Purification of electrowon Nd via chloride molten salt electrolysis

SEM image in Figure (a) shows electrowon Nd with Nd metal (bright spots) surrounded by byproducts (dark area). The byproducts, identified as Cl and K by EDS, were removed using an arc-melting system.
SEM image in Figure (a) shows electrowon Nd with Nd metal (bright spots) surrounded by byproducts (dark area). The byproducts, identified as Cl and K by EDS, were removed using an arc-melting system.

CMI researchers from Lawrence Livermore National Laboratory and Case Western Reserve University conducted the activity for this highlight

Innovation
First fully sustainable Nd electrowinning process enabled by novel reactor designs and a dimensionally stable anode that reduces greenhouse gas emissions.

Achievement
Arc-melting process enabled the production of Nd metal (95 atomic percent purity achieved) without Cl residue from electrowon Nd. 

Significance and Impact

  • Nd metal production at 2.3 kWh/kg energy consumption vs. 3.3 kWh/kg state-of-art, with corresponding GHG reduction.
  • Eliminated Cl from  deposit, increasing Nd purity to >95 at.% in large regions.
  • Significantly reduced GWP as confirmed through LCA .

Hub Goal Addressed
Decarbonized rare earth metals production.

The highest purity Nd by EDS is about 95 at.%, visible in the bright area in Figure (b). 
The highest purity Nd by EDS is about 95 at.%, visible in the bright area in Figure (b).