Dec 26, 2019 1. Short-cylinder ball mill: The length (L) of the cylinder is less than twice the diameter (D) of the cylinder, that is, the ball mill with L ≤ 2D is a short-cylinder ball mill. Single-bin structure ball mill, which is mainly used for coarse grinding or primary grinding, has high efficiency. 2. Medium-long cylinder ball mill, that is L = 3D. 3