Pittsburgh coal dust

If the index of explosibility is 1.0, the material is equivalent to the Pittsburgh coal in term of explosion hazard. Above 1.0, the tested material is more hazardous below 0.1, the explosion hazard is negligible, the dust cloud can not be ignited by spark or flame but a very hot surface at the least. Powders are sorted into 4 groups via these indices (Table 3.18). Indices of explosibility for several plastics powders are collected in Table 3.19. 

Interferon induction by influenza virus in monkey kidney (LLC-MKj) cell monolayers pre-treated with coal dust was inhibited in relation to coal rank (Hahon 1983). Maximal inhibition of viral interferon induction was noted with high rank coal and the degression of this activity was related to coal s position in the carboniferous series anthracite, bituminous, subbituminous, lignite, and peat. Adsorption of poly(4-vinylpyridine-M-oxide) to bituminous coal dust from the Pittsburgh seam, Cambria County, Pa., not only occurred at a more rapid rate than to cell monolayers, but also less polymer was required to pretreat coal dust than cell mono-layers to achieve comparable amelioration of interferon production (Hahon 1976). 

Gardner, B.R., Winter, R.J., Moore, M.J., "Explosion Development and Deflagration to Detonation Transition in Coal Dust/Air Suspensions", 21st Symposium (International) on Combustion, The Combustion Institute, Pittsburgh,USA, 1987, pp. 335-343. 

Previous work has shown that the 3.3-5.5 /xm coal fraction has a particle size distribution similar to that of respirable mine dust collected on personal samplers during mining operations (13). This fraction was used for the spark-source analyses. The coals used in this investigation are identified in Table I. The respirable dusts were obtained from personal sampler filters submitted to the Dust Group, Pittsburgh Technical Support Center, Federal Bureau of Mines. The samples were collected during actual mining operations. 

EUem (Ref 4) points out that Th, when alloyed with Ag, Cu. or Au, becomes much more ignitable, bursting into flame on rubbing. Th—Ag alloys in approx 1 1 proportions are actually self-igniting (Ref 5). M. Jacobson et al (Ref 2) indexed the explosibility of both Th and Th hydride dusts based on ign temp, spark energy for ign, min expin concn, expln press and rate of press rise as compared with Pittsburgh seam coal, and report that both of these dusts have severe explosibility indices of >10... 

Determining the explosion characteristics that are listed below for the dust, considered relative to those for Pittsburgh seam coal ... 

Subscript 1 refers to the appropriate explosion characteristics for Pittsburgh seam coal (the standard dust used by the U.S. Bureau of Mines) and subscript 2 refers to the appropriate explosion characteristics for the specific dust present in the plant. 

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