Abstract: A method, a device and a plant for cleaning irregular pieces consisting of different materials, for example cast iron pieces with parts of compressed coal dust sticking thereon and coal pieces made of compressed coal dust with parts of a contaminating film adhering thereon, wherein the cleaning of both materials is carried out in only one cleaning device comprising a cleaning jacket which has a substantially horizontal longitudinal axis, is rotatable in both directions of rotation, is pivoted in order to swing in the vertical longitudinal plane, and is provided with cleaning tools which are fastened to the cleaning jacket along jacket generating lines or helicoidal lines. The cleaning tools have two geometrical different operative sides in order to form an active side for each of both materials to be cleaned when rotating in an associated direction of rotation.

Abstract: A method and a mill (1) or crushing station (A) for crushing rubble, wherein the crushed material fills the mill discharging hopper (9) for a height (H1) which is higher than the height (H) of a hopper discharging opening (11) so that a continuous material plug (6) is formed which closes said discharging opening (11). The discharging means (2; 17) can be either integrated into the mill discharging hopper (9) or form a separated discharging device (2) which is associated to the mill (1). In operation the plug (6) is continuously removed from the plug bottom and fed to the plug top so that said continuous plug prevents the formation and exhausting of dust. The known dust separation chambers are thus superfluous.

Abstract: Screen for the sifting of materials of differing weight, in which at least part of the screening orifices is covered by elastic diaphragms formed by lamellae.