The core machine in the powder grinding line is a powder grinding machine, which will influence the performance of the whole grinding line. There are two things that can be considered to choose a suitable powder grinding mill. The powder mill can be chosen according to the requirement of discharging size. In general, powder mill can be divided into four types, and different types of the grinding mill have different discharging size. The discharging fineness of the ball mill is usually 150 to 250 meshes, the Raymond mill is 80 to 325 meshes, HGM is 80 to 800 meshes, and three-ring and medium speed micro powder mill can reach 2000 meshes. The powder grinding mill can also be selected according to the nature of materials. If the material has high hardness, it's better to use the ball mill, and that with medium hardness can adopt Raymond mill and HGM German high-efficiency powder grinding mill.