Electric spearation  fulfills a crucial role in the separation of waste with metal content, between conductors and non-conductors. Separating particles of both type are crown-electrode drum-separators, which work based on the different charges (electrons attached to the surface of particles in an enviroment ionized by the elecrtodes) and differing charge-losses (transfusion), by which the electrostatic forces conductor particles in contact with the grounded rotor drum take on its charge and so are repulsed from it. Insulating particles, retaining their charges, attach to it which carries them on with itself.