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.

Prefer Planetary Ball Mills for Greater Fineness

Planetary Ball Mills

Torrey Hills Technologies, LLC is the leading supplier of Planetary Ball Mills to the major process industries. In the ball mills many products including pharmaceuticals, adhesives, chemicals, foods, electronics, pigments, battery compounds and plastics are manufactured. In small batch high efficiency mixing the Planetary Ball Mills are widely used. For mixing, homogenization and dispersion up to 0.1µm they are used in research institutions, universities and even industrial production. In the mining, metallurgy, electronics, agriculture, electrical, chemical, materials, nuclear industries, cosmetics and pharmaceutical its users are present.

By continually revolving the large plate and rotating the containers concurrently with the planetary ball mill accessories the planetary ball mill performs mixing. The independently adjustable factors are both the plate revolution (centrifugal) speed and container rotation speed. Designing precise solutions for mixing various systems is allowed by this unique mixing capability allows the operator. Grinding media can be added into the containers to further improve the mixing efficiency. The strict weight balancing is not required as the machines are built in such way. Very quietly with noise = 70 (dB)these machines run. Balls and Ball Mill Jars are sold separately.

Advantages        

•             Efficient grinding for superior results up to 0.1µm

•             Grinding jar volumes from 50ml to 5L in 8 different materials

•             Adjustable speed ratios

•             No strict weight balancing required

•             Reliable for continuous use

Planetary Ball Mill PM 400

Wherever the highest degree of fineness is required planetary ball mills or laboratory ball mill with its laboratory ball mill accessories are used. The mills apart from the size reduction processes and classical mixing also have the energy input necessary for mechanical alloying processes and meet all the technical requirements for colloidal grinding. Very high pulverization energy is the result of the extremely high centrifugal forces of planetary ball mills and therefore it has short grinding times. With 4 grinding stations the PM 400 is a robust floor model.

An entirely new type of mill for high energy input you may also be interested in the High Energy Ball Mill. Extremely fine particles within the shortest amount of time are the result of the unique combination of high friction and impact results in.

Know More about the Planetary Ball Mills in Depth

Working

In case of continuously operated ball mill, the material to be ground is fed from the left through a 60° cone and the product is discharged through a 30° cone to the right. As the shell rotates, the balls are lifted up on the rising side of the shell and then they cascade down from near the top of the shell. In doing so, the solid particles in between the balls and ground are reduced in size by impact.

Applications

For grinding materials such as feldspar, coal, pottery and pigments the retsch planetary ball mill is used. Although, the wet option is performed at low speed, grinding can be carried out either wet or dry. An example of an application for rubber balls is blending of explosives. In increasing solid-state chemical reactivity ball milling for systems with multiple components, has been shown to be effective. Additionally, for production of amorphous materials ball milling has been shown effective.

Advantages of the ball mill

Over other systems ball milling boasts several advantages: for both batch and continuous operation it is suitable; the cost of installation and grinding medium is low; for open as well as closed circuit grinding it is suitable as well; for materials of all degrees of hardness it is applicable.

Wherever the highest degree of fineness is required planetary ball mills are used. These mills also meet all technical requirements for colloidal grinding in addition to well-proven mixing and size reduction processes. Necessary for mechanical alloying they also provide the energy input. Very high pulverization energy and therefore short grinding times is the result of the extremely high centrifugal forces of a Fritsch planetary ball mill.

The PM 100 is a convenient benchtop model with 1 grinding station

An entirely new type of mill for high energy input, you may also be interested in the High Energy Ball Mill Emax. Extremely fine particles within the shortest amount of time are the result of the unique combination of high friction and impact.

Application Examples

Alloys, bentonite, bones, carbon fibres, catalysts, cellulose, cement clinker, ceramics, charcoal, chemical products, clay minerals, coal, coke, compost, concrete, electronic scrap, fibres, glass, gypsum, hair, hydroxyapatite, iron ore, kaolin, limestone, etc.