Nov 29, 2018 The cylinder length-diameter ratio of rod mill is generally 1.5-2.0, while the cylinder length-diameter ratio of ball mill is smaller, only slightly greater than 1. In addition, the cylinder speed of the rod mill is lower than that of the ball mill, so the grinding medium works in the cascading state. 2. Discharging way of ball mill and rod millThe size of a mill is usually characterized by the ratio length to diameter and this ratio most frequently varies from 0.5 to 3.5. The. Chat Online Ball MillsaVRee. A typical ball mill will have a drum length that is 1 or 1.5 times the drum diameter. Ball mills with a drum length to diameter ratio greater than 1.5 are referred to as tube mills.Ball Mill Length Diameter Ra12for example the length ratio of the rod mill to the diameter is generally 12 and the inside lining plate on the end cap is the vertical planehe length ratio of the barrel to the diameter of the ball mill is small and in most cases the ratio is only slightly greater than 1.