Recycling probably isn’t high on the priority list at GM these days but with an administration keen to promote its green credentials it may be a good time for GM and other car producers to consider a closed loop recycling program for their new hybrid and electric car projects in the way Toyota has for the PGM’s used in their exhaust catalysts. Rare metals pundit Jack Lifton recently wrote on the topic in www.autobloggreen.com.
With so much press coverage being spent on the fragility of rare earth metal supplies, (many quote 90% of all metals fall into this bucket) one would expect a simple project risk management analysis to have flagged this up as an issue requiring attention. One of the problems in extracting rare earths from automobile parts is that the technology is not well developed. For clean segregated scrap, such as segregated Li-ion battery scrap, the process is relatively straightforward. The problems arise when the collection and recycling process is handled by the existing recycling industry. More often than not metallic parts and components will not be segregated by metal type. Mixed metal scrap will be much more of a challenge as this research article shows. There are potentially three extraction processes, none of which are fully developed commercially and all of which have drawbacks either in terms of yielding pure metals or in cost, or both.
- Aqueous based technology ” the drawback is it produces mixed metal oxides or fluorides which are then as expensive as the original ore to refine
- Electro-slag refining ” works well for large clean pieces of scrap but less well for contaminated or fine swarf (e.g. grit). In addition, the transition metals often get pulled across into the end product which then requires extensive further refining to access the RE’s
- Liquid Metal Extraction ” is a process that offers some promise because it can accept multi metal inputs and distinct metal outputs, but has not been developed commercially for RE’s. However it has worked for silver extraction from lead ores, so the basic technology is understood.
However the development of end of life (EOL) product management legislation may force the pace even if rising rare earth metal costs do not. EOL imperatives are forcing manufacturers in Europe and Japan to design in re-cyclability that may not be justifiable economically but is being required by legislation. Though we have deep reservations about such red tape, the one benefit that may come out of it is an earlier examination of how rare earth metals can be identified in a range of products appropriate for recycling. Fortunately there is a precedent that has been set by the recycling of PGM’s and it is possible the model would work for some rare earths. China’s steady restriction on exports and acquisitive involvement in new mining sources can’t help but lead to a rise in prices sooner rather than later. The reality is the cost of recycling the small volumes involved will mean costs have to rise a lot before rare earth recycling will become economically viable.