Copper Recovery from Waste Wire Harness Using Alkali Hydroxides

Waste wire harnesses composed of thin copper wires coated with polyvinyl chloride (PVC) are difficult to recycle due to hydrogen chloride (HCl) emission during conventional thermal treatment. In this study, copper recovery from waste wire harnesses was investigated using alkali hydroxide-assisted pyrolysis with sodium hydroxide (NaOH) or potassium hydroxide (KOH) under an inert atmosphere. The coexistent heating with alkali hydroxides enabled the decomposition and carbonization of PVC while effectively capturing chlorine species, thereby suppressing HCl gas release. As a result, thin copper wires were successfully separated and recovered. The addition of alkali hydroxides significantly improved PVC gasification efficiency and copper–PVC separation compared with pyrolysis without alkali hydroxides. No notable differences were observed between NaOH and KOH in terms of chlorine capture or gaseous byproduct formation. These findings demonstrate a simple and effective method for recovering copper from waste wire harnesses without HCl emission.