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US 4,305,726 AGranted
Method of treating coal to remove sulfur and ash
OwnerGeorge E. Brown, Jr.inventor
Life of this patent
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Abstract
The present invention is directed to an improved method of chemically treating coal to remove sulfur and ash. It is especially adapted for use on high sulfur, refuse coal. In practice the coal is treated with hydrochloric acid and hypochlorous acid in the presence of ferric and ferrous sulfate to convert the iron pyrites to other sulfur compounds. These are then converted to various salts of calcium through neutralization with lime.
Claims11
A method of treating pulverized coal to remove sulfur comprising:
- adding spent sulfuric acid pickle liquor to said coal,
- adding to said coal a mixture of water with chlorine gas added thereto, the amount of pickle liquor and chlorine gas being an amount sufficient to provide a mixture having a pH of less than about 3, and
- physically separating said coal from said mixture.
A process for removing ash and sulfur from coal wherein sulfur is present consisting essentially of the following steps:
- (a) forming a coal and water mixture,
- (b) treating the mixture with an acidic oxidizing agent so as to convert the sulfur to a sulfur containing acid(s), said oxidizing agent comprising HCL, HOCL and nascent oxygen formed through the addition of CL.sub.2 to water, the amount of CL.sub.2 being an amount sufficient to convert the sulfur to a sulfur containing acid(s),
- (c) physically separating any ash from the mixture,
- (d) treating the remaining coal mixture containing the sulfur containing acid(s) with lime whereby the sulfur is precipitated as calcium salts, and
- (e) physically separating the calcium salts from the coal.
2 more elements
Dependencies are inferred from the claim text.