EXTRACTION OF RARE-EARTH NITRATES OF THE YTTRIUM SUBGROUP AND Y(III) BY TRI-N-BUTYLPHOSPHATE FROM MULTICOMPONENT SOLUTIONS

Extraction of nitrates of trivalent rare earths of the yttrium subgrou p and Y(III) from multicomponent solutions by tri-n-butylphosphate at 298.15 K and pH2 is studied. Physicochemical and mathematical models d escribing the distribution of the lanthanides (Sm-Lu) and Y(III) in mu lticomponent solutions as a function of the total concentration of the rare earths in the aqueous solution and of the concentrate compositio n are derived.