2740522A
Cited
US2729557A
Cited
US3128249A
Cited
US3130167A
Cited
US2980610A
Cited
US3157595A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |