"Coal dust" refers to the fine particles of coal that are produced when coal is broken down or pulverized. It is a form of dust made up of tiny particles of coal, much like the dust you may encounter in your house, but with coal instead.
Sentences with «coal dust»
He remembers seeing the snow often turn black from coal dust and pollution within a day or two after falling on the ground. (goldmanprize.org)
Coal dust settles onto houses, farmland, and water sources. (goldmanprize.org)