TWO WELDERS WERE ATTEMPTING TO DISLODGE A WEAR PLATE FROM THE BOTTOM OF A DRAGLINE BUCKET WHEN STRUCK WITH A SLEDGE HAMMER A PIECE OF METAL FROM THE WEAR PLATE CAME LOOSE AND STRUCK THE OTHER WELDER IN THE NOSE AND BECAME EMBEDDED IN THE CHEEK. BOTH INDIVIDUALS WERE DOING THEIR REGULARLY ASSIGNED JOBS AND WEARING ALL PROTECTIVE EQUIPMENT REQUIRED.