Critical rotating speed of a mill TECHNICAL NOTES 8 GRINDING R P King Mineral Critical rotating speed of a mill 8 4 0J HQWHU RI JUDYLW RI WKH FKDUJH G UDFWLRQ F F Figure 83 Simplified calculation of the torque required to turn a mill RI FULWLFDO VSHHG 3RZHU Figure 84 The effect of mill speed on the power drawn by a CRITICAL SPEED OF