Crushers and mills reduce solid products to a desired particle or aggregate size in dry or slurry forms. In addition, mills are used for mixing and dispersing solids within liquids. Selection criteria for crushers and mills should be based on feed size, material, and hardness. Processing equipment types include ball or media mills, cone and gyratory crushers, disk attrition mills, colloid and roll mills, screen mills and granulators, pin mills, impact mills and breakers, hammer and cage mills, jaw crushers, jet and fluid energy mills, roll crushers, disc mills, and vertical rollers and dry pans. 

Ball and media mills, cone and gyratory crushers, and disk attrition mills are three types of crushers and mills. Ball and media mills use a grinding media (balls, rods, etc.) to reduce materials into particles. Water, liquids, and other additives assist the grinding process by reducing friction, deflocculating, and cooling. Media mills are also used to distribute a powder into a liquid (e.g., a pigment in a paint base). Motion is transmitted by tumbling, rotating, stirring rods, or vibration. Cone and gyratory crushers consist of a cone-shape bowl with a gyrating head. Feed is crushed between the cone and the head. Disk attrition mills and double-disk mills are modern versions of the ancient buhrstone mill; however, the stones are replaced with opposing plates that may be grooved, serrated, or spiked.

Crushers and mills include colloid and roll mills, screen mills and cutters, and pin mills. Colloid and roll mills emulsify and disperse media with high-speed rollers. Often, these rotors have a serrated outer surface. Some dispersion mills also include fine beading within the liquid to increase dispersion. Roller mills or three-roll mills disperse and refine a powder or pigment into a liquid by passing the paste through a series of rolls which rotate at different speeds. Typically, three roll, colloid, and other dispersion mills are used with paints, resins, and adhesives. Screen mills and cutters are crushers and mills which generate a uniformly-sized product or granules. Some granulators use rotating knives, while others crush or shear action against a screen or grate to control granule size. Pin mills contain a rotor with rows of rods that impact and/or propel particles into anchored pins or surfaces. Pin mills are high-speed pulverizers and disintegrators. Their final product is finer than that of coarse crushers and impactors.

Impact mills and breakers, hammer and cage mills, and jet and fluid energy mills are additional types of crushers and mills. Impact mills and breakers thrust feed against a breaking surface. The feed is propelled by gravity or a rotating impeller or rotor that is either vertical or horizontal. Vertical impact mills, cage mills, Bradford breakers, hammer mills, and granulators are types of impact mills. Hammer and cage mills produce coarse crushing or fine milling with fixed or swinging steel hammers. Hammer crushers and cage mills come in vertical and horizontal rotor configurations with one or multiple rows of hammers. Jaw crushers and mills crush feed between fixed and alternating plates. These crushers and mills produce granules.

Crushers and mills included just and fluid energy mills, roll crushers, disc mills, and vertical roller and dry pan crushers. Jet and fluid energy mills produce fine grinding. This is done through the collision of a stream of feed particles against a wall, or into an opposing jet.

Roll crushers pulverize feed between two rolls, or a single roll and a fixed surface. Roll crushers are used for intermediate grinding and tend to produce weaker-shaped particles than impact mills. Disc mills shred tough, fibrous materials such as wood, cellulose, rubber, or polymer. Vertical roller and dry pan crushers and mills use a vertical crushing wheel / muller which revolves around a solid or perforated pan. Another option is having the pan, rollers, or grinding table rotate. These crushers and mills are used in foundries and mineral and ore processing facilities. They can reduce coarse feed into a powder in one step.