A research team at ETH Zurich develops a process for extracting europium from old fluorescent light bulbs.
Rare earths are an important component of numerous green and digital technologies. The demand for these critical raw materials is growing, while their production is highly concentrated geographically. Recycling, therefore, plays an important role in the efforts of many countries to achieve greater raw material autonomy; the EU, for example, is aiming for a 25 percent share in its Critical Raw Materials Act – but so far, less than one percent of rare earths are being recycled due to a lack of economic viability. A research team from ETH Zurich in Switzerland wants to change this: Using a new process, the rare earth element europium can be extracted quickly and efficiently from old fluorescent lamps.
According to the scientists, their development was inspired by nature, or more precisely, by certain molecules known as tetrathiometallates, which serve as a binding site for metals in enzymes. With their help, europium could be separated from other rare earths in significantly fewer steps and in quantities at least 50 times higher than in previous methods.
Marie Perrin, the doctoral student involved in the project, explains that the new process could also reduce dependence on raw material imports and the high volume of electronic waste. In the past, fluorescent lamps were a central field of application for europium, but they are now gradually being withdrawn from circulation and often sent abroad from Switzerland for disposal. Instead, the lamps could become urban mines for europium, says Perrin.
The research team is now working on extending the approach to other rare earths. They also want to put their recycling method into practice with a start-up.
More urban mining: A UN report recently noted that billions of euros worth of raw materials is lost in electronic waste and called for significantly more recycling. Numerous companies have long recognized the increasing importance of this type of resource recovery and have launched corresponding projects, including Heraeus and Vacuumschmelze in Germany, Solvay in France, and Mkango in the UK.
Photo: iStock/Dirk von Mallinckrodt
