Metal impurity removal and Ni/Co crystallization

Ammonium phosphate addition [1-4] in precipitating Al and Fe phosphate salts (white solids) from EC-leachate solution
Ammonium phosphate addition [1-4] in precipitating Al and Fe phosphate salts (white solids) from EC-leachate solution

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

InnovationChemical treatment discovered with two important results:

  • Metal impurities Al and Fe are removed from LIB leachate
  • A Ni/Co sulfate double salt is recovered.*  

Achievement 
Ammonium phosphate addition to electrochemically produced leachates  induces Al and Fe precipitation (up to 99% Al and Fe yield) at pH 3-4. After filtration, Tutton’s salt crystals of Ni/Co ammonium sulfate crystallize.

Significance and Impact

  • Reduces consumable acids and bases (pH swings) required by other pretreatment processes without additional water consumption. 
  • Minimal interference to recovery of high value metals Co, Ni, Mn & Li.
  • After Al and Fe precipitates are filtered, Ni/Co crystals form in the parent solution (25-35% recovered).
  • Next steps: Assess compatibility and integration with current metal recovery methods (solvent extraction, ion-exchange, precipitation, and electrodialysis)

Hub Target Addressed 
Recovery and conversion into high value end products
 

Tutton’s salt Ni/Co ammonium sulfate crystal from filtered EC-leachate solution. Crystal is comprised of 86% Ni and 14% Co with 25-35% Ni/Co recovered.
Tutton’s salt Ni/Co ammonium sulfate crystal from filtered EC-leachate solution. Crystal is comprised of 86% Ni and 14% Co with 25-35% Ni/Co recovered.