Separation of copper and polyvinyl chloride from thin waste electric cables: A combined PVC-swelling and centrifugal approach.

Waste electric cables from end-of-life vehicles and electronic and electrical equipment present a significant problem in terms of environmental protection and resource recycling. Herein we detail a novel recycling method for thin waste electric cables, by combining polyvinyl chloride (PVC) swelling and centrifugal separation to simultaneously recover PVC and high-purity copper. PVC coverings were swollen in an organic solvent at ambient temperatures, which creates a gap between the covering and the copper wire and facilitates centrifugal separation. Electric cables (12 g) were 100% separated, and more than 95% of the plasticizer was extracted by stirring in 100-mL acetone or ethyl acetate that facilitated the separate recovery of copper, the PVC covering, and the plasticizer. In contrast, >97% separation, with <10% extraction of the plasticizer, was achieved with a mixture of 10 mL butyl acetate and 90 mL water. High-purity copper and PVC with controlled plasticizer content were recovered, which is highly advantageous for recycling both copper and PVC.

Validation of a deplasticizer-ball milling method for separating Cu and PVC from thin electric cables: A simulation and experimental approach.

There is increasing demand in the electronics recycling industry for an effective method to separate polyvinyl chloride (PVC) and Cu from thin electric cable waste. Herein, a novel separation technique involving PVC embrittlement via plasticizer extraction and crushing by ball milling is proposed. The method was developed by varying the size, quantity, and hardness of the cables, as well as the size and quantity of the milling balls, to determine a combination that resulted in complete separation of PVC and high-purity Cu (>99.9%) from thin electric cables. The experimental crushing behavior was demonstrated via a sphere-to-cylinder discrete element model combined with a statistical approach. The mechanism of PVC crushing generated cracks from the edge to the center of the cable via ball impacts that were strong enough to overcome the elastic repulsion force of the PVC. The resulting method was found to be effective at separating PVC and high-purity Cu (>99.9%) from de-plasticized thin electric cables with diameters of 1.5-2.7 mm.