A ball mill is a very efficient type of grinder which is used for crushing and turning materials into fine powder. The ball mill is an essential piece of grinding equipment that is used for producing powders such as silicates, cement, fertilizer, pyrotechnics, glass ceramics, selective laser sintering and other similar compounds. Either wet or dry, the grinding process with a ball mill needs to be carried out at low speed, in order a fine powder to be created. Its working principle is straightforward: the impact of the balls inside the ball mill causes size reduction until it transforms the material into powder.
The construction of the ball mills is very simple. It is composed of an empty cylindrical shell, which rotates around its own axis. The shell contains balls, which are known as media. These balls are made from stainless steel, chrome steel or rubber (less frequently). The inner surface of the cylindrical shell is made from abrasion-resistant material, because it needs to withstand many hits by small, but rigid balls. The high-quality ball mill is usually very expensive and not affordable for many companies. So, many people decide to make their own inexpensive ball mill models.
The most important aspect of the grinding process with a ball mill is to maintain the low operating speed, also known as critical speed. The critical speed is the speed by which the balls inside the ball mill rotate along the direction of the cylindrical device. The ball mills are widely used in the mechanical alloying process where the ball mill is not used for grinding, but for cold welding. There are two ball mill types: overfall and grate type. The essential properties of the grinding media are: hardness, composition, size and density.
The ball mill is popular in many industries, not only in the construction industry. The most common materials that can be crushed with a ball mill are: cement, fire-proof materials, developing materials, silicate items, chemical substance manure, glass and ceramic. The ball mill operates smoothly, easily and gradually.
