critical speed of ball mill calculation
WEBBall Mill Operating Speed Mechanical Operations Solved ... Calculations: The critical speed of ball mill is given by, where R = radius of ball mill; r = radius of ball. For R = 1000 mm and r = 50 mm, nc = rpm. But the mill is operated at a speed of 15 rpm. Therefore, the mill is operated at 100 x 15/ = % of critical speed.