Claims
- 1. A process for reducing the pyritic sulfur content of coal comprising the steps of:
- (1) contacting an aqueous slurry of water, an alkaline earth metal base and pyrite-containing coal at elevated temperature with oxygen, said alkaline earth metal base being present in an amount at least equal to the stoichiometric amount of pyrite, and said aqueous slurry being maintained at a pH of from about 5.0 to about 12.0; and
- (2) recovering coal particles of reduced pyritic sulfur content.
- 2. The process of claim 1 wherein the pH is from about 6.5 to 10.
- 3. The process of claim 1 wherein the temperature is from about 150.degree. F. to about 350.degree. F.
- 4. The process of claim 1 wherein the oxygen is at a pressure of from about 50 to 500 psig.
- 5. The process of claim 1 wherein the alkaline earth metal base is selected from the group consisting of calcium hydroxide, lime, limestone, magnesium oxide, magnesium carbonate, dolomite and mixtures thereof.
- 6. The process of claim 5 wherein the alkaline earth metal base is limestone.
- 7. The process of claim 1 wherein the coal contacted at elevated temperature with oxygen is agglomerated with hydrocarbon oil.
- 8. The process of claim 1 wherein the aqueous slurry contains from about 5 to 50%, by weight, coal.
- 9. The process of claim 5 wherein the aqueous slurry of water and coal particles contains from about 10 to 30%, by weight, coal particles.
- 10. A process for reducing the sulfur content of coal comprising the steps of:
- (1) contacting an aqueous slurry of water, an alkaline earth metal base and pyrite-containing coal particles at elevated temperature with oxygen, said alkaline earth metal base being present in an amount at least equal to the stoichiometric amount of pyrite, and said aqueous slurry being maintained at a pH of from 5.5 to 12.0; and
- (2) contacting the slurry of coal particles with hydrocarbon oil to form coal-oil agglomerates; and
- (3) recovering coal-oil agglomerates wherein the coal has reduced sulfur content.
- 11. The process of claim 10 wherein the temperature is from about 150.degree. F. to about 350.degree. F.
- 12. The process of claim 11 wherein the oxygen is at a pressure of from about 50 to 500 psig.
- 13. The process of claim 10 wherein the pH is maintained at 6.5 to 10.0 by adding an alkali material to the aqueous slurry.
- 14. The process of claim 10 wherein the alkaline earth metal base is selected from the group consisting of calcium hydroxide, lime, limestone, magnesium oxide, magnesium carbonate, dolomites and mixtures thereof.
- 15. The process of claim 14 wherein the alkaline earth metal base is limestone.
- 16. The process of claim 10 wherein the aqueous slurry of water and coal particles contains from about 5 to 50%, by weight, coal particles.
- 17. The process of claim 11 wherein the aqueous slurry of water and coal particles contains from about 10 to 30%, by weight, coal particles.
- 18. The process of claim 10 wherein the hydrocarbon oil is removed from the recovered coal-oil agglomerates to recover coal of reduced sulfur content.
RELATED APPLICATIONS
This patent application is a continuation-in-part of patent application Ser. No. 876,784 filed Feb. 10, 1978, which is a continuation-in-part of patent application Ser. No. 690,477 filed May 27, 1976, now abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
3824084 |
Dillon et al. |
Jul 1974 |
|
4018571 |
Cole et al. |
Apr 1977 |
|
4054420 |
Longanbach |
Oct 1977 |
|
4092125 |
Stambaugh et al. |
May 1978 |
|
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
876784 |
Feb 1978 |
|
Parent |
690477 |
May 1976 |
|