Development of the reverse hybrid jig: Separation of polyethylene and cross-linked polyethylene from eco-cable wire

Abstract We have developed various types of jigs for resources recycling focusing primarily on plastic-plastic separation. The RETAC jig could be used to separate plastics heavier than water (specific gravity (SG) > 1.0) with different SGs while the hybrid jig—a process combining jig and flotation—was developed to separate plastics with similar SGs but different surface wettabilities. Meanwhile the reverse jig—a RETAC jig with a top screen—is used to separate plastics lighter than water with different SGs. In this study, a novel method that combines the principle of reverse and hybrid jigs, called “reverse hybrid jig separation” was developed to separate plastics lighter than water having similar SGs but different surface wettabilities. The tests were carried out with wastes from an eco-cable wire recycling facility in Japan, which is composed of polyethylene (PE) and cross-linked polyethylene (XLPE). The reverse hybrid jig separation results showed that bubble attachment to and detachment from plastic particles strongly influenced the separation efficiency. In addition, the effects of particle size on separation efficiency were also evaluated.