High Vanadium Content Research Articles

Hot Deformation Behavior of Vanadium-microalloyed Medium-carbon Steel for Fracture Splitting Connecting Rod

Single compression tests were carried out with a Gleeble-3800 thermal simulator to investigate hot deformation behavior of two vanadium-microalloyed medium-carbon steels for fracture splitting connecting rod. The tests were performed to a total true strain of 0.92 at true strain rates ranging from 10−2 to 10 s−1 and deformation temperature of 900 – 1150 °C. The results show that hot deformation behavior of the tested steels is similar to that of conventional medium-carbon microalloyed steels and dynamic recrystallization is easier to occur at higher deformation temperature and lower strain rate. The austenite deformation resistance and activation energy of deformation increase with increasing vanadium content from 0. 15% to 0. 28% and thus the starting time of dynamic recrystallization was delayed. Finer recrystallized austenite grain could be obtained at higher strain rate, lower deformation temperature and higher vanadium content. TEM observation of the specimens quenched just before and after deformation reveals that vanadium is mainly in dissolved solute condition in austenite and thus affects the dynamic recrystallization behavior of the tested steels mainly through solute-drag effect.

Unveiling of a Trinuclear Cyclic Peroxidovanadate: A Potential Oxidant in Vanadium-Catalyzed Reactions.

The first peroxidovanadium trimer was prepared in the form of its tetrabutylammonium salt, (NBu4)3[V3O3(O2)6]·2H2O. Its X-ray structure analysis revealed a unique cyclic structure of the [V3O3(O2)6](3-) ion incorporating the yet unobserved μ3-η(2):η(1):η(1) coordination mode of one of its peroxido ligands. While relatively stable in nonaqueous solvents, the [V3O3(O2)6](3-) ion quickly decomposes in diluted aqueous solutions. A higher vanadium concentration or a higher CH3CN content in the mixed CH3CN/H2O solvent facilitates the formation of oligomers [V2O2(O2)4(H2O)](2-) and [V3O3(O2)6](3-). (51)V NMR investigations indicated that the trinuclear species is incorporated in vanadium-catalyzed oxidations in the presence of H2O2.

Sulfuric Acid Assisted Extraction and Fractionation of Porphyrins From Heavy Petroleum Residuals With a High Content of Vanadium and Nickel

Primary porphyrin extracts were obtained from carbon tetrarchloride solutions of different heavy oil residuals with assistance of sulfuric acid. According to data of chromatographic separation of extracts porphyrinic fractions appear in amount of 13.0–24.2%. Based on UV/visible absorption spectroscopy the presence of porphyrins of etio and phyllo types mostly with rhodo and deoxophylloerythroetioporphyrins in lower amount was established. The content of porphyrins in obtained fractions was determined at the level of 15.3–44.8% of the total weight. It was shown that a higher concentration of porphyrins in sulfuric acid extracts occurs for the case of the high vanadium and nickel content and low amounts relation of asphaltenes to resins.

PM2.5 and Survival Among Older Adults

Fine particulate (PM2.5) air pollution has been consistently linked to survival, but reported effect estimates are geographically heterogeneous. Exposure to different types of particle mixtures may explain some of this variation. We used k-means cluster analyses to identify cities with similar pollution profiles, (ie, PM2.5 composition) across the United States. We examined the impact of PM2.5 on survival, and its variation across clusters of cities with similar PM2.5 composition, among Medicare enrollees in 81 US cities (2000-2010). We used time-varying annual PM2.5 averages, measured at ambient central monitoring sites, as the exposure of interest. We ran by-city Cox models, adjusting for individual data on previous cardiopulmonary-related hospitalizations and stratifying by follow-up time, age, gender, and race. This eliminates confounding by factors varying across cities and long-term trends, focusing on year-to-year variations of air pollution around its city-specific mean and trend. We then pooled the city-specific effects using a random effects meta-regression. In this second stage, we also assessed effect modification by cluster membership and estimated cluster-specific PM2.5 effects. We followed more than 19 million subjects and observed more than 6 million deaths. We found a harmful impact of annual PM2.5 concentrations on survival (hazard ratio = 1.11 [95% confidence interval = 1.01, 1.23] per 10 μg/m). This effect was modified by particulate composition, with higher effects observed in clusters containing high concentrations of nickel, vanadium, and sulfate. For instance, our highest effect estimate was observed in cities with harbors in the Northwest, characterized by high nickel, vanadium, and elemental carbon concentrations (1.9 [1.1, 3.3]). We observed null or negative associations in clusters with high oceanic and crustal particles. To the best of our knowledge, this is the first study to examine the association between PM2.5 composition and survival. Our findings indicate that long-term exposure to fuel oil combustion and power plant emissions have the highest impact on survival.

Assessment of total and organic vanadium levels and their bioaccumulation in edible sea cucumbers: tissues distribution, inter-species-specific, locational differences and seasonal variations.

The objective of this study is to investigate the levels, inter-species-specific, locational differences and seasonal variations of vanadium in sea cucumbers and to validate further several potential factors controlling the distribution of metals in sea cucumbers. Vanadium levels were evaluated in samples of edible sea cucumbers and were demonstrated exhibit differences in different seasons, species and sampling sites. High vanadium concentrations were measured in the sea cucumbers, and all of the vanadium detected was in an organic form. Mean vanadium concentrations were considerably higher in the blood (sea cucumber) than in the other studied tissues. The highest concentration of vanadium (2.56μgg(-1)), as well as a higher degree of organic vanadium (85.5%), was observed in the Holothuria scabra samples compared with all other samples. Vanadium levels in Apostichopus japonicus from Bohai Bay and Yellow Sea have marked seasonal variations. Average values of 1.09μgg(-1) of total vanadium and 0.79μgg(-1) of organic vanadium were obtained in various species of sea cucumbers. Significant positive correlations between vanadium in the seawater and V org in the sea cucumber (r=81.67%, p=0.00), as well as between vanadium in the sediment and V org in the sea cucumber (r=77.98%, p=0.00), were observed. Vanadium concentrations depend on the seasons (salinity, temperature), species, sampling sites and seawater environment (seawater, sediment). Given the adverse toxicological effects of inorganic vanadium and positive roles in controlling the development of diabetes in humans, a regular monitoring programme of vanadium content in edible sea cucumbers can be recommended.

Characteristics of nanostructured Zn1−xVxO thin films with high vanadium content elaborated by rf-magnetron sputtering

Nanostructured Zn1−xVxO (0⩽x⩽0.50) thin films were synthesized by rf-magnetron sputtering at two different substrate temperatures (room temperature (RT) and 200°C) and with variable sputtering powers (60, 80 and 100W). In this method, single targets based on Zn1−xVxO nanopowders prepared by the sol–gel process were used. Characterization of the Zn1−xVxO nanoparticles showed that they crystallize in the hexagonal wurtzite structure. Their size ranged from 20 to 40nm. The effect of process parameters on the physical and chemical properties of Zn1−xVxO thin films has been studied. For x⩽0.30, the results obtained at 200°C and 60W indicate that the films have a high quality of crystallinity. Vegard’s law is respected, indicating that vanadium is incorporated in the ZnO matrix. The chemical compositions of these films were found to be close to the stoichiometry. The films exhibit a columnar structure and a smooth surface. Their average transmission, from the visible to the NIR, was in the range of 75–90%. The values of the band gap of the Zn1−xVxO thin films with x⩽0.30 and elaborated at 200°C and 60W, vary from 3.29 to 3.74eV. This is consistent with blue shifting of near-band edge cathodoluminescence emission. Under particular growth conditions, the investigation shows that the Zn0.80V0.20O sample presents the best properties for potential use in various optoelectronic applications, namely: a single wurtzite phase, low surface roughness (Ra∼0.2nm), a high transparency of 90% in the UV–Vis–NIR, a wide band gap of 3.74eV and a resistivity of ∼5×10+3Ωcm.

Preparation and chemical characteristics of Karunguruvai Khadi used in the traditional Siddha formulation of herbo-mineral-based medicine

IntroductionKhadi is an extract that has been used in the preparation of Pooneeru (muppu) in Siddha medicine, but it has not been scientifically evaluated for modern medicinal purposes. The present study examines the preparation and chemical composition of Khadi. Materials and methodsAccording to the method of the palm leaf literature, Karunguruvai and Samba paddy grains were selected for the preparation of Khadi. After removing the husk of the paddies, the cleaned Karunguruvai and Samba rice were processed according to the methods of Swami and Ramasamy Khon. The processed Khadi of Karunguruvai and Samba were analyzed for chemical constituents and were microbiologically assessed. The chemical composition of the paddy grains was also evaluated to compare with the Khadi constituents. ResultsThe major elements of the paddy grains of Karunguruvai and Samba were calcium (CaO) and sodium (Na2O). The predominant trace elements in the Samba rice were nickel and cadmium, whereas Karunguruvai rice contained arsenic, nickel, copper, and cadmium. Samba Khadi contained the trace elements mercury, chromium, lead, copper, and cobalt, whereas Karunguruvai Khadi had a high content of mercury, vanadium, arsenic, nickel, copper, cadmium, barium, and strontium. Karunguruvai Khadi also contained silicon dioxide (SiO2), aluminum oxide (Al2O3), iron oxide (FeO), manganese oxide (MnO), calcium oxide (CaO), and sodium carbonate (Na2O). By contrast, Samba Khadi contained only ferrous oxide (FeO), calcium oxide (CaO), sulfur dioxide (SO2), and carbon dioxide (CO2), which were chemical constituents of the Samba rice. DiscussionThe composition of Karunguruvai rice was compared with Samba rice and it is identified the absence of heavy metals in Samba as well as Karunguruvai rice. Both of rice powders have more or less similar chemical compounds except phosphorous content. Karunguruvai rice possesses more CaO than Samba rice. The bacterial and fungal activities were assessed during the different stages of Khadi preparation—no activities were found in any form of the Khadi. This suggests that Khadi may have a preventive effect against fungal and bacterial infections. ConclusionThe result of the chemical analysis of Khadi extracts showed that Khadi prepared from the Karunguruvai paddy grains (rice) was the best base solvent for ion exchange in the preparation of muppu than Samba Khadi. The analysis of the composition of these two types of Karunguruvai Khadi show that it is a good solvent for the elimination of heavy metals and for the enrichment of elements in Pooneeru powder (muppu), the chuurnam of Siddha drugs. These characteristics enhance the therapeutic potential and safety of the drugs for healing chronic diseases.

Vanadium oxide supported on porous clay heterostructure for the partial oxidation of hydrogen sulphide to sulfur

Vanadium oxide supported on porous clay heterostructures (PCH) catalysts have been synthesized, characterized and evaluated in the selective oxidation of H2S to elemental sulfur. The catalysts were characterized by XRD, adsorption–desorption of N2 at −196°C, diffuse reflectance UV–vis, H2-TPR, Raman spectroscopy and XPS. The catalysts with higher vanadium content are more active and selective, exhibiting a H2S conversion close to 70% after 360h on stream with a high selectivity toward elemental sulfur and a low formation of undesired SO2. The catalysts with V2O5 crystallites have shown a higher activity and resistance to the deactivation. The analysis of the spent catalyst has revealed the formation of V4O9 crystals during the catalytic test, which has been reported as the active phase in the selective oxidation of the H2S.

Inhibition Performance Study of Vanadate on AA2024-T3 at High Temperature by SEM, FIB, Raman and XPS

The inhibition of AA2024-T3 by vanadate at temperatures ranging from 10° to 80°C was studied using various characterization techniques. SEM showed that in the presence of vanadate, no corrosion was observed on any intermetallic particles, including the reactive Al2CuMg (S phase) at temperatures up to 50°C. Although trenching occurred around the S phase particles when solution temperature increased to 70°C and above, S phase was protected by vanadate-bearing film. Raman spectroscopy showed a peak indicating polymeric vanadate, which increased in intensity with increasing temperature with the highest intensity at 80°C. The high vanadium concentration at 80°C was attributed to fast reduction reaction kinetics of vanadate by Al or Mg. This reduction reaction is confirmed by XPS, and the reduced forms of vanadium appeared to promote vanadate (V5+) polymerization leading to the formation of vanadate films. Additionally, elevated temperatures appeared to increase vanadate polymerization kinetics. This reductive adsorbed vanadate film also enabled the samples treated in vanadate at higher temperature to have residual inhibition in NaCl without inhibitors. The reduced forms of vanadium were found to be easily oxidized under ambient aerated solution conditions. Exposure of treated samples in air further increased the corrosion resistance.

Morphology of Carbides Crystallizing in Fe-C-V and Fe-C-V-Si Alloys

Abstract Fe-C-V alloys with high vanadium content are included in the family of white cast irons, because all carbon present in this material is bound into vanadium carbides.The study presents the results of microstructural examinations of the volume solidifying Fe-C-V and Fe-C-V-Si alloys containing carbon in the range of 1.38÷4.14%, vanadium in the range of 6.77÷16.34% and silicon in the range of 0÷3.10%. Attention was focused on near-eutectic alloys.In Fe-C-V and Fe-C-V-Si alloys, depending on the chemical composition, can crystallize eutectic composed of ferrite and VC-type carbides highly differentiated morphology. In these alloys were observed following types of eutectic: fibrous eutectic, spiral, quasi-regular and globular.Moreover, both these alloys are crystallized in the form of non-faceted dendrites primary carbides and faceted dendrites primary carbides. The paper presents examples of the different microstructures. Also in order to examine the shape of the primary carbides and eutectics in a closer detail the specimens were deep-etched with aqua regia and then examined in the SEM.

Influence of the Content and Distribution of Vanadium in the M1 Phase of the MoVTe(Sb)NbO Catalysts on their Catalytic Properties in Light Alkanes Oxidation

Phase-pure MoVTe(Sb)NbO mixed oxides, with an M1 structure, and various compositions were prepared, characterized and tested as catalysts for the oxidative dehydrogenation of ethane, in order to study the influence of vanadium content and its distribution over the crystallographic sites on the catalytic properties of these oxides. A linear variation in catalytic activity was observed, as a function of the total vanadium content. This property, which has already been demonstrated for propane oxidation, is shown to remain unaffected by the alkane reaction, the nature of the propene α-dehydrogenation elements (Te or Sb), the presence or absence of niobium. The use of XPS to study the surface composition of the catalysts allowed a direct proportionality to be established between the rate of ethane conversion and the V5+ surface content, thus explaining the first correlation observed with bulk V content. This result also emphasizes the fact that a maximum level of intrinsic catalytic activity can be found, and that high vanadium content might be detrimental to this activity, or to the stability of the catalysts. Finally, crystallographic data found in the literature are used to further interpret and discuss these results.

Red mud a byproduct of aluminum production contains soluble vanadium that causes genotoxic and cytotoxic effects in higher plants

Red mud (RM) is a byproduct of aluminum production; worldwide between 70 and 120million tons is produced annually. We analyzed RM which was released in the course of the Kolontar disaster in Hungary into the environment in acute and genotoxicity experiments with plants which are widely used for environmental monitoring. We detected induction of micronuclei which reflect chromosomal damage in tetrads of Tradescantia and in root cells of Allium as well as retardation of root growth with contaminated soils and leachates. Chemical analyses showed that RM contains metals, in particular high concentrations of vanadium. Follow-up experiments indicated that vanadate causes the effects in the plants. This compound causes also in humans DNA damage and positive results were obtained in carcinogenicity studies. Since it was found also in RM from other production sites our findings indicate that its release in the environment is a global problem which should be studied in more detail. Capsule abstractOur findings indicate that the red mud causes genotoxic effect in plants probably due to the presence of vanadate which is contained at high concentrations in the residue.

Study on Microstructures of Al-4 wt pct V Master Alloys

Aluminum (Al)-V master alloys have attracted attention, because they can potentially be efficient grain refiners for wrought aluminum alloys. In this paper, the microstructure and factors affecting the microstructure of Al-4 wt pct V master alloys were investigated by means of controlled melting and casting processes followed by structure examination. The results showed that the type and morphology of the V-containing phases in Al-V master alloys were strongly affected by the temperature of the melt, concentration of vanadium in solution in the melt and the cooling conditions. Two main V-containing phases, Al3V and Al10V, which have different shapes, were found in the alloys prepared by rapid solidification. The Al3V phase formed when there were both a high temperature (1273 K to 1673 K (1000 °C to 1400 °C)) and a relatively high vanadium content of 3 to 4 wt pct, while the Al10V phase formed at a low temperature (<1373 K (1100 °C)) or a low vanadium content in the range of 1 to 3 wt pct. The results also showed that the type of V-containing phase that formed in the Al-4 wt pct V master alloy was determined by the instantaneous vanadium content.

Synthesis, characterization of MCM-41 with high vanadium content in the framework and its catalytic performance on selective oxidation of cyclohexane

V-MCM-41 with high content of vanadium in the framework was synthesized by using direct hydrothermal method under alkaline condition. Tartaric acid is the complexing reagent and cetyltrimethylammonium bromide is the structure-directing agent. The samples were characterized by X-ray fluorescence, X-ray diffraction, high-resolution transmission electron microscopy, N2 adsorption–desorption, Fourier-transform infrared spectroscopy, diffuse reflectance ultraviolet–visible spectroscopy and X-ray photoelectron spectroscopy techniques. The catalytic performance for the selective oxidation of cyclohexane was also examined. The results showed that the vanadium atoms were successfully introduced into the MCM-41 framework and the vanadium content reached up to 8.1wt.%. Moreover, the V-MCM-41 samples possessed regular and stable structure with high specific surface area (692–939m2g−1), large pore diameter (3.6–4.6nm) and large pore volume (0.86–0.95cm3g−1). The samples exhibited excellent catalytic performance of up to 22.57% cyclohexane conversion and 99.53% selectivity for cyclohexanone and cyclohexanol in the cyclohexane oxidation.

New typology and origin of tsavorite based on trace-element chemistry

New electron-microprobe analyses of ‘tsavorites’ from the Neoproterozoic Metamorphic Mozambique Belt deposits allow the characterization of green grossular according to its trace-element chemistry (V, Cr, Mn). Five chemical types are defined: type 1, vanadian grossular with V >Cr >Mn (in atoms per formula unit); type 2, vanadian grossular with V >Mn >Cr; type 3, Mn-bearing vanadian grossular with Mn > V > Cr; type 4, Mn-bearing chromian grossular with Mn > Cr > V; and type 5, Cr- and Mn-bearing grossular with Cr > Mn > V. These types are also characterized by different absorption spectra in the ultraviolet–visible–near infrared. Type 1 tsavorite spectra show a total absorption below 430 nm due to the high vanadium contents. Type 2 tsavorite spectra present the classical absorption bands of V. Types 3 and 4 tsavorite spectra display additional shoulders at 407 and 408 nm due to Mn 2+ , whereas spectra of Cr-bearing types 4 and 5 tsavorite show the two additional bands of Cr 3+ at 697 and 701 nm. The different absorption spectra also indicate Fe 2+ -Ti 4+ charge transfer. We measured OH − equivalent to 0.08 to 0.38 wt% eq. H 2 O within the structure. Concentrations of vanadium, chromium and manganese are good chemical “fingerprints” for determining the geographic provenance of economic tsavorite from Kenya, Tanzania and Madagascar.

Beneficial effects of natural Jeju groundwaters on lipid metabolism in high-fat diet-induced hyperlipidemic rats

BACKGROUNDGroundwater is believed to possess many beneficial effects due to its natural source of various minerals. In this study, we examined the effects of natural Jeju groundwater S1 (Samdasoo™), S2 and S3 pumped up from different locations of Jeju Island, Korea, along with local tap water, on body weight gain, serum lipids and lipoproteins, and liver histopathology in high-fat diet-induced hyperlipidemic rats.MATERIALS/METHODSRats were randomly and equally divided into 6 groups. Different water samples were supplied to the hyperlipidemic rats as their daily drinking water and the widely-used anti-hyperlipidemic drug simvastatin was used as a positive control. Body weight, serum lipids and lipoproteins were measured weekly. Liver weight, liver index and liver histopathology were examined after the execution of the rats.RESULTSAfter drinking Jeju groundwaters for two months, S2 but not S3 significantly reduced weight growth and serum triglycerides levels and increased high density lipoprotein-C (HDL-C) without affecting total cholesterol or LDL-C. S1 and particularly S2 significantly reduced the severity of liver hypertrophy and steatosis. All Groundwaters had much higher contents of vanadium (S3>S2>S1>>tap water) whereas S1 and S2 but not S3 markedly blocked autoxidation of ferrous ions.CONCLUSIONJeju Groundwater S1 and particularly S2 exhibit protective effects against hyperlipidemia and fatty liver and hypothesize that the beneficial effect of Jeju Groundwaters may be contributed from blockade of autoxidation of ferrous ions rather than their high contents of vanadium.

Metal-insulator transition in SrTi1−xVxO3 thin films

Epitaxial SrTi1−xVxO3 (0 ≤ x ≤ 1) thin films were grown on (001)-oriented (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) substrates using the pulsed electron-beam deposition technique. The transport study revealed a temperature driven metal-insulator transition (MIT) at 95 K for x = 0.67. The films with higher vanadium concentration (x &amp;gt; 0.67) were metallic corresponding to a Fermi liquid system. In the insulating phase (x &amp;lt; 0.67), the resistivity behavior was governed by Mott's variable range hopping mechanism. The possible mechanisms for the induced MIT are discussed, including the effects of electron correlation, lattice distortion, and Anderson localization.

Redox Multiphoton Polymerization for 3D Nanofabrication

We report for the first time on the redox multiphoton polymerization of an organic-inorganic composite material, in which one of the components, a vanadium metallo-organic complex, initiates the polymerization. The composite employs multiphoton absorption to self-generate radicals by photoinduced reduction of the metal species from vanadium (V) to vanadium (IV). We exploit this material for the fabrication of fully 3D structures by multiphoton polymerization with 200 nm resolution, employing a femtosecond laser operating at 800 nm, in the absence of a photoinitiator. Nonlinear absorption measurements indicate that the use of an 800 nm laser initiates the photopolymerization due to three-photon absorption of the vanadium alkoxide. The laser power required to induce this three-photon polymerization is comparable to what is required for inducing two-photon polymerization in materials using standard two-photon absorbers, most likely due to the high content of vanadium in the final composite (up to 50% mole).

Process Optimization and Properties of Laser Cladding High Vanadium High Speed Steel Coatings on Nodular Cast Iron

As withstanding very high loads, thermal cycling leading to thermal fatigue, and severe environmental in the steel industry, rolls with long service life are specially required. High speed steel with high vanadium content is a newly-developed wear-resistance material that has been studied and used in some countries for making steel rolls. As a surface treatment technology, laser cladding can fabricate coating to improve the wear resistance of substrate. In this paper, the substrates for laser cladding were nodular cast iron rolls, Nd: YAG solid pulsed laser was used to explore the feasibility of preparation high vanadium high speed steel (HVHSS) coatings. The Nd: YAG laser cladding results that the coated layers combined metallurgically with the substrate with a lot of microcracks. The average microhardness up to 650 HV is more than 2 times as high as that of the substrate. After laser remelting, a fully dense and crack free HVHHS coating with an excellent metallurgical bonding was deposited. The presence of VC in the coating mainly improves the microhardness of coating up to about 650 HV.

Investigation of extraction of vanadium(V) with di-2-ethylhexylphosphoric acid

to the formation of hydrogen bond between the dioxonium ion and the phosphoryl group P=O. It indicates that di-2-ethylhexylphosphoric acid extracts vanadium(V) with the formation of ionic associates. For the evaluation of the number of extractant molecules solvating the dioxonium ion the method of molar ratios was used. It follows from the extraction isotherm that one molecule of di-2-ethylhexylphosphoric acid corresponds to 10 vanadium ions. Considering our previous data on the ionic state of vanadium(V) in the range under study this means that one molecule of extractant corresponds to one decavanadate anion [8]. Hence, the method of saturation of organic phase permits not only to establish the number of solvating molecules of extractant in the composition of complex, but also to make the preliminary conclusion that vanadium(V) enters the composition of extracted complex as decavanadate anion. It is confirmed by the results of studies of the IR spectra of extracts of vanadium(V) with di-2-ethylhexylphosphoric acid. At high concentrations of vanadium(V) a broadening of absorption band at 1030 cm –1 is observed at the side of low frequencies and two shoulders at ~970 cm –1 and ~920 cm –1 appear. The comparative analysis of IR spectra of the extract of vanadium(V) with di-2ethylhexylphosphoric acid and the reported data on the IR spectra of vanadium(V) dioxocation and decavanadate anions [8] permits to attribute the low intensity bands at ~960 cm –1 and ~920 cm –1 to two types of binding of vanadium with terminal oxygen atoms of f- and g-type of decavanadate anion. Hence, the method of saturation and the results of IR studies of the extracts of vanadium(V) with di-2DOI: 10.1134/S1070363213060261 Di-2-ethylhexylphosphoric acid is known as the cation-exchanging extractant. It is widely used for the extraction of vanadium(IV) [1-5]. The extraction of vanadium(V) in a form of dioxocation with this substance proceeds with the very low distribution coefficient, and due to that it is not utilized [6]. We have worked up the conditions under which the change in the extraction mechanism from the cationexchanging to the solvate one takes place in the course of extraction what permits to extract vanadium(V) with di-2-ethylhexylphosphoric acid with high distribution coefficient. In this work we present the results of study of extraction of vanadium(V) with di-2-ethylhexylphosphoric acid. The investigation of extraction of vanadium(V) with di-2-ethylhexylphosphoric acid was carried out by means of IR and electronic spectroscopy. For the evaluation of the composition of extracted complex IR spectra of pure di-2-ethylhexylphosphoric acid and the vanadium(V) extract were recorded. In the IR spectra of the extract together with the absorption bands of di2-ethylhexylphosphoric acid the bands at 1650, 1750, 2140, and 3390 cm –1 are present which are characteristic of dioxonium ion [7]. The bands at 1170, 1370, and 2900 cm –1 which are also characteristic of H5O2 + ion are partially overlapped with more intense bands of di-2-ethylhexylphosphoric acid. The absorption band of P=O bond (νP=O) in the vanadium(V) extract has the frequency 1210 cm –1 . In the IR spectrum of pure di-2ethylhexylphosphoric acid the band of P=O bond (νP=O) has a maximum at 1225 cm –1 . As it was shown above, in the vanadium(V) extracts the dioxonium ion is presented. Due to that the shift of the band of P=O bond to the side of low frequencies may be attributed as