Patent US4167397A successfully refreshed from Google Patents.
US4167397A
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US
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Coal desulfurization
Assignee: Standard Oil Co
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Filing: 1978-03-31
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Granted: 1979-09-11
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Expires: 1998-03-31
Abstract
Abstract The pyritic sulfur content of coal can be significantly reduced by contacting the coal with an aqueous solution of a salt which increases the dielectric constant of the solution.
Inventors
- 👤 Stephen L. Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:57
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
A process for removing pyritic sulfur from coal comprising (1) contacting particulate coal with an aqueous treating solution comprising an aqueous solution containing salt of a Group I or II metal, said treating solution having a dielectric constant greater than the dielectric constant of water, said aqueous salt being incapable of oxidizing the sulfur in said particulate coal, and (2) agitating said coal when in the form of an aqueous slurry to cause pyrites in said coal to be physically separated from the coal.
Claim 2
Dependent Claim
84 words
A process for removing pyritic sulfur from coal comprising (1) contacting particulate coal with an aqueous treating solution comprising an aqueous solution containing salt of a Group I or II metal, said treating solution having a dielectric constant greater than the dielectric constant of water, said aqueous salt being incapable of oxidizing the sulfur in said particulate coal, and (2) agitating said coal when in the form of an aqueous slurry to cause pyrites in said coal to be physically separated from the coal.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said coal is characterized in having discrete striations of ash and pyrite in the coal matrix.
Claim 4
Dependent Claim
13 words
The process of claim 2 wherein said treating solution further contains a base.
Claim 5
Dependent Claim
22 words
The process of claim 3 wherein contacting of the coal with said treating solution and agitation of said coal are accomplished simultaneously.
Claim 6
Dependent Claim
17 words
The process of claim 4 wherein contacting and agitation are accomplished simultaneously with float-sinking of the coal.
Claim 7
Dependent Claim
10 words
The process of claim 3 wherein said salt is NaCl.
Claim 8
Dependent Claim
10 words
The process of claim 6 wherein said base is NaOH.
Claim 9
Dependent Claim
22 words
The process of claim 3 wherein said solution is at least 0.1 normal in said salt and 0.01 normal in said base.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-10 | 1983-03-12 | 1983-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-10 | 1987-03-12 | 1987-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-10 | 1991-03-12 | 1991-09-11 | $7700.00 | Window Closed / Lapsed |