Effect of Asymmetric Wear of Point Attack Bits on Coal-Cutting Parameters and Primary Dust Generation

摘要

The Bureau of Mines conducted a series of experiments using Illinois No. 6 coal to determine the effectof 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.