关键词: 废旧塑料, 摩擦电选, 荷电机理, 荷电装置

Abstract: Plastics are widely used in the fields of engineering construction, food safety, transportation, and medical treatment due to the advantages of light material, stable chemical properties, low cost, wear resistance, and corrosion resistance. If it is not handled properly, it will cause serious environmental pollution and waste. The prevention and control of plastic pollution have become an environmental issue of global concern. At present, the recycling methods for processing waste plastics include primary recycling, energy recycling, mechanical recycling and chemical recycling. Mechanical recycling has become the most commonly used method for processing waste plastics due to its simple processing technology, low equipment cost, and low investment. Commonly used mechanical treatment methods include wind separation, flotation, electrostatic separation, optical separation, etc. As a new type of dry separation method, triboelectric separation has been paid more and more attention by researchers because of its advantages of simple process, less pollution, less investment and low cost. It uses the contact, collision, friction between minerals, or the friction between minerals and the feeding trough, to generate charges of different magnitudes and opposite signs. When fed into a high-voltage electric field, the resulting motion trajectories are also significantly different due to the different signs of the particle charges, separating the two minerals. It mainly includes two processes of triboelectric charging and electrostatic sorting. The materials to be sorted carry charges of different polarities after friction, which is the prerequisite for triboelectric sorting and separation. Aiming at the sorting and recycling of waste plastics, this work introduces the charging mechanism, influencing factors, charging device, and sorting device of triboelectric separation in detail, and points out the technical problems of recycling waste plastics by triboelectric separation. The future development direction of triboelectric separation technology is prospected. It is suggested that the theoretical study of turbocharging should be improved from a microscopic point of view with the help of modern analytical instruments. Develop and design an electrified sorting device that can precisely control humidity. Optimize the structural design of the charging device, enhance the charging effect, or fully charge the particles through multi-stage charging.

Key words: waste plastics, Triboelectric separation, Tribocharging mechanism, Charged device