Method of extracting coal from a coal refuse pile

Patent · Tue Jan 01 04:00:00 EST 1991

OSTI ID:867922

Yavorsky, Paul M ^[1]

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1. Monongahela, PA

A method of extracting coal from a coal refuse pile comprises soaking the coal refuse pile with an aqueous alkali solution and distributing an oxygen-containing gas throughout the coal refuse pile for a time period sufficient to effect oxidation of coal contained in the coal refuse pile. The method further comprises leaching the coal refuse pile with an aqueous alkali solution to solubilize and extract the oxidized coal as alkali salts of humic acids and collecting the resulting solution containing the alkali salts of humic acids. Calcium hydroxide may be added to the solution of alkali salts of humic acid to form precipitated humates useable as a low-ash, low-sulfur solid fuel.

• Research Organization: National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV
• Assignee: United States of America as represented by Secretary of (Washington, DC)
• Patent Number(s): US 5035722
• OSTI ID: 867922
• Country of Publication: United States
• Language: English

Related Subjects

/44/
acid
acids
added
alkali
alkali salt
alkali salts
alkali solution
aqueous
aqueous alkali
calcium
calcium hydroxide
coal
coal refuse
collecting
comprises
comprises leaching
contained
containing
containing gas
distributing
effect
extract
extracting
extracting coal
form
fuel
gas
humates
humic
humic acid
hydroxide
leaching
low-ash
low-sulfur
method
oxidation
oxidized
oxygen-containing
oxygen-containing gas
period
period sufficient
pile
precipitated
refuse
refuse pile
resulting
resulting solution
salts
soaking
solid
solid fuel
solubilize
solution
solution containing
sufficient
throughout
time
time period
useable