Seven major European research institutes (Fraunhofer, CEA, TNO, VTT, SINTEF, Tecnalia and SP) have joined forces to invest in a joint program (Value from Waste) aimed at tackling the recycling of rare earth metals from waste. SINTEF is coordinating the program, which is using two groups of material technologies in an effort to find good analytical and extraction methods. The approach chosen by the researchers involves an electrolysis technology well-known from the aluminium industry.
The aim is to extract valuable materials from the waste streams. The challenges lie in the fact that the material must be sufficiently clean in order to be recycled, and we have to be sure that it is not contaminated by other harmful materials.—Odd Løvhaugen, SINTEF ICT
Researchers are therefore focusing much of their work on finding out which products could contain pollutants, which methods are best for analyzing and measuring the content of the polluted materials, and when such products can be expected to be found in waste.
They are also evaluating extraction methods, techniques to recycle nanoparticles in the treatment process, and how the constituents of ash can be analysed after incineration.
On the basis of tests, SINTEF researchers believe that the electrolysis technology used in aluminium plants can be used to recycle magnetic alloys from discarded magnets and scrap material from magnet manufacturers. It will take some time before there are enough scrap eco-cars to be able to recycle their motors, which is why they are turning to the magnet manufacturers for the magnetic alloys.
However, the process is still slow, and much work remains to be done before the researchers will know whether they will be able to achieve their goal. If they are successful, they will have found a method that is much simpler than alternative processes based on the use of strong acids.
Several other problems must also be solved for the stages before the electrolysis process, such as collection and disassembly methods for used magnets. Further, the magnets themselves must also be demagnetized locally, since the long-distance transport of intact permanent magnets is prohibited.
Other challenges include finding methods that can identify and characterize nanoparticles in gases, water and solid materials. And we must create a toolbox of methods to evaluate the behavior of nanoparticles in waste treatment processes.—Odd Løvhaugen
Koen Binnemans, Peter Tom Jones, Bart Blanpain, Tom Van Gerven, Yongxiang Yang, Allan Walton, Matthias Buchert (2013) “Recycling of rare earths: a critical review,” Journal of Cleaner Production, Volume 51, Pages 1-22, doi: 10.1016/j.jclepro.2012.12.037