In order to clarify the extraction process with saponified extractant

the solvent extraction experiments of rare earth elements (REEs)

lanthanum and cerium

by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA

HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010-0.1000 mol·L

-1

; EHEHPA in a range of 0.2877-0.8631 mol·L

-1

with saponification rate of 0.3 (mole fraction)

and the initial aqueous pH in a range of 1.00-4.00. Firstly

the extracted species were determined by the saturation extraction capacity method. Secondly

according to the equilibrium aqueous pH values

the extraction processes were divided into three different categories: extraction with saponified EHEHPA

extraction with un-saponified EHEHPA

and hydrolysis process. Finally

for the first two processes

in order to predict the distribution ratio

two semi-empirical calculation models were developed with. The calculation results are in good agreement well with the experimental data.