Urban Mining: The Potential of Trash

In today's throw-away society it is increasingly obvious, with mineral prices at a high, that finite resources cannot sustain our consumption for technology. In response, the mining and stripping of valuable materials is becoming profitable. Urban mining is the term used to describe the resource recovery of certain materials from the waste stream. Specifically, urban mining reclaims precious metals including elements such as iron, copper, manganese, nickel, palladium, platinum tin and zinc from recycling end of life products such as electronic consumables and from abandoned buildings and infrastructure which contain a wealth of secondary raw materials.

Copper; one of the most widely used metals and its high
global demand is expected to exceed primary production
this year. Screenshot: Galileo, 2012

Landfill mining is currently been researched in Germany to combat rising prices of metals through possible reopening and extraction of sealed landfills to recycle potential scrap metal. Professor Stefan Gäth from Justus-Liebig University in Giessen (near Frankfurt) is investigating the financial viability of old landfills in Baden-Württemberg and Hessen. By drilling up to 40 metres deep at various landfills Prof. Gäth estimates a vast amount of raw materials can possibly be reclaimed, for example the landfill in Reiskirchen (Giessen) has an economic value 65 to 120 million Euros. He has particular interest in waste from the sixties, a time when waste was disposed thoughtlessly and has a higher percentage of valuable materials. The only problem is the cost involved and the long period required in analysing the recycling potential for each landfill, but Gäth believes the environmental relief and commodity potential outweighs the costs of landfill remediation. Prof. Gäth hopes to find a method that can effectively recycle an entire landfill which would save around €500 thousand per year in landfill costs (Galileo, 2012).

Research into urban and landfill mining are still developing as its an energy-intensive and costly enterprise so more efficient collection methods are needed. In a circular economy, future demands may eventually exceed the supply from the waste stream and the returns for some materials may not be higher than from its primary equivalent. However, the recycling potential from urban deposits is significant enough to encourage a self-sufficient metals sector and lessen reliance on metal imports. For practical application it is recommended that changes are needed in consumption patterns and a proper systemic registration of material usage is made to maximise knowledge of urban deposits (Resource Efficiency Atlas, 2011). Urban or landfill mining can be viewed as an essential strategy in the reduction/decoupling of resource consumption for a sustainable society.

References

1. Galileo (2012). 'Urban Mining'. Prosieben TV, Germany: http://www.prosieben.de/tv/galileo/videos/clip/1902208-urban-mining-1.3313257/

2. Mining Journal (2011). 'Europe's 'urban' mining strategy. http://www.mining-journal.com/reports/europes-urban-mining-strategy?SQ_DESIGN_NAME=print_friendly

3. Resource Efficiency Atlas (2011). 'Urban Mining'. http://www.ressourceneffizienzatlas.de/en/examples/strategies/detail/article/urban-mining-staedte-als-rohstoffquelle.html