Hot water separation process for copper and insulating material recovery from electric cable waste

Abstract

Recycling in the electric cable industry, especially the complete separation of metal and insulating material for reuse, has always been a problem. The present processes to recover copper and insulating material from cable waste involve the grinding of cables into smaller pieces to improve metal liberation from the insulating material. The method results in fine thread-shaped metal wedges in the insulating material, which prevents the re-use of the insulating material.A 'hot water separation process' was used to recover metal and insulating material from cable waste, with no need to grind the cable into smaller pieces to improve the liberation of copper from the insulating material. Based on the differences in coefficient of thermal expansion of the insulating material and copper, the cables are cut into a suitable length and placed into a blender with hot water. The insulating material and copper are separated and collected individually. By controlling the water temperature, blending speed and cutting length, complete separation can be achieved. This process is suitable for recycling many types of cable waste, including oil-containing wires, which are usually more difficult to recover.

Application of Subcritical Water to Dechlorinate Polyvinyl Chloride Electric Wires

“…Electric wires consist of one conductor, which is usually copper or aluminum, covered with insulating material, which can be polyvinyl chloride (PVC), polyethylene (PE), rubber, etc. [1].…”

A Brief Review of Poly(Vinyl Chloride) (PVC) Recycling

“…Wire insulation obtained from waste electronic equipment, household appliances and cars is the source of plasticised PVC recyclate. The mechanical separation of the insulation from the metal core is not a problem [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ]. A polymer mixture is obtained with PVC as the main polymer [ 66 , 70 ].…”

Simultaneous recovery of high-purity copper and polyvinyl chloride from thin electric cables by plasticizer extraction and ball milling

“…Several studies have reported on laboratory-scale processes to overcome these obstacles associated with thin electric cables. For example, Sheih and Tsai 25 reported on the perfect recovery of both Cu and PVC using a hot water separation process. In brief, wires were cut into 3 to 5 mm long pieces (bigger than the pieces in the common shredding process), which were then mixed with hot water at 80 °C in a blender at 4200 rpm for 5 min, resulting in the swelling of the PVC and its separation from the Cu.…”