Bench-scale PVC swelling and rod milling of waste wire harnesses for recovery of Cu, PVC, and plasticizers

In this study, we conducted bench-scale investigations for the recovery of Cu wires, PVC coatings, and plasticizers from long non-uniform cables by wet and dry rod milling, using n-butyl acetate or acetone as swelling solvents at ambient temperatures of 17, 25, and 35 °C. In wet milling, acetone presented a faster separation rate at ≥ 35 °C due to its improved swelling power. However, at 17 and 25 °C, the separation rates of both solvents were comparable. During the dry milling, the acetone-swollen cables tended to de-swell rapidly, whereas cables swollen with n-butyl acetate remained swollen for a longer period, resulting in a greater separation rate. At optimal conditions, both methods fully recovered Cu wires, PVC coatings, and near-quantitative diisononyl phthalate yield. Overall, the results can significantly contribute to the development of future industrial wet or dry milling processes.