Innovative technologies and processing architectures in Urban Mining: Two key issues to ensure secondary raw materials supply

The term Urban Mining (UM) usually identifies the whole set of operations (e.g. collection, analysis, processing, quality control, recycling, etc.) aimed to perform the recovery of Secondary Raw Materials (SRM) from Municipal Waste (MW) or, more in general, in large stocks of materials incorporated into cities (e.g. buildings and infrastructure) and/or also in landfills. UM can assume different aspects according to different urban tissue characteristics, in fact, not being associated to “finite physically identifiable body”, embedding the resources to exploit, UM is influenced by the geographic location and the socioeconomical context of the anthropic settlement generating the waste (e.g. secondary resources). Different innovative technologies and process architectures have been presented and discussed in this paper, with particular reference to two different classes of waste products: i) plastics (e.g. polyolefins separation and recovery) and ii) Construction and Demolition Waste (C&DW) (e.g. utilisation of C&DW from a material that is actually largely land filled or reused in low-grade applications to a resource for the production of high-grade recycled concrete).