PDF Back to Basics Hammer Milling and Jet Milling Fundamentals AIChE
ness ranging from 1 to 5, while a jet mill can grind materials with Mohs hardness as high as 10. High hardness materials become very abrasive; therefore, they are not suitable for highspeed hammer mills. In a typical jet mill, grinding action is caused mainly by particleparticle collisions, so wear to the mill's internals is less of an issue.