Breakthrough Technology Saves Europium from Wasteland
Rare Earths: The Critical Materials of the Energy Transition and Digitalization
Europium, along with 16 other rare earth elements, is a crucial component in the development of wind turbines, car batteries, displays, and other energy-efficient technologies. However, these elements are often difficult to extract and recycle, with less than 1% of rare earth metals currently being recovered.
New Method Allows for Efficient Europium Recovery from Old Light Bulbs
A recent breakthrough in recycling technology has made it possible to recover europium from used energy-saving light bulbs. According to a study published in Nature Communications, europium can be easily and efficiently extracted from old light bulbs using a new method developed by researchers at ETH Zurich.
The Power of Minor Differences
The key to this process lies in the minor differences in the chemical properties of europium and other rare earth elements. Europium, unlike its related elements, is easier to reduce and can transform into a bivalent form (Eu2+) under certain conditions.
The Zurich Solution
The researchers used used energy-saving light bulbs containing europium-doped yttrium oxide (Y2O3:Eu3+) as a phosphor as the source material. They crushed the bulb, extracted the dye, and filtered out all remaining components. After drying, they obtained a powder – essentially the phosphor. They then mixed this powder with a solution of tetrathiotungstate, a compound with properties similar to those found in enzymes and involved in electron transfer.
Results
The process resulted in the recovery of around 99% of the europium contained in the light bulbs. This single-step method could prove more practical than conventional multi-stage extractions.
Next Steps
The experts working with Marie Perrin from ETH Zurich now aim to extend the process to other rare earth elements.
Reference
Recovery of europium from E-waste using redox active tetrathiotungstate ligands (https://www.nature.com/articles/s41467-024-48733-z)