C. Tolbert, C. Stetson, D. Prodius, C. Orme, D. Appy, I. Nlebedim, A. Wilson
Idaho National Laboratory,
United States
Keywords: crystallization, drying, lanthanides, battery materials, primary recovery, recycling, waste treatment
Summary:
Lanthanides are important to many technologies including magnets used in high efficiency traction motors. While common in the environment and industrial waste streams, lanthanides are often present at very low concentrations. This presentation will discuss the synergistic lanthanide recovery from an aqueous magnet leachate to single ppm concentrations using Na2SO4 addition and subsequent dimethyl ether fractional crystallization (DME-FC) treatment. It was found that combining DME-FC with low concentrations of Na2SO4 (~0.1 M) results in synergistic isolation of lanthanides while making use of Na2SO4, an excessive byproduct of hydrometallurgical metal production. Combined Na2SO4 + DME reduced lanthanide metal ion’s (Pr, Nd, Sm, Gd, Dy, and Ho) solubilities by 1,000-25,000x with final concentrations ranging from 2ppm to 200ppm. This can be compared to Na2SO4 0.1 M alone providing a 10-200x reduction and DME providing a 100-1,500x reduction in lanthanide solubilities. Final solution concentrations of lanthanides were 99.8% lower than what could not be achieved with either individual process. The results also reveal different periodic trends in the solubility reduction for DME and Na2SO4. The presentation will also discuss the recovery of battery salts from solutions and critical materials from seawater with DME FC as well as the drying of critical material slurries and byproducts using DME as a liquid desiccant.