Isolation of Ni/Co-rich salt crystals from low pH solutions

image of two green samples, left is Dimethyl ether fractional crystallization (DME-FC) reaction vessel containing ion exchange column strip solution. Right is Solid Product on stainless-steel nucleation scaffold.
Left: Dimethyl ether fractional crystallization (DME-FC) reaction vessel containing ion exchange column strip solution.

Right: Solid Product on stainless-steel nucleation scaffold.

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

Innovation 
Dimethyl ether fractional crystallization (DME-FC) produced Ni and Co enriched crystals from a highly acidic solution (pH = -0.75) without consuming chemicals.

Achievement

  • DME-FC is compatible with acidic aqueous streams, including leachates, solvent extraction solutions, and ion exchange stripping solutions.
  • Selective crystallization of Ni and Co, while Li, Mn, and Fe preferentially remain in solution.

Significance and Impact

  • DME-FC avoids the use of base/evaporation and generation of waste (brine byproducts) in the purification and isolation of battery salt solids.
  • Allows the reuse of the acidic solutions.

Hub Target Addressed 
Advancing next-generation atom- and energy-efficient separations for multiple applications.

table shows atomic absorption spectroscopy compositional analysis of the original solution and solid product, with the separation factors for the DME-Driven Fractional Crystallization
Atomic absorption spectroscopy compositional analysis of the original solution and solid product, with the separation factors for the DME-Driven Fractional Crystallization listed below.