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U.S. Department of Energy
Office of Scientific and Technical Information

Process for producing deep cleaned coal

Patent ·
OSTI ID:6487499

This patent describes a physio-chemical process for producing deep cleaned coal, comprising the steps of: providing a supply of air-dried coal of particle size fractions of no greater than 1/4 inchx0 mesh; immersing the coal in an organic solvent selected from the group consisting of butylamine, propylamine, and ethylene diamine, to form a mixture, having coal in an amount to provide no greater than 40 weight percent solids content, for a time period sufficient to swell the coal and to induce natural fracturing of the coal; processing the mixture to recover the organic solvent; subjecting the swelled coal to grinding to a particle size range of minus 28 mesh or finer; subjecting the swelled coal to leaching with a 10 to 20% aqueous hydrogen peroxide solution containing 1 to 2% sulfuric acid at ambient conditions to remove residual pyrite from the coal; and subjecting the swelled coal to leaching with an aqueous solution containing 3 to 6% ammonium hydrogen fluoride and 2 to 3% of nitric acid or hydrochloric acid to remove residual ash from the coal.

Assignee:
Babcock and Wilcox Co., New Orleans, LA
Patent Number(s):
US 4787918
OSTI ID:
6487499
Country of Publication:
United States
Language:
English