A comprehensive review of urban mining and the value recovery from e-waste materials

E-waste is the source of both hazardous materials and valuable secondary resources. The challenge is to identify the potential for recovering value from this waste stream for different supply chains when there are diverse definitions in the field. The urban mining approach employs recycling and circular solutions inspired by principles such as industrial metabolism, industrial ecology, and the circular economy. This study presents a systematic review of peer-reviewed literature on urban mining and a comprehensive analysis of the many definitions of value recovery. This includes the stages of e-waste urban mining, the value recovery potential according to circular economy principles, location, and critical raw materials (CRMs). The results suggest that the exploitation of anthropogenic urban mines depends on Waste-to-Resources (WtR) and Waste-to-Energy (WtE) ratios, and the techniques borrowed from conventional mining. We highlight the importance of e-waste as a secondary source of CRMs (e.g., Au, Ag, Cu, Li, and Co), and provide recommendations regarding the critical analysis of the potential of urban mining to mitigate the impact of e-waste through circular processes and value recovery. Innovation is needed to promote a sustainable circular economy, and a harmonized regulatory framework relating to social aspects and technical potential.