The working principle and characteristics: Conventional magnetic liner mainly affected by the impact, grinding force and electrochemical corrosion and wear, magnetic materials and magnetic lining N, S poles are alternately arranged to form a curved open magnetic system, with the strong magnetic adsorption broken ball, 20-30mm magnetic minerals forming the protective layer, greatly reducing the wear of the magnetic liner directly improve the liner life. Although magnetic liner one-time investment is large, but far below the average annual consumption of manganese steel liner, liner costs 7-9 million annual savings, long life, low cost, light weight, easy disassembly and save 6% -7% of electricity, saving the ball 1% -2%, increasing the volume and increase the amount of ore to further improve grinding efficiency, improved mill operating rate of 1% to 5%. Through ten years of industry operating statistics show that the magnetic liner is manganese steel liner replacements.