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

scholarly journals Solvent Extraction Equilibrium in the CuSO4–H2SO4–LIX 984–ESCAID 103 Systern

1999 ◽  
Vol 23 (8) ◽  
pp. 518-519
Author(s):  
Francisco Jose Alguacil ◽  
Jaime Simpson ◽  
Patricio Navarro
Keyword(s):  
Solvent Extraction ◽  
Thermodynamic Model ◽  
Distribution Coefficients ◽  
Extraction System ◽  
Extraction Equilibrium ◽  
Solvent Extraction System ◽  
Measured Distribution

A previously determined thermodynamic model for extraction equilibrium is used as a basis to predict experimentally measured distribution coefficients for the CuSO4–H2SO4–LIX 984–Escaid 103 solvent extraction system at 25 °C and aqueous copper concentrations in the range 0.01–2.0 gL−1, the copper loading isotherm is also obtained.

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.

scholarly journals Fighting Sulfidation With a Chromium Bearing Fuel Additive

1976 ◽  
Author(s):  
A. H. Mitchell ◽  
N. S. Bornstein
Keyword(s):  
Gas Turbine ◽  
Field Tests ◽  
Ion Concentration ◽  
Fuel Additive ◽  
Protective Oxide ◽  
Sulfate Ions ◽  
Alkali Salt ◽  
Turbine Vanes ◽  
Oxide Ions ◽  
Alkali Salts

Sulfidation attack, the accelerated rate of oxidation of gas turbine vanes (stators) and blades (buckets) is a form of hot corrosion, which can occur whenever alkali salts are present in the inlet air and/or as an impurity in the fuel. The corrosive alkali salt found on affected hardware is primarily sodium sulfate, which is composed of sodium ions, sulfate ions and oxide ions. The oxide ions react with and disrupt the normally protective oxide scale which results in accelerated rates of oxidation. Chromium oxide reacts with oxide ions. By reducing the oxide ion concentration of the fused salt, the sulfidation process is prevented before it starts. The ability of a chromium additive in the fuel to suppress sulfidation attack has been demonstrated in laboratory and burner rig tests and more recently in the field. Field experience consists of over 6000 hr of gas turbine operation. It is the purpose of this paper to describe the sulfidation inhibiting process and report the laboratory, burner rig, and field tests.

High Oxide‐Ion Conductivity in a Hexagonal Perovskite‐Related Oxide Ba 7 Ta 3.7 Mo 1.3 O 20.15 with Cation Site Preference and Interstitial Oxide Ions

Small ◽  
2021 ◽  
pp. 2106785
Author(s):  
Taito Murakami ◽  
Toshiya Shibata ◽  
Yuta Yasui ◽  
Kotaro Fujii ◽  
James R. Hester ◽  
...  
Keyword(s):  
Ion Conductivity ◽  
Site Preference ◽  
Cation Site ◽  
Oxide Ion Conductivity ◽  
Oxide Ions ◽  
Oxide Ion

scholarly journals Hg (II) extraction in a PEG-based aqueous two-phase system in the presence of halide ions. I. Liquid phase analysis

2006 ◽  
Vol 4 (2) ◽  
Author(s):  
Laura Bulgariu ◽  
Dumitru Bulgariu
Keyword(s):  
Salt Solution ◽  
Distribution Coefficients ◽  
Ion Concentration ◽  
Phase System ◽  
Two Phase ◽  
Rich Phase ◽  
Halide Complexes ◽  
Observed Behaviour ◽  
Partition Behaviour ◽  
Solution Acidity

AbstractThe partition behaviour of Hg (II) was studied in an aqueous polyethylene glycol (PEG) — (NH4)2SO4 two-phase system as a function of halide, halide concentration, and pH. For a system prepared by mixing equal volumes of 40 % (w/w) PEG (1550) with 40 % (w/w) (NH4)2SO4, Hg(II) remains almost exclusively in the salt-rich phase. The addition of NaX (X = Cl−, Br−, I−) enhances Hg (II) partition into the PEG-rich phase due to the formation of halide complexes. The efficiency of halide extractants increases in the order: Cl− < Br− < I−. Mercury extraction is improved at lower halide ion concentration by higher stock salt solution acidity. From the distribution coefficients determined as a function of halide ion concentration, the extracted species were identified. The Hg (II) extractability is determined by the type and stability of the Hg (II) halide species, and depends on the stock salt solution acidity. The observed behaviour is discussed and a possible extraction mechanism is proposed.

scholarly journals Unraveling the correlation between oxide-ion motion and upconversion luminescence in β-La2Mo2O9:Yb3+,Er3+ derivatives

2017 ◽  
Vol 5 (42) ◽  
pp. 10965-10970 ◽  
Author(s):  
Qian He ◽  
Mingzi Sun ◽  
Xiao-jun Kuang ◽  
Bolong Huang ◽  
Shi Ye ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Upconversion Luminescence ◽  
Upconversion Emission ◽  
Ion Motion ◽  
Thermally Driven ◽  
Oxide Ions ◽  
Oxide Ion

The upconversion emission of Er3+ in β-La2(Mo,W)2O9 can reveal the short-range thermally-driven jumps and long-range motion of oxide-ions.

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