Electro-separation of lithium from brines

Lab-scale electrochemical flow cell
Lab-scale electrochemical flow cell 

CMI researchers from Idaho National Laboratory and University of Texas Rio Grande Valley conducted the activity for this highlight

Innovation 
A two-step lithium recovery method separates and concentrates lithium from brine sources. Carbon dioxide captured by a recyclable agent is used to mineralize divalent metal ions and remove them from solution, and electrodialysis further purifies and concentrates the Li.

Achievement

  • >80% of lithium is recovered from brine surrogate solutions.
  • >99% of divalent metal ions are precipitated as carbonate salts.
  • >75% of the reagent used for CO2 capture is recycled.
  • A patent based on this technology has been elected.

Significance and Impact

  • Development of sustainable lithium recovery technology applicable to domestic resources.
  • Use of greenhouse gas, CO2, to mineralize Ca2+ and Mg2+.
  • Next step: Development of improved electrodialysis membranes for Li purification.

Hub Target Addressed 
Recovery or purification processes to expand U.S. lithium production.

Step 1 Process Products: Metal carbonates (e.g., CaCO3) Reagent for CO2 capture (upper phase) and concentrated LiOH with NaOH and KOH in the lower aqueous phase.
Step 1 Process Products: 
Metal carbonates (e.g., CaCO3)
Reagent for CO2 capture (upper phase) and concentrated LiOH with NaOH and KOH in the lower aqueous phase.