EE PERFORMED GENERAL CLEAN UP DUTIES IN THE PULVERIZER UNTIL 1:00 PM. AT THIS TIME THE CHAIN ON THE DRIVE SPROCKET ON THE #3 CONVEYOR HEAD PULLEY JUMPED OUT OF THE SPROCKET TEETH, CAUSING THE CONVEYOR, & SUBSEQUENTLY THE ENTIRE SECONDARY PLANT, TO STOP OPERATING. TO REPAIR, IT WAS DECIDED TO REMOVE A CHAIN LINK WITH SLEDGEHAMMER. EE WAS WEARING GLOVES.THE CHAIN UNDER TENSION HIT EE