Penn State scientists have created a new cellulose technology for recovering rare earth elements like neodymium from electronic waste.
Neodymium is in great demand to create strong magnets used in motors for electronics including hybrid cars, aircraft generators, loudspeakers, hard drives and in-ear headphones.
But mineral deposits containing neodymium are hard to reach and are found in just a few places on Earth such as China and other conflict zones.
The only way forward is to recycle these elements from old computers and printed circuit boards – collectively known as electronic waste (e-waste).
But separating such valuable elements from other minerals and components in e-waste has so far proven to be challenging.
Now a Penn State team headed by assistant professor Amir Sheikhi and Patrictia Wamea – a former member of Sheikhi’s lab – have proposed a cost-effective nanotechnology for separating neodymium from e-waste with the help of plant cellulose.
In this new process, ‘hairy’ cellulose nanocrystals bind selectively to neodymium ions, separating them from other ions, such as iron, calcium and sodium.
The nanoparticles are known as ‘hairy’ due to cellulose chains attached to their two ends, which perform critical chemical functions, notes Sheikhi.
Once the nanoparticles attract and bind with the positively charged neodymium ions, they lead to particle aggregation of larger pieces that can then be effectively recycled and reused.
According to Sheikhi, the new process is effective in its removal capacity, selectivity and in its speed:
“It can separate neodymium in seconds by selectively removing the element from some of the tested impurities.”
In addition to e-waste, neodymium can also be extracted from industrial wastewater, mining tails and permanent magnets that are no longer in use.
“This contribution to rare earth recycling will have a strategic and economically-viable impact on several industries,” adds Sheikhi.
“The more neodymium we recycle, the more we can manufacture electric and hybrid vehicles and wind turbines, leading to less strain on the environment.”
Image and content: Kate Myers/Penn State University