The recovery of metals from WEEE: state of the art and future perspectives

Metals are essential elements in the modern technology as they are widely used for several industrial applications such as the manufacturing of electronic devices. Besides common metals, such as copper, iron and aluminium, electronic appliances can contain precious metals as well as metals defined as critical, including rare earth elements (REEs). In this regard, the chance to recycle metals from end-of-life appliances, namely Waste Electrical and Electronic Equipment (WEEE), has benefits for both the economy and the environment in terms of its protection and conservation. However, the existing recycling industry for the recovery of metals from WEEE is still in its infant stage and mostly addressed to the recovery of base metals; precious metals are also extracted, while REEs are practically almost never recycled. The present work provides a comprehensive overview of the recycling technologies currently applied for the recovery of metals from WEEE, including the recovery of REEs, for which few and fragmented information is available in literature due to the limited experience and the restriction imposed by trade secrets. Advantages as well as limits of both conventional technologies and recent research developments are discussed and future perspectives are lastly pointed out.