A classifier mill having first and second series of beaters (1, 2) on respective sides (3, 4) of the periphery (5) of a rotary pulverizer disc (6) within a chamber (7), an independently rotary classifier (8) coaxial therewith and radially inwards of the second series of beaters (2), an entry (9) for material into the chamber (7) at a position intermediate the pulverizer axis and the first series of beaters (1), and an exit (10) for fines coaxial with the classifier (8) and remote from the pulverizer (6), is further provided within the chamber (7) with an annular wall (18) extending radially outwards from clear of the periphery (19) of the classifier (8) to beyond the periphery (5) of the second series of beaters (2), and with a cylindrical wall (20) extending from the annular wall (18) past the peripheries of both series of beaters (1, 2), the cylindrical wall (20) being provided with a series of circumferentially spaced openings (21) disposed radially outwards with respect to only the first series of beaters (1), which openings (21) may be provided with screens (22).