MINER WAS USING A CROWBAR TO PULL NAILS IN DESANDING PLANT. CROWBAR SLIPPED AND RIGHT ELBOW JAMMED INTO NAIL BEHIND HIM. MINER COMPLETED SHIFT & NOTIFIED SUPERVISOR. HE WAS TAKEN TO CLINIC THE NEXT DAY & RELEASED TO REGULAR DUTY. ON TWO SEPARATE OCCASIONS HE RETURNED TO CLINIC FOR FLUID BUILD-UP AT INJURED AREA. THE SECOND TIME HE WAS REFERRED TO A SPECIALIST & ARM WAS PUT IN CAST.