Protein process may transform rare earths recovery

A naturally occurring protein has been found to have the power to extract and purify rare earth elements from complex metal mixtures. A consortium of three US universities say lanmodulin is the magic ingredient behind a new one-step recycling process.

The researchers believe lanmodulin provides an alternative to chemical processes in the recovery of rare earths from electronic scrap and pre-combustion coal. The solution does no harm to the environment, according to scientists at the Lawrence Livermore National Laboratory (LLNL) who are partners with Pennsylvania State University and Idaho National Laboratory.  

‘Lanmodulin has several unique and exciting properties. We were all amazed to discover that a natural protein can be so efficient for metal extraction,’ says project supervisor Gauthier Deblonde of LLNL. ‘I have worked on many molecules for metal purification but this one is really special.’

This is because the protein is the most relevant macromolecule characterised to date and is able to tolerate challenging industrial conditions such as low pH, high temperature and molar amounts of competing ions.

‘Leveraging biomolecules for metal recovery technologies is appealing since most biochemical processes occur with quantitative yields, fast kinetics and high selectivity and fidelity,’ notes Deblonde.

Test results also shows that bio-sourced macro-molecules outperform man-made chelators – small synthetic molecules that bind very tightly to metal ions. ‘As such, they may bring a shift to the currently highly constrained and non-sustainable methods used for rare earth extraction and purification.’

The R&D project is funded by the US Department of Energy’s Energy Innovation Hub and the Critical Materials Institute.