Statistics show that less than 1% of the rare earth elements contained in e-waste in Europe is recovered. This makes the region highly dependent on the supply of strategic raw materials from China. however, they can now be profitably recovered from e-waste locally. Scientists from Switzerland have taken a step in this direction by creating a technology to quickly and cheaply extract rare earth elements from obsolete equipment.
A team of chemists from ETH Zurich set out to profitably extract rare earth elements from waste, although technically these same reactions can be used to obtain valuable raw materials from ore. Rare earth elements are chemically bound to other substances in both products and ores, but e-waste recycling is one level higher in environmental priorities and therefore most important for Europe.
The starting point is the study of tetrathiometalates, inorganic molecules containing four sulfur atoms around tungsten or molybdenum. These molecules bind metals in natural enzymes and are even used for anti-cancer therapy and for disorders of copper metabolism in humans. Similarly, tetrathiometalates can be adapted to bind rare earth elements in compound solutions.
Scientists began their work with tetrathiometalates by extracting europium from the phosphor layer of fluorescent lamps. In recent years, Switzerland has been getting rid of fluorescent lights, including energy-saving ones, sending them to landfills outside the country. Together with the lamps, potentially valuable raw materials are lost, which also end up in landfills. In the process of experiments, scientists are developing a technology for profitable extraction of europium from the luminophore of lamps.
Furthermore, the proposed solution helps recover 50 times more europium from scrap compared to previous alternative processes. Riding the wave of success, the group of scientists has created a start-up company called REEcover to commercialize the technology to extract rare earth elements from e-waste and promises to similarly extract other rare chemicals that Europe desperately needs by extracting them from waste.