Mapping and Characterisation of Mining Waste Dumps for Sustainable Resource Management

The sustainable management of mining wastes, a byproduct of extractive activities, represents a critical challenge in the context of the Critical Raw Materials Act (European Commission, 2023) and the transition to a circular economy. Mining waste dumps may contain significant residual amounts of ore minerals or metals, including Critical Raw Materials (CRMs), making their mapping and evaluation essential for environmental remediation and possible resource recovery. Developing detailed regional or national maps is pivotal to identifying mining waste dumps' location, typology, distribution, and spatial extent. Integrating Geographic Information System (GIS) software with complementary tools such as Google Earth, topographic maps, and orthophotos offers a comprehensive approach to efficiently identifying and analysing these sites.

Sampling and characterising mining waste dumps is crucial to assessing their economic potential and environmental impact (Beltré et al., 2023). Mineralogical analyses (e.g., X-ray diffraction, Scanning Electron Microscopy, RAMAN, and Electron Microprobe) and chemical analyses (e.g., Portable X-ray Fluorescence, ICP-MS, or ICP-OES) enable the evaluation of mineral processing residues. This differentiation helps identify economically viable dumps and prioritise remediation efforts for non-viable sites with contamination risks. (Lemière et al., 2011)

These methodologies are now applied to developing the Metallogenic Map of Sardinia, which will include the mapping of different mining waste dumps in Sardinia and their sampling.

The crucial challenges of this project are accurately estimating dump volumes due to difficulties in identifying underlying bedrock and quantifying critical metal content. Addressing these gaps is crucial for effective resource valorisation and site rehabilitation. To date, 140 mining waste samples have been collected and are under analysis to assess their economic and environmental potential. This study integrates GIS technologies with environmental and economic assessments as a pathway to support sustainable exploitation and management of mining waste dumps, aligning with EU strategic goals for CRMs.

 

Keywords: Critical Raw Materials, Circular Economy, Resource valorisation

• European Commission (2023) - Study on the Critical Raw Materials for the EU. Fifth list. Final report.
• Rosario-Beltré, A. J., Sánchez-España, J., Rodríguez-Gómez, V., Fernández-Naranjo, F. J., Bellido-Martín, E., Adánez-Sanjuán, P., & Arranz-González, J. C. (2023). Critical Raw Materials recovery potential from Spanish mine wastes: A national-scale preliminary assessment. Journal of Cleaner Production, 407. https://doi.org/10.1016/j.jclepro.2023.137163
• Lemière,, Cottard, F., & Piantone BRGM, P. (2011). Mining waste characterization in the perspective of the European mining waste directive.