TA11A Case Studies on Minerals and Metals Products
C120-122
8:00 AM - 12:00 PM, Tuesday
() Identifying Dominant Impacts in Global Copper Production using Life Cycle Impact Assessment.
Classen, M.1, Althaus, H.1, 1 Technology & Society Laboratory, EMPA, Dubendorf, Switzerland
ABSTRACT- In the last decade a broad discussion arose on environmental issues in mining and impacts due to metal production. Beside discussions on specific technical issues life cycle impact assessment (LCIA) evaluates the production system as a whole. Dominant impacts can be identified by valuing different impacts within the production chain against each other. Based on this information the effectiveness of decisions can be improved. Copper is taken as an example to identify dominant impacts in the metal production chain. The inventory data is taken from the ecoinvent database and covers all the processes from extraction, beneficiation and tailings management to hydro- and pyrometallurgical processes including land use and transformation, the disposal of slags as well as the co-production of sulphuric acid from the off-gas. An analysis of the impact assessment with Ecoindicator 99 (H, A) stresses the role of resource depletion in the case of copper. In a global view the catching of sulphur dioxide and a shift in technology led to a reduction of emissions, while in some regions of the world it still is an issue. The heavy metal emissions in the pyrolytical processes are assessed as the most harmful, contributing fifty percent to the total impact within the life cycle. Compared to the metallurgical step the mineral extraction plays a minor role. Here, dust emissions and off-gas from blasting are identified as dominant processes. Land degradation and tailings management show a low impact compared to the total. Due to the high uncertainties long-term emissions have been excluded from the inventory considered. How ever the inclusion of these emissions effecting from site closure on to the distant future indicate considerable additional impacts. As a result the importance of secondary copper can be shown. The biggest potential lies in the improvement of the abatement technology of pyrolytical processes.
Key words: copper, long-term emissions, life cycle assessment