The duality between critical raw material recovery and the restoration of mining waste dumps

The mining industry constitutes a fundamental pillar of modern society and has gained increasing strategic relevance in the current geopolitical context. The growing demand for critical raw materials should not be limited to the exploration of new geological deposits, but should also incorporate alternative and innovative approaches such as urban mining, recycling, and waste valorisation.Traditionally, mining wastes have been accumulated in waste dumps, often with a primary focus on ensuring geotechnical stability, while environmental restoration efforts have largely been limited to geomorphological reshaping and visual landscape mitigation. However, many waste dumps contain elements currently classified as critical raw materials, which frequently co-occur with contaminants due to their inherent toxicity.In this context, the duality between the valorization of mining wastes for the recovery of critical raw materials and the mitigation of their potential environmental impacts through restoration techniques becomes particularly relevant. This study presents several case studies that integrate the reprocessing of mining waste dumps for the recovery of valuable elements, as well as the valorisation of mining wastes as soil amendments, with restoration strategies based on phytoremediation and the application of organic and inorganic amendments, including carbon foams, biochar, and nanomaterials.The results highlight the importance of adopting a holistic approach to mining waste management, in which environmental restoration and critical raw material recovery are addressed simultaneously as part of a sustainable strategy aligned with the principles of the circular economy.AcknowledgementsThis work was funded by the research project RESIST, PID2024-160647OB-I00 (MICIU/AEI/10.13039/501100011033/FEDER, EU). Bryan Salgado acknowledge the Spanish National Research Council for the "JAE Intro ICU 2025" fellowship (Ref. CN-IGME-03).