scholarly journals Separation of Micro-Macrocomponent Systems: 149Pm – Nd, 161Tb-Gd, 166Ho-Dy and 177Lu-Yb by Extraction Chromatography

2017 ◽  
Vol 59 (2) ◽  
Author(s):  
F. Monroy-Guzman
Keyword(s):  
Neutron Irradiation ◽  
Radiochemical Separation ◽  
Extraction Chromatography ◽  
Distribution Coefficients ◽  
Separation Factors ◽  
Daughter Radionuclide ◽  
Separation Conditions

<p><sup>149</sup>Pm, <sup>161</sup>Tb,<sup> 166</sup>Ho, and <sup>177</sup>Lu have advisable nuclear properties to be used in radiotherapy. They can be produced by neutron irradiation of a lanthanide target followed by β<sup>-</sup> decay and a posterior radiochemical separation of micro-amounts of daughter radionuclide from macro-amounts of the parent target. In order to accomplish the radiochemical separation of micro-macro systems: Nd/<sup>149</sup>Pm, Gd/<sup>161</sup>Tb, Dy/<sup>166</sup>Ho and Yb/<sup>177</sup>Lu, this work proposes the use of an extraction chromatographic with Ln SPS resin.  Distribution coefficients and separation factors were determined and established the separation conditions of these micro-macro systems.</p>

scholarly journals Separation of tungsten and rhenium on alumina

2004 ◽  
Vol 69 (8-9) ◽  
pp. 683-688 ◽  
Author(s):  
Jurij Vucina ◽  
Dagoljub Lukic ◽  
Milovan Stoiljkovic
Keyword(s):  
Nitric Acid ◽  
Sodium Chloride ◽  
Aqueous Phase ◽  
Aqueous Media ◽  
Distribution Coefficients ◽  
Experimental Conditions ◽  
Efficient Separation ◽  
Separation Factors ◽  
Ph Range

The conditions for the efficient separation of tungsten(VI) and rhenium (VII) on alumina were established. The distribution coefficients K d for tungstate and perrhenate anions, as well as the separation factors ?(? = KdWO42-/Kd ReO4-) were determined using hydrochloric or nitric acid as the aqueous media. Asolution of sodium chloride in the pH range 2?6 was also examined. Under all the tested experimental conditions, alumina is a much better adsorbent for tungsten than for rhenium. The obtained results indicated that the best separation of these two elements is achieved when 0.01? 0.1 mol dm-3HCl or 1.0mol dm-3 HNO3 are used as the aqueous media. If NaCl is used as the aqueous phase, the best separation is achieved with 0.20 mol dm-3 NaCl pH 4?6. Under these experimental conditions, the breakthrough and saturation capacities of alumina for tungsten at pH4 are 17 and 26 mg W/g Al2O3 respectively. With increasing pH, these values decrease. Thus, at pH 6 they are only 4 and 13 mg W/g Al2O3, respectively.

(Liquid + Liquid) Equilibrium for Ternary System of (Water + Phenol + Cyclohexane) at T = 298.2 K

2013 ◽  
Vol 3 (2) ◽  
pp. 75-84
Author(s):  
Hossein Ghanadzadeh ◽  
Milad Sangashekan ◽  
Shahin Asan
Keyword(s):  
Ternary System ◽  
Root Mean Square ◽  
Atmospheric Pressure ◽  
Distribution Coefficients ◽  
Mean Square ◽  
Liquid Equilibrium ◽  
Separation Factors ◽  
Experimental Solubility ◽  
Tie Line

Experimental solubility curves and tie-line data for the (water + phenol + 2-ethyl-1-hexanol) system was obtained at T = 298.2 K and atmospheric pressure. The tie-line data was determined by techniques karl-fischer and refractometry. This ternary system exhibits type-2 behavior of LLE. Distribution coefficients and separation factors were measured to evaluate the extracting ability of the solvent. The consistency of the experimental tie-line data was determined through the Othmer–Tobias and Bachman equations. The data were correlated with the NRTL (a = 0.25) and UNIQUAC models and the parameters estimated present root mean square deviations below 0.50%.

scholarly journals Column Separation of Am(III) and Eu(III) by α-Zirconium Phosphate Ion Exchanger in Nitric Acid

2020 ◽  
Vol 4 (1) ◽  
pp. 14
Author(s):  
Elmo W. Wiikinkoski ◽  
Iiro Rautsola ◽  
Junhua Xu ◽  
Risto Koivula
Keyword(s):  
Zirconium Phosphate ◽  
Distribution Coefficients ◽  
Ion Exchanger ◽  
Molar Ratio ◽  
Experimental Conditions ◽  
Column Separation ◽  
Phosphate Ion ◽  
Trivalent Lanthanide ◽  
Separation Factors ◽  
Equimolar Solution

The trivalent lanthanide-actinide separations are a major challenge in reprocessing of nuclear fuels. To achieve this, commonly organic extractants and solvents are utilized in elaborate processes. Here we report a simple new method that can perform a supportive or alternative role. A nanocrystalline α-zirconium phosphate ion exchanger was utilized for Eu(III)/Am(III) column separation. Comprehensive preliminary studies were done using batch experiments to optimize the final separation conditions. The distribution coefficients for Eu were determined as a function of pH (from 0 to 3) and salinity (Na, Sr). The distribution coefficients for Am were determined as a function of pH, and Eu concentration, from 1:40 to 10,000:1 Eu:Am molar ratio. The exchanger always preferred Eu over Am in our experimental conditions. Separation factors (Eu:Am) of up to 400 were achieved in binary Eu-Am solution in pH 1. The breakthrough capacity was determined in dynamic column conditions using Eu: 0.3 meq∙g−1, which is approximately 4% of the theoretical maximum capacity. Two types of hot column separation tests were conducted: (i) binary load (selective Am elution), and (ii) continuous equimolar binary feed. In both cases separation was achieved. In (i), the majority (82% of the recovered 93%) of Am could be purified from Eu with extremely high 99.999% molar purity, while alternatively even more (95% of the recovered 93%) at a lower purity of 99.7 mol %. In (ii), up to 330 L∙kg−1 of the equimolar solution per mass of the exchanger could be treated with Am purity above 99.5 mol % in the total eluate. Alternatively, up to 630 L∙kg−1 above 95 mol %, or up to 800 L∙kg−1 above 90 mol % purities.

Effect of oxide ions on separation factors of actinides from lanthanides in reductive extraction

2009 ◽  
Vol 97 (4-5) ◽  
Author(s):  
Hirotake Moriyama ◽  
K. Moritani ◽  
T. Toda ◽  
H. Hayashi
Keyword(s):  
Distribution Coefficients ◽  
Ion Concentration ◽  
Extraction System ◽  
Separation Factors ◽  
Oxide Ions ◽  
Oxide Ion ◽  
Metal Phases

AbstractThe distribution coefficients of Am, Ce, and Eu between the salt and metal phases were measured at 1073 K in a reductive extraction system of equimolar NaCl-KCl melt and liquid Ga. By changing the solute concentrations, it was observed that the distribution coefficients were dependent on the oxide ion concentration in the system, possibly due to the formation of such compounds as AmO

Simplified and automatable radiochemical separation strategy for the production of radiopharmaceutical quality 86Y using single column extraction chromatography

2018 ◽  
Vol 142 ◽  
pp. 28-31 ◽  
Author(s):  
Eduardo Aluicio-Sarduy ◽  
Reinier Hernandez ◽  
Hector F. Valdovinos ◽  
Christopher J. Kutyreff ◽  
Paul A. Ellison ◽  
...  
Keyword(s):  
Radiochemical Separation ◽  
Extraction Chromatography ◽  
Single Column ◽  
Separation Strategy ◽  
Column Extraction

Preparation and Characterization of a High-Efficient Potassium Adsorbent H8Nb22O59·8H2O

2014 ◽  
Vol 1079-1080 ◽  
pp. 46-49
Author(s):  
Chang Wang ◽  
Peng Fei Cao ◽  
Xiang Long Zhang
Keyword(s):  
Ion Exchange ◽  
Calcination Temperature ◽  
Ph Value ◽  
Distribution Coefficients ◽  
Adsorptive Capacity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
High Efficient ◽  
Separation Factors

The adsorbent of H8Nb22O59·8H2O and the precursor of Rb8Nb22O59 were characterized by X-ray diffraction (XRD), Thermogravimetric and differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The ion-exchange properties of H8Nb22O59·8H2O for Na+ and K+ were also investigated, including the saturation adsorptive capacity, distribution coefficients and separation factor. The results show that the crystallinity of Rb8Nb22O59 was affected by the calcination temperature. The structure of Rb8Nb22O59 was not changed when Rb+ was extracted from Rb8Nb22O59, indicating that this process was topotactical. The calcination temperature and pH value had a significant influence on the ion-exchange capacities of H8Nb22O59·8H2O for Na+ and K+. Specifically, the uptake amouts of Na+ and K+ by H8Nb22O59·8H2O increased with the calcination temperature, while the distribution coefficients of Na+ and K+ for H8Nb22O59·8H2O increased with the pH value. Moreover, the separation factors for K+ was larger than that for Na+ and it increased with the increase of calcination temperature. Overall, the improvement of the crystallinity of H8Nb22O59·8H2O was beneficial to its selectivity for K+.

THE EXTRACTION OF THORIUM AND SOME LOWER LANTHANIDE NITRATES BY DIBUTYL BUTYL PHOSPHONATE

1962 ◽  
Vol 40 (8) ◽  
pp. 1684-1689 ◽  
Author(s):  
P. G. Manning
Keyword(s):  
Nitric Acid ◽  
National Laboratory ◽  
Nitric Acid Concentration ◽  
Distribution Coefficients ◽  
Metal Species ◽  
Trace Metal Concentration ◽  
Oak Ridge ◽  
Separation Factors ◽  
Lanthanide Nitrates ◽  
Aqueous Nitric Acid

The distribution of thorium and a number of lanthanides between nitric acid and solutions of dibutyl butyl phosphonate in odorless kerosene has been examined as a function of the aqueous nitric acid concentration. Experiments were conducted at trace metal concentration using radioisotopes. Separation factors (denoted by S and defined as the ratio of the distribution coefficients, K, for two metal species) have been measured for some lanthanide–lanthanide couples and also for some thorium–lanthanide couples. Results indicate that separation factors between successive lanthanides (given by S = KZ+1/KZ) at the lower end of the rare-earth series are superior to those obtained with either tributyl phosphate (TBP) (D. Scargill et al. J. Inorg. & Nuclear Chem. 4, 304 (1957)) or trioctyl phosphine oxide (TOPO) (J. M. Schmitt. Oak Ridge National Laboratory. Unpublished data), but as Z increases, SDBBP ~STBP > STOPO. For thorium–lanthanide couples, S′DBBP > S′TBP. Measurements over a range of extractant concentrations indicate that the lanthanides are extracted as trisolvates.

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