An Elaborative Description about the Ball Mills

Used in grinding (or mixing) materials like chemicals, ores, paints and ceramic raw materials a ball mill, a type of grinder, is a cylindrical device. Partially filled with the material to be ground plus the grinding medium ball mills rotate around a horizontal axis. Including flint pebbles, stainless steel balls and ceramic balls, different materials are used as media. The material is reduced to a fine powder by an internal cascading effect.

On the principle of critical speed the grinding works. As along the direction of the cylindrical device that speed after which the steel balls (which are responsible for the grinding of particles) start rotating, critical speed can be understood. This causes no further grinding.

For grinding crushed materials the ball mill with ball mill jars is a key piece of equipment. For powders such as silicates, refractory material, cement, glass ceramics, fertilizer, etc it is widely used in production lines. It is used for ore dressing of both non-ferrous and ferrous metals as well. Either wet or dry the ball mill can grind various ores and other materials. Due to different ways of discharging material there are two kinds of ball mill, grate type and overfall type. Key properties of grinding media are density, size, composition, and hardness.

Size

The smaller is the particle size of the final product the smaller the media particles. At the same time, as compared to the largest pieces of material to be ground, the grinding media particles should be substantially larger.

Density

As compared to the material being ground the media should be denser. If the grinding media floats on top of the material to be ground it becomes a problem.

Hardness

To grind the material the ball mill media needs to be durable enough. At the same time it should not be so tough that it also wears down the tumbler at a fast pace where possible.

Composition

There are special requirements various grinding applications. On the fact that some of the grinding media will be in the finished product some of these requirements are based. On how the media will react with the material being ground others are based.