Browsing by Author "Valjus, Tuire"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Assessing the opportunities of landfill mining as a source of critical raw materials in Europe
    (Eurowaste, 2017-10-16) Särkkä, H.; Kaartinen, T.; Hannus, Esa; Hirvonen, S.; Valjus, Tuire; Lerssi, J.; Dino, G. A.; Piergiorgio, R.; Griffiths, Zoe; Wagland, Stuart; Coulon, Frederic
    Many of the metals in landfill constitute valuable and scarce natural resources. It has already been recognised that the recovery of these elements is critical for the sustainability of a number of industries. Arsenic (which is an essential part of the production of transistors and LEDs) is predicted to run out sometime in the next five to 50 years if consumption continues at the present rate. Nickel used for anything involving stainless steel and platinum group metals (PGMs) used in catalytic converters, fertilisers and others are also identified as critical materials (CM) to the EU economy at risk of depletion However, despite the increasing demand, none of this supply is supported by recycling. This is due to the high cost of recovery from low concentrations when compared to conventional mining. As demonstrated by the two pilot case studies of this study, mining landfill sites only for their metals content is not expected to be financially viable. However, other opportunities such as Waste-derived fuels from excavated materials exist which if combined , form the concept of ‘enhanced landfill mining’. have the potential to be highly energetic. The energy potential is comparable to the levels of energy of Refuse-Derived Fuels (RDF) produced from non-landfilled wastes.
  • Thumbnail Image
    ItemOpen Access
    Investigation of municipal solid waste (MSW) and industrial landfills as a potential source of secondary raw materials
    (2018-03-31) Särkkä, Heikki; Kaartinen, Tommi; Hannus, Esa; Hirvonen, Sami; Valjus, Tuire; Lerssi, Jouni; Dino, Giovanna A.; Rossetti, Piergiorgio; Griffiths, Zoe; Wagland, Stuart T.; Coulon, Frederic
    Many of the secondary raw materials (SRM) in landfills constitute valuable and scarce natural resources. It has already been recognised that the recovery of these elements is critical for the sustainability of a number of industries and SRM recov¬ery from anthropogenic waste deposits represents a significant opportunity. In this study, the characterisation of the different waste fractions and the amount of SRM that can potentially be recovered from two landfill sites in Finland is presented. The first site was a municipal solid waste (MSW) landfill site and it was specifically in¬vestigated for its metals, SRM, plastics, wood, paper, and cardboard content as well as its fine fraction (<20 mm). The second site was an industrial landfill site contain¬ing residual wastes from industrial processes including 1) aluminium salt slag from refining process of aluminium scrap and 2) shredding residues from automobiles, household appliances and other metals containing waste. This site was investigated for its metals and SRM recovery potential as well as its fine fraction. Results suggest that the fine fraction offers opportunities for metal (Cr, Cu, Ni, Pb, and Zn) and SRM extraction and recovery from both landfill site types while the chemical composition of the industrial waste landfill offered greater opporutinity as it was comparable to typical aluminium salt slags. Nevertheless, the concentrations of rare earth metals (REE) and other valuable elements were low even in comparison with the concentra¬tions found in the Earth’s crust. Therefore mining landfill sites only for their metals or SRM content is not expected to be financially viable. However, other opportunities, such as waste-derived fuels from excavated materials especially at MSW landfill sites, still exists and fosters the application and feasibility of landfill mining.