Rationally designed rare earth separation by selective oxalate solubilization

Ionic radii and comparative extraction factor as a function of different REEs.
Ionic radii and comparative extraction factor as a function of different REEs. 

CMI researchers at Ames Laboratory conducted the research for this highlight

Achievement
A simple, environmentally benign and efficient process for chemical separation of rare earth oxalates (CSEREOX), within two rare earth element subgroups was developed. 

Significance and impact

  • Separation of REEs is performed in aqueous media at neutral pH which minimizes operations with mineral acids.
  • Process was demonstrated for recovery of Dy from magnets, which are typically very diluted (<5%).
  • The process is applicable to feedstock derived from ores & recycling, including e-wastes.

Next steps

  • Identify conditions to increase Dy separation efficiency to =95% (currently at 68%) for e-wastes applications. 
  • Work to secure a patent, which is pending: US20190160394A1.
Graphical abstract for publication highlighting the ability to separate within two REE subgroups.
Graphical abstract for publication highlighting the ability to separate within two REE subgroups.