A ball mill works on the principle of impact and attrition.Size reduction is done by impack as the ball from near the top of the shell
the material continuously passes through the cylinder thereby being continuously impacted and ground by the grinding medium,Finally it becomes standard finished product
- Ball mill consist of a hollow cylindrical shell rotating about its axis.
- Axis of the shell horizontal or at small angle to the horizontal
- It is partially filled with balls made up of Steel,Stainless steel or rubber
- Inner surface of the shell is lined with abrasion resistant materials such as Manganese,Steel or rubber
- Length of the mill is approximately equal to its diameter
- Balls occupy about 30-50% of the volume.dia of the ball 12 mm-125 mm
- Shell is rotated through a drive gear (60-100 rpm) and large mills, shell might be in 3m in dia and 4.25 m in length.
- Operation may be batch or continuous,wet or dry…in a continuosly operated ball mill outlet is normally covered with coarse screen to prevent the escape of the balls..