The dual paradigm of mining waste: “from ecotoxicological 2 sources to potential polymetallic resources” – an example from 3 Iberian Pyrite Belt (Portugal)

The main goal of this study was to identify potential chemical elements present in three 20 types of polymetallic mine waste, stored in the old mine site of São Domingos, located in the Iberian 21 Pyrite Belt, Alentejo, Southern Region of Portugal. This study involves the characterization of po-22 tential resources in those mine residues, bearing in mind that its reprocessing can facilitate the en-23 vironmental remediation and rehabilitation activities which are underway at the site. X-Ray Fluo-24 rescence (XRF) and micro ()-XRF 2D mapping surveys were performed. Univariate and multivar-25 iate data analysis reveal that differences in compositions are mainly related with element concen-26 tration per type of waste. Image processing and clustering analysis allowed the recognition of dis-27 tinct elemental spatial distribution patterns. Some of these residues, although classified as archeo-28 logical-industrial heritage materials may present toxicity to the ecological environment and to hu-29 man health. This fact enhances, therefore, geoethical doubts regarding its remining and exploitabil-30 ity. In this context, a multi-criteria decision analysis considering two geoethical alternatives was 31 performed.