The initial event in a coal dust explosion is the creation of a localized air blast, which is generally caused by a methane explosion.
Reference:
Meyering, M., Fourie, P. & Sevenster, P. 1969. Notes on dispersibility of coal dusts. http://hdl.handle.net/10204/12887 .
Meyering, M., Fourie, P., & Sevenster, P. (1969). Notes on dispersibility of coal dusts Retrieved from http://hdl.handle.net/10204/12887
Meyering, MC, PJ Fourie, and PG Sevenster Notes on dispersibility of coal dusts. 1969. http://hdl.handle.net/10204/12887
Meyering M, Fourie P, Sevenster P. Notes on dispersibility of coal dusts. 1969 [cited yyyy month dd]. Available from: http://hdl.handle.net/10204/12887