Evaluations of bit sleeve and twisted-body bit designs for controlling roof bolter dust.
2013 SME Annual Meeting, February 24 - 27, Denver, Colorado, Preprint 13-015. Englewood, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2013 Feb; :1-5
Drilling into coal mine roof strata to install roof bolts has the potential to release substantial quantities of respirable dust. Due to the proximity of drill holes to the breathing zone of roof bolting personnel, dusts escaping the holes and avoiding capture by the dust collection system pose a potential respiratory health risk. Controls are available to complement the typical vacuum collection system and minimize harmful exposures during the initial phase of drilling. This paper examines the use of a bit sleeve to improve dust extraction during the critical initial phase of drilling. A twisted-body drill bit is also evaluated to determine the quantity of dust liberated by different bit designs. Based on these laboratory tests, the bit sleeve may reduce dust emissions by fifty percent during the initial phase of drilling before the drill bit is fully enclosed by the drill hole. Because collaring is responsible for the largest dust liberations, overall dust emissions are also substantially reduced. The use of a twisted-body bit has minimal improvement on dust capture compared to the commonly used dust hog-style bit.
Mining-industry; Mining-equipment; Coal-mining; Coal-dust; Coal-miners; Rock-mechanics; Environmental-control-equipment; Equipment-design; Underground-mining; Dust-control; Dust-control-equipment; Respirable-dust; Breathing-zone; Dust-collectors; Laboratory-testing; Emission-sources
2013 SME Annual Meeting, February 24 - 27, Denver, Colorado, Preprint 13-015