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Coal-cutting forces and primary dust generation using radial gage cutters.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 8800, 1983 Nov; :1-24
The Bureau of Mines determined coal-cutting forces and primary dust generation of four styles of radial gage bits as used on end rings of continuous mining machines. Direct comparisons for reference were made with two widely used conical plumb-bob types having 60 degrees and 90 degrees (nominal) included tip angles. The cutting forces for all of the gage bits were similar to those of the 60 degrees-tip plumb-bob bit. All bits except the RAD-3 gage bit generated similar amounts of primary total dust at shallow cutting, but during deeper cutting, the amounts varied and the gage bits produced as much as 2 1/2 times the dust produced by the 60 deg. bit. This seems atypical since past experience has always shown differences in dust generation at shallow cutting. The specific energy was more like that found previously with other bits, since the values were spread at shallow cutting but became nearly similar at deeper cuts. The 90 deg. bit and the RAD-3 gage bit are not recommended for use except in extremely difficult cutting conditions where dust and forces are of secondary importance. The choice among the remaining four bits can be made on the basis of dust, energy, forces, or cost, as circumstances dictate.
Coal-mining; Mining-equipment; Dust-control; Cutting-tools; Drag-bits; Geometric-forms; Friction-factor; Ignition; Dust-explosions; Mine-safety; Mining-industry
IH; Report of Investigations
NTIS Accession No.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 8800