US4462808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dispersant for high solids coal-water slurries
Assignee: ChampionX LLC
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Filing: 1983-08-04
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Granted: 1984-07-31
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Expires: 2003-08-04
Abstract
Abstract An improved coal-water slurry containing finely divided coal particles and a dispersing agent which is comprised of a water-soluble homopolymer of a monomer represented by the formula: ##STR1## wherein: M is hydrogen, lithium, sodium, potassium, magnesium, or calcium; R is allyl or methallyl; R 1 is hydrogen, allyl or methallyl; R 2 is hydrogen or sulfonate; R 3 is hydrogen or sulfonate; and providing that R 2 is not the same as R 3 . These improved coal-water slurries are best formulated at a pH of at least 6 and, preferably, above 8. The dispersants have a molecular weight between 1000-20,000.
Inventors
- 👤 Anthony E. Gross
- 👤 Merle L. Branning
- 👤 Dodd W. Fong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:47
CPC Classifications
C; C10; C10L; C10L1/00; C10L1/32; C10L1/326; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/03; Y10S516/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
An improved coal-water slurry of the type comprising at least 45% by weight of finely divided coal particles and a dispersing agent, said slurry being characterized as having a Brookfield viscosity at 60 rpm of less than 3000 centipoise, the improvement comprising adjusting the ph of said slurry to at least 6 and using as the dispersing agent a water-soluble homopolymer of a monomer represented by the formula: ##STR10## wherein: M is hydrogen, lithium, sodium, potassium, magnesium, or calcium; R is allyl or methallyl; R 1 is hydrogen, allyl or methallyl; R 2 is hydrogen or sulfonate; R 3 is hydrogen or sulfonate; and providing that R 2 is not the same as R 3 .
Claim 2
Dependent Claim
116 words
An improved coal-water slurry of the type comprising at least 45% by weight of finely divided coal particles and a dispersing agent, said slurry being characterized as having a Brookfield viscosity at 60 rpm of less than 3000 centipoise, the improvement comprising adjusting the ph of said slurry to at least 6 and using as the dispersing agent a water-soluble homopolymer of a monomer represented by the formula: ##STR10## wherein: M is hydrogen, lithium, sodium, potassium, magnesium, or calcium; R is allyl or methallyl; R 1 is hydrogen, allyl or methallyl; R 2 is hydrogen or sulfonate; R 3 is hydrogen or sulfonate; and providing that R 2 is not the same as R 3 .
Claim 3
Dependent Claim
30 words
The improved coal slurry of claim 1 wherein the improvement comprises using as the dispersing agent the water-soluble homopolymer of claim 1 having a molecular weight ranging between about 1000-20,000.
Claim 4
Dependent Claim
70 words
An improved coal-water slurry of the type comprising at least 45% by weight of finely divided coal particles and a dispersing agent, said slurry being characterized as having a Brookfield viscosity at 60 rpm of less than 3000 centipoise, the improvement comprising adjusting the pH of said slurry to at least 6 and using as the dispersing agent a water-soluble homopolymer of 3-carboxy-3-sulfo-N,N-diallylpropionamide having a molecular weight between about 1000-20,000.
Claim 5
Dependent Claim
70 words
An improved coal-water slurry of the type comprising at least 45% by weight of finely divided coal particles and a dispersing agent, said slurry being characterized as having a Brookfield viscosity at 60 rpm of less than 3000 centipoise, the improvement comprising adjusting the pH of said slurry to at least 6 and using as the dispersing agent a water-soluble homopolymer of 3-carboxy-3-sulfo-N,N-diallylpropionamide having a molecular weight between about 1000-20,000.
Claim 6
Dependent Claim
36 words
The improved coal slurry of claim 3 wherein the homopolymer of 3-carboxy-3-sulfo-N,N-diallylpropionamide has a molecular weight between about 2500-17,500 and is present in the slurry at a dosage of from 0.01-5.0 weight percent based on coal.
Claim 7
Dependent Claim
53 words
The improved coal slurry of claim 3 wherein the pH of the slurry is at least 8 and the dispersing agent is a homopolymer of CASDAPA having a molecular weight between about 5000-17,500 which is present in the slurry at a dosage of from 0.1 to about 2.0 weight percent based on coal.
Claim 8
Dependent Claim
52 words
The improved coal slurry of claim 3 wherein the pH of the slurry is at least 8 and the dispersing agent is a homopolymer of CASDAPA having a molecular weight between about 12,000-17,000 which is present in the slurry at a dosage of from 0.4 to 0.5 weight percent based on coal.
References Cited (Backward Citations)
US4282006A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-31 | 1988-01-30 | 1988-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-31 | 1992-01-30 | 1992-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-31 | 1996-01-30 | 1996-07-31 | $7700.00 | Window Closed / Lapsed |