In most industries size reduction falls in two general categories: crushing and milling.
Crushing typically means reducing large chanks to sizes about 0,5 to 0,75 or smaller. Milling usually means reducing mmaterial to sizes in the low-micron or even nano-size range.
Milling may be done wet or dry. Attrition milling technologies relate to chemical processing applications. Media milling is one common way to achive desired results.
Attrition mills are more appropriate for mid-range size particles. Such millsutilize 3-10mm media to produce material ranging in size from approximately 1 to 10 microns.
Attrition milling is simple and effective. Feed material is placed in a stationary tank with the grinding media. A rotating shaft with arms or discs then agitates the material and media. Both impact and shearing action result in size reduction as well as homogenous particle dispersion with very little wear on the tank walls. These efficient forces must be present for the most effective grinding action.
Attrition mill designed and produced by Materials Research Centre