### Determining Energy Cost For Milling Solid Matter In A

2. the calculation of ball mill rational mode the main parameter that determines the mode of ball mill operation is drum rotation working velocity. the angular velocity of drum mill rotation ω is directly proportional to the grinding mode coefficient ψ: r g = % d j & % = % &.A ball mill grinds material by rotating a cylinder with steel grinding balls, causing the balls to fall back into the cylinder and onto the material to be ground. the rotation is usually between 4 to 20 revolutions per minute, depending upon the diameter of the mill. the larger the diameter, the slower the.