LIQUID–LIQUID EXTRACTION OF RARE EARTH ELEMENTS WITH MONO-2-ETHYLHEXYL ETHER OF 2-ETHYLHEXYLPHOSPHONIC ACID

The liquid–liquid extraction of rare earth elements with mono-2-ethylhexyl ether of 2-ethylhexylphosphonic acid from chloride and nitrate solutions has been studied. The highest distribution coefficients were achieved at pH ≥ 1 in the aqueous phase. The time required to reach extraction equilibrium was determined, and the liquid–liquid extraction isotherm was obtained. We demonstrated the possibility of separating rare earth elements into medium and heavy groups with a separation factor of βmedium/heavy = 20.5.