Claims
- 1. 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.
- 2. The process of claim 1 wherein the recovered coal is metallurgical coal.
- 3. The process of claim 2 wherein the oxidant is oxygen.
- 4. The process of claim 3 wherein the oxygen is maintained at a pressure of from 5 to 500 psig.
- 5. The process of claim 4 wherein the temperature is from about 150.degree. F. to 400.degree. F.
- 6. 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.
- 7. 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.
- 8. The process of claim 7 wherein the stability constant-log K is greater than 2.
- 9. The process of claim 8 wherein the pressure of oxygen is from about 25 to 400 psig.
- 10. The process of claim 9 wherein the pressure of oxygen is from about 50 to 300 psig.
- 11. The process of claim 10 wherein the temperature is from about 175.degree. F. to 350.degree. F.
- 12. 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.
- 13. The process of claim 12 wherein the salts are alkali metal and ammonium salts.
- 14. The process of claim 13 wherein the complexing agent is selected from the group consisting of sodium oxalate, potassium oxalate and ammonium oxalate.
- 15. The process of claim 2 wherein the oxidant is selected from the group consisting of ozone and singlet oxygen.
- 16. 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.
- 17. The process of claim 2 wherein the oxidant is an inorganic oxidant selected from the group consisting of peroxides and superoxides.
- 18. The process of claim 17 wherein the oxidant is hydrogen peroxide.
RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 726,082, filed Sept. 23, 1976 and now abandoned.
US Referenced Citations (5)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
726082 |
Sep 1976 |
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