US4421520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reducing the tendency of dried coal to spontaneously ignite
Assignee: Arch Resources Inc
•
Filing: 1981-12-21
•
Granted: 1983-12-20
•
Expires: 2001-12-21
Abstract
Abstract Mined, crushed, coal particles are dried and then contacted with a water-base dispersion or emulsion of latex paint type solids. The latex paint type solids form an elastic film that reduces the tendency of the dried coal to spontaneously ignite.
Inventors
- 👤 J. David Matthews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:35
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
In a method for producing a dried particulate coal fuel having a reduced tendency to spontaneously ignite wherein crushed mined coal is heated in a drying zone with a hot gas to vaporize water from the coal and dry the coal to a moisture content of less than about 20 percent by weight of water and wherein the dried coal is removed from said drying zone, the improvement comprising contacting and intimately mixing said removed dried coal particles with a water-base dispersion comprised of water and latex paint type solids, whereby an elastic film is formed on said dried coal particles.
Claim 2
Dependent Claim
101 words
In a method for producing a dried particulate coal fuel having a reduced tendency to spontaneously ignite wherein crushed mined coal is heated in a drying zone with a hot gas to vaporize water from the coal and dry the coal to a moisture content of less than about 20 percent by weight of water and wherein the dried coal is removed from said drying zone, the improvement comprising contacting and intimately mixing said removed dried coal particles with a water-base dispersion comprised of water and latex paint type solids, whereby an elastic film is formed on said dried coal particles.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein said crushed mined coal is selected from the group consisting of sub-bituminous, lignite, brown coals and combinations thereof.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein said crushed mined coal is heated to a temperature from about 130° F. to about 250° F. in said coal drying zone.
Claim 5
Dependent Claim
44 words
The method of claim 1 wherein said removed dried coal is contacted with about 0.5 gallon to about 2 gallons of said dispersion per short U.S. ton of coal and said dispersion contains at least 0.25% by wt. of said latex paint type solids.
Claim 6
Dependent Claim
28 words
The method of claim 1 wherein said removed dried coal is cooled to a temperature below 100° F. before said removed dried coal is contacted with said dispersion.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the coal is dried to a moisture content of between 5 and 20 percent by weight of water.
References Cited (Backward Citations)
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Cited
US2138825A
Cited
US2222945A
Cited
US2278413A
Cited
US2854347A
Cited
US4331445A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |