MAG PLANT OPERATOR WAS WORKING WITH CO-WORKERS, ATTEMPTING TO REMOVE A BROKEN SECTION OF THE AUXBURNER PIPE SUPPORT SADDLE. THE 85# SUPPORT SECTION WAS BEING REMOVED THRU THE DISCHARGE HOPPER INSPECTION DOOR WHEN IT FLIPPED OVER STRIKING EMPLOYEE'S RIGHT HAND ON THE 4TH FINGER AGAINST THE CALCINER SHELL. MEDICAL TREATMENT REVEALED A FX TIP OF THE FINGER RESULTING IN RESTICTED DUTY.