Rensselaer Republican, Volume 18, Number 5, Rensselaer, Jasper County, 8 October 1885 — Flour Dust and Coal Dust. [ARTICLE]

Flour Dust and Coal Dust.

Explosions in flour-mills have had in numerous instances a well-ascertained cause in the presence of an impalpable dust floating in the interior of the mill. This dust, mixed with heated air in confined and unventilated spaces, has taken fire, whether from a match carelessly struck, from a lamp, pr from sparks emitted by the machinery, and when thus ignited has proved as destructive as gunpowder. But the theory that a similar cause may exist for explosions in collieries is a comparatively new one, and owes its rise to the marked resemblance between flourmill explosions—notably those which occurred at Minneapolis some time ago —and the disasters of like character which so often take place in coal mines, and are attended with such peculiar and distressing fatality. The suggestion of an identity of cause in these two classes of casualties has led to numerous experiments in England and on the continent of Europe; and the results have been such as to lead to a well-defined belief that coal dust, instead of the carbureted hydrogen gas commonly known as fire-damp, is the principal source of colliery explosions. It was found that the dust of certain kinds of coal was highly explosive, while that of other varieties showed less liability, and some none at all, but that even where fire-damp was the chief source of the disaster it was greatly aggravated by the presence of coal dust. The experiments were made by English, French, and Prussian scientists, and the English and Prussian reports agree substantially in the conclusion that coal dust is the principal agency in colliery explosions. So generally is this view adopted in England that a Coroner’s jury, in their verdict upon the Usworth mine explos'.on, by which some forty lives were lost, declared it as their opinion that “the explosion was caused by a shot, the fire of which acted upon the coal dust and a small percentage of gas.” The French observers are inclined to doubt whether coal dust alone is liable to explode, however fine or highly heated; but they admit that it increases the destructive effects of a fire-damp explosion.