US4290896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dewatering fine coal slurries using organopolysiloxanes
Assignee: Dow Silicones Corp
•
Filing: 1980-05-27
•
Granted: 1981-09-22
•
Expires: 2000-05-27
Abstract
Abstract Aqueous slurries of fine coal are dewatered by a process which comprises mixing an organopolysiloxane with the slurry, separating the slurry to recover the fine coal and further drying the fine coal, if desired. The use of water-soluble organopolysiloxanes or water-emulsifiable organopolysiloxanes provides improved separating and/or improved drying of fine coal in the dewatering process that is disclosed.
Inventors
- 👤 David J. Gordon
- 👤 James K. Wessel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:27
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C02F1/545; B; B01; B01D; B01D37/00; B01D37/03
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
120 words
A process for dewatering an aqueous slurry of fine coal, said process comprising (I) mixing a dewatering-improving amount of a water-dispersible organopolysiloxane with the aqueous slurry of fine coal, said organopolysiloxane having the formula R a H b SiO.sub.(4-a-b)/2 wherein a and b are numbers, the sum of which has an average value of from greater than zero to less than four, b has an average value of from zero to a and R denotes an organic radical bonded to a silicon atom by a silicon-carbon bond, (II) separating the organopolysiloxane-containing aqueous slurry of fine coal into an aqueous portion and a fine coal portion, said fine coal portion having a water content of less than 20 percent by weight,
Claim 2
Dependent Claim
120 words
A process for dewatering an aqueous slurry of fine coal, said process comprising (I) mixing a dewatering-improving amount of a water-dispersible organopolysiloxane with the aqueous slurry of fine coal, said organopolysiloxane having the formula R a H b SiO.sub.(4-a-b)/2 wherein a and b are numbers, the sum of which has an average value of from greater than zero to less than four, b has an average value of from zero to a and R denotes an organic radical bonded to a silicon atom by a silicon-carbon bond, (II) separating the organopolysiloxane-containing aqueous slurry of fine coal into an aqueous portion and a fine coal portion, said fine coal portion having a water content of less than 20 percent by weight,
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said aqueous slurry of fine coal is the product of a flotation process.
Claim 4
Dependent Claim
24 words
The process of claim 1 wherein said aqueous slurry of fine coal has a water content of from 65 to 75 percent by weight.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein said separating comprises a filtering process.
Claim 6
Dependent Claim
31 words
The process of claim 1 wherein the fine coal portion containing less than 20 percent by weight water is dried by a heating process to further reduce the water content thereof.
Claim 7
Dependent Claim
19 words
The process of claim 1 wherein said fine coal has a nominal particle size of 28 to 200 mesh.
Claim 8
Dependent Claim
33 words
The process of claims 1, 2, 3, 4, 5 or 6 wherein the water-dispersible organopolysiloxane is a water-soluble organopolysiloxane which is mixed with the aqueous slurry of fine coal as an aqueous solution.
Claim 9
Dependent Claim
31 words
The process of claim 7 wherein the water-soluble organopolysiloxane bears at least one silicon-atom-bonded radical having the formula --CH 2 CH 2 CH 2 (OCH 2 CH 2 ) 12 OH.
Claim 10
Dependent Claim
33 words
The process of claims 1, 2, 3, 4, 5 or 6 wherein the water-dispersible organopolysiloxane is a water-insoluble organopolysiloxane which is mixed with the aqueous slurry of fine coal as an aqueous emulsion.
Claim 11
Dependent Claim
13 words
The process of claim 9 wherein the water-insoluble organopolysiloxane is an emulsion-polymerized polydimethylsiloxane.
Claim 12
Dependent Claim
13 words
The process of claim 9 wherein the water-insoluble organopolysiloxane is an emulsion-polymerized polymethylsilsesquioxane.
Claim 13
Dependent Claim
32 words
The process of claim 9 wherein the water-insoluble organopolysiloxane bears at least one silicon-atom-bonded radical having the formula --CH 2 CH 2 CH 2 --(OCH 2 CH(CH 3 )) 2 .5 OH.
Claim 14
Dependent Claim
44 words
A process of claim 9 wherein the water-insoluble organopolysiloxane has the formula (CH 3 ) 3 SiO{(CH 3 ) 2 SiO} 98{ (CH 3 )(W)SiO} 2 Si(CH 3 ) 3 wherein W denotes --(CH 2 ) 3 NHCH 2 CH 2 NH 2 .
References Cited (Backward Citations)
US2587636A
Cited
US3294725A
Cited
US3946061A
Cited
DE2149329A1
Cited
US3817861A
Cited
US4026880A
Cited
US3729496A
Cited
US3700715A
Cited
US4210531A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |