Recovering critical materials: gold, neodymium, and tantalum.
Researchers from Flinders University proposed a new extraction technique for recovering gold from electronic waste and ore that avoids the use of mercury and cyanide, which are often used in small-scale gold recycling and mining operations.
“The study featured many innovations including a new and recyclable leaching reagent derived from a compound used to disinfect water,” said Justin Chalker, a professor of chemistry at Flinders University’s College of Science and Engineering, in a statement. “The team also developed an entirely new way to make the polymer sorbent, or the material that binds the gold after extraction into water, using light to initiate the key reaction.”
The new process uses trichloroisocyanuric acid, a low-cost and benign compound that is widely used in water sanitation and disinfection. When activated by salt water, the reagent can dissolve gold. The gold can then be selectively bound to a novel sulfur-rich polymer developed by the team. The selectivity of the polymer allows gold recovery even in highly complex mixtures. Finally, the gold can then be recovered by triggering the polymer to “un-make” itself and convert back to monomer. This allows the gold to be recovered and the polymer to be recycled and re-used. [1]
Researchers from IOCB Prague developed a new method for separating lanthanides, or rare earth elements, that allows neodymium or dysprosium to be purified from used neodymium magnets. The process was used to recycle a magnet from an electric car, which resulted in 99.7% pure neodymium.
“We’ve developed a new type of chelator, which is a molecule that binds metal ions. This chelator specifically precipitates neodymium from dissolved magnets, while dysprosium remains in solution, and the elements are easily separated from each other. The method is also adaptable for the other rare earths found in neodymium magnets,” said Kelsea G. Jones, a doctoral student and researcher at IOCB Prague, in a press release. “The separation is done in water and generates no hazardous waste. We achieve the same or better results than current industrial methods that rely on organic solvents and toxic reagents.”
The process is currently undergoing a feasibility study that will direct commercialization efforts. [2]
Researchers from West Virginia University used microwaves to improve the recovery of critical materials like tantalum, gallium, and indium from discarded electronics.
The approach involves shredding electronic waste, mixing it with fluxes that trap impurities, and heating the mixture with microwaves. Carbon, in the form of plastics and adhesives in e-waste, heats rapidly and reacts with the small amount of critical materials present in the mixture, producing a pure, sponge-like metal. In tests, the team was able to recover about 80% of the gallium, indium, and tantalum from e-waste, at purities between 95% and 97%.
The team plans to launch larger pilot projects next to test the method on smartphone circuit boards, LED lighting parts, and server cards from data centers as part of fine-tuning the recycling process for large-scale applications. [3]
[1] Mann, M., Nicholls, T.P., Patel, H.D. et al. Sustainable gold extraction from ore and electronic waste. Nat Sustain (2025). https://doi.org/10.1038/s41893-025-01586-w
[2] Jones, K. G., David, T., Loula, M. et al. Macrocyclic Chelators for Aqueous Lanthanide Separations via Precipitation: Toward Sustainable Recycling of Rare-Earths from NdFeB Magnets. Journal of the American Chemical Society 2025. https://doi.org/10.1021/jacs.5c04150
[3] Pokharel, A., Jayasekera, K.S., Sabolsky, E.M. et al. Microwave-assisted recycling of tantalum and manganese from end-of-life tantalum capacitors. Sci Rep 15, 12366 (2025). https://doi.org/10.1038/s41598-025-96574-7
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