Mine Safety and Health Administration Ball Mill Safety DVD573 - 1998 Developed cooperatively by MSHA and Lehigh Portland Cement Company. Outlines the various steps -- precautions and procedures -- that must be taken to safely and efficiently shut down a ball mill, enter, inspect, service (repair or perform routine maintenance), and restart the operation. Procedures discussed/ demonstrated include: planning, crew selection and briefing, safe work permits, electrical lockout, isolating maintenance area, hatch/door removal, safe access, ventilation and respiratory protection, welding/ cutting, hatch/door installation, and cleanup.