Rotational speeds of veitical mills vary when they are processing different materials. Vertical mill operators should be well mastered of the rotational speed and fineness to an exact material. They should adjust the rotational speed according to different needs. Medium speed vertical mill have the common speed of 120-300 revolutions per minute.
Speed influence on efficiency: In the same milling conditions, different grinding effects are generated by mill speed. Generally speaking, low milling speed mainly has the effect of grinding, because the impact on materials is relatively small.  When materials drop down to grinding roller, they will be milled into micro powder.
When the speed is high, the impact of the mill is big. The material cannot naturally fall to the roller. In this occasion, it mainly depends on the impact of mill machine to crush materials. Thus it is suitable for coarse powder processing. Equipments including Raymond mill and high pressure grinding mill often use this processing method.
Thus, we can see, different mill speed can generate grinding different effects. Specific questions please contact Shanghai Clirik Machinery Co.,LTD. Please call 0086-21-20236178, 86-13917147829.