A colloid mill is a machine that is used to reduce the particle size of a solid in suspension in a liquid, or to reduce the droplet size of a liquid suspended in another liquid. This is done by applying high levels of hydraulic shear to the process liquid. It is frequently used to increase the stability of suspensions and emulsions. The colloid mill is used for various applications such as Superfine grinding, homogenizing, emulsifying, dispersing, mixing and extracting of liquids, ointments and highly viscous products in pharmaceutical, cosmetics, suspensions & emulsion industry.

The product is fed to the hopper which leads the product into the gap between taper rotor and stator. The product is subjected to a high degree of shearing, cutting and rubbing between two metal toothed surfaces of rotor and stator and towards the discharge section. The processed product continuously leaves the mill through drain pipe if required, it can be re-circulated by three way cock and re-circulating pipe assembly.