rotational speed for ball milling

ATTRITORS AND BALL MILLS HOW THEY WORK Robert E the mill The common range of mill speeds is 65 to 80 of critical depending on mill type size and the application The critical speed of a ball mill is calculated as 5419 divided by the square root of the radius in feet The rotational speed is defined as a percentage of the critical speed Smaller diameter millsCRITICAL SPEED OF THE BALL MILL Let a grinding ball of mass m is in motion in a mill of diameter D meters It is at a position making an angle a at the center called the angle of repose The force acting on the ball are described in the figure The centripetal force acting