In an earlier post we posed the question why fluorescent powder from waste light bulbs, which could be said to contain higher concentrations of heavy rare earth elements (REE) than virgin rock ore that is being mined, is not economical for urban mining. The question is worth revisiting in light of recent developments.
The first has been some new research by S. Mueller, et al., comparing concentrations of rare earth found in geologic deposits (using Mount Weld, Australia as the reference case) and rare earth found in anthropogenic deposits in Switzerland, i.e. waste products (using Neodynium magnets in electric cars, Europium in fluorescent lamps, and Erbium in optical fibres as reference cases). The research found that anthropogenic sources of REE, while smaller than the geologic deposit in Mount Weld, had both higher concentrations and longer mine life. Despite this, there was currently no recycling or urban mining taking place of these anthropogenic deposits in Switzerland. The authors approach evaluated the “host rock” in the fluorescent lamp case as the phosphors and base the mass fraction on this and found good potential for urban mining. Despite this, recyclers in Switzerland are currently land-filling the phosphor powders “with an option for retrieval” (p.231). This might have something to do with the “geologic context” of the phosphors being four lamp recyclers in Switzerland. This is in contrast to the one recycler we mentioned, Nordic Recycling, recycling all the lamps from Norway and Sweden (and sometimes Danish lamps too). Perhaps the concentration is part of what made it possible (again, if not economical) for Nordic to send phosphor powder to Solvay in France for further REE recycling.
New research, in which IIIEE was involved (Machacek , Richter, Habib, & Klossek, 2015), discusses the importance of EPR legislation to first make the collection systems for concentrating dispersed waste products as a necessary precursor to commercial scale urban mining or recycling of REE from waste lamps. Commercial scale recycling by Solvay only became interesting because of the 2011 price volatility of heavy REE.
However, we only saw this happening on such a scale in Europe, while in other geographic regions like the U.S., there were only pilot or smaller scale demonstration projects. Recycling is only possible if the dispersed products can be collected in the first place and if there is a viable recovery process. Besides the Solvay commercial process, we have also seen in Europe lots of research recently to further develop REE recovery from waste lamp phosphors (for examples check out the work of D. Dupont at KU Leuven or C. Tunsu at Chalmers). So it seems there is reverse logistic infrastructure to bring the waste products back, there is a recycling process to yield the powder, and there are processes for then separating the rare earth back into pure elemental form for use again. The problem then does not seem technical, but rather economic.
It is important to remember that recycling of REE was only one of the responses to the 2011 price spikes. Other responses included redesigning lamps with less REE content and looking for alternative non-Chinese mining deposits. There was evidence of fluorescent phosphor re-design with less rare earth content and research projects to develop LEDs without any rare earths at all. New mining operations outside China was the strategy pursued by Molycorp and Lynas in reopening Mountain Pass mine in California and the Mount Weld mine in Australia respectively. Potential mining operations were explored in Europe as well, with Norra Kärr deposit in Sweden, and in Greenland. The Mountain Pass mine has since shut down again and despite Mount Weld being described as the richest known deposit of rare earths in the world, even Lynas is struggling now too. This has to do the with prices falling since the spike in 2011 and again making alternative sources from China less attractive.
Some commentators have argued that the price spike and resulting response with new primary and urban mining projects showed that China do not have a real monopoly on rare earths and the world can find alternative supply when needed. Maybe China out-competing alternative mining and recycling projects does not constitute a real monopoly, but is it a risk nonetheless? The ability of production to ramp up in the U.S. and Australia worked this time, but also showed the significant investment costs involved, underestimation of the complexity of commercial production and the risk of the boom-bust cycle resulting in a failed venture like Mountain Pass. So while alternative mining is possible, it might be that such risks may make investors wary.
So China remains by far the biggest player in the market, not because it is the only country that can supply REE but because it seems the only country that can supply relatively cheap REE. How it does this has been attributed to illegal mining and environmentally damaging mining practices. These negative externalities are not part of the price in China, but are part of the price in countries with more stringent mining and environmental regulations. The problem is that producers buy REE based on price as the main consideration.
Mining outside of China may avoid some of the worst environmental impacts, but urban mining REE from waste products not only avoids the environmental impact of extraction, but also contributes towards waste reduction and resource efficiency goals – all part of the circular economy agenda. These positive externalities are also not considered in the price when producers are buying primary mined REE from China rather than secondary sourced REE from domestic waste. If we are truly moving towards a circular economy, this issue will need to be addressed. We discuss this a bit more in the following article:
Machacek, E., Richter, J. L., Habib, K., & Klossek, P. (2015). Recycling of rare earths from fluorescent lamps: Value analysis of closing-the-loop under demand and supply uncertainties. Resources, Conservation and Recycling,104, 76-93.
The article looks at the potential for closed loop recycling of REE phosphors and at the case of Solvay-Rhodia. However, since the article, Solvay have now announced the intended closure of their recycling facilities. So it seems that urban mining, like conventional mining, is also vulnerable to boom-bust cycles even with the EU strategy circular economy strategy promotion.