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U.S. Department of Energy
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Reduction of dust and energy during coal cutting using point-attack bits, with an analysis of rotary cutting and development of a new cutting concept. Report of investigations, 1976

Technical Report ·
OSTI ID:7322153
The objective of this work was to study cutting characteristics of point attack bits with the intent of reducing airborne respirable dust and energy during cutting. Linear cutting of two coal types using four bit types at three depths of cut with three space-depth ratios was performed with a modified horizontal milling machine using an optical particle size monitor for respirable dust sampling. The cutting action of one bit on a rotary hard head mining machine was mathematically analyzed and compared to the linear cutting test results. Airborne respirable dust per unit mass cut was found to be a monotonically increasing function of specific energy. Specific dust and energy decrease with increasing depth of cut. The amount of nonairborne respirable dust was 100 to 1,000 times greater than the airborne dust. The plumb-bob bit produced the most airborne respirable dust and the highest specific energy of the four bits tested. Rotary cutting was shown to be a greater dust producer and energy consumer than linear cutting because of the constantly changing depth of cut, space-depth ratio, and bit attack angle relative to the horizontal bedding planes.
Research Organization:
Bureau of Mines, Twin Cities, MN (USA). Twin Cities Mining Research Center
OSTI ID:
7322153
Report Number(s):
PB-261332; BM-RI-8185
Country of Publication:
United States
Language:
English