Gas-driven REE separation

Recovered Sm-Rich Solids

CMI researchers at Ames Laboratory and Idaho National Laboratory conducted the research for this highlight


  • Gas sparging of a concentrated Sm-Co-Fe leachate under pressure produces high purity Sm crystallites
  • Dissolved gas drives selective precipitation of Sm; Co and Fe retained in aqueous phase
  • Nucleation Scaffold grants surface selectivity

Significance and impact

  • Reagent-free treatment to produce a highly selective separation
  • No lasting impact to solution chemistry 
  • Reduced reagent costs
  • No heating/cooling requirements
  • >99% purity Sm sulfate product

Next steps

  • Develop pathways for subsequent metal separations and supernate reuse
  • Investigate additional REE leachates
Recovered Sm-Rich Solids