In the lab, proteins separate rare earths at over 90% purity

A mixed stream of minerals enters a separation process, and two nearly similar elements emerge apart: Battelle researchers used engineered proteins to separate lanthanum and neodymium in a single laboratory stage. The tests delivered more than 90% purity and yield, according to the results reported by Interesting Engineering.

The trick is to borrow biology's selectivity. Battelle modified calcium-binding peptides so they interact with particular rare earth elements at the molecular level. Instead of relying on repeated chemical processing, the proteins recognize target elements inside a mixed material stream; tests also removed non-rare-earth ions from simulated leachates and industrial feedstock materials.

That matters because separating rare earths is one of the hardest steps in the mineral supply chain. The elements often behave similarly during conventional chemical separation. Yet individual materials are needed for permanent magnets in electric vehicles and wind turbines, and they also appear in smartphones, defense equipment and advanced computing hardware.

And so what, concretely? If the approach survives scale-up, a processor could gain another route for recovering strategically important materials in the United States, potentially with fewer processing stages. The current result does not show that an industrial plant can do this: researchers still have to determine how the proteins handle different feedstocks, how they are produced and recovered in large quantities, and whether they remain durable over repeated processing cycles while costs stay under control.

The work was supported through DARPA's Environmental Microbes as a Bioengineering Resource program. Dr. Kate H. Kucharzyk, a research leader at Battelle, said engineered proteins could add a new tool to mineral recovery. For now, the evidence is a laboratory demonstration, not a commercial separation system.