Rare earth recycling from electronic waste approaches commercialisation
March 1, 2022
In 2018, a team of researchers from the US Department of Energy’s Critical Materials Institute (CMI) at Ames Laboratory, Iowa State University, USA, developed a novel way to extract rare earth elements from high-powered magnets in electronics waste. TdVib LLC, a manufacturer specialising in activated smart materials and electromagnetic technologies, has now signed a license agreement to commercialise the technology.
Licensing to TdVib is an important step in the technology’s progress from lab to commercialisation. The company was initially awarded a Phase I and then Phase II Small Business Technology Transfer (STTR) funding, which encourages small businesses to pursue federal research and development with potential for commercialisation.
Ikenna Nlebedim, the lead researcher on the recycling project, explained that big companies shred certain electronics items – such as computer hard drives – to protect the information on them. Once these drives are shredded, recycling has traditionally been more complex, because most recycling methods depend on separating the magnets from other materials. The CMI’s recycling process, however, is designed to extract the rare earths directly from shredded e-waste.
“We take that shredded mix and we put it in solution, but our solution targets the magnet – and it leaves the rest of the components of the mixture undissolved – and dissolves the magnet that contains the rare earths,” explained Nlebedim. “So, with the rare earth in solution, we filter off the rest of the e-waste and later pull the rare earth out of the solution. And that’s how we do our recycling. It’s a very efficient and robust process.”
This recycling technology is said to have an advantage over other processes because the solution used to dissolve magnets is water- rather than acid-based. Nlebedim explained that the process begins without acids and the byproducts are treated to eliminate acid-contaminated wastes, which makes it more environmentally friendly.
Other recycling processes involve heating the e-waste to temperatures above 316ºC to demagnetise the magnets. The CMI process does not require pre-heating, which translates to a reduction in pollution and energy usage.
Since the solution used in this process is copper-based, the processed e-waste is infused with copper. This copper can either be recovered or reused in other operations. Copper is the key to making the process economically viable and environmentally friendly.
Another important aspect of the technology is its scalability. Upscaling processes from the lab to larger operations often leads to unexpected problems. However, according to Dan Bina, president and CEO of TdVib, upscaling has improved this process.
”It is typical for efficiency to decrease during scaling of new processes, but we have observed the opposite with the acid-free dissolution process, without compromising the purity,” Bina stated. “We have increased the leaching efficiency of rare earths from magnets contained in shredded hard drives from around 70% obtained during laboratory research to 90% in our facility. For pre-concentrated magnets the dissolution efficiency can exceed 98%.”
As part of the STTR Phase II, which is now in progress, CMI aims to produce three to five tons of rare earth oxide in the next one to two years.
