Electrostatic Separator
Principle: ”If one or more of the materials of a granular mixture can acquire a surface charge on or just before entering an electrostatic field, the particles of that material will be attracted towards the active electrode or repelled from it depending on the charge on the particles.” It is the method of separation of solid particles based on differential attraction or repulsion of charged particles under the influence of an electric field. The difference in electrical properties of different materials is responsible for such a separation.
Diagram:
Construction: It consists of rotating drum, a hopper for feed, an active electrode & collecting bin
Working: The charged particles fed on drum from hopper. Conductive particles assume potential of drum, opposite to that of active electrode, hence attracted towards active electrode. Non-conductive particles get repelled by electrode ,attracted by drum, falls straight in collecting bin due to gravity.