The Mutual Separation of ^<227>Ac, ^<227>Th, ^<223>Ra, and ^<223>Fr by the Solvent Extraction Technique Using Bis(2-ethylhexyl)phosphoric Acid as an Extractant(Chemistry)

The separation and purification of ^Ac, ^Th, ^Ra, and ^Fr were studied by the solvent extraction method using HDEHP (bis(2-ethylhexyl)phosphoric acid) as an extractant. The mutual separation of Ac, Th, and Ra was achieved, and new milking processes for ^Fr and ^Ac are presented

Reductive Extraction of Actinides and Lanthanides from Molten Chloride Salt into Liquid Zinc

As one of the basic investigations on the group partitioning of actinides and lanthanides by pyrochemical reductive extraction system, their distribution behavior in a binary phase system of molten chloride and liquid zinc was studied, Generally speaking, actinides were a litte more easily reduced and extracted from the salt phase into the metal phase than lanthanides. However, the separation factors which were the differences in the distribution coefficient between actinides and lanthanides were not so large even at lower temperatures, and the group partitioning of these elements seemed less attractive in this system. The present results were much the same as those in the LiF-BeF_2/Zn system and the effect of the selection of the salt phase on the separation factors were hardly observed. For some details, the thermodynamic quantities of actinides and lanthanides in the system were calculated from the equilibrium distributions and discussed

Revaluation of equilibrium quotient between titanium ions and metallic titanium in NaCl–KCl equimolar molten salt

In this study, the effect of oxide ion on the equilibrium between titanium ions and metallic titanium was investigated in NaCl–KCl equimolar molten salt. The soluble species containing Ti^[3+] and O^[2−] was not confirmed in the molten salt by absorption spectroscopy. The result of XRD for the solidified sample containing Ti^[3+] and O^[2−] implies that O2− reacts with Ti^[3+] and Cl^− to form TiOCl(s). The concentration quotient of the equilibrium between titanium ions (Ti^[2+], Ti^[3+]) and metallic Ti, Kc, was revaluated at 740℃ as follows:3Ti^[2+]⇄2Ti^[3+]+Ti, Kc=8.0×10^[−2] mol L−1=1.2×10^[−1] mol kg^[−1]. In addition, the solubility product of TiOCl(s) in NaCl–KCl equimolar molten salt, Ksp, at 700℃ was determined using the results of absorption spectra, Ksp=1.2×10^[−2] mol^2 L−2=5.1×10^[−3] mol^2 kg^[−2]

Raman spectroscopic study on NpO[2](+)–Ca(2+) interaction in highly concentrated calcium chloride

Coordination circumstance of neptunyl ion in concentrated CaCl[2] solutions was analyzed by Raman spectrometry. Besides the symmetric stretch (ν[1]) mode of NpO[2](+) and NpO[2](2+), the asymmetric stretch (ν[3]) mode of NpO[2](+) was found. The Raman intensity of the ν[3] mode increased with the concentration of CaCl[2] in the system. This would be attributable to the cation–cation interaction between Np(V) and Ca(II)

Quantitative analysis of neodymium, uranium, and palladium in nitric acid solution by reflection absorption spectrophotometry

Quantitative analysis of Nd, U, or Pd in 3 mol dm[−3] (M) HNO3 was performed by reflection absorption spectrophotometry at ultraviolet–visible–near-infrared (UV/Vis/NIR) region. A sample chamber with optics for reflection measurement was designed and attached to a UV/Vis/NIR spectrophotometer by optical fibers. The reflection absorbance showed linear relations with concentrations of Nd, U, and Pd at the absorbance region less than 0.1. The quantitative analysis was found to be possible for 3 M HNO3 solutions containing [Nd] ~0.2 M, [U] ~0.04 M, or [Pd] ~0.01 M