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Assessment of airborne dust generated from small truck-mounted rock drills.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9616, 1995 Jan; :1-11
Recently the United States Bureau of Mines dust research program studied small surface mine drills to assess their dust generation hazards and the effect of dust control technologies implemented. Most of the drills were truck mounted and used Rotoclone dry dust collection systems. Initial dust source surveys and the assessment of dust control enhancements for small mobile rock drills were presented in this report. A significant amount of airborne respirable dust was emitted from the Rotoclone type dust collector. Respirable dust concentrations measured around the drill deck ranged from 8.658 to 95.15mg/m3 with concentrations ranging from 1.37 to 2.69mg/m3 at distances of 12.2 to 30.5 meters downwind. Wind direction and speed were factors in the dust concentrations measured on the bench. Dust collector improvements were made on several drills to control dust from the emission sources. The results showed that adding a low flow of water to the collector exhaust may reduce the dust emitted by 92%, increasing drill deck shroud containment and increasing the Rotoclone speed may reduce respirable dust levels by 63%, vertically extending the Rotoclone exhaust may reduce downwind respirable dust levels by 62%, and enclosing the Rotoclone hopper discharge may reduce levels by 80%. Wet drilling, by injecting small amounts of water into the bailing air, appeared to be more effective than an improved Rotoclone drill deck shroud by 29%. Repositioning the operator away from the drill during most of its operation can keep him or her out of the dust cloud and reduce dust levels by 69%.
Dust-control; Dust-analysis; Dusts; Mining-industry; Respirable-dust; Silica-dusts; Coal-mining; Surface-mining; Control-technology; Mining-equipment; Air-flow; Occupational-exposure
Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
Report of Investigations
NTIS Accession No.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9616
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division