PROMOTING THE EFFICIENT USE OF MINERAL WASTE

This doctoral dissertation investigates the valorisation of mineral waste within a circular economy framework, focusing on two major waste streams: Extractive Waste (EW) and Construction and Demolition Waste (C&DW). The study is structured in three papers, each addressing a distinct aspect of mineral waste recovery. The first paper presents a Decision Support Tool (DST) for assessing the sustainability of recovering Critical Raw Materials (CRMs) from EW deposits. The tool integrates technical, economic, environmental, and social criteria to support strategic decision-making for resource recovery. Its practical relevance has also been demonstrated through an Academic Proof-of-Concept project funded by the Italian PNRR (NODES programme). The second paper analyses the compliance of recycled aggregates (RAs) obtained from C&DW with existing technical standards for use in construction. The results highlight critical gaps in material quality, often linked to insufficient component separation and basic treatment processes. These findings emphasise the need for greater investment in technological innovation and applied research to optimise C&DW processing and produce higher-quality RAs capable of replacing natural aggregates in more demanding engineering applications. The third paper presents a full-scale experimental study on the use of C&DW-derived aggregates in reinforced embankments. As one of the first applications of this kind, the field testing provides a more comprehensive understanding of material behaviour under near-real conditions, beyond what is typically captured in laboratory settings. The study demonstrates that RAs can be successfully employed in complex geotechnical structures, offering a tangible contribution to the circular economy in the construction sector. Collectively, the three studies offer a multi-disciplinary contribution to the valorisation of mineral waste. While each paper addresses a different material stream and research focus, from strategic resource assessment (EW) to technical qualification and field application in construction (C&DW), they converge in promoting a more circular and evidence-based approach to mineral waste management and reuse