Tomatoes and corncobs used to salvage rare earth elements

iMeche | Tomatoes and corncobs used to salvage rare earth elements

Tomatoes, corncobs and other organic materials have been used to capture rare earth elements from electronic waste, offering a potential alternative to environmentally damaging mining practices.

Researchers from Penn State university in Pennsylvania used micro- and nanoparticles created from the organic materials to capture neodymium from aqueous solutions.  

“Waste products like corncobs, wood pulp, cotton and tomato peels often end up in landfills or in compost,” said assistant professor Amir Sheikhi, a corresponding author of a paper on the work. “We wanted to transform these waste products into micro- or nanoscale particles capable of extracting rare earth elements from electronic waste.”  

Rare earth metals are used to manufacture strong magnets used in motors for electric and hybrid cars, loudspeakers, headphones, computers, wind turbines, TV screens and more. Mining these metals is challenging and environmentally costly, Sheikhi said, as large land areas are required to mine even small amounts of the metals. Some efforts have turned to recycling the metals from electronic waste like old computers or circuit boards.  

The challenge lies in efficiently separating the metals from refuse, Sheikhi said.