The magnetic liner is composed of ferrite and modified nonmagnetic steel and is arranged in an alternative order of N and S poles of the magnetic system on the curved surface. When the ball mill operates, the magnetic liners attract the broken balls and magnetic mineral onto the surface to form a certain thickness of protection layer to prevent the tumbling media and fine ore from directly contacting the liners, which lengthening the service life of the liners. When installed, the magnetic liners are directly attached onto the inner wall of the cylinder with no bolts.

It is widely used for all kinds of minerals with strong, medium and weak magnetism. If it is used for non-magnetic materials, certain quantity of ferromagnetic substances such as broken steel balls and iron scrap must be added regularly so as to form a protective layer.