US4324560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyrite removal from coal
Assignee: C0NSOLIDATION COAL Co
•
Filing: 1980-03-05
•
Granted: 1982-04-13
•
Expires: 2000-03-05
Abstract
Abstract Pyrite is removed from coal by crushing, air classification and organic heavy medium separation. A superior method is taught wherein only a fraction of the total coal treated need be treated with organic media separation.
Inventors
- 👤 Anthony G. Fonseca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:39
CPC Classifications
B; B03; B03B; B03B5/00; B03B5/28; B03B5/30; B03B5/44; B03B5/442; B03B9/00; B03B9/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
A method for the separation of pyrite and refuse from coal when a majority of said coal is crushed to a suitable size for air classification, comprising (a) crushing said coal to a suitable size; (b) passing said crushed coal through an air classifying means, said means separating crushed coal into a fine, low pyrite fraction suitable for immediate use and a coarse, pyrite-rich fraction and drying said coarse fraction to a surface water content of not more than 5% by weight. (c) contacting the coarse pyrite rich fraction with an organic heavy media selected from the group consisting of perchloroethylene, trichloroethylene, carbon tetrachloride, pentachloropropane, tetrachloropropane, 1,1,1-trichloroethane, chloroform, methylene chloride, 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, and 1,1,2,2-tetrachloroethane. (d) thoroughly mixing the organic media and coal; (e) allowing the coal to separate in the organic media forming a sink pyrite-rich refuse phase and a float coal phase; (f) recovering the float coal phase; and (g) separating coal from the float coal phase.
Claim 2
Independent Claim
158 words
A method for the separation of pyrite and refuse from coal when a majority of said coal is crushed to a suitable size for air classification, comprising (a) crushing said coal to a suitable size; (b) passing said crushed coal through an air classifying means, said means separating crushed coal into a fine, low pyrite fraction suitable for immediate use and a coarse, pyrite-rich fraction and drying said coarse fraction to a surface water content of not more than 5% by weight. (c) contacting the coarse pyrite rich fraction with an organic heavy media selected from the group consisting of perchloroethylene, trichloroethylene, carbon tetrachloride, pentachloropropane, tetrachloropropane, 1,1,1-trichloroethane, chloroform, methylene chloride, 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, and 1,1,2,2-tetrachloroethane. (d) thoroughly mixing the organic media and coal; (e) allowing the coal to separate in the organic media forming a sink pyrite-rich refuse phase and a float coal phase; (f) recovering the float coal phase; and (g) separating coal from the float coal phase.
Claim 3
Dependent Claim
23 words
A method as described in claim 1 wherein the organic heavy media is recovered from the sink organic phase and reused in (c).
Claim 4
Dependent Claim
19 words
A method as described in claim 2 wherein the organic heavy media recovered from (f) is reused in (c).
Claim 5
Dependent Claim
27 words
A method as described in claim 3 wherein the water content of the coal is from about 2.5 to about 5% by weight prior to step (c).
Claim 6
Dependent Claim
30 words
A method as described in claim 3 wherein up to about 80% by weight of the coal is crushed to a size of about -200 mesh prior to air classification.
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) | 1985-04-12 | 1985-10-12 | 1986-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-12 | 1989-10-12 | 1990-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-12 | 1993-10-12 | 1994-04-13 | $7700.00 | Window Closed / Lapsed |