### critical velocity of ball mill

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, N C = 30.7 Rpm. 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. Ball Mill Grinding Theory - Crushing Motion/Action Inside