grinding mill

A grinding mill is a unit operation designed to break a solid material into smaller pieces. There are many different types of grinding mills and many types of materials processed in them. Historically mills were powered by hand (mortar and pestle), working animal, wind (windmill) or water (watermill). Today they are also powered by electricity.

The grinding of solid matters occurs under exposure of mechanical forces that trench the structure by overcoming of the interior bonding forces. After the grinding the state of the solid is changed: the grain size, the grain size disposition and the grain shape.

Grinding may serve the following purposes in engineering:

• increase of the surface area of a solid


• manufacturing of a solid with a desired grain size


• pulping of resources


• Grinding mills utilize one or more methods to achieve particle size reduction/shape including compression, impact, abrasion and attrition. Choosing a grinder type is dependent on the material type and properties, amount of size reduction required, particle shape, particle distribution, throughput, maintenance, energy requirements and overall processing cost per ton. Grinders are often categorized as coarse, fine and ultra fine, with particle size getting progressively smaller. Common types of grinding mills include AG mills, SAG mills, rod mills, ball mills, pebble mills, vibratory mills, high pressure grinding rolls, and stirred media mills. Grinding mills come in all sizes, from laboratory use and small scale pilot plants to full production continuously run equipment.