AN UNPLANNED EXPLOSION OCCURRED AT 0835 IN THE COAL ELEVATOR. ABOUT 3 MIN. PRIOR TO THE EXPLOSION , THE DUST COLLECTOR WAS DUMPED (ROUTINE PROCEDURE) INTO THE ELEVATOR. IT IS BELIEVED THAT SMO LDERING SYNCOAL FINES CREATED ENOUGH HEAT THAT ALONG WITH OTHER CONDITIONS BEING JUST RIGHT AN IGNITION OF THE SYNCOAL DUST OCCURED IN THE ELEGVATOR SHAFT. THERE WAS STRUCTURAL DAMAGE, BUT NO