title: Particle size and surface area effects on explosibility using a 20-L chamber.
abstract: The Mine Safety and Health Administration (MSHA) specification for rock dust used in underground coal mines, as defined by 30 CFR 75.2, requires 70% of the material to pass through a 200 mesh sieve (<75 µm). However, in a collection of rock dusts, 47% were found to not meet the criteria. Upon further investigation, it was determined that some of the samples did meet the specification, but were inadequate to render pulverized Pittsburgh coal inert in the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) 20-L chamber. This paper will examine the particle size distributions, specific surface areas (SSA), and the explosion suppression effectiveness of these rock dusts. It will also discuss related findings from other studies, including full-scale results from work performed at the Lake Lynn Experimental Mine. Further, a minimum SSA for effective rock dust will be suggested.
authors.affiliation: Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA.
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Harris
authors.affiliation: Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sapko
authors.affiliation: Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA.
authors.forename: Isaac A
authors.initials: IA
authors.lastname: Zlochower
authors.affiliation: Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA.
authors.forename: Inoka E
authors.initials: IE
authors.lastname: Perera
authors.affiliation: Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, Pittsburgh, PA 15236, USA.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Weiss
keywords: Dust explosion; Explosion prevention; Mining; Particle size; Specific surface area