Re-Processing of Mining Waste: An Alternative Way to Secure Metal Supplies of European Union
Résumé
In France, a recently started project handled by the French geological survey (BRGM) is aimed at identifying interesting old mining wastes deposits at the national level and assessing the metal recovery potential of these dumps. By crossing several databases and information from BRGM archives, 95 old mining sites with sizeable tailings dumps were identified. Selection criteria used to draw up this list were chosen mainly on the basis of the " Criticality Report " compiled for the European Commission in 2010, in which 14 mineral raw materials-12 critical metals-have been explicitly named as highly critical for the industrial development of the European Union. In most of these mines which date back hundreds of years or more, only a single or at best a couple of metals were extracted with processes whose performances were considerably lower than those used today. Knowing the type of ore commodities and the processes characteristics, it has been thus possible to assess the presence of valuable elements for each tailings dump. From this list an Ag-Pb French abandoned mine has then been selected as a case study to evaluate the potential of extraction of metals still remaining in the tailings with special focus on Ag and Sb. A global site characterization methodology is proposed which can be extrapolated to other sites according to key parameters.