Pyrite separation from high-sulfur coals

Separation of Ultrafine Pyrite from High Sulfur Coals by Selective Dispersion and Flocculation... 

The removal of sulfur from high-sulfur coal is costly and incomplete. One method is to pulverize the coal to the consistency of talcum powder and remove the pyrite (FeSg) by magnetic separation. Reducing the sulfur content of fuel oil is also costly. It involves the formation of hydrogen... 

Over the past decades, advances have been made that reduce environmental impacts of coal burning in large plants. Some arc standard and others experimental. Limestone (mainly calcium carbonate) scrubber smokestacks react with the emitted sulfates from the combustion and contain the chemical products, thereby reducing the release of SO., into the atmosphere by a large factor (of ten or more). Pulverization of coal can also allow for the mechanical separation of some sulfur impurities, notably those in the form of pyrites, prior to combustion. Currently deployed—with more advanced versions in the development stage—are various t yies of fluidized bed reactors, which use coal fuel in a pulverized form, mixed with pulverized limestone or dolomite in a high temperature furnace. This technique reduces sulfate release considerably. There are... 

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