What is the effect of the rotational speed of a ball mill?

The rotational speed of a ball mill directly determines the motion of the steel balls inside the mill and the grinding efficiency.

When the rotational speed is low, the balls are lifted relatively low and roll down from the top of the ball load under their own weight, resulting in a cascading motion. At this speed, the impact force of the balls is small, but the grinding effect is strong. The ore is mainly crushed by grinding, but the grinding efficiency is low.

When the rotational speed is high, the balls are lifted higher. After rising to a certain height, the balls detach from the mill and fall along a parabolic trajectory, entering a cascading motion. At the point of impact, there is a significant impact force, and the ore is mainly broken by impact, resulting in the highest grinding efficiency.

When the rotational speed of the ball mill exceeds a certain limit (very high speed), the balls rotate with the mill and do not fall, entering a centrifugal motion state. At this time, the balls have neither impact force nor grinding effect, causing the grinding process to stop.