INFLUENCE OF KINETIC-PROPERTIES OF EXTRACTION SYSTEMS ON THE SEPARATION AND PRECONCENTRATION OF SOME ELEMENTS BY COUNTERCURRENT CHROMATOGRAPHY

The influence of kinetic properties of several extraction systems on the separation of some elements by countercurrent chromatography (CCC) has been studied. The chromatographic behaviour of Eu(III), Fe(III), Ta(V), Nb(V), Hf(IV), Zr(TV) has been investigated in two kinetically different extraction systems on the basis of di-2-ethylhexylphosphoric acid (D2EHPA) and tetraphenylmethylenediphosphine dioxide (DTPMDP). It has been shown that the values of mass transfer coefficients determine the type of elution (isocratic or step), which is necessary for the element separation. The data on batch extraction (mass transfer coefficients and partition coefficients) and parameters of chromatographic peaks (half-widths) can be interrelated by the expression proposed.