Basics of Size Reduction-Coarse to Medium Grinding


Size reduction has become an essential part of many different manufacturing processes. From pharmaceutical production to agricultural and even cosmetic applications, size reduction is an integral part of the production of almost every product out there.

What is Size Reduction?

Size reduction is, essentially, the breaking down of materials from a few large particles, usually to a fine powder. There are three different kinds of powders that result from a size reduction process. These kinds relate to the particle sizes within each powder. They are: coarse, medium, and fine. This webinar will discuss the size reduction of material to create coarse and medium powders. Click here to view a webinar on fine grinding.

There are four different mechanisms that can be used to create a coarse or medium powder. These are:


Shearing is the act of cutting a particle into different pieces so that it is smaller, and thus its size is reduced. The machines that are usually used in shearing are granulators and rotary knife cutters.


Attrition is the act of grinding down material by having them rub tightly against one another. This is commonly referred to as autogenous grinding. The type of machine that is used in attrition grinding is generally the attrition mill.


Crushing is the act of pressing tightly on the top and bottom, or both sides, of a material so that its size is reduced. The most commonly used crushers for size reduction are jaw crushers, cone mills, and flake mills. Crushers generally create a very coarse material.


Impact size reduction is the act of dealing a forceful blow to the particle so that it breaks apart into smaller pieces, thus reducing its size. The machines that are most commonly used for impact size reduction are hammer mills and pin mills.

If you want to learn more about coarse and medium size reduction, be sure to watch the entire webinar.