The separator of this invention comprises an inlet mouth for material (1). This inlet mouth (1) communicates with a cylindrical element (3), which has a slot on the other side of the inlet mouth (1). The cylindrical element is perforated on the lateral surface. The inlet mouth (1) is equipped with a device (2) consisting of a series of fins arranged on the central axis of said inlet mouth (1) and cylindrical element (3). Inside the cylindrical element (3) are arranged brushes (4) mounted on the central shaft that are put in rotation and force, by effect of centrifugal force, the material onto the lateral surface of cylindrical element (3). The material composed by pulp or particles with dimensions smaller than the size of the cylindrical elements holes (3), for the effect of centrifugal force, passes through the holes in the perforated metal cylindrical element.On the outer face of the cylinder (3) are disposed outside elements (5) that glide, possibly rotating, on cylindrical element (3). The external elements (5) take away the material composed of pulp or particles smaller than the size of the holes of cylindrical element (3) passing through said cylindrical element holes (3). Preferably, the external elements (5) scrape the outer face of the cylinder (3) over the entire length of the cylinder (3).The material in the pulp is carried out by a first screw conveyor (7). The stones fall through a slit in a second screw conveyor (6).
