A mill for crushing a bed of materials by compression includes: a horizontal-axis cylinder the interior wall having a runway track for a crushing roller placed inside the cylinder, a unit rotating the cylinder at a speed that spins the material outward, the crushing roller, a unit for pressing the crushing roller against the runway track of the cylinder, an inlet for supplying material for crushing at one end of the cylinder and an outlet for crushed material at the other end, a unit for controlling the movement of the material so it travels over only a fraction of the length of the cylinder in each revolution and passes between the cylinder and the roller several times before reaching the outlet. The runway track is followed by a downstream lip opposing material flow, downstream of the crushing roller in the direction in which the material travels.