critical speed equation of a ball mill Grinding Mill ChinaON THE CRITICAL SPEEDS OF THE TUMBLING A new theory of grinding in tumbling mills is suggested According to this theory the critical speed of ball mill is **-ball mill critical speed equation-**,Ball Mill Operating Speed Mechanical Operations 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 …… Get more