Question

Calculate the operating speed of ball mill if Operating speed is
55% of critical speed and Critical speed is 40% more than
operating speed Data: Diameter of ball mill = 8 mm and Dia. of
ball is 60mm.

Answer 1

The critical speed of ball mill is given by, where R = radius of ball mill; r = radius of ball. But the mill is operated at a speed of 15 rpm. Therefore, the mill is operated at 100 x 15/30.7 = 48.86 % of critical speed.