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Incendivity of Some Coal-Cutter Materials by Impact-Abrasion in Air-Methane.

PB234690

Publication Date	1974
Personal Author	Blickensderfer, R.; Deardorff, D. K.; Kelley, J. E.
Page Count	26
Abstract	Test equipment that simulated frictional impacts between coal-cutter bits and mineral inclusions at a coal face during operation of a continuous coal mining machine was used by the Bureau of Mines in the laboratory to study the incendivity of impacts between various rocks, metals, and hard-metal alloys in an explosive mixture of air-7 pct natural gas. Quartzitic sandstone was found to be the most incendive of several rocks tested. Among the metals tested, the type of steel used in commercial coal-cutter tools was the most incendive material tested. A 17-4PH stainless steel was less incendive and appears to be the most promising high-strength steel alloy, reasonably economical, for use in coal-cutter bits. Some hard-metal alloys, primarily titanium and zirconium diboride composites, were also evaluated as possible replacements for the conventional cobalt-bonded tungsten carbide used in the tip of coal-cutter bits. The source of ignition during frictional impact between metal and rock was studied. (Modified author abstract)
Keywords	Coal mining Cutting tools Spark ignition Mine gases Electric sparks Methane Coal mines Safety Tests Rock Metals Alloys Steels Sandstones Borides Carbides Titanium boride Zirconium borides
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	BUREAU OF Mines, Washington, D.C.; Bureau Of Mines, Albany, Oreg. Albany Metallurgy Research Center.
Supplemental Notes	Prepared by Albany Metallurgy Research Center, Oreg.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197422

Incendivity of Some Coal-Cutter Materials by Impact-Abrasion in Air-Methane.

Incendivity of Some Coal-Cutter Materials by Impact-Abrasion in Air-Methane.
PB234690

Publication Date	1974
Personal Author	Blickensderfer, R.; Deardorff, D. K.; Kelley, J. E.
Page Count	26
Abstract	Test equipment that simulated frictional impacts between coal-cutter bits and mineral inclusions at a coal face during operation of a continuous coal mining machine was used by the Bureau of Mines in the laboratory to study the incendivity of impacts between various rocks, metals, and hard-metal alloys in an explosive mixture of air-7 pct natural gas. Quartzitic sandstone was found to be the most incendive of several rocks tested. Among the metals tested, the type of steel used in commercial coal-cutter tools was the most incendive material tested. A 17-4PH stainless steel was less incendive and appears to be the most promising high-strength steel alloy, reasonably economical, for use in coal-cutter bits. Some hard-metal alloys, primarily titanium and zirconium diboride composites, were also evaluated as possible replacements for the conventional cobalt-bonded tungsten carbide used in the tip of coal-cutter bits. The source of ignition during frictional impact between metal and rock was studied. (Modified author abstract)
Keywords	Coal mining Cutting tools Spark ignition Mine gases Electric sparks Methane Coal mines Safety Tests Rock Metals Alloys Steels Sandstones Borides Carbides Titanium boride Zirconium borides
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	BUREAU OF Mines, Washington, D.C.; Bureau Of Mines, Albany, Oreg. Albany Metallurgy Research Center.
Supplemental Notes	Prepared by Albany Metallurgy Research Center, Oreg.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197422