Efficient separation of REEs from low grade sources

CMI researchers from Idaho National Laboratory conducted the activity for this highlight

Innovation

Working electrodes with plate and three-dimensional meshes were incorporated into an electrochemical membrane reactor (EMR) system for efficient separation of low value and high value materials with minimal chemical consumption and waste generation.

Achievement

  • Iron removal from 4900 ppm to 5 ppm; Cu, Pb, Cr and Zr removal to 1 ppm, ~90% removal of Al from a simulated red mud solution.
  • 93% to 99% of Y (~209 ppm), La (~96 ppm), Ce (~1 ppm) and Nd (~267 ppm) retained in solution for subsequent isolation.
  • Recovery of excess acid from leachate.

Significance and Impact

The EMR can cost effectively separate valuable materials and recover  REEs from the leachate of secondary and unconventional sources such as mine tailings, E-waste and industrial wastewater.

Gub Target Addressed

  • Minimizing hazardous chemical use and waste generation.
  • Efficient co-recovery of materials.
bar chart shows selectivity of the electrochemical membrane reactor (EMR)
The selectivity on the y-axis represents the ability of EMR to separate low value materials and REEs into two different phases from simulated leachate. For example, the definition of Y to Fe selectivity is (CY separated/ CY initial)/ (CFe separated/ CFe initial).