EXTRACTION EQUILIBRIA OF RARE-EARTHS BY A NEW REAGENT (2-ETHYLHEXYL-3-PENTADECYLPHENYL) PHOSPHORIC-ACID

A new reagent (2-ethylhexyl-3-pentadecylphenyl) phosphoric acid (EPPA = HR) was synthesized from cardanol (1, 37300-39-5) and was used to in vestigate the extraction behaviour of lanthanum(III), europium(III) an d lutetium(III) from hydrochloric acid solutions. The species extracte d were found to be Ln(HR2)3 (where Ln = La(III) or Eu(III) or Lu(III)) . The extraction behaviour of the above lanthanides has also been comp ared with yttrium and other rare earths. It was observed that the extr action increases with increase in atomic number of rare earths. In add ition, the extraction efficiency of EPPA has also been compared with w ell known acidic organophosphorus extractants like di-2-ethylhexyl pho sphoric acid (DEHPA), 2-ethylhexyl-mono-2-ethylhexyl phosphoric acid ( EHEHPA).