Jet mill
![Illustration of a jet mill. Red arrow shows material entering the mill. Blue arrows show compressed air entering and circulating in the mill. Green arrow shows small particles leaving mill.](/Images/godic/202501/21/JetMillSketch5501.jpg")
![Flow past a solid particle reacting to centrifugal force: streamlines, drag force Fd and force by gravity or centrifugal force Fg. Fd points toward the center of the mill, and Fg points to the wall.](/Images/godic/202501/21/Stokes_sphere.svg5501.png")
A jet mill grinds materials by using a high speed jet of compressed air or inert gas to impact particles into each other. Jet mills can be designed to output particles below a certain size, while continue milling particles above that size, resulting in a narrow size distribution of the resulting product. Particles leaving the mill can be separated from the gas stream by cyclonic separation.