Abstract When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393–455 °C, pyrite (FeS2) in coal is partially converted to magnetite (Fe304). The maximum amount of Fe304 formed during the time of heating corresponds to 5–20% of the total pyrite present, depending on the coal sample. The magnetite forms as an outer crust on the …

Made available by U.S. Department of Energy Office of Scientific and Technical Information ...

Oxidation of pyrite in coal to magnetite ScienceDirect. May 01, 1984· To obtain a suitable build-up of Fe304 from pyrite in coal, therefore, the coal should be Oxidation of pyrite in coal to magnetite: A. N. Thorpe et al. heated to a relatively low temperature (390-408) at a low partial pressure of air (1.6-2.4 kPa).

A method for increasing the magnetization of pyrite-containing pulverized coal comprises heating the coal in an atmosphere of inert gas, desirably nitrogen, containing 3 to 60 torr, preferably 12 to 16 torr, partial pressure of air to a temperature in the range 390° to 455° C., desirably 400° to 410° C., for a time sufficient, preferably 2 minutes to 2 hours, for converting enough pyrite ...

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393-455 ??C, pyrite (FeS2) in coal is partially converted to magnetite (Fe304). The maximum amount of Fe304 formed during the time of heating corresponds to 5-20% of the total pyrite present, depending on the coal sample. The magnetite forms as an outer crust on the pyrite …

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393–455 °C, pyrite (FeS 2) in coal is partially converted to magnetite (Fe 3 0 4 ). The maximum amount of Fe 3 0 4 formed during the time of heating corresponds to 5–20% of the total pyrite present, depending on the coal sample.

The sulfur content of coal treated in accordance with this method can be reduced by subjecting the treated coal to a low-strength magnetic field for moving at least 50% by weight of the pyrite from the coal although a smaller fraction, about 5 to …

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393–455 °C, pyrite (FeS 2) in coal is partially converted to magnetite (Fe 3 0 4).The maximum amount of Fe 3 0 4 formed during the time of heating corresponds to 5–20% of the total pyrite present, depending on the coal sample. The magnetite forms as an outer …

oxidation and flotation; (2) the quantification of pyrite surface oxidation kinetics under different oxidation potentials; and (3) finding new coal-pyrite depressants. It has been demonstrated, for the first time, that borate, a pH buffer and electrolyte used by many previous investigators in studying pyrite oxidation, actively

heating the coal in an atmosphere having an inert gas that is inert to pyrite containing 3 to 60 torr partial pressure of air to a temperature in the range of 390° C. to 455° C. for at least two minutes for converting sufficient pyrite to magnetite to allow separation of at least a portion of the pyrite from the coal in a low-strength magnetic field.

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393–455 °C, pyrite (FeS 2) in coal is partially converted to magnetite (Fe 3 0 4).The maximum amount of Fe 3 0 4 3 0 4

Method for oxidation of pyrite in coal to magnetite and low field magnetic separation thereof. Patent number: 4661118 Abstract: A method for increasing the magnetization of pyrite-containing pulverized coal comprises heating the coal in an atmosphere of inert gas, desirably nitrogen, containing 3 to 60 torr, preferably 12 to 16 torr, partial ...

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393-455 ??C, pyrite (FeS2) in coal is partially converted to magnetite (Fe304). The maximum amount of Fe304 formed during the time of heating corresponds to 5-20% of the total pyrite present, depending on the coal sample. The magnetite forms as an outer crust on the pyrite …

OSTI.GOV Patent: Method for oxidation of pyrite in coal to magnetite and low field magnetic separation

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393-455 ??C, pyrite (FeS2) in coal is partially converted to magnetite (Fe304). The maximum amount of Fe304 formed during the time of heating corresponds to 5-20% of the total pyrite present, depending on the coal sample.

A method for increasing the magnetization of pyrite-containing pulverized coal comprises heating the coal in an atmosphere of inert gas, desirably nitrogen, containing 3 to 60 torr, preferably 12 to 16 torr, partial pressure of air to a temperature in the range 390.degree. to 455.degree. C., desirably 400.degree. to 410.degree. C., for a time sufficient, preferably 2 minutes to 2 hours, …