CONVEYOR BELT FIRE (25' BELT) AT THE FEED END OF THE RAW MATERIAL DRYER WHEN THE PLANT EXPERIENCED A POWER FAILURE DUE TO AN ELECTRICAL FEEDER UNDERGROUND SHORTING OUT, TAKING DOWN ALL POWER I N THE PLANT. LOCAL FIRE DEPT EXTINGUISHED WITHIN 45 MINS. NO ONE WAS IN AREA WHEN FIRE STARTED. MSHA WAS CALLED. LOOKING AT INSTALLING SLAM GATE AT FEED END.