A rare story of rare earths

What do electric motors, permanent magnets, smartphones, energy-saving light bulbs and display screens all have in common? They all contain components made from rare earth metals – a group of 17 chemical elements.  

Rare earth elements (REEs) have properties that are indispensable for digitalisation and electrification. Some have special magnetic properties, while others are needed to build semiconductors. Others still can be made to glow.  

REEs are considered ‘critical’ – not because they are particularly rare, as their name misleadingly suggests, but because the manufacture of many products depends on them, their supply chains are exposed to global uncertainties and extracting them is technologically challenging and problematic from an environmental standpoint. 

Global demand for REEs has risen sharply in recent years, while supply remains severely limited. Approximately 70 per cent of REEs worldwide come from Chinese mines. And because China has managed to establish a quasi-monopoly, over 90 per cent of REEs are refined in China. 

In March 2024, the European Union adopted the Critical Raw Materials Act with the aim of reducing this dependency and increasing self-sufficiency. One of the ways to achieve this is by ensuring that, by 2030, a quarter of the REEs processed in the EU will come from recycling efforts. But this is easier written into legislation than performed in practice. Less than one per cent of REEs processed comes from recycling at present, because the extraction process is very time-consuming and difficult to perform with precision. Until now. 

A promising doctoral thesis

Marie Perrin studied at the École Polytechnique in Paris and undertook a research placement at the Massachusetts Institute of Technology in Cambridge, USA. In 2019, she came to Zurich to research REEs and their chemistry in the research group headed by ETH professor Victor Mougel.  

Victor Mougel and Marie Perrin discovered that certain molecules bind REEs with high affinity and can thus selectively separate them. They applied this property to europium and found that it can be recovered from fluorescent tubes (which europium is used in).  

To do this, the fluorescent tubes are ground into a powder. This fluorescent tube powder is then treated with an acid, which dissolves the metallic components and allows the glass to be filtered out. When the acid is dried, the residue is a powder containing europium and yttrium. When the extracting agent is then added, the europium reacts and precipitates out. The benefits are twofold: pure europium salts on the one hand, and the extracting agent on the other. Marie Perrin’s approach is 10 to 100 times more accurate than other methods used to separate europium. Since existing processes often have to be repeated to achieve the required purity, the amount of highly toxic acids and waste can also be reduced. 

Marie Perrin’s discovery has already caused quite a stir. Since publishing her findings and filing for a patent, she has won numerous awards, including the Gold Medal of the European Young Chemists’ Award and the World Builders prize awarded by the European Patent Office. She and her supervisor have received the ETH Spark Award, which recognises the most promising patent applications. In addition, her research findings have attracted considerable mass media attention.  

To really understand the attention given to Marie Perrin’s discovery, we need to remind ourselves of the background described at the start of this article. There is the need for europium and the difficulty of extracting it; there are questions surrounding the economic viability and environmental impact of extraction, not to mention geopolitical dependence on China. Added to that is the political will of the EU to change this situation. It is this combination of factors that makes the research findings so explosive.  

From research to industry

Filing the patent application suddenly raised new questions, Marie Perrin explains over a coffee: ‘To avoid this technology being licensed in its early stages without any further development, we decided to go down the spin-off route. We want to use our expertise for scaling up at the same time. We are very grateful for programmes such as the ETH Pioneer Fellowship, which is supported by the ETH Foundation and enables us to make the leap from science to entrepreneurship. We also recently received support from the Peter Bopp Foundation, thanks to which we can continue further developing the technology without having to rely on external investors.’ 

The patent-protected method for isolating europium works with very high accuracy on a laboratory scale, so current efforts are focused on scaling up the process for industrial applications. On the other hand, the spin-off, REEcover, relies on industry partners to further develop the method into a fully-fledged process with suppliers and customers. The search for partner companies brings its own difficulties.  

Marie Perrin is more than just a researcher. She also acts as a press spokesperson for her own cause. She explains things clearly and sparks enthusiasm when describing how the processes she uses works. Everything sounds feasible and understandable, even when she discusses the challenges that the spin-off encounters.  

The hope is that the process can be scaled up. On the one hand, because it would make an enormously important contribution to establishing the circular economy. And, on the other hand – and perhaps even more importantly – because every discovery that leads to an innovation tells a story. A story of people who have followed their curiosity, let their creativity run free and, working together with others, developed something that solves a pressing problem. Switzerland as a centre of innovation needs stories like these, because they inspire people and because they demonstrate the value of cutting-edge research.