Extraction Of Zirconium Research Articles

Extraction behavior of uranium(VI), plutonium(IV), zirconium(IV), ruthenium(III) and europium(III) with γ-pre-irradiated solutions of N,N′-methylbutyl substituted amides in n-dodecane

The extraction of plutonium(IV), uranium(VI), zirconium(IV), europium(III) and ruthenium(III) with γ-pre-irradiated n-dodecane solutions of methylbutyl substituted hexanamide (MBHA), octanamide (MBOA) and decanamide (MBDA) from 3.5M HNO3 has been studied as a function of absorbed dose up to 184×104 Gray. The distribution ratios (Kd) of uranium(VI) decreased gradually up to a dose of 50×104 Gray and became almost constant thereafter, while ruthenium(III) and europium(III) were not extracted in the entire dose range studied. The Kd values of Pu(IV) decreased gradually up to 10×104 Gray, for MBOA, and 30×104 Gray for MBHA and MBDA and then increased up to a dose of 72×104 Gray, indicating the synergistic effect of radiolytic products at higher doses. The extraction of zirconium(IV) was found to increase gradually up to 72×104 Gray. However, the steep fall in Kd values of plutonium(IV), zirconium(IV) beyond a dose of 72×104 Gray was atrributed to third phase formation. The radiolytic degradation of amides was monitored by quantitative IR spectroscopy and was found to follow the order MBOA>MBDA>MBHA at 184×104 Gray having the amines and carboxylic acids as the main radiolytic products.

Extraction behavior of uranium(VI), plutonium(IV) and some fission products with gamma pre-irradiatedn-dodecane solutions of N,N′-dihexyl substituted amides

The extraction behavior of uranium(VI), plutonium(IV) and some fission products like zirconium(IV), ruthenium(III) and europium(III) from 3.5M nitric acid with γ-irradiated organic phase pre-equilibratedn-dodecane solutions of dihexyl derivatives of hexanamide (DHHA), octanamide (DHOA) and decanamide (DHDA) has been investigated as a function of absorbed dose upto 184·104 Gy. The results indicate that the extraction of uranium(VI) decreases gradually with dose upto 72·104 Gy and becomes almost constant thereafter, while, the extraction of plutonium(IV) decreases upto a dose of 20·104 Gy and then increases rapidly up to a dose of 82·104 Gy indicating synergistic effects of radiolytic products formed at higher doses. Extraction of zirconium(IV) increases gradually upto a dose of 72·104 Gy. Europium(III) does not get extracted with any of these amides in the entire dose range (0–184·104 Gy) studied, however, ruthenium shows insignificant increase in extraction with dose. The decrease inD values noticed in the case of plutonium and zirconium after the dose of 72·104 Gy which was attributed to the third phase formation and emulsification. Infrared studies confirm the final products of radiolysis as the respective amines and carboxylic acids. The degraded amide contents have been estimated by quantitative IR spectrophotometric technique. Extraction data obtained for uranium(VI) and plutonium(IV) with TBP/n-dodecane system have also been compared under similar experimental conditions.

Extractive separation of group IVB elements: Analysis of alloy samples

A method is proposed for the extraction and mutual separation of quadrivalent titanium, zirconium and hafnium from hydrochloric acid using triphenylphosphine oxide dissolved in toluene as an extractant. The optimum conditions for the extraction and separation have been evaluated from critical study of acid concentration, extractant concentration, period of equilibration and effect of diluent. The effect of foreign ions on the extraction and determination is also discussed. The probable composition of the extracted species has been deduced from log D-log C plots. The method affords mutual separation of titanium, zirconium and hafnium and is applicable to the analysis of alloy samples.

Zirconium Extraction from ZrSiO<sub>4</sub> after Mechanical Activation

Zirconium Extraction from ZrSiO<sub>4</sub> after Mechanical Activation

Extraction of uranium, plutonium and some fission products with γ-irradiated unsymmetrical and branched chain dialkylamides

The extraction behavior of uranium(VI), plutonium(IV) and some fission products like zirconium, ruthenium and europium from 3.5M nitric acid with γ-irradiated dibutyl (DBEHA), di-isobutyl (DIBEHA), methylbutyl (MBEHA) derivatives of ethylhexylamide and di-isobutyl octanamide (DIBOA) in n-dodecane has been investigated as a function of absorbed dose up to 184 Mrad. The results indicate that the Kd values for extraction of uranium(VI) decreases gradually up to 45 Mrad and becomes almost constant beyond this dose up to 184 Mrad, while extraction of plutonium(IV) increases rapidly beyond a dose of 45 Mrad due to synergistic effect of the radiolytic products formed at higher doses. The extraction of zirconium(IV) increases gradually up to 45 Mrad and attains a limiting value at higher doses. Ruthenium and europium are not extracted in the entire dose range studied. Infrared studies confirm the final products of radiolysis as the respective amines and carboxylic acids. Radiolytic degradation of the pure amides was determined by estimating the residual amide contents using quantitative IR spectrometry and were found to follow the order DIBEHA > DBEHA > MBEHA > DIBOA.

Synergistic Extraction of Zirconium(N) and Hafnium(IV) with N-Benzoyl-N-phenylhydroxylamine and Phenols

Synergistic Extraction of Zirconium(N) and Hafnium(IV) with N-Benzoyl-N-phenylhydroxylamine and Phenols

Equilibrium studies of the extraction of zirconium(IV) from sulfuric acid solutions with Di(2‐ethylhexyl)phosphoric acid

AbstractEquilibrium studies were made at 25°C in the extraction of zirconium(IV) from sulfuric acid solutions with di(2‐ethylhexyl)phosphoric acid (D2EHPA, HR) dissolved in kerosene. The reaction stoichiometry was numerically determined and the compositions of the extracted species were found to be ZrR4 and ZrR4(HR) at low loading ratios of D2EHPA (α < 0.09), but became ZrR4 and ZrR4(HR)3 at relatively higher loading ratios (0.10 < α < 0.32). The equilibrium constants for the formation of these species were also obtained. Furthermore, numerical treatment of the experimental data excluded the existence of polynuclear complexes under the conditions studied (α < 0.32).

Extraction behavior of uranium, plutonium and some fission products with gamma-irradiated N, N′-dialkylamides

The extraction behavior of uranium(VI), plutonium(IV) and fission products like zirconium, ruthenium and europium from 3.5M nitric acid medium with gamma-irradiated dibutyl derivatives of hexanamide (DBHA), octanamide (DBOA) and decanamide (DBDA) in dodecane has been investigated as a function of absorbed dose up to 184 MRads. The results indicate that the Kd value for extraction of uranium(VI) decreases gradually, while Kd for extraction of plutonium(IV) decreases rapidly with dose up to 35 MRads, increasing thereafter with dose, indicating synergistic effects of radiolytic products at higher doses. Ruthenium and europium are not extracted in the entire dose range up to 184 MRads, while extraction of zirconium(IV) increases steadily up to 50 MRads and increases radiply thereafter, indicating synergistic effect of radiolytic products similar to that of plutonium(IV) beyond a dose of 50 MRads. The extractability of uranium(VI) and plutonium(IV) with 1M dibutyl decanamide (DBDA) in dodecane was studied for uranium loading up to 75 mg/ml and plutonium loading up to 3 mg/ml. The percent extraction was found to vary from 91 to 71 for uranium and 95 to 89 for plutonium, respectively. Quantitative stripping of uranium can be achieved with 0.01M nitric acid and plutonium with 0.5M nitric acid and 0.05M hydroxylamine soluton in two steps from an organic phase loaded with 53.2 mg/ml of uranium.

Extraction of actinides and fission products by octyl(phenyl)- N, N-diisobutylcarbamoylmethyl-phosphine oxide from nitric acid media

Extraction of promethium(III), uranium(VI), plutonium(IV), americium(III), zirconium(IV), ruthenium(III), iron(III) and palladium(II) has been carried out with a mixture of octyl(phenyl)- N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and tributyl phosphate (TBP) in dodecane. The effects of nitric acid, TBP and CMPO concentrations on the extraction of these metal ions have been studied. The nature of the species of the above metal ions extracted into the organic phase has been suggested.

EXTRACTIVE SEPARATION OF URANIUM AND ZIRCONIUM SULFATES BY AMINES

ABSTRACT This paper describes an amine extraction process for zirconium and uranium separation. The behaviour of an extraction system containing uranium (VI) sulfate, zirconium (IV) sulfate, 0.2 and 0.5 M sulfuric acid (as the original aqueous phase), tertiary amine tri-n-lauryl- amine or primary amine Primene JMT in benzene (as the original organic phase) is discussed on the basis of equilibrium data. The measured dependences show that the degree of extraction of zirconium at the sulfuric acid concentration of 0.5 M and above is only slightly affected by a presence of uranium in solution. From this surprising behaviour it follows that zirconium may be employed for the displacement of uranium from the organic phase. This effect is more pronounced with the primary amine Primene JMT than with TLA.

Extraction of zirconium(IV) from sulfuric acid solutions with amines and mathematical simulation of extraction processes

The knowledge of extraction equilibrium and its mathematical description is basic information necessary for the design of separation process and equipment. The comparison of the extraction of zirconium sulfate in aqueous sulfuric acid solutions with high-molecular amines-tri-n-laurylamine, tri-n-octylamine, di-n-nonylamine, Primene JMT, p-dodecylaniline—in organic solvents has been investigated by varying the concentration of acid, solvent and aqueous zirconium. Stoichiometric equations for the extraction of zirconium(IV) at various acid concentrations were suggested. Taking into account these extraction equilibria, the presence of the various species of zirconium in the aqueous phase with known thermodynamic stability constants, mass balance equations and equation for electroneutrality, a model capable of predicting equilibrium compositions of the phases with great reliability and without restrictions on the composition of the aqueous phases is suggested.

Liquid-liquid extraction of zirconium from hafnium and other elements with dicyclohexyl-18-crown-6

Zirconium was quantitatively extracted with 2.5 × 10 −2 M dicyclohexyl-18-crown-6 in dichloromethane from 8.5 M hydrochloric acid. It was stripped with 0.5 M hydrochloric acid and was determined spectrophotometrically as its complex with Arsenazo III. Hafnium was not extracted under these conditions, but from the residual aqueous phase it was extracted with 7.0 × 10 −2 M dicyclohexyl-18-crown-6 in dichloromethane from 9.0 M hydrochloric acid. It was stripped with 0.1 M perchloric acid and determined spectrophotometrically at 540 nm as its complex with xylenol orange. The separation of zirconium and hafnium from other metals is also described.

Studies on extraction and separation of zirconium(IV) and niobium(V) using poly(4-vinylpyridine) resin : Dawood A. Mohammed, University of Baghdad, College of Science, P.O. Box 29649, Baghdad, Iraq.

Studies on extraction and separation of zirconium(IV) and niobium(V) using poly(4-vinylpyridine) resin : Dawood A. Mohammed, University of Baghdad, College of Science, P.O. Box 29649, Baghdad, Iraq.

Extraction of Zirconium(IV) and Separation of 95Zr-95Nb from Acidic Thiocyanate Media by LIX 54 and its Mixtures with TBP

Article Extraction of Zirconium(IV) and Separation of 95Zr-95Nb from Acidic Thiocyanate Media by LIX 54 and its Mixtures with TBP was published on January 1, 1990 in the journal Radiochimica Acta (volume 49, issue 1).

Extraction of zirconium(IV) from HCl solutions by mixtures of Aliquat-336 and Alamine-336 with TBP

Synergism has been observed in the extraction of zirconium(IV) by mixtures of Aliquat 336 or Alamine 336 with a neutral donor TBP from aq. HCl solutions. Although the extractant dependency for Zr(IV) is found to be nearly second power with respect to TBP alone, monosolvate is found to be formed for extraction by its mixture with Aliquat 336 or Almine 336. Quantitative extraction is observed with mixtures at a lower acidity than that with individual extractants. The species formed is tentatively assigned to be Q2ZrCl6. TBP, where\(Q{\mathbf{ }} = {\mathbf{ }}R_3 {\mathbf{ }}\mathop N\limits^ + (CH_3 )\) for Aliquat 336 and\(R_3 {\mathbf{ }}\mathop N\limits^ + H\) for Alamine 336.

Solvent Extraction of Zirconium (IV) from Thiocyanate and Hydrochloric Acid Solutions by LIX 26 and DOSO

Solvent Extraction of Zirconium (IV) from Thiocyanate and Hydrochloric Acid Solutions by LIX 26 and DOSO

Extraction and spectrophotometric determination of zirconium(IV) with N-phenylbenzohydroxamic acid and phenylfluorone

N-Phenylbenzohydroxamic acid reacted with zirconium(IV) in 3.5 M hydrochloric acid to give a colourless complex that could be extracted into chloroform. The chloroform extract of the zirconium(IV) complex, on a second extraction from a dilute hydrochloric acid medium (0.5 M) in the presence of phenylfluorone and acetone, formed an intensely coloured complex with an absorption maximum at 534 nm. The molar absorptivity under optimum conditions was 1.125 × 104 dm3 mol–1 cm–1. The system obeyed Beer's law up to 7 p.p.m. of zirconium(IV) in the extract. Large amounts of many cations and anions, including a ten-fold molar excess of vanadium(IV), iron(III) and molybdenum(VI), were tolerated. Equimolar amounts of aluminium(III), fluoride, phosphate and vanadium(V) were also tolerated. A slight interference from titanium(IV) and niobium(V) was observed when the mole ratio of zirconium(IV) to foreign ion exceeded 1.0 : 0.3. The method was applied successfully to the determination of zirconium(IV) in zircon sand.

Solvent extraction of titanium(IV), zirconium(IV) and hafnium(IV) salicylates using liquid ion exchangers

A solvent extraction method is proposed for the extraction of quadrivalent titanium, zirconium and hafnium from salicylate media using liquid ion exchangers such as Aliquat 336 and trioctylamine dissolved in xylene. The optimum conditions were evaluated from a critical study of the following: pH, salicylate concentration, amine concentration, diluent and period of equilibration. The method allows the separation of titanium, zirconium and hafnium from binary mixtures containing commonly associated metal ions and is applicable to the analysis of real samples such as BCS-CRM 387 nimonic 901, BCS-CRM 243/4 ferro-titanium, BCS-CRM 307 magnesium alloy and BCS-CRM 388 zircon. Titanium is determined either with hydrogen peroxide or by atomic absorption spectrometry whereas zirconium and hafnium are determined spectrophotometrically with Alizarin Red S and Xylenol Orange, respectively. The results of both separation and analysis are reported. The method is precise, accurate and fast.

EXTRACTION AND SEPARATION OF ZIRCONIUM(IV) WITH 3-HYDROXY-2-METHYL-1-PHENYL-4-PYRIDONE

Abstract ABSTRACT The extraction of zirconium(IV) from aqueous hydrochloric, sulphuric and perchloric acid solutions with 3-hydroxy-2-methyl--1-phenyl-4-pyridone (HX) dissolved in chloroform is described. Perchlorate and thiocyanate ions show a synergistic effect on zirconium extraction with HX. The synergistic effect of thiocyanate is stronger than the effect of perchlorate. The composition of the extracted zirconium(IV) complexes is studied and a simple and rapid method for the separation of zirconium from niobium is described.

Extraction of zirconium and hafnium thiocyanate with polyurethane foam

Conditions for the extraction of zirconium and hafnium thiocyanate by polyether-type polyurethane foam were studied in detail. The composition of the extractable species was found to be dependent on both the thiocyanate and metal-ion concentrations. The extraction efficiency for zirconium and hafnium depended on the size of the counter-cation as well as on the type of anion.