EE WAS CLEANING UP A PILE OF DUST ALONG #3 CLINKER BELT IN THE AREA WHERE THE FLOOR BEGINS TO SLOPE TOWARD THE FEED END OF THE BELT. AS EE WAS LIFTING A LOADED SHOVEL, HIS RIGHT FOOT SLIPPED O N SOME LOOSE CLINKER IN THE PILE. WHEN EE SLIPPED, HE TWISTED HIS RIGHT FOOT AND KNEE.