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At present, little information is available on the opportunities and challenges to recover valuable critical raw materials (CRM) and secondary raw materials (SRM) from extractive waste (EW) deposits. In this study, an integrated framework describing the key steps required to assess the viability of CRM recovery from EW deposits is presented. The framework has been tested and validated using a pilot site located in the Northern region of Lombardy, Gorno. A tiered characterisation approach was used to support the framework and obtain information on (i) the deposit features and their characteristics including geocharacterisation of the waste layers, (ii) the physicochemical properties of the waste layers, and (iii) the presence of CRM/SRM hot spots using a combination of drone technology and geographic information system (GIS) data collection. Zinc (0.65 to 19.3 wt %) and Cadmium (22-544 ppm) and to a lower extent Gallium (6.0-88.6 ppm) were the most abundant elements that could be potentially recovered from the waste rocks. Assuming that all Zn, Cd and Ga were from exploitable minerals (eg. sphalerite, calamine, etc...), there are good opportunity of significant revenues ranging between 13.4 and 63 M€ for Zn, 18.5 and 88 k€ for Cd and 132 and 530 k€ for Ga. While caution is needed in extrapolating these potential revenues, there are promising and supporting the potential economic viability of landfill mining at EW deposits.

The present paper deals with the different approaches to follow to evaluate the problems (eg. environmental impacts) and potentialities (eg. chance to recover valuable materials from wastelandfill mining approach) connected to mining waste management. Very few research investigated the chance to recover raw materials (RM), critical raw materials (CRM) and secondary raw materials (SRM) from mining waste, on the contraty , several studies investigated the environemtal problems associated to mining waste management (transoport, landfilling, temporary waste facilities, etc.): these two perspectives have been presentend and developed in section 2 (Resource efficiency and environmental protection (REEP) approach). Mining industry represents the most important productive activity (at global level) to exploit RM fundamental for society development. Indeed, resource security is a priority for governments of developed countries. This priority is partly due to considerable concern over the security of the supply of CRM. Their supply is essential to the maintenance and development of the EU economy, as its industries rely on a steady supply of raw materials (RM). Over the centuries, the need for RM continued to expand, as did the number of RM utilised in industry, involving also metals and elements not known or used in the past (Bellenfant et al. 2013). Most of CRM are exploited from countries outside of the EU, causing high economic dependence on non-EU countries (China above all). RM and CRM can be exploited from ore deposits (primary mining), but are also present in landfills and waste streams. The consequence of mining industry is not only the volume of mineral products obtained but also generation of mining waste (also referred to as extractive waste-EW). Extractive wastes (including waste rock-WR, operating residues-OR, and tailings) represent, on the one hand, a problem due to environmental impacts associated to their production and management and, on the other hand, a potential source to recover SRM and CRM. The need of minimizing the negative impacts

Sulfides entering subduction zones can play an important role in the release of sulfur and metals to the mantle wedge and contribute to the formation of volcanic arc-associated ores. Fractionation of stable sulfur isotopes recorded by sulfides during metamorphism can provide evidence of fluid-rock interactions during metamorphism and give insights on sulfur mobilization. A detailed microtextural and geochemical study was performed on mineralized samples from two ocean floor-related sulfide deposits (Servette and Beth-Ghinivert) in high-pressure units of the Italian Western Alps, which underwent different metamorphic evolutions. The combination of microtextural investigations with d 34 S values from in situ ion probe analyses within individual pyrite and chalcopyrite grains allowed evaluation of the effectiveness of metamorphism in modifying the isotopic record and mobilizing sulfur and metals and have insights on fluid circulation within the slab. Textures and isotopic compositions inherited from the protolith are recorded at Beth-Ghinivert, where limited metamorphic recrystallization is attributed to limited interaction with metamorphic fluids. Isotopic modification by metamorphic processes occurred only at the submillimeter scale at Servette, where local interactions with infiltrating hydrothermal fluid are recorded by metamorphic grains. Notwithstanding the differences recorded by the two deposits, neither underwent intensive isotopic reequilibration or records evidence of intense fluid-rock interaction and S mobilization during metamorphism. Therefore, subducted sulfide deposits dominated by pyrite and chalcopyrite are unlikely to release significant quantities of sulfur to the mantle wedge and to arc magmatism sources at metamorphic grades below the lower eclogite facies.

In Piemonte, stone has always been the most widely used raw material for buildings, characterizing the architectural identity of the city of Turin. All kinds of rocks, metamorphic, igneous and sedimentary, are represented, including gneisses, marbles, granitoids and less commonly limestones. The great variety of ornamental stones is clearly due to the highly composite geological nature of the Piemonte region and related to the presence of the orogenic Alpine chain and the sedimentary Tertiary Piemonte Basin.This paper provides a representative list of the most historic ornamental stones of Piemonte, which have been used over the centuries in buildings and architecture. The main stones occurring in Turin have been identified and described from a petrographic and mineralogical point of view in order to find out the corresponding geological units and quarry sites, from which they were exploited. This allows the associated cultural and scientific interest of stones to be emphasized in the architecture of a town which lies between a mountain chain and a hilly region.