Abstract: A jet-type grinding system for grinding relatively large particles, such as coal and the like, wherein the particles to be ground are entrained in a circulating gaseous vortex in which the particles are caused to pulverize each other, the system including a mill having a grinding chamber succeeded by a classifier section in which smaller ground particles are initially separated from larger ground particles, this classifier section constituting a primary separator, the primary separator being in operative connection with a secondary separator into which ground particles pass from the first separator for additional classification and separation into smaller and larger particles, and a tertiary separator inoperative connection wtih the secondary separator to provide passage from the secondary to the tertiary separator of ground particles for additional classification and separation of smaller from larger particles, the passage of all of the particles from one separator to the other being by centrifugal force, an

Abstract: A jet-type grinding mill wherein particles are entrained in a circulating gaseous vortex and caused to pulverize each other during their passage through the mill, the mill having a classifier or separator section wherein there are a pair of coaxial tubular nozzles, one within and radially spaced from the other, the two nozzles forming an auxiliary cyclone-type separator means whereby the lightest of the ground particles pass through the inner nozzle as final product while the heavier ground particles are recycled back for further processing.