EXTRACTION OF Mo(VI) FROM NITRIC ACID MEDIUM BY DI(OCTYL-PHENYL) PHOSPHORIC ACID

Kumar, Anuj; Mohapatra, P. Κ.; Pathak, P. N.; Manchanda, V. Κ.

doi:10.1081/sei-100103282

Cited by 13 publications

(6 citation statements)

References 20 publications

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“…Zirconium is mostly interfered by molybdenum. This is the reason why some separation methods have been developed in order to extract or eliminate the molybdenum [24][25][26][27][28][29][30]. Some TIMS studies corrected mathematically the molybdenum interference by an interference correction equation [1,8,12,18].…”

Section: Introductionmentioning

confidence: 99%

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry

Quemet

Maillard

Ruas

2015

International Journal of Mass Spectrometry

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A new Thermal Ionization Mass Spectrometer (TIMS) analytical procedure was developed to measure with high accuracy the zirconium isotope abundance and concentration without molybdenum correction in nuclear samples. A zirconium selective separation using UTEVA column was used before the TIMS measurement in order to remove all possible isobaric interferences (Mo, Y, Nb and Ru) in the solution. The separated solution was then deposited onto a filament previously outgassed for 4 hours to reduce the molybdenum traces in the filament. Then, the filament was introduced into the TIMS source and was maintained for 4 hours at a current of 5 A (ionization filament) and 1.2 A (evaporation filament) in order to eliminate all molybdenum trace present in the filament and in the sample. This methodology allowed the zirconium isotope abundance determination without using the molybdenum interference correction equation. The analytical results obtained with a natural solution after separation is in good accordance with the reference values: bias lower than 0.16 % for the 90 Zr, 91 Zr, 92 Zr and 94 Zr isotope abundance, and a bias of ~0.8 % for the minor isotope (96 Zr) were observed. This zirconium abundance determination methodology was used on three nuclear samples. Then, the calibration of a 91 Zr spike solution was performed by reverse isotope dilution using a SPEX standard zirconium solution. The zirconium concentration determination was then performed on the three nuclear samples by isotope dilution using the SPEX standard zirconium solution and the 91 Zr spike solution. The final uncertainties were estimated to be lower than 1 %.

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Section: Introductionmentioning

confidence: 99%

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry

Quemet

Maillard

Ruas

2015

International Journal of Mass Spectrometry

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“…For instance, pervanadyl (VO þ 2 ) and molybdenyl (MoO 2þ 2 ) ions formed at pH 1.0 or decavanadate (V 10 O 4À 28 ) and heptamolybdate (Mo 7 O 6À 24 ) ions prevalent at pH 2-3.5, the former pair being susceptible to neutralization by counterions like Cl À from an acidic chloride medium extractable into tri-nbutyl phosphate, this we have shown in the previous works (1,2,3,8). The recovery of V(V) from aqueous H 2 SO 4 solutions using organophosphorous and amine extractants is well documented (9,10,11). Vanadium and molybdenum from leached spent catalysts have been co-extracted with trialkylamine, co-stripped and separated by crystallization (12).…”

Section: Introductionmentioning

confidence: 99%

Separation of Simulated Mixed Mo(VI) and V(V) From HNO₃and HCl Solutions by Selective Extraction and Stripping with Tri-N-Butyl Phosphate as Extractant

Ojo

2013

Separation Science and Technology

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Equilibrium study was carried out to determine the optimum conditions required for Mo(VI) extraction from HNO 3 solutions and subsequently, simulated mixed Mo(VI), and V(V) were extracted from HNO 3 (pH ¼ 1.0) and 6.0 mol L À1 HCl solutions with TBP dissolved in n-hexane. The variation of pH (selective extraction) and selective stripping were investigated as methods of separation of Mo(VI) and V(V). The latter method was found inefficient for separations from HNO 3 solutions (pH ¼ 1.0) except supplemented with selective stripping (back-extraction with 2.0 mol L À1 H 2 SO 4 /14.5 mol L À1 NH 4 OH). While from 6.0 mol L À1 HCl, selective stripping was adequate to quantitatively strip in turns the Mo(VI) and V(V) co-extracted into the TBP phase. About 100% of the co-extracted V(V) from the HCl medium was stripped in a two-stage process, in contrast to a single-stage required for Mo(VI) of the same result. The selective stripping method was found to be better because an initial appreciable co-extraction had occurred prior to stripping separation. Based on analytical and spectra data, the extracted complexes from HNO 3 and HCl media were formulated as ((MoO 2 ) 7-8n (VO 2 ) 2n Á (NO 3 ) 16 ) (16-18)n-Á m TBP (where n>m) and (MoO 2 Cl 2 Á VO 2 Cl) Á xTBP, respectively.

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“…In the presence of 1–11 M HCl, additional species such as H 3 MoO 4 Cl, MoO 2 Cl 2 , and MoO 2 Cl 3 – exist . Given the complicated Mo chemistry at its higher concentrations involving dimeric and possibly polymeric oxo cations and anions, most publications focus on speciation of Mo at low concentration (≤0.1 mM Mo), at which point the polymeric species may be negligible. − Additionally, UV spectroscopy served as the primary means to determine the speciation of Mo, and due to very high extinction coefficients for Mo species under acidic condition (>10 3 cm –1 ·mol –1 ·L in 200–250 nm), many experiments were limited to low Mo concentrations. Yet metallurgical practices, or processes to recover valuable enriched 98/100 Mo for 99 Mo/ 99m Tc production, require processes that can accommodate high Mo concentrations of up to ∼0.4 M Mo.…”

Section: Introductionmentioning

confidence: 99%

Molybdenum(VI) Coordination in Tributyl Phosphate Chloride Based System

Tkáč

Abdul

Breshears

et al. 2018

Ind. Eng. Chem. Res.

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Fundamental coordination chemistry of Mo(VI) at its macroconcentrations in solvent extraction systems is of great importance for industrial processes that require the purification or recovery of large concentrations of Mo. The coordination of Mo(VI) in tri-n-butyl phosphate (TBP) from solutions of hydrochloric acid and up to 0.3 M Mo was investigated using UV, FTIR, and 31 P NMR spectroscopies, as well as EXAFS. From these techniques we resolved near-neighbor atoms, speciation, structural information on the coordination environment, and thermodynamic parameters affiliated with the solvent extraction of Mo(VI) and HCl. The solvated extracted form of Mo(VI) as MoO 2 Cl 2 •2TBP was identified. High extraction yield of Mo at >5 M HCl concentration is driven by replacing HCl in the organic phase by Mo. The existence of additional organic Mo adducts is also discussed with the aid of density functional theory, however no evidence of dimeric or polymeric Mo species was found to be present in TBP.

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EXTRACTION OF Mo(VI) FROM NITRIC ACID MEDIUM BY DI(OCTYL-PHENYL) PHOSPHORIC ACID

Cited by 13 publications

References 20 publications

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry

Separation of Simulated Mixed Mo(VI) and V(V) From HNO₃and HCl Solutions by Selective Extraction and Stripping with Tri-N-Butyl Phosphate as Extractant

Molybdenum(VI) Coordination in Tributyl Phosphate Chloride Based System

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EXTRACTION OF Mo(VI) FROM NITRIC ACID MEDIUM BY DI(OCTYL-PHENYL) PHOSPHORIC ACID

Cited by 13 publications

References 20 publications

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry

Determination of zirconium isotope composition and concentration for nuclear sample analysis using Thermal Ionization Mass Spectrometry

Separation of Simulated Mixed Mo(VI) and V(V) From HNO3and HCl Solutions by Selective Extraction and Stripping with Tri-N-Butyl Phosphate as Extractant

Molybdenum(VI) Coordination in Tributyl Phosphate Chloride Based System

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Separation of Simulated Mixed Mo(VI) and V(V) From HNO₃and HCl Solutions by Selective Extraction and Stripping with Tri-N-Butyl Phosphate as Extractant