Marie Perrin

Demand for rare earth elements is skyrocketing as these metals are used in smartphones, LED displays, wind turbines and electric vehicles. REE mining and processing can produce up to 2 000 tonnes of toxic waste—including one tonne of radioactive material—for every tonne of REEs extracted. Europe relies almost entirely on imports and less than 1% of rare earths are recycled. Traditional recovery processes require toxic chemicals, large-scale batch operations and between 100 and 1000 repeated steps to achieve high purity. 

Perrin’s method to recover europium tackles these issues head-on. The process begins by disassembling fluorescent lamps to extract the phosphor powder, which contains rare earth elements, while safely removing mercury. The powder is then dissolved in acid, creating a solution rich in REEs. Sulphur-based molecules (tetrathiotungstate ligands) are introduced, triggering a redox reaction that forms a golden precipitate enriched in europium, while yttrium - another REE - remains in solution. The europium solid is filtered out and treated with ammonium oxalate in water, which simultaneously recovers the extractant for reuse. A final calcination step produces europium oxide, completing the recycling process. 

From scientific curiosity to sustainable innovation 

Born in the U.S. to a French family, Perrin grew up with two major influences, Maria Salomea Skłodowska-Curie and her mother, “My mom is the best chemist I know and early on, I wanted to follow a scientific path”. Perrin earned her master’s degree from Ecole Polytechnique and Paris-Saclay University before completing a PhD at ETH Zürich. During her doctoral research under Professor Victor Mougel, she initially focused on using REEs for water purification and fertilizer regeneration. However, a discovery of their unique separation properties shifted her work towards REE recycling. 

With guidance from ETH’s Technology Transfer Office and Professor Mougel, Perrin filed a patent application for the method. She later published her work in Nature and has participated in several incubator programs and startup competitions. These have helped provide funding, industry partnerships and mentorship. Perrin, Mougel and long-time friend Maria Pujos co-founded REEcover to help manufacturers move towards a circular economy, where waste becomes a valuable resource rather than a liability. As Perrin explains, “We reached out to many companies but struggled to make an impact at first. When we began to make contacts, we realised that many industries do not have power over their supply chain.” 

Initially focused on recovering europium from energy-saving lamps, the Switzerland-based startup is now expanding into recycling rare earths from magnets, which are vital for electric vehicles, wind turbines  and electronics. The team is also running proof-of-concept studies to scale the technology for other REE waste streams. 

Towards the UN Sustainable Development Goals (SDGs) 

Perrin’s work makes rare earth recovery more efficient and sustainable, contributing to SDG 12 (responsible consumption and production) and reducing the needs for REE mining, thereby contributing to SDG 15 (life on land).