The Spiral Fluid Jet Mill is the most convenient technology available for grinding and classifying in a single process pass particle size from 250 nanometer to 50 micrometer.
It consists of a shallow circular grinding chamber in which the material to be pulverized is acted by a number of gaseous fluid jets. The rotating process gas must discharge at the center through a static classifier, carrying the fines with it, while the coarse particles are retained into the grinding area.