US4158548A
Expired / Lapsed
US
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Process for removing sulfur from coal
Assignee: Atlantic Richfield Co
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Filing: 1978-03-15
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Granted: 1979-06-19
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Expires: 1998-03-15
Abstract
Abstract A process for reducing the pyritic sulfur content of coal comprising: (1) contacting coal particles with an aqueous solution of iron complexing agent, and an oxidant; and; (2) recovering coal particles of reduced sulfur content.
Inventors
- 👤 Emmett H. Burk, Jr.
- 👤 Jin S. Yoo
- 👤 John A. Karch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:45
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
38 words
A process for reducing the pyritic sulfur content of coal comprising: (1) contacting coal particles with an aqueous solution of iron complexing agent, and an oxidant at elevated temperature; and (2) recovering coal particles of reduced sulfur content.
Claim 2
Dependent Claim
38 words
A process for reducing the pyritic sulfur content of coal comprising: (1) contacting coal particles with an aqueous solution of iron complexing agent, and an oxidant at elevated temperature; and (2) recovering coal particles of reduced sulfur content.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the recovered coal is metallurgical coal.
Claim 4
Dependent Claim
10 words
The process of claim 2 wherein the oxidant is oxygen.
Claim 5
Dependent Claim
19 words
The process of claim 3 wherein the oxygen is maintained at a pressure of from 5 to 500 psig.
Claim 6
Dependent Claim
16 words
The process of claim 4 wherein the temperature is from about 150° F. to 400° F.
Claim 7
Dependent Claim
26 words
The process of claim 5 wherein the iron complexing agent is present in a mole ratio of iron complexing agent to pyrite of 0.05 to 10.
Claim 8
Dependent Claim
28 words
The process of claim 6 wherein the iron complexing agent is a compound which forms ferrous or ferric complexes having a stability constant-log K of more than 1.
Claim 9
Dependent Claim
14 words
The process of claim 7 wherein the stability constant-log K is greater than 2.
Claim 10
Dependent Claim
17 words
The process of claim 8 wherein the pressure of oxygen is from about 25 to 400 psig.
Claim 11
Dependent Claim
17 words
The process of claim 9 wherein the pressure of oxygen is from about 50 to 300 psig.
Claim 12
Dependent Claim
16 words
The process of claim 10 wherein the temperature is from about 175° F. to 350° F.
Claim 13
Dependent Claim
53 words
The process of claim 11 wherein the complexing agent is selected from the group consisting of carboxylic acids and carboxylic acid salts, diols and polyols, amines, amino acids and amino acid salts, amino polycarboxylic acids and amino polycarboxylic acid salts, phosphonic acids and phosphonic acid salts, condensed phosphates, and salts of condensed phosphates.
Claim 14
Dependent Claim
14 words
The process of claim 12 wherein the salts are alkali metal and ammonium salts.
Claim 15
Dependent Claim
23 words
The process of claim 13 wherein the complexing agent is selected from the group consisting of sodium oxalate, potassium oxalate and ammonium oxalate.
Claim 16
Dependent Claim
19 words
The process of claim 2 wherein the oxidant is selected from the group consisting of ozone and singlet oxygen.
Claim 17
Dependent Claim
25 words
The process of claim 2 wherein the oxidant is an organic oxidant selected from the group consisting of hydrocarbon peroxides, hydrocarbon hydroperoxides and hydrocarbon peracids.
Claim 18
Dependent Claim
21 words
The process of claim 2 wherein the oxidant is an inorganic oxidant selected from the group consisting of peroxides and superoxides.
Claim 19
Dependent Claim
11 words
The process of claim 17 wherein the oxidant is hydrogen peroxide.
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) | 1982-06-18 | 1982-12-18 | 1983-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-18 | 1986-12-18 | 1987-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-18 | 1990-12-18 | 1991-06-19 | $7700.00 | Window Closed / Lapsed |