Rare earth metals production using alternative feedstock that eliminates HF

Area of Science:

• Materials Science
• Metallurgy
• Green Chemistry

Background:

• Rare earth (RE) metals are crucial for permanent magnets, supporting clean energy technologies.
• Current RE metal production relies on RE-fluoride, which requires hazardous chemicals like hydrofluoric acid (HF).
• Existing methods pose significant safety and environmental challenges.

Purpose of the Study:

• To develop a safer and more environmentally friendly method for producing rare earth metals.
• To demonstrate the efficacy of Na-RE-F as an alternative precursor salt.
• To reduce reliance on hazardous chemicals in RE metal synthesis.

Main Methods:

• A scalable hydrometallurgical approach was used to synthesize Na-RE-F salts from various RE feedstocks (acetate, nitrate, chloride).
• The synthesis process completely avoids the use or generation of hydrofluoric acid (HF).
• Calciothermic reduction of the synthesized Na-RE-F was performed at temperatures below 900°C.

Main Results:

• Na-RE-F salts were successfully produced without HF, and the resulting powder is stable in air.
• The in-situ formation of NaF flux during heating lowered the reduction temperature.
• Rare earth metals were successfully produced via calciothermic reduction of Na-RE-F.

Conclusions:

• The Na-RE-F route offers a safer, greener, and more scalable alternative for rare earth metal production.
• This method supports the sustainable manufacturing of critical materials for decarbonization efforts.
• The process minimizes hazardous chemical usage and simplifies production steps.