Environmental potential of shredder fines valorisation

Millions of tonnes of shredder fines are disposed of annually across the world. In Sweden, fines are primarily utilised in landfill covering. Given the decreasing landfilling and the increasing environmental concerns, the valorisation of this residue is becoming ever important. In order to guide sustainable investment decisions and governance of fines valorisation, this study aimed to assess the environmental potential of different valorisation alternatives. In doing so, three conceptual valorisation process schemes were formulated together with the shredding industry, each based on principally different resource recovery strategies: 1) maximising copper recovery, 2) maximising construction aggregates recovery, and 3) optimising full resource recovery. A streamlined life cycle assessment (LCA) of these valorisation alternatives was performed in relation to the impact categories of climate change, ozone depletion, acidification, and resource depletion. The results of this study generally suggest that in the context of Sweden, Alternatives 1 and 3 are preferable over Alternative 2 regarding all the impact categories. There, Alternative 3 is more preferable regarding climate change, while Alternative 1 is preferable regarding the other impact categories. Several environmental hot spots occur along the different life cycle stages of the fines-derived secondary raw materials. The Monte Carlo simulation of the parameter uncertainties generally confirms the overall LCA findings.