A spectroscopic study of molybdenum extracts in organic solutions of dibutyl hydrogen phosphate in equilibrium with aqueous nitric acid solutions

Голецкий, Н. Д.; Zilberman, B. Ya.; Fedorov, Yu. S.; Пузиков, Е. А.; Лумпов, А. А.; Mashirov, L.G.; Sidorenko, G. V.

doi:10.1134/s1066362211060099

Cited by 4 publications

(12 citation statements)

References 12 publications

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“…These frequencies are somewhat lower than those observed in the Mo extracts in the system Zr-free HDBP-xylene [19]: 920-923 and 953-955 cm -1 . In the spectrum of the saturated extract obtained from 1 M HNO 3 , an illdefined band at 810 cm -1 , associated with HDBP, is manifested; the other spectra exhibit no absorption in this region.…”

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasecontrasting

confidence: 69%

“…In the system with Zr-free HDBP, the concentration of this form of the acid is considerably lower than in the system with HDBP ZS at approximately the same Mo concentration. Similar behavior of HNO 3 in the HDBP phase under the action of Mo was demonstrated in [19]. Thus, the concentration of molecular HNO 3 in HDBP in the system containing Zr and Mo simultaneously is appreciably higher than in the systems containing Zr and Mo separately.…”

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasesupporting

confidence: 68%

“…In the spectrum of the saturated extract obtained from 1 M HNO 3 , an illdefined band at 810 cm -1 , associated with HDBP, is manifested; the other spectra exhibit no absorption in this region. Thus, even at high loadings, bands assigned in [19] to a complex of hydroxymolybdenyl or dimolybdenyl are not manifested either. At the same time, bands characteristic of molecular HNO 3 at 1300 and 1670 cm -1 and of nitrate ion bound to Zr at 1560 cm -1 are absent; therefore, for 1 M HNO 3 this region is not shown in Fig.…”

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasementioning

confidence: 83%

“…To elucidate the nature and composition of extractable Mo complexes, we examined the IR spectra of Mo extracts with HDBP ZS at HNO 3 to compare them with the spectra of Mo species in Zrfree HDBP solutions in diluent, considered in detail in our previous paper [19]. The main point is as follows: whether Zr and Mo compete for HDBP in the formation of acid salts, or HDBP ZS extracts Mo by the cation-exchange mechanism similarly to the extraction of REE (e.g., of Y characterized by very high distribution ratios).…”

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasementioning

confidence: 99%

“…The vibrations of the Р=О groups can be analyzed in more detail using the technique of differential spectra [19], i.e., the extract spectra minus spectrum of the metal-free extractant in diluent. In so doing, it is ap- propriate to compare the differential spectra of the Mo extracts in HDBP ZS with the sum of the differential spectra of HDBP ZS without Mo and of the Mo extract in Zr-free HDBP at the same Mo concentration [19].…”

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasementioning

confidence: 99%

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Extraction of molybdenum from nitric acid solutions with solutions of dibutyl hydrogen phosphate zirconium salt

et al. 2012

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The extraction of Мо with a solution of dibutyl hydrogen phosphate (HDBP) zirconium salt (ZS) in xylene and in TBP-xylene and TBP-decane mixtures was studied in comparison with the Mo extraction in similar systems without Zr. The Mo extraction is enhanced to the largest extent (by a factor of 7 with 1.5 M HNO 3 ) at the HDBP : Zr ratio of 12, but the majority of experiments were performed at the ratio HDBP : Zr = 9, characteristic of the extraction of TPE and REE. The plots of D Mo vs. HNO 3 concentration in all the cases pass through a minimum at ~3 M HNO 3 , and the minimum is the deeper, the higher the TBP concentration. At the same time, in the system with HDBP ZS at the TBP concentration in the solvent exceeding 50%, further decrease in D Mo is not observed. The dependence of the Mo distribution ratio D Mo on the HDBP concentration at a fixed ratio HDBP : Zr = 9, the composition of the saturated systems, and the spectra of the saturated and unsaturated (with respect to Mo) systems suggest formation of mixed HDBP-Zr-Mo complexes. Assumptions concerning their composition and structure were made. According to the IR data, in these complexes in the absence of TBP the nitrate ion is not coordinated to the Mo atom. Bridged structures Мо-О-Мо are not formed either. Addition of TBP leads to a decrease in D Мо in the extraction with HDBP ZS, but, at the same time, the slope of the dependence of D Mo on the HDBP concentration increases, and the limiting capacity of the solvent for Mo also somewhat increases. These effects are primarily attributed to an increase in the HNO 3 concentration in the organic phase in the presence of TBP.The use of dialkyl hydrogen phosphate zirconium salts (HDAP ZSs) for partitioning of long-lived radionuclides of transplutonium (TPE) and rare earth (REE) elements and Sr is known for a relatively long time [1-3], but the extraction behavior of Mo was not examined in these studies.In our papers on TPE and REE partitioning, it was suggested to use acidic zirconium salt of dibutyl hydrogen phosphate (HDBP ZS) as TBP-compatible extractant, because HDBP is the first product of TBP degradation and is removed by washing the extractant with a Na 2 CO 3 solution. It was suggested to use a 0.2 M solution of HDBP ZS (HDBP : Zr = 9) in 30% TBP in paraffin hydrocarbons [4][5][6][7][8][9][10][11]. However, the Mo extraction with HDBP ZS solution was given less attention in these papers, compared to the extraction of REE and TPE, and the data we obtained previously [6-8, 12, 13] are insufficient for understanding the extraction behavior of Мо. For this purpose, it is necessary to study systematically the role of various components of the system in the extraction, including the role of TBP.The latter fact made it necessary to perform additional studies on the Mo extraction with HDBP ZS solutions in xylene and in 30% TBP/xylene. The results of these studies are discussed below together with data for the system HDBP ZS-30% TBP/decane. This paper is a part of a cycle of papers on the Mo extraction from nitri...

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Section: Ir and Uv Spectra Of Mo Species In The Organic Phasecontrasting

confidence: 69%

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasesupporting

confidence: 68%

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasementioning

confidence: 83%

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasementioning

confidence: 99%

Section: Ir and Uv Spectra Of Mo Species In The Organic Phasementioning

confidence: 99%

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Extraction of molybdenum from nitric acid solutions with solutions of dibutyl hydrogen phosphate zirconium salt

et al. 2012

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Synthesis of hexavalent molybdenum formo- and aceto-hydroxamates and deferoxamine via liquid-liquid metal partitioning

Breshears

Brown

Bloom

et al. 2018

Inorganica Chimica Acta

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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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A spectroscopic study of molybdenum extracts in organic solutions of dibutyl hydrogen phosphate in equilibrium with aqueous nitric acid solutions

Cited by 4 publications

References 12 publications

Extraction of molybdenum from nitric acid solutions with solutions of dibutyl hydrogen phosphate zirconium salt

Extraction of molybdenum from nitric acid solutions with solutions of dibutyl hydrogen phosphate zirconium salt

Synthesis of hexavalent molybdenum formo- and aceto-hydroxamates and deferoxamine via liquid-liquid metal partitioning

Molybdenum(VI) Coordination in Tributyl Phosphate Chloride Based System

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