Preparation method of high-purity vanadium pentoxide

Abstract

The invention relates to the technical field of vanadium pentoxide preparation, and particularly discloses a preparation method of high-purity vanadium pentoxide, which comprises the following steps: S1, vanadium slag pretreatment: carrying out microwave activation on vanadium slag, and then carrying out ball milling and roasting to obtain clinker; the sulfuric acid-oxalic acid composite acid and the clinker are mixed and leached, the pH is adjusted after leaching is completed, and vanadium-containing leachate is obtained through filtering; s3, vanadium enrichment: heating the vanadium-containing leachate, adding a sodium carbonate solution while stirring, adjusting the pH value, preserving heat and curing, and then carrying out hot filtration to obtain vanadium-rich filter residues; s4, vanadium purification: mixing the vanadium-rich filter residues with a sodium hydroxide solution, stirring, introducing compressed air while stirring, and carrying out hot filtration after the reaction is finished, so as to obtain vanadium-rich filtrate; and S5, calcining: carrying out two-stage calcining on the ammonium metavanadate precursor to obtain high-purity V2O5. The preparation method is high in vanadium recovery rate, and the purity of the prepared V2O5 is 99% or above.

Description

TECHNICAL FIELD

[0001] The application relates to the field of vanadium pentoxide preparation, in particular to a preparation method of high-purity vanadium pentoxide. BACKGROUND

[0002] High-purity vanadium pentoxide refers to improving the content of vanadium pentoxide and reducing the content of trace elements such as iron, magnesium, arsenic, silicon, phosphorus and sulfur according to the metallurgical industry standard vanadium pentoxide YB / T 5304-2017, so as to meet the requirements of high-end vanadium fields such as military industry, aerospace, clean materials and vanadium batteries and the international standard of vanadium pentoxide exported to the European Union. The high-purity vanadium pentoxide defined in the application is vanadium pentoxide with a purity of greater than or equal to 99.5%.

[0003] Vanadium pentoxide is an important functional material and has wide application in the fields of lithium ion battery positive electrode material, SCR denitration catalyst and special glass. At present, the sodium roasting-water leaching purification process (such as CN118343833A) is generally used in industrial production. Vanadium pentoxide is prepared by high-temperature roasting of vanadium slag with sodium carbonate or sodium sulfate, water leaching, precipitation, calcination and other steps. However, this technical route has significant technical bottlenecks in practical application. First, during the sodium salt roasting process, impurity elements such as silicon and iron are easy to form stable composite oxides (such as FeV2O4) with vanadium, which leads to an increase in the dissolution rate of impurities in the subsequent acid leaching stage. Even through multiple recrystallization purification, the Fe and Si contents in the product are still generally higher than 500 ppm, which is difficult to meet the index requirements of high-purity V2O5. Second, the strong alkaline sodium salt system has a prominent corrosion problem on the reaction equipment, especially the molten sodium salt generated in the high-temperature roasting stage, which can accelerate the intergranular corrosion of the stainless steel reaction kettle, significantly shorten the service life of the equipment and increase the maintenance cost. In addition, the calcination temperature in the traditional process is usually higher than 650℃, and under high-temperature conditions, the V2O5 lattice is easy to have oxygen vacancy defects and crystal distortion, which leads to a decrease in the thermodynamic stability of the material and directly affects its cycle performance in lithium batteries.

[0004] In recent years, some improved processes attempt to use acid leaching instead of sodium roasting (such as CN118978180A). Although the impurity content is reduced to some extent, it still faces problems such as low vanadium recovery rate and complex process control. For example, the direct sulfuric acid leaching method needs to rely on high-concentration acid and long-time reaction due to the chemical inertness of the vanadium iron spinel phase in the vanadium slag, which leads to an increase in acid consumption and a multiplication of the difficulty of subsequent purification of the leaching solution. In the extraction purification process, the conventional single-stage extraction has a low Fe 3+ , Al 3+The selective separation efficiency of impurities is insufficient, and deep impurity removal often needs to be achieved through multi-stage extraction and stripping operation, thereby causing problems such as increased vanadium loss rate (>5%) and organic phase emulsification. In the precipitation process, the traditional ammonia water precipitation method is prone to form amorphous or fine crystal agglomerated ammonium metavanadate precursors due to uncontrollable nucleation rate, and the specific surface area of V2O5 obtained after calcination is low (<10 m 2 / g), and the grain boundaries are densely defective, which seriously restricts the catalytic activity and ion migration efficiency.

[0005] In summary, the existing vanadium pentoxide preparation technology still has the common problems of incomplete impurity removal, high process energy consumption, many product crystal defects, and low vanadium recovery rate, and a new process with efficient purification, low energy consumption, short process and excellent product performance is urgently needed. SUMMARY

[0006] To solve the above technical problems, the application provides a high-purity vanadium pentoxide preparation method based on vanadium slag purification and fractional extraction, which has short process time, high impurity removal rate, high product purity, and high vanadium recovery rate.

[0007] The application provides a preparation method of high-purity vanadium pentoxide, which adopts the following technical scheme: A preparation method of high-purity vanadium pentoxide, comprising the following steps: S1, vanadium slag pretreatment: the vanadium slag is activated by microwave and then ball milled to D90 < 0.3 mm, and then calcined to obtain clinker; this step is mainly to improve the reaction activity of the vanadium slag and increase the specific surface area.

[0008] S2, composite acid leaching: mix sulfuric acid and oxalic acid with the clinker, first leach at 50°C for 0.5-1h, and then leach at 80°C for 1.5-2h, after leaching, adjust pH to 3.5-4, and after 0.5-1h, filter to obtain a vanadium-containing leaching solution; the first step of leaching mainly dissolves vanadate, and oxalic acid mainly plays a complexing role to form a soluble complex with V (IV); the second step of high-temperature leaching aims to further decompose stable vanadium iron spinel, and oxalic acid plays a reducing role to reduce part of the dissolved Fe 3+ to Fe 2+ , and generate ferrous oxalate precipitate under the subsequent condition of pH = 3-3.5, and the filter residue is mainly leaching residue mainly composed of iron slag, and the leaching solution is a vanadium-containing leaching solution containing a small amount of impurities. The composite leaching of sulfuric acid and oxalic acid is a necessary pre-step for the subsequent process, which can simultaneously achieve vanadium leaching and preliminary impurity removal of the vanadium slag clinker.

[0009] S3, vanadium enrichment: the vanadium-containing leaching solution is heated to 60-80°C, and a sodium carbonate solution is slowly added under stirring, the pH is adjusted to 4-4.5, and the solution is aged for 1-2 h, and then hot filtration is performed to obtain a vanadium-enriched residue; after the addition of the sodium carbonate solution, vanadium ions form polyvanadate precipitates, and at the same time, residual Fe 3+ , Al 3+ ions in the solution are completely hydrolyzed to form hydroxide precipitates, and phosphorus, arsenic, silicon and other impurities are removed by co-precipitation, and the residue obtained after hot filtration is an enrichment of vanadium and impurities such as iron and aluminum, and soluble impurity ions such as Ca 2+ , Mg 2+ are discarded with the filtrate.

[0010] S4, vanadium purification: the vanadium-enriched residue is mixed with a 2-4 mol / L sodium hydroxide solution, stirred at 80-90°C, and compressed air is simultaneously introduced, and the reaction is performed for 1.5-2 h, and then hot filtration is performed to obtain a vanadium-rich filtrate. Under alkaline oxidation conditions, vanadium is converted into soluble sodium vanadate, while the hydroxides of impurities such as iron and aluminum are not dissolved under these conditions and are completely fixed in the residue, and hot filtration is performed to achieve complete separation of vanadium and impurities.

[0011] S5, precipitation: the vanadium-rich solution is concentrated, and the pH is adjusted to 8-9, NH4VO3 seed crystals are added, and ammonia water is titrated at a constant rate to maintain a precipitation rate of 0.5-1.2 g / (L·min) to obtain ammonium metavanadate precursors; S6, calcination: the ammonium metavanadate precursors are subjected to two-stage calcination to obtain high-purity V2O5.

[0012] Further preferably, the microwave activation conditions are 300-500 W for 5-10 min.

[0013] Further preferably, the ball-to-material ratio is controlled to be (8-10):1 during the vanadium slag ball milling process.

[0014] Further preferably, the mass fraction of sulfuric acid is 20-30%, preferably 25%.

[0015] Further preferably, the mass fraction of oxalic acid is 5-10%, preferably 8%.

[0016] Further preferably, the mass liquid-to-solid ratio is (3-5):1, preferably 3:1, during the composite acid leaching process.

[0017] Further preferably, the amount of NH4VO3 seed crystals added during the precipitation process is 0.5-1.5% of the mass of the obtained ammonium metavanadate precursors, preferably 1%.

[0018] Further preferably, the D50 of the NH4VO3 seed crystals is 50-100 nm.

[0019] Further preferably, the titration speed of the ammonia water is 0.8-1 mL / min during the precipitation process to maintain the supersaturation index S=1.05-1.15, so as to obtain monodisperse NH4VO3 crystals.

[0020] The crystal lattice of the seed surface can match the sodium metavanadate to grow along a specific crystal face, reduce crystal defects, and avoid impurities from being embedded in the crystal lattice, thereby improving the purity.

[0021] Further preferably, the first-stage calcination temperature is controlled at 300 DEG C during the calcination process to remove the crystal water in the ammonium metavanadate precursor, and the second-stage calcination temperature is controlled at 500 DEG C to decompose NH4VO3 into V2O5.

[0022] Further preferably, the oxygen flow rate is 1-1.5 m 3 / h during the calcination process.

[0023] Further preferably, the purity of the high-purity vanadium pentoxide is greater than or equal to 99.5%.

[0024] Beneficial effects: The high-purity vanadium pentoxide preparation method provided by the application solves the key problems of incomplete impurity removal, low vanadium recovery rate, and many product crystal defects in the traditional technology through innovative process design.

[0025] 1. In the vanadium slag pretreatment, the application adopts microwave activation-ball milling cooperative treatment to improve the reaction activity of the vanadium slag, increase the specific surface area, and improve the efficiency of subsequent vanadium leaching.

[0026] 2. In the vanadium leaching process, the application uses a composite acid composed of sulfuric acid and oxalic acid to treat the vanadium slag, which not only realizes the leaching of vanadium, but also preliminarily removes impurities such as iron and aluminum, thereby improving the purity of the final vanadium pentoxide.

[0027] 3. After preliminary impurity removal, the application further combines with alkaline oxidation leaching to selectively separate a small amount of residual impurities, thereby realizing efficient separation of vanadium and impurities.

[0028] 4. In the precipitation process, the application uses NH4VO3 seed crystals for induced precipitation, which can further reduce impurity embedding and improve product purity. In the calcination process, two-stage oxygen-controlled calcination is used to significantly reduce the residual amount of V2O4, thereby ensuring the purity of the product. As a downstream application, especially in the field of vanadium batteries, high-purity V2O5 has high electrochemical activity. DETAILED DESCRIPTION

[0029] Following, the embodiments of the present application are illustrated by specific examples, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure of the present specification. The present application can also be implemented or applied by other different specific embodiments, and various modifications or changes can be made to the details in the present specification based on different views and applications without departing from the spirit of the present application.

[0030] In addition, it should be understood that one or more method steps mentioned in the present application does not exclude that there can be other method steps before and after the mentioned combination steps or other method steps can be inserted between these explicitly mentioned steps, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool to identify each method step, and is not intended to limit the arrangement order of each method step or to limit the scope of the present application, and the change or adjustment of the relative relationship without substantial change of the technical content is also considered as the scope of the present application.

[0031] If the specific conditions of the experiments are not specified in the examples, they are generally in accordance with the conventional conditions in the art or in accordance with the conditions recommended by the reagent companies; the materials, reagents, etc. used in the examples can be purchased through commercial channels, unless otherwise specified.

[0032] Examples Example 1 Pretreatment of vanadium slag Vanadium slag was selected, with a total vanadium content of 12.53% in terms of V2O5, and was pretreated by three different treatment methods. The total amount of vanadium slag treated by each treatment method was 100 g.

[0033] Microwave and ball milling combined treatment: the vanadium slag was activated for 8 min under the condition of 400 W, then zirconia abrasive was used to mill the vanadium slag with a ball-to-material ratio of 8:1, and vanadium slag powder with a particle size D90<0.3 mm was obtained. After conventional roasting, vanadium slag clinker was obtained.

[0034] Microwave single treatment: only activate the vanadium slag for 8 min under the condition of 400 W, then roast to obtain vanadium slag clinker.

[0035] Ball milling single treatment: only use zirconia abrasive to mill the vanadium slag with a ball-to-material ratio of 8:1, then roast to obtain vanadium slag clinker.

[0036] Example 2 Acid leaching Composite acid leaching: Take 25% sulfuric acid and 8% oxalic acid, and compound them according to a volume ratio of 2.5:1 to obtain composite acid. Use the composite acid to leach the vanadium slag clinker prepared in Example 1, and control the mass liquid-to-solid ratio to be 3:1.

[0037] Microwave and ball milling synergistic treatment of vanadium slag clinker: first heated to 50℃ leaching 1h, then heated to 80℃ leaching 2h, after leaching, adjust pH to 3.5, aging 1h, then filtered, to obtain vanadium-containing leaching solution.

[0038] Microwave single treatment of vanadium slag clinker: first heated to 50℃ leaching 1h, then heated to 80℃ leaching 2h, after leaching, adjust pH to 3.5, aging 1h, then filtered, to obtain vanadium-containing leaching solution.

[0039] Ball milling single treatment of vanadium slag clinker: first heated to 50℃ leaching 1h, then heated to 80℃ leaching 2h, after leaching, adjust pH to 3.5, aging 1h, then filtered, to obtain vanadium-containing leaching solution.

[0040] The vanadium-containing leaching solution obtained by the three different vanadium slag clinker leaching methods was detected, and the detection results are shown in Table 1 below.

[0041] Table 1 Vanadium leaching rate Single acid leaching: The vanadium slag clinker prepared by microwave and ball milling synergistic treatment in Example 1 was subjected to single acid leaching with 25% by mass of sulfuric acid, and the mass liquid-solid ratio was controlled to be 3:1. The leaching steps were as follows: first heated to 50℃ leaching 1h, then heated to 80℃ leaching 2h, after leaching, adjust pH to 3.5-4, aging 1h, then filtered, to obtain vanadium-containing leaching solution, and the vanadium leaching rate was 73.3%.

[0042] As can be seen from the results, the vanadium slag is pretreated by microwave and ball milling synergistically, and combined with the sulfuric acid-oxalic acid system, the leaching rate of vanadium element can be greatly improved, and the vanadium leaching rate is as high as 96.8%, and the leaching time is short. This also shows that the microwave + ball milling synergistic pretreatment combined with the sulfuric acid-oxalic acid composite acid system can significantly improve the vanadium recovery rate, so the vanadium slag powder prepared by this method is used as the object for subsequent preparation of high-purity vanadium pentoxide.

[0043] Example 3 Preparation of high-purity vanadium pentoxide The vanadium-containing leaching solution obtained by microwave and ball milling synergistic treatment of vanadium slag clinker in Example 2 and by composite acid leaching was used as the object, and was subjected to vanadium enrichment, vanadium purification, precipitation and calcination treatment in sequence to prepare high-purity vanadium pentoxide.

[0044] Vanadium enrichment: the vanadium-containing leaching solution was heated to 80℃, and sodium carbonate solution was slowly added under stirring, the pH was adjusted to 4-4.5, and the temperature was kept for 2h, and then hot filtration was performed to obtain vanadium-rich filter residue; Vanadium purification: the vanadium-rich filter residue was mixed with 2mol / L sodium hydroxide solution, stirred at 90℃, and compressed air was simultaneously introduced, and the reaction was carried out for 2h, and after the reaction was completed, hot filtration was performed to obtain vanadium-rich filtrate.

[0045] Precipitation: The vanadium-rich solution obtained in the above step was added with 1% NH4VO3 seed ethanol dispersion suspension (D50=80 nm) in terms of the total mass of the product obtained, and after uniform dispersion, ammonia water was titrated at a constant rate of 0.8 ml / min to maintain the supersaturation index S between 1.05-1.15, to obtain the ammonium metavanadate precursor.

[0046] Calcination: The ammonium metavanadate precursor prepared above was subjected to two-stage calcination in a rotary kiln, with the calcination conditions being 300°C for 0.5 h and 500°C for 2 h, the rotary kiln cylinder rotation frequency being 22 Hz, the kiln internal negative pressure being -16 to -10 Pa, the oxygen flow being controlled at 1 m 3 / h, and finally high-purity V2O5 was obtained.

[0047] Example 4 High-purity vanadium pentoxide preparation: The difference from Example 3 is that in the precipitation step, the vanadium-rich solution obtained in the above step was added with 0.5% NH4VO3 seed ethanol dispersion suspension (D50=80 nm) in terms of the total mass of the product obtained, and after uniform dispersion, ammonia water was titrated at a constant rate of 0.8 ml / min to maintain the supersaturation index S between 1.05-1.15, to obtain the ammonium metavanadate precursor.

[0048] The other steps are the same as in Example 3.

[0049] Example 5 High-purity vanadium pentoxide preparation: The difference from Example 3 is that in the precipitation step, the vanadium-rich solution obtained in the above step was added with 1.5% NH4VO3 seed ethanol dispersion suspension (D50=80 nm) in terms of the total mass of the product obtained, and after uniform dispersion, ammonia water was titrated at a constant rate of 0.8 ml / min to maintain the supersaturation index S between 1.05-1.15, to obtain the ammonium metavanadate precursor.

[0050] The other steps are the same as in Example 3.

[0051] Example 6 High-purity vanadium pentoxide preparation: The difference from Example 3 is that in the precipitation step, the vanadium-rich solution obtained in the above step was added with 1% NH4VO3 seed ethanol dispersion suspension (D50=50 nm) in terms of the total mass of the product obtained, and after uniform dispersion, ammonia water was titrated at a constant rate of 0.8 ml / min to maintain the supersaturation index S between 1.05-1.15, to obtain the ammonium metavanadate precursor.

[0052] The other steps are the same as in Example 3.

[0053] Example 7 Preparation of high-purity vanadium pentoxide: the difference from Example 3 is that in the precipitation step, 1% of an ethanol dispersion suspension (D50 = 100 nm) of NH4VO3 seed crystals is added to the vanadium-rich solution obtained in the above step, and after uniform dispersion, ammonia water is titrated at a constant rate of 0.8 ml / min to maintain the supersaturation index S between 1.05 and 1.15, to obtain an ammonium metavanadate precursor.

[0054] The other steps are the same as in Example 3.

[0055] Comparative Example Comparative Example 1 Preparation of vanadium pentoxide: the difference from Example 3 is that no NH4VO3 seed crystals are added during the precipitation process, and the other steps are the same as in Example 3.

[0056] Comparative Example 2 Preparation of vanadium pentoxide: the difference from Example 3 is that one-stage calcination is used in the calcination process, with conditions of calcination at 500°C for 2.5 h, and the other steps are the same as in Example 3.

[0057] Comparative Example 3 Using the vanadium-containing leachate obtained by microwave and ball milling treatment of vanadium slag clinker in Example 2 and single acid leaching as the object, vanadium enrichment, vanadium purification, precipitation, and calcination treatment are sequentially performed to prepare high-purity vanadium pentoxide, wherein the vanadium enrichment, vanadium purification, precipitation, and calcination treatment steps are the same as in Example 3.

[0058] Performance detection Chemical composition detection is performed on the vanadium pentoxide obtained in Example 3 and Comparative Examples 1-2, and the test method is as follows: The determination method of vanadium pentoxide content is in accordance with YB / T5328.

[0059] The determination method of silicon content is in accordance with YB / T5329.

[0060] The determination method of iron content is in accordance with YB / T5330.

[0061] The determination method of phosphorus content is in accordance with YB / T4219.

[0062] The determination method of sulfur content is in accordance with YB / T5333.

[0063] The determination method of arsenic content is in accordance with YB / T5334.

[0064] The determination method of potassium oxide and sodium oxide content is in accordance with YB / T5335.

[0065] The determination method of vanadium tetraoxide content is in accordance with YB / T4248.

[0066] The test results of the main chemical components of examples 3-7 and comparative examples 1-3 are recorded in Table 2.

[0067] Table 2 Test results of main chemical components As can be seen from the test results of comparative examples 1-2 in Table 2, the directional induction crystallization of exogenous seeds and the combination of two-stage calcination can significantly improve the purity of V2O5, especially the content of tetravalent vanadium is significantly reduced.

[0068] As can be seen from the test results of examples 3 and comparative example 3 in Table 1 and Table 2, the purity of V2O5 obtained by using sulfuric acid to leach the vanadium slag clinker is relatively low, which shows that the single acid has a lower leaching rate and the purity of V2O5 obtained is also low compared with the composite acid, and also shows the necessity of the pre-leaching step of the composite acid for the oxidation and alkali leaching impurities of the present application.

[0069] The above is only a preferred embodiment of the present application, and is not any form and substantial limitation of the present application. It should be noted that, for ordinary skilled persons in the art, without departing from the method of the present application, some improvements and supplements can also be made, which should be considered as the protection scope of the present application. For those skilled in the art, without departing from the spirit and scope of the present application, some changes, modifications and equivalent changes made by using the disclosed technical content are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above-mentioned embodiments according to the essential technology of the present application are still within the scope of the technical solutions of the present application.

Claims

1. A method for preparing high-purity vanadium pentoxide, characterized in that, It comprises the following steps: S1, vanadium slag pretreatment: the vanadium slag is activated by microwave and then ball milled to D90<0.3mm, and then roasted to obtain clinker; S2, composite acid leaching: the composite acid of sulfuric acid and oxalic acid is mixed with the clinker, first leached at 50℃ for 0.5-1h, and then leached at 80℃ for 1.5-2h, after the leaching is completed, the pH is adjusted to 3.5-4, and after 0.5-1h, filtration is performed to obtain a vanadium-containing leaching solution; S3, vanadium enrichment: the vanadium-containing leaching solution is heated to 60-80℃, and sodium carbonate solution is slowly added under stirring, the pH is adjusted to 4-4.5, and incubation is performed for 1-2h, and then hot filtration is performed to obtain a vanadium-rich filter residue; S4, vanadium purification: the vanadium-rich filter residue is mixed with 2-4mol / L sodium hydroxide solution, stirred at 80-90℃, and compressed air is simultaneously introduced, and the reaction is performed for 1.5-2h, and after the reaction is completed, hot filtration is performed to obtain a vanadium-rich filtrate; S5, precipitation: the vanadium-rich solution is concentrated, and the pH is adjusted to 8-9, NH4VO3 seed crystals are added, and ammonia water is titrated at a constant speed, and the precipitation rate is maintained at 0.5-1.2g / (L·min) to obtain ammonium metavanadate precursor; S6, calcination: the ammonium metavanadate precursor is subjected to two-stage calcination to obtain high-purity V2O5.

2. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In the vanadium slag pretreatment process, the microwave activation conditions are 300-500W for 5-10min, and the ball-to-material ratio of ball milling is (8-10):

1. ​ 3. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In the composite acid leaching process, sulfuric acid with a mass fraction of 20-30% and oxalic acid with a mass fraction of 5-10% are mixed to obtain the composite acid of sulfuric acid and oxalic acid. ​ 4. The method of claim 3, wherein the high purity vanadium pentoxide is prepared by the steps of: The mass liquid-to-solid ratio of the composite acid to the vanadium slag clinker is (3-5):

1. ​ 5. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In the precipitation process, the addition amount of the NH4VO3 seed crystals is 0.5-1.5% of the mass of the obtained ammonium metavanadate precursor. ​ 6. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In the precipitation process, the D50 of the added NH4VO3 seed crystals is 50-100nm. ​ 7. The method for preparing high-purity vanadium pentoxide according to claim 1, characterized in that, In the precipitation process, the titration speed of the ammonia water is 0.8-1mL / min, and the supersaturation index S is 1.05-1.

15.

8. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In the calcination process, the two-stage calcination temperatures are 300℃ and 500℃, respectively. ​ 9. The method for preparing high-purity vanadium pentoxide according to claim 1, characterized in that, During the calcination, the oxygen flow rate is 1-1.5 m 2 / h. 10.The method for preparing high-purity vanadium pentoxide according to any one of claims 1-9, characterized in that, The purity of the obtained high-purity vanadium pentoxide is ≥99.5%.

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