Potential metal resources in waste incineration ash deposits
2012 (English)In: SUM 2012 Symposium on Urban Mining, 2012Conference paper, Presentation (Refereed)
Incineration of waste has always been connected to large metal flows, and it has long been a concern from an environmental point of view, with special focus given to high metal concentrations in the flue gas. However, these metal flows could have also been seen as a potential resource stock available for extraction. This study aims to assess the potential of Swedish waste incineration ash deposits as sources for metal extraction. A second, and equally important aim, is to contribute knowledge for priority-setting of future research on metal extraction methods from such residues.
The results from this study indicate that the metal flows are still considerable. The total amounts of scrap metal in these deposits are significant, and nearly amount to the annual collection of both ferrous and non-ferrous scrap in Sweden. Furthermore, for some of the metals studied the annual flows in Sweden seem to be higher than the metal flows in slag from the copper and steel industries. The main research regarding the extraction of metals from MSWI ash has focused on fly ash. However, by looking at the total potential amounts in different deposits, the results in this study suggest that, from an environmental and economic point of view, the highest potential seems to be for metal stocks in the bottom ash. One metal that has not been high on the research agenda is Titanium, which, due to a high raw material value combined with large amounts in deposits, is ranked at the top from both the economic and environmental perspectives. The results also show that there currently seems to be less incentive to extract the scarcer metals both from an economic and an environmental point of view.
The article gives suggestions for future research. For example, how much of the metals in the deposits are in a chemical form, making them suitable for extraction? Which challenges arise if the focus of extraction is turned towards the bottom ashes, with their lower concentrations but higher total amounts? Furthermore, research is needed on how accessible different types of deposits are, and what type of institutional and technological challenges and possibilities would arise in a real-world extraction activity.
Place, publisher, year, edition, pages
Waste incineration ashes, landfill mining, potential metal resources, bottom ash, fly ash
IdentifiersURN: urn:nbn:se:liu:diva-85946OAI: oai:DiVA.org:liu-85946DiVA: diva2:574053
SUM 2012 Symposium on Urban Mining, 21-23 May 2012, Bergamo, Italy
Invited to special issue in Waste Management2012-12-042012-12-042012-12-10