The extraction of Ag+ ions was studied in the systems tetra-n-butyl S-dithiopyrophosphate [(BuO)2P(S)(O)P(S)(BuO)2]—TBDTPP in CCl4/HNO3 and TBDTPP/LiNO3. The extraction coefficients were determined as a function of the electrolyte and TBDTPP concentration. Infrared absorption
studies have been undertaken to obtain information on the changes in the organic phase during the extraction of Ag(I). Analysis
of the spectra has shown a shift of the P=S stretching band in the direction of lower frequencies. This is indicative of bond
weakening and a decrease in the double bond character of P=S, due to withdrawal of electron density by the metal ion, and
constitutes evidence for the coordination of Ag+ by thiophosphoryl groups of TBDTPP.
The extraction of uranium was studied in the system of 0.1 M OETAPP in CHCl3/HCl or HNO3. The distribution coefficients of HCl and HNO3 were calculated as a function of OETAPP concentration. The amount of OETAPP in the aqueous phase containing HCl and HNO3 was found from the measurements of surface tension of this phase. The distribution of HCl and HNO3 between an organic and aqueous phase was studied as a function of the concentration in the aqueous phase of the acid in question.
The solvation energy of the extracted complexes was calculated on the basis of the measured potential differences. The cohesion
and adhesion energies of the studied systems are given as well.
Ferric nitrate and ferric chloride were extracted from HNO3 and HCl solutions with 0.1M OETAPP. The composition of the extracted complexes was determined by the dilution method. Extraction
from HNO3 and from 8 and 10M HCl leads to the formation of the monosolvate Fe(NO3)3 (OETAPP) whereas 6M HCl yielded the disolvate. The solvation energy for FeCl3 (OETAPP) has been determined from the hydration energy of FeCl3 combined with the experimental electromotive forces of cells corresponding to the extraction systems.
Authors:P. Grychowski, B. Petelenz, and J. Mikulski
The influence of perchloric acid and hydrogen peroxide concentrations on the elution rates of vanadium and titanium from Dowex-50W X 8 resin was studied. The amounts of perchloric acid and of hydrogen peroxide were adjusted to provide an optimum eluent for the separation of vanadium from the irradiated titanium (TiO2) target.
The extraction of thorium and hafnium was studied in the system of 0.1M OETAPP in CHCl3/HCl or HNO3 at acid concentrations of 1–10 M. It has been found by the dilution method that under the experimental conditions mono- and
disolvates of thorium nitrate or hafnium chloride, the disolvate of thorium chloride or the monosolvate of hafnium nitrate
are formed. The solvation and hydration energies of thorium chloride in the system of 1M ThCl4 in 1M HCl−1M OETAPP in CHCl3 as well as their difference were calculated.
Authors:P. Grychowski, J. Mikulski, J. Moravec, V. Šára, and L. Šourkova
The infrared spectra of the complexes UO2 (NO3)2-octaethyltetraamidepyrophosphate (OETAPP) and UO2 Cl2-OETAPP were investigated to test their formation and structure. Under the experimental conditions used, a stoichiometry of
1∶1 was found for both complex types.