Towards recycling of scarce metals from complex products

Detta är en avhandling från ; Chalmers tekniska högskola; Gothenburg

Sammanfattning: Cars and electronic equipment have come to depend on materially complex designs and are drawing attention to issues around sustainable materials management. The dependence of these products and other applications on metals that can be considered scarce, has been brought into political and scientific focus. This is largely because of potential regional scarce metal supply constraints and the crucial roles the metals may play in current society and in diffusing a variety of ‘green’ technologies. If the societal dependence on scarce metals continues, the demand for these metals may become larger still. It is therefore increasingly relevant to manage scarce metals sustainably. Ultimately, the metals need to be recycled if such sustainable management is to be achieved. However, recycling industries are not well-adjusted to recovering all scarce metals, and concurrently policy-makers and the research community are only in early stages of finding ways to approach challenges associated with managing scarce metal resources. As a result, instead of being recycled many scarce metals risk being irreversibly lost. Thus, there is need for knowledge in multiple domains if recycling rates of scarce metals are to increase. This thesis aims to contribute with such knowledge, by studying recycling of scarce metals from end-of-life cars (ELVs) and waste electrical and electronic equipment (WEEE). First, by quantifying scarce metals entering Swedish ELV recycling, tracking the metals through recycling, and identifying where metals end up. Second, by identifying factors that impact on developing industry abilities for recycling scarce metals from ELVs and WEEE. Third, by identifying and discussing research approaches used in waste management (WM), WEE and ELV related research. Fourth, by suggesting measures that may raise recycling rates of scarce metals. Methodologically, the research is based on material flow analysis (MFA), the technological innovation system (TIS) framework and bibliometric analysis. Results indicate that 2,000-3,000 tonnes of scarce metals annually enter Swedish ELV recycling. Only 8 of 25 studied metals are estimated have any potential for being recycled such that metal properties are reutilised. Salient factors that impact on developing industry recycling abilities include: The material composition of ELVs and WEEE and the current value of contained metals; long-term metal price trends; access by industry actors to metal markets, an experienced work force, waste treatment technology and financial capital; business models and long-term goals within recycling industries; and EU and Swedish policy. These factors create socio-technical system challenges that need to be addressed by industry actors, policy-makers and researchers if recycling is to develop. Furthermore, some environmental system analysis methods and most socio-technical change approaches have only marginally been adopted in WM, WEEE and ELV related research. Hence, valuable scientific tools are left unutilised. Overall, results highlight that for individual metals to be recycled, there is need for long-term, high impact and metal specific measures that target build-up of entire values chains. The thesis contributes theoretically to TIS literature by adapting the TIS framework to a new empirical field, and to using it for studying industry developments where multiple and potentially conflicting goals are salient features. Empirically the thesis increases the resolution of knowledge about metal and material flows, and industry conditions, in Swedish ELV and WEEE recycling.

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