Recent Researches in Electrostatic Separation Technologies for the Recycling of Waste Electric and Electronic Equipment

Global electric and electronic equipment has increased greatly in recent decades, generating increasing amounts of waste. In EU alone the waste of electric and electronic equipment (WEEE) is one of the fastest growing streams of waste, with an average 3-5% yearly increase. Recycling materials from waste assures environmental protection, minimizes the waste, and provides secondary raw materials for the manufacturing industry. Electrostatic separation technologies are increasingly used to recover metals and plastics from WEEE or to separate plastic mixtures by polymer type. Triboelectrostatic separation is based on the differences in surface proprieties of granular materials that charge with opposite polarity when in contact, making it suitable for a wide range of material mixtures. The technology is clean and environmentally friendly, with no concern of further disposal and secondary pollution. It is characterized by low energy consumption, simplicity, and moderate cost maintenance. Recent results obtained at the Technical University of Cluj-Napoca and the University of Poitiers in the field of corona-electrostatic and tribo-electrostatic separation of granular materials originating from WEEE are reviewed in this paper.