US4880858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water absorbing polymers
Assignee: Ciba Specialty Chemicals Water Treatments Ltd
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Filing: 1987-08-31
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Granted: 1989-11-14
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Expires: 2007-08-31
Abstract
Abstract A wet filter cake of coal fines or other inorganic particulate material is converted to a crumbly mass by blending with water absorbent polymer particles.
Inventors
- 👤 David Farrar
- 👤 Peter Flesher
- 👤 Malcolm Skinner
- 👤 John Clarke
- 👤 David Marshall
- 👤 Malcolm Hawe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:53
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/13; C10; C10L; C10L9/00; C10L9/10; C22; C22B; C22B1/00; C22B1/14; C22B1/24; C22B1/242; C22B1/244
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
87 words
A process comprising mixing a sticky mass of coal fines and water with polymer particles that are non-film forming and non-sticky when wet by the water in the sticky mass and that are a water absorbing polymer, and thereby forming a crumbly mixture of substantially dry coal fines and substantially non-sticky swollen polymer particles, wherein said water absorbing polymer is swellable but insoluble in water, said water absorbing polymer formed from a water soluble monoethylenically unsaturated monomer or monomer blend in the presence of a crosslinking agent.
Claim 2
Dependent Claim
87 words
A process comprising mixing a sticky mass of coal fines and water with polymer particles that are non-film forming and non-sticky when wet by the water in the sticky mass and that are a water absorbing polymer, and thereby forming a crumbly mixture of substantially dry coal fines and substantially non-sticky swollen polymer particles, wherein said water absorbing polymer is swellable but insoluble in water, said water absorbing polymer formed from a water soluble monoethylenically unsaturated monomer or monomer blend in the presence of a crosslinking agent.
Claim 3
Dependent Claim
31 words
A process according to claim 1 in which the said polymer particles are added as a dry powder and have a dry particle size of from 50 μm to 500 μm.
Claim 4
Dependent Claim
37 words
A process according to claim 1 in which the swollen polymer particles have a size greater than the size of most of the coal fines and the swollen polymer particles are separated from the dry coal fines.
Claim 5
Dependent Claim
36 words
A process according to claim 1 in which the polymer particles are added to the wet sticky mass of coal fines while the polymer particles are in the form of a dispersion in water immiscible liquid.
Claim 6
Dependent Claim
38 words
A process according to claim 1 in which polymer particles have a size at least 90% below 50 μm and are added to the wet sticky mass of coal fines while present as a dispersion in water-immiscible liquid.
Claim 7
Dependent Claim
57 words
A process according to claim 1 in which the polymer particles have a size below 10 μm and are added to the wet sticky mass of coal fines while present as a dispersion in water-immiscible liquid wherein the polymer particles in the dispersion contain at least 30% by weight water, based on the dry weight of polymer.
Claim 8
Dependent Claim
76 words
A process according to claim 1 in which the polymer particles are added to the wet sticky mass of coal fines while present as a dispersion made by reverse phase polymerisation and comprising 25 to 45% by weight of the said polymer particles, 25 to 45% by weight water and 25 to 45% by weight water-immiscible liquid in which the polymer and water are dispersed, the polymer particles having a dry size of below 10 μm.
Claim 9
Dependent Claim
32 words
A process according to claim 1 in which the wet sticky mass of coal fines are mixed with a flocculant or with a counter-ionic coagulant before addition of the water absorbing polymer.
Claim 10
Dependent Claim
35 words
A process according to claim 1 in which the wet sticky mass of coal fines is a filter cake and a flocculant or counter-ionic coagulant is mixed with the cake before addition of the polymer.
Claim 11
Dependent Claim
37 words
A process according to claim 1 in which the wet sticky mass of coal fines is a filter cake formed by coagulating a slurry or concentrate by addition of a coagulant and then filtering the coagulated product.
Claim 12
Dependent Claim
42 words
A process according to claim 10 in which sufficient dissolved co-ionic dispersing agent is incorporated into the filter cake to increase the fluidity of the filter cake and liberate bound water from the particles, and the absorbent polymer particles are thereafter added.
Claim 13
Dependent Claim
52 words
A process according to claim 1 in which the absorbent polymer is a polymer of 5 to 100 mole % acrylic acid as free acid or water soluble salt, 0 to 95 mole % acrylamide, 0 to 50 mole % other monoethylenically unsaturated monomers and 50 to 500 ppm cross linking agent.
Claim 14
Dependent Claim
22 words
A process according to claim 1 in which the wet sticky mass of coal fines is a filter cake of coal fines.
Claim 15
Dependent Claim
47 words
A process according to claim 1 in which the polymer particles are added to the wet sticky mass of coal fines while the polymer particles are in the form of a dispersion in water immiscible liquid and the addition is conducted in the absence of oil-in-water emulsifier.
Claim 16
Dependent Claim
21 words
A process according to claim 1 in which the crosslinking agent is selected from diethylenically unsaturated monoers and polyethylenically unsaturated monomers.
Claim 17
Dependent Claim
84 words
A process according to claim 1 wherein the water absorbing polymer is formed from monomers selected from the class consisting of anionic monomers selected from the group consisting of methacrylic acid, acrylic acid, allyl sulfonate, 2-acrylamido methyl propane sulfonic acid, and water soluble salts thereof, non-ionic monomers selected from the group consisting of methacrylamide, acrylamide, methacrylic esters and acrylic esters, and cationic monomers selected from the group consisting of dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, dialkylaminoalkyl acrylamides, dialkylaminoalkyl methacrylamides, acid salts thereof and quaternary salts thereof.
Claim 18
Dependent Claim
46 words
A process comprising mixing a wet sticky mass of inorganic particles with polymer particles that are non-film forming and non-sticky when wetted by the mass and that are water absorbent, thereby forming a crumbly mixture of substantially dry inorganic particles and substantially non-sticky swollen polymer particles.
Claim 19
Dependent Claim
46 words
A process comprising mixing a wet sticky mass of inorganic particles with polymer particles that are non-film forming and non-sticky when wetted by the mass and that are water absorbent, thereby forming a crumbly mixture of substantially dry inorganic particles and substantially non-sticky swollen polymer particles.
References Cited (Backward Citations)
CA671463A
Cited
GB915589A
Cited
US3562291A
Cited
GB1395543A
Cited
US3973355A
Cited
US3935099A
Cited
US4059552A
Cited
GB1573201A
Cited
US4370429A
Cited
US4345046A
Cited
US4542176A
Cited
EP0072213A1
Cited
EP0072214A1
Cited
US4470827A
Cited
GB2122218A
Cited
EP0101253A2
Cited
EP0105237A2
Cited
GB2148938A
Cited
US4740329A
Cited
US4690971A
Cited
WO1986006000A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |