A ball mill is a type of grinding machine that uses steel or ceramic balls to grind materials into a fine powder. It works on the principle of impact and attrition.
Impact occurs when the balls are lifted by the rotating mill and then drop onto the material to be ground. The force of the impact breaks the material into smaller pieces. On the other hand, attrition occurs when the balls rub against each other and against the material to be ground. This friction helps to wear down the material into a powder.
The material to be ground is fed into the mill through the feed port. The grinding medium is then rotated inside the mill, which causes the balls to impact and grind the material. The ground material is then discharged from the mill through the discharge port.
The critical speed of a ball mill is the speed at which the grinding medium reaches the centrifugal force required to stick to the inner wall of the mill. At this speed, the grinding medium will rotate around the mill with the shell, and there will be no grinding action. To achieve effective grinding, the ball mill must operate above its critical speed. (Ball Mills Working Principle & Advantages, n.d.).
