Urban mining as a contribution to the resource strategy of the Canton of Zurich

Urban mining is increasingly being recognised as an important component of resource strategies of public authorities, not only because it contributes to environmental protection, but also because it is a source of valuable recyclable materials. We demonstrate that the sustainable livelihoods (SL) framework can be used for public policy making in waste management by presenting the approach and experiences of a review study termed 'urban mining potential analysis' and its application to antimony, copper, gypsum, gold and rare earth elements. This article uses the rare earth element (REE) group to illustrate and present an overview over information and knowledge gaps concerning urban mining. The analysis shows that rare earth element recycling can be more environmentally friendly than primary production, particularly if the latter comes from countries with weak enforcement of environmental legislation. On the other hand REE recycling often cannot compete with large scale primary production because market prices do not reflect the social and environmental impacts of production, and because the avoided impacts of waste decontamination and reduced waste production are not considered. The urban mining potential analysis can be used to support decision making and the setting of priorities for future research and public action. The findings of the study and expert opinions based thereon contribute to the selection of measures and the formulation of public waste management and resource strategies in general.