The explosibility of three canadian coal dusts

Explosibility measurements on coal dusts from the Cape Breton Development Corporation's Lingan Mine, TransAlta's Highvale Mine and the Quintette Mine in B.C. have been carried out along with some tests on Pittsburgh Standard coal dust. The Quintette coal dust would not explode in the classical Hartmann apparatus, but did explode in the new 20-L vessel using a more powerful ignition source. The minimum explosible concentrations of the Lingan, Highvale and Pittsburgh coal dusts were all about the same (40 - 45 mg/L), that of the Quintette was higher (140 mg/L). The difference may be attributed to the much greater mean particle size of the Quintette dust. The explosion pressures (in kPa) were: Highvale, 600, Pittsburgh, 520, Lingan, 510, and Quintette, 440. The minimum oxygen concentrations required for explosions were (in % oxygen): Highvale 10.4, Lingan 10.5, and Quintette 14. The minimum ignition temperatures of dust clouds were (in °C): Highvale 510, Lingan 600, Quintette 620 and Pittsburgh 620. Further work is required to reconcile limit values.