Description/ Specification of Ball Mill
Ball Mills are used for reduction of size for a wide variety of material. Depending on the construction and size the application will be different. The basic principle of size reduction is impact and attrition. It has a hollow cylindrical shell rotating on its longitudinal axis. It is partly filled with balls (30-50%) and partly with the material to be ground. The shell is rotated on its axis by means of electrically driven motors. With the rotation of the shell, balls rise along the wall inside and then fall form the upper portion of the shell. Grinding occurs due to impact of falling balls. It also occurs due to the attrition between balls which grinds the material trapped between them. Balls can be of materials like Chrome steel, NI-chrome, ceramic, rubber etc. The internal surface of the material is lined with liner plates made of abrasion resistant material like manganese steel. Particle size of the ground material depends on the size of balls, speed of rotation, and the amount of time the material stays in the grinding zone. The speed of the mill depends on the application. The larger the diameter of the shell, slower is the speed used. At a speed above critical sped the grinding action ceases and the mill acts like a centrifuge, so that the material instead of falling stays in the perimeter. There are continuous feed type ball mill and batch type ball mill. For continuous type mills the material is fed continuously through an inclined chute and output is also taken out continuously. Batch type ball mills find use where the particle size needs to uniform such as dyes, minerals. They can grind very hard material like quartz, ceramic, silica etc. The various types of ball mill designs cater to wide variety of industries like mining, power, coal, cement, paints, ceramics, pharmaceuticals just to name a few. There is also a special type of ball mill called Planetary ball mill which are of smaller size and used to grind samples in laboratory. These mills particles of extreme fineness and area of application includes ceramic, glass, chemicals alloys etc.
Ball Mill
Ball Mills are used for reduction of size for a wide variety of material. Depending on the construction and size the application will be different. The basic principle of size reduction is impact and attrition. It has a hollow cylindrical shell rotating on its longitudinal axis. It is partly filled with balls (30-50%) and partly with the material to be ground. The shell is rotated on its axis by means of electrically driven motors. With the rotation of the shell, balls rise along the wall inside and then fall form the upper portion of the shell. Grinding occurs due to impact of falling balls. It also occurs due to the attrition between balls which grinds the material trapped between them. Balls can be of materials like Chrome steel, NI-chrome, ceramic, rubber etc. The internal surface of the material is lined with liner plates made of abrasion resistant material like manganese steel. Particle size of the ground material depends on the size of balls, speed of rotation, and the amount of time the material stays in the grinding zone. The speed of the mill depends on the application. The larger the diameter of the shell, slower is the speed used. At a speed above critical sped the grinding action ceases and the mill acts like a centrifuge, so that the material instead of falling stays in the perimeter. There are continuous feed type ball mill and batch type ball mill. For continuous type mills the material is fed continuously through an inclined chute and output is also taken out continuously. Batch type ball mills find use where the particle size needs to uniform such as dyes, minerals. They can grind very hard material like quartz, ceramic, silica etc. The various types of ball mill designs cater to wide variety of industries like mining, power, coal, cement, paints, ceramics, pharmaceuticals just to name a few. There is also a special type of ball mill called Planetary ball mill which are of smaller size and used to grind samples in laboratory. These mills particles of extreme fineness and area of application includes ceramic, glass, chemicals alloys etc.
