Technico-economic comparison between two new triboelectric charging processes of insulating granular products and their application to the electrostatic separation of WEEE Comparaison technico-économique entre deux nouveaux procédés de chargement triboélectrique des produits granulaires isolants et leur application dans la séparationélectrostatique des DEEE

It seems important to point out that the combination of triboelectric charging and electrostatic separation techniques is one of the best alternatives for the recycling of waste electrical and electronic equipment (WEEE). Our job is to evaluate and study two new tribo-charging devices to isolate particles from products to be recycled; the first device consists of a PMMA cylinder in which one or more coaxial propellers drive the plastic pellets in a helical motion which promotes their triboelectric charging; the second device is arranged on two parallel axes of rotation, in the same cylinder, to create two descending helical aerodynamic movements, either in the same direction or in opposite directions, and thus to cause a large number of collisions between insulating granules , which will charge by triboelectric effect. The experimental design methodology was used for the modelling and optimization of two charging processes for electrostatic separation application using a treadmill separator where the products used are mainly: PA, PC, HIPS, ABS and PVC. The effectiveness of the device was evaluated by experiments carried out with mixtures of three different plastics, on an electrostatic separator with a metal conveyor. The feasibility of the separation is related to the nature of the walls of the tribo-aero electric charging device, but is not significantly influenced by the mass flow.