Electrostatic separation of metals and plastics from granular industrial wastes

The paper presents the main conclusions of authors' 15-year involvement in theoretical study, laboratory experimentation, equipment development and industry application of electrostatic separation technologies. The roll-type separator with combined corona-electrostatic field is the most advantageous technical solution when the purpose is to isolate conductive particles from nonconductive ones. The theoretical analysis and the laboratory tests of electrostatic separation point out the multitude of factors which influence the efficiency of this equipment: the configuration of the electric field, the size and the shape of the processed particles, the speed and the radius of the rotating roll electrode and the environmental conditions. The optimum electrode arrangement and operating parameters (high-voltage level, roll speed, feed rate) differ from one application to another. In-plant tests are recommended for the fine tuning of the electrostatic separation technology.