### Ball Mill Critical Speed

Jun 19, 2015 Jun 19, 2015 http://www.pauloabbe.com/size-reduction/resources/mill-speed-critical-speed. Charge movement at Various Mill Critical Speed. The Formula derivation ends up as follow: Critical Speed is: N c =76.6(D 0.5) where: N c is the critical speed,in revolutions per minute, D is the mill effective inside diameter, in feet.