The hidden potential of landfill
A recent study carried out by Cranfield University has demonstrated the potential value of extracting rare earth elements (REE) and valuable metals from landfill sites.
The study, the first of its kind, analysed samples from up to 30 metres deep from four different UK landfill sites. These were carefully prepared to remove larger objects, and then analysed for the content of REE and other valuable metals. The most economically attractive, Neodymium (Nd), which the team estimates has a combined value of over $9 million. From other metals detected they further estimate over $141 million of the precious metal Palladium (Pd) was present across the four sites. Additionally, the combined value of Copper (Cu) and Aluminium (Al) could exceed $400 million.
Cranfield's Dr Stuart Wagland and Dr Frédéric Coulon worked on the project. Dr Wagland said: "There is clearly potential value in our landfills, considering we only looked at the soil-like materials within the landfill sites. It is unlikely that the recovery of only REEs and critical metals would be economically viable, however recover copper and aluminium and it starts to make sense. Further resource recovery is possible with the extraction of larger metal items and the reprocessing of plastics, adding even more value to the operation.
"Landfill mining has benefits beyond resource recovery though, as land can be reclaimed and the long-term management issues of the landfill site are removed."
Following decades of reliance on landfill disposal as a method of managing wastes from commercial, industrial and household sources, the UK has around 4,000 landfill sites. Significant quantities of Waste Electrical and Electronic Equipment (WEEE) were disposed in landfill, especially prior to the implementation of the 2002 European Union WEEE Directive. They are also considered to contain substantial amounts of material which could have otherwise been recycled, such as aluminium cans, plastic bottles and paper.
Many UK landfill sites are now closed but they will remain active for many years after closure and require extensive management.