Current through Register Vol. XLI, No. 24, June 14, 2024
Section 56-17-2 - Definitions2.1. Unless the context in which a word or phrase appears clearly requires a different meaning, all terms used in this rule that are not defined herein shall have the meanings set forth in W. Va. Code §22A-1-2.2.2 "Coal dust" shall mean the fraction of very fine coal particles deposited throughout an underground mine by air currents and transport that pass through a standard 20-mesh per linear inch sieve differentiated from "loose coal" which is larger in size and shall not pass through a standard 20-mesh per linear inch sieve. Coal dust is not easily wetted and accumulations less than fully saturated (thirty (30) percent moisture) are able to participate in an explosion.2.3. "Excessive Accumulation of Coal Dust" shall mean an accumulation of coal dust in excess of twenty (20) percent total content within the top one eighth inch (1/8") of mine dust located on the surface of the mine floor and any rib or structures.2.4. "Rock dust" shall mean pulverized stone used to cover coal dust and thereby render accumulations of coal dust inert. Rock dust shall be composed of calcite, dolomite, or an equivalent mineral one hundred (100) percent of which shall pass through a standard 20-mesh per linear inch sieve and at least seventy (70) percent of which shall pass through a standard 200-mesh per linear inch sieve. Rock dust shall not contain more than a total of five (5) percent free and combined silica (Si02) and no more than five (5) percent combustible matter. Rock dust shall not exceed regulatory respirable dust levels when applied and particles when wetted and dried shall not cohere to form a cake which may not disperse into separate particles by a blast of air.2.5. "OMHST" shall mean the Office of Miners' Health, Safety and Training.