A multistage hammer mill (10) has a plurality of milling stages arranged concentrically about each other. The plurality of milling stages arranged so that substantially all material in a first inner most of the milling stages passes through all subsequent adjacent milling stages. The milling stages include a first milling stage and a second milling stage. A central feed opening (12) enables material flow into a primary impact zone (14) of the first milling stage. The first milling stage has an impact mechanism (16) and a first screen arrangement (20a). The impact mechanism (16) rotates about a rotation axis (18). The first screen arrangement (20a) is disposed circumferentially about and radially spaced from the impact mechanism (16) and is provided with a plurality of apertures (22) through which impacted material of a first size range can pass. The second milling stage has a second arrangement (20b) disposed circumferentially about and radially spaced from the first screen arrangement (20a) and a circular array of impact elements (50a) disposed between the first screen arrangement (20a) and the second screen arrangement (20b).
