Solvent extraction of protactinium with tri-iso-octyl-amine (TIOA) in xylene, benzene, carbon tetrachloride and chloroform
from HCl, HF, HNO3, HClO4 and H2SO4 media was studied using 233Pa as a radiotracer. The extraction efficiencies of protactinium were determined as a function of shaking time, concentrations
of mineral acids in aqueous phase, extractant concentrations and diluents in organic phase. The extraction mechanism was discussed.
The results show that the extracted species in the organic phase is [(R3N−H)nPa(OH)xCl