Method of extracting coal from a coal refuse pile

Patent · Tue Jul 30 00:00:00 EDT 1991

OSTI ID:5806711

Yavorsky, P M

This patent describes a method of extracting coal from a coal refuse pile. It comprises soaking the coal refuse pile with an aqueous alkali solution; distributing an oxygen-containing gas throughout the coal refuse pile for a time period sufficient to effect oxidation of coal contained in the coal reuse pile; 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, wherein the method is conducted at ambient pressure. This patent also describes a method of further comprising adding calcium hydroxide to the resulting solution containing alkali salts of humic acids to produce precipitated calcium humates and an alkali solution.

• Assignee: Secretary of the Interior, Washington, DC (USA)
• Patent Number(s): US 5035722; A
• Application Number: PPN: US 7-408586
• OSTI ID: 5806711
• Resource Relation: Patent File Date: 18 Sep 1989
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
SOLVENT EXTRACTION
COAL FINES
LEACHING
CRACK PROPAGATION
HUMIC ACIDS
OXIDATION
PURIFICATION
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DISSOLUTION
ENERGY SOURCES
EXTRACTION
FOSSIL FUELS
FUELS
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
SEPARATION PROCESSES
010402* - Coal
Lignite
& Peat- Purification & Upgrading
010300 - Coal
Lignite
& Peat- Preparation- (1987-)