Advantages: 1, working surface of the lining can adsorb a layer of ferromagnetic material to form a protective layer, make the liner surface away from direct abrasion, to extend the life of the liner 5 to 8 times of the original; 2, reduce the replacement, repair liner time, improve equipment operation rate; 3, can be adsorbed on a magnetic cylinder itself, which no or little use bolts, easy installation and maintenance; 4, thinner than high manganese steel liner, can increase the volume of the cylinder, improve the processing capacity of the ball mill. 5, protective layer sound insulation , reduce noise; 6, Magnetic can remain for decades.