Advanced development of fine coal desulfurization and recovery technology. Quarterly technical progress report, October 1, 1976--December 31, 1976. [53 references]

• Main Authors: Fisher, R.W., Wheelock, T.D.
• Language: unknown
• Published: 2013
• Subjects: 01 COAL; LIGNITE; AND PEAT; ASHES; REMOVAL; COAL; AGGLOMERATION; DESULFURIZATION; ELECTRIC POTENTIAL; FLOTATION; LEACHING; PELLETIZING; PYRITE; AMMONIUM COMPOUNDS; COAL FINES; COAL PREPARATION; CYANIDES; ELECTRON MICROSCOPY; IOWA; IRON CHLORIDES; OXYGEN; SODIUM CARBONATES; SODIUM COMPOUNDS; THIOCYANATES; ALKALI METAL COMPOUNDS; CARBON COMPOUNDS; CARBONACEOUS MATERIALS; CARBONATES; CARBONIC ACID DERIVATIVES; CHALCOGENIDES; CHEMICAL REACTIONS; CHLORIDES; CHLORINE COMPOUNDS; CRYOGENIC FLUIDS; DISSOLUTION; ELEMENTS; ENERGY SOURCES; FABRICATION; FLUIDS; FOSSIL FUELS; FUELS; HALIDES; HALOGEN COMPOUNDS; IRON COMPOUNDS; IRON SULFIDES; MICROSCOPY; MINERALS; MOLDING; NONMETALS; NORTH AMERICA; Carbonic acid
• Online Access: http://www.osti.gov/servlets/purl/5232614; https://www.osti.gov/biblio/5232614; https://doi.org/10.2172/5232614

The improvement and technical development of promising methods for desulfurizing and recovering fine coal underway includes froth flotation, selective oil agglomeration, pelletization, and a chemical desulfurization process which involves leaching fine coal with a hot dilute solution of sodium carbonate containing dissolved oxygen under pressure. A preliminary assessment of the state of the art and review of the technical literature has been made. Equipment and apparatus have been assembled for small-scale laboratory experiments in froth flotation, oil agglomeration and chemical desulfurization. Preliminary froth flotation tests have been carried out on an Iowa coal to establish baseline data. Quite unexpectedly these tests indicated that aluminum nitrate may be an activator for coal because it served to increase the recovery of coal. Several potential flotation depressants for pyrite have been screened by measurement at the zeta potential and floatability of pyrite or coal in aqueous suspensions containing the potential depressants. The following reagents show some promise as pyrite depressants: ferric chloride, sodium cyanide, ammonium thiocyanate, and the disodium salt of ethylenediaminetetraacetic acid. Preliminary plans have been prepared for a continuous flow bench-scale system to demonstrate the process. This system will include equipment for grinding and pretreating the coal as well as equipment for demonstrating froth flotation, selective oil agglomeration and pelletization. An investigation of coal microstructure as it relates to coal beneficiation methods has also been initiated. The distribution of various forms of pyrite by size and crystal structure has been determined for two cannel samples of coal through application of scanning electron microscope techniques.