Patent US4500041A successfully refreshed from Google Patents.
US4500041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing high-concentration slurry of coal
Assignee: Electric Power Development Co Ltd
•
Filing: 1982-12-03
•
Granted: 1985-02-19
•
Expires: 2002-12-03
Abstract
Abstract High concentrated coal-water slurry is produced by coarsely crushing coal, thereafter pulverizing the coarsely crushed coal, together with water and a slurry dispersant, according to necessity, in a wet-type ball mill, and feeding back one portion of the finely pulverized coal slurry thus obtained into the inlet of the wet-type ball mill.
Inventors
- 👤 Kazuhiko Nakaoji
- 👤 Mitsugu Kamao
- 👤 Hayami Itoh
- 👤 Shuhei Tatsumi
- 👤 Shoichi Takao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:39
CPC Classifications
C; C10; C10L; C10L1/00; C10L1/32; C10L1/326
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
59 words
A process for producing high-concentration coal-water slurry by pulverizing coal consisting essentially of first coarsely crushing the coal, thereafter subjecting the coarsely crushed coal thus obtained to a pulverizing process, together with water, in a wet-type pulverizing machine, and feeding back one portion of the finely pulverized coal slurry thus obtained into the inlet of said wet-type pulverizing machine.
Claim 2
Dependent Claim
59 words
A process for producing high-concentration coal-water slurry by pulverizing coal consisting essentially of first coarsely crushing the coal, thereafter subjecting the coarsely crushed coal thus obtained to a pulverizing process, together with water, in a wet-type pulverizing machine, and feeding back one portion of the finely pulverized coal slurry thus obtained into the inlet of said wet-type pulverizing machine.
Claim 3
Dependent Claim
24 words
The process according to claim 1 in which said one portion of said finely pulverized coal slurry is 90 to 20 percent by weight.
Claim 4
Dependent Claim
43 words
The process according to claim 2 in which the coal particles in the final coal slurry has a particle size constitution comprising 20 to 30% by weight of 200-mesh and larger size and up to 80% by weight of 350-mesh and smaller size.
Claim 5
Dependent Claim
63 words
The process according to claim 2 in which the coal particles in the final coal slurry have a particle size constitution comprising up to 1% by weight of 48-mesh and larger size, 20 to 30% by weight of 200-mesh and larger size, up to 80% by weight of 350-mesh and smaller size, and up to 40% by weight of 200- to 350-mesh size.
Claim 6
Dependent Claim
17 words
The process according to claim 1 in which a slurry dispersant is added to the pulverizing process.
Claim 7
Dependent Claim
28 words
The process according to claim 5 in which the slurry dispersant comprises at least one surface active agent suitably selected from anionic, nonionic, and cationic surface active agents.
Claim 8
Dependent Claim
27 words
The process according to claim 5 in which the slurry dispersant is used in a quantity of 0.01 to 3 percent by weight relative to the coal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |