Towards sustainable metal cycles: the case of copper

摘要: Developing an approach that delivers improved environmental performance for metal cycles is the aim of this thesis. Integral to the sustainable use of metals is the need to reduce environmental impacts associated with the mining, refining and recycling activities that supply metal to the economy. Currently, the links between the location and duration of these activities, their resultant impacts and the responsible parties are poorly characterised. Consequently, the changes to technology infrastructure and material flow patterns that are required to achieve sustainable metal cycles remain unclear to both industry and government actors. To address this problem, a holistic two-part methodology is developed. Firstly, a reference schema is developed to address the complexity of structuring analyses of the material chain at different geographical and time scales. The schema identifies actors and system variables at each scale of analysis and guides the level of information detail and performance indicators to be used in material chain characterisation. Material chain characterisation involves modelling material and energy flows for current activities as a series of connected nodes and linking these flows to resultant environmental impacts. The approach identifies the material chain activity responsible for each environmental impact and makes trade-offs between impacts explicit. Sensitivity analysis of the models identifies the key variables that enhance performance. The influence of actors over these variables is assessed to target areas for improvement. This first part of the methodology is illustrated using case studies that assess the current performance of …