Abstract: Coal Cleaning (Desulfurization) by High-Intensity Magnetic Separation

Haydn H. Murray, Bruce Wright

Much of the bituminous coal reserves of the eastern United States contains sulfur values in excess of 3%. Approximately half or more of this sulfur is in the mineral pyrite, a common accessory iron sulfide in coal. Pyrite is present in a range of particle sizes in the coal and it is the fine pyrite which is difficult to remove by conventional coal-preparation techniques. Pyrite is paramagnetic and newly developed techniques using high intensity (20 kg) magnetic separation can remove up to 90% of the pyrite and up to 50% of the ash. To liberate the fine pyrite the coal must be pulverized so that it will pass through a 200-mesh screen (0.074 mm). Coals V and VI, major commercially mined coals in Illinois and Indiana, were studied and the results indicate that a high-intensi y magnetic separation process could be utilized economically to lower substantially the sulfur and ash content so that in many areas the stack-gas and particulate-emission standards could be met. This would mean that more bituminous coals from the eastern United States could be utilized and thus our coal reserves extended.

AAPG Search and Discovery Article #90961©1978 AAPG Annual Convention and Exhibition, Oklahoma City, Oklahoma