The ball mill is a type of grinding mill, purposed similarly to the sag mill or other mining crushers. These machines are used to grind or mix metals or raw materials for further processing. Various materials are placed into the mill drum and rotated with the mined materials that are to be crushed. The ball mill contains materials meant for crushing and grinding, such as balls of ceramic, small rocks, or balls made from stainless steel. The internal device of the ball mill grinds material into powder-like substances, and can rotate continuously for optimal grinding and refinery production.
A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints. Ball mill 's rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles and stainless steel balls. An internal cascading effect reduces the material to a fine powder. Industrial ball mill 's can operate continuously, fed at one end and discharged at the other end. Large to medium-sized ball mill 's are mechanically rotated on their axis, but small ones normally consist of a cylindrical capped container that sits on two drive shafts (pulleys and belts are used to transmit rotary motion). Ball mill 's are also used in pyrotechnics and the manufacture of black powder, but cannot be used in the preparation of some pyrotechnic mixtures such as flash powder because of their sensitivity to impact.
Ball milling boasts several advantages over other systems: the cost of installation, power and grinding medium is low; it is suitable for both batch and continuous operation, similarly it is suitable for open as well as closed circuit grinding and is applicable for materials of all degrees of hardness.
Ball mill are specially developed for a vast range of applications:
1. Size reduction of various materials like mineral ores,cement, silicate,building material, refractory material, fertilizer, ferrous metal, nonferrous metal and glass ceramics and etc.
2. Feed sizes of 25mm to product sizes of 0-400mesh
3. Wet or dry grinding
4. Continuous grinding process
5. Mineral processing
Horizontal Ball Mills
Horizontal ball mills are the most common type. The basic design is the same but the details can vary slightly. A drum, which is usually detachable, has a door that can be used to load in the material to be processed. Sometimes like for paint mixers there will be a screen that keeps the metal balls in place. When the substance to be processed (and the balls) are in the drum, the door is closed and the drum is reinstalled horizontally on the mill where it is rotated until the job is done. Some ball mills have a timer and some have a window where the processed material can be viewed.
Vertical Ball Mills
Small vertical ball mills are about the size of a blender and are intended for laboratory or shop use. They are small enough to fit on a lab table or workbench and only big enough to process the small quantities need for desktop applications -- they are not intended for commercial or industrial use. These ball mills are often called planetary ball mills. The rotating drums are not usually detachable -- the material is poured into the top and the cap is replaced, like a kitchen blender. Like all ball mills, the speed and ball size have an effect on how the vertical ball mill works. Vertical ball mills often come with a variety of ball sizes (and have variable speed settings) for more efficient processing.
Industrial Ball Mills
Industrial ball mills are much larger than the other types of ball mills. They vary in size from approximately the size of a refrigerator to approximately the size of a bus. They are always horizontal. What distinguishes the industrial ball mill (besides its large size) is that they have multiple chambers and have a forced-air system constantly moving material through the rotating drum. The different chambers are separated by screens of progressively smaller mesh. The chambers contain balls of progressively smaller size. The size of the balls and the screen mesh keeps the balls in their own chamber. Material is forced from one chamber to the next as it is ground small enough to fit through the mesh screens.
