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Effect of asymmetric wear of point attack bits on coal-cutting parameters and primary dust generation.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 8761, 1983 Jan; :1-16
The Bureau of Mines conducted a series of experiments using Illinois no. 6 Coal to determine the effect of asymmetric wear on airborne respirable dust (ard), specific energy, cutting force, and normal force. Plumb-bob-type bits--one new bit and four ground with different sized flats--were used. Constant-depth linear cuts at 0.32, 0.64, 1.27, and 2.54-Cm cut depths were made. Both cutting force and normal force increased as the flat area increased. Specific energy demonstrated a statistically significant increase with flat area at the 0.32- and 1.27-Cm cut depth only. Specific ard showed a statistically significant decrease with increasing flat area only at the 0.64-Cm cut depth. Increasing cut depth increased cutting force but decreased specific energy and specific ard. Normal force increased with increasing cut depth for the new bit but exhibited a maximum at 0.64 Cm for the bits with flats.
Mine-workers; Mining-equipment; Mining-industry; Cutting-tools; Tools; Coal-dust; Coal-mining; Dusts
IH; Report of Investigations
NTIS Accession No.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 8761