The ball mill is horizontal cylindrical rotation device, driven by brim gearwheel. There are two chambers and grid. Material goes into the first chamber through the feeding inlet. Inside the first chamber, there are stage liners and ripple liners as well as steel balls. The shell rotates so as to generate electricity, and this force brings ball to a certain height and then balls drop down by gravity, the impact is the grinding force to the material. After the primary grinding, materials go into the second chamber through segregate screen. In the second chamber, there are flat liners and steel ball, after the secondary grinding, material is discharged from the discharging. Then the whole grinding process is finished.