Preparation method of high-purity vanadium pentoxide

Abstract

The invention relates to the technical field of hydrometallurgy, and discloses a preparation method of high-purity vanadium pentoxide, which comprises the following steps: S1, adding aluminum salt into raw materials to react, standing, and filtering to obtain filtrate; s2, heating the filtrate, adjusting the pH value of the filtrate, and adding a precipitator into the filtrate; s3, continuing to heat the filtrate and adjust the pH value of the filtrate, and performing liquid-solid separation to obtain a first precipitate; s4, the first precipitate is subjected to an alkali dissolution reaction to obtain a vanadium-containing solution, the pH value and the temperature of the vanadium-containing solution are adjusted, a chromium removal agent is added into the vanadium-containing solution for a reaction, and a chromium removal solution is obtained; and S5, the chromium removal liquid is subjected to sedimentation and liquid-solid separation, a second precipitate is obtained, and the second precipitate is dried and calcined to prepare a vanadium pentoxide product. By means of the scheme, the problems that an existing vanadium pentoxide impurity removal process is long in technological process, high in production cost and high in impurity content are solved, the impurity removal efficiency is effectively improved, and environmental pollution is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrometallurgy, and particularly relates to a preparation method of high-purity vanadium pentoxide. BACKGROUND

[0002] High-purity vanadium pentoxide has become an indispensable key basic raw material for strategic industries such as new energy storage, environmental protection catalysis and high-end electronic materials due to its high purity and excellent physical and chemical properties. The market demand for vanadium electrolyte is growing significantly, and high-purity vanadium pentoxide is the core precursor for preparing high-performance vanadium electrolyte. The purity of vanadium pentoxide product directly determines the key performance indicators such as conductivity, stability and cycle life of the final electrolyte.

[0003] At present, in the process of producing vanadium pentoxide from vanadium-containing solution (such as vanadium solution after sodium roasting), it is difficult to deeply remove impurity elements such as silicon (Si) and chromium (Cr). These impurity elements not only affect the efficiency of ammonium polyvanadate (APV) precipitation process and the purity of the product, but also remain in the final product, resulting in a decrease in the purity of vanadium pentoxide and the inability to meet the stringent requirements of high-end application fields.

[0004] Therefore, it is urgent to propose a process method that can efficiently and deeply purify vanadium-containing solution, especially achieve the removal of silicon and chromium impurities, which is of great significance for improving the quality of vanadium pentoxide products and promoting the development of downstream strategic industries. SUMMARY

[0005] Therefore, the present application provides a preparation method of high-purity vanadium pentoxide, which solves the problems of long process flow, high production cost and high impurity content in the existing vanadium pentoxide impurity removal process, effectively improves the impurity removal efficiency and reduces environmental pollution.

[0006] To achieve the above purpose, the present application provides a preparation method of high-purity vanadium pentoxide, which specifically includes the following steps: S1, adding an aluminum salt to the raw material for reaction and standing, and then filtering to obtain a filtrate; S2, heating the filtrate and adjusting the pH value of the filtrate, and adding a precipitant to the filtrate; S3, continuing to heat the filtrate and adjust the pH value of the filtrate, and then performing liquid-solid separation to obtain a first precipitate; S4, performing alkali dissolution reaction on the first precipitate to obtain a vanadium-containing solution, adjusting the pH value and temperature of the vanadium-containing solution, adding a chromium removal agent to the vanadium-containing solution for reaction to obtain a chromium removal solution; S5, performing sedimentation and liquid-solid separation on the chromium removal solution to obtain a second precipitate, and drying and calcining the second precipitate to prepare vanadium pentoxide product.

[0007] According to one embodiment of the present application, in step S1, the raw material is a sodium-converted vanadium-containing leaching solution, and the temperature of the raw material is 60-70°C.

[0008] According to one embodiment of the present application, in step S1, the aluminum salt is aluminum sulfate with eighteen waters, and the amount of the aluminum salt is added in terms of the molar ratio of Al element to Si element in the raw material, the molar ratio being n(Al):n(Si)=0.8-1.2, the reaction time is 1-2h, the reaction temperature is 50-70°C, and the standing time is ≥24h.

[0009] According to one embodiment of the present application, in step S2, the temperature range of heating is 60-80°C, sulfuric acid is added to the filtrate to adjust the pH value of the filtrate, the adjustment range of the pH value is 5-6, and the precipitant is an ammonium salt.

[0010] According to one embodiment of the present application, in step S3, the temperature range of heating is 90-95°C, sulfuric acid is added to the filtrate to adjust the pH value of the filtrate, and the adjustment range of the pH value is 2-3.

[0011] According to one embodiment of the present application, in step S3, a heat preservation reaction is performed before the solid-liquid separation, the heat preservation reaction time is 30min, and the first precipitate is ammonium polyvanadate.

[0012] According to one embodiment of the present application, in step S4, sodium hydroxide and water are added to the first precipitate to perform an alkali dissolution reaction, the adjustment range of the pH value is 9-10.5, and the adjustment range of the temperature is 50-70°C.

[0013] According to one embodiment of the present application, in step S4, the chromium removing agent is a magnesium salt and a barium salt, the magnesium salt is added to the vanadium-containing solution to perform a first stage reaction, and the barium salt is added to perform a second stage reaction after the first stage reaction is completed, the first stage reaction time is 10-30min, and the second stage reaction time is 30-60min.

[0014] According to one embodiment of the present application, in step S4, the amount of the magnesium salt is added in terms of the molar ratio of Mg element to Cr element in the raw material, the molar ratio being n(Mg):n(Cr)=0.2-0.5, and the amount of the barium salt is added in terms of the molar ratio of Ba element to Cr element in the raw material, the molar ratio being n(Ba):n(Cr)=1-1.5.

[0015] According to one embodiment of the present application, in step S5, the settling time is ≥24h, the second precipitate is ammonium metavanadate, the content of Si in the vanadium pentoxide product is ≤0.01%, the content of Al is ≤0.005%, and the content of Cr is ≤0.005%.

[0016] The present application has at least the following beneficial technical effects: taking the sodiumized vanadium-containing leaching solution as raw material, sequentially passing through key steps of aluminum salt silicon removal, ammonium polyvanadate precipitation preliminary impurity removal, alkali dissolution transformation, magnesium salt and barium salt synergistic deep chromium removal, realizing efficient and deep removal of impurity elements such as silicon, chromium and aluminum, and finally obtaining high-purity vanadium pentoxide product with extremely low impurity content, meeting the quality requirements of high-purity vanadium pentoxide. The operation is simple and highly consistent with industrial production, effectively shortening the process and reducing production cost, and the whole process has no large amount of pollutant emission, small environmental pollution, and consideration of vanadium yield and impurity removal efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other embodiments can be obtained by those skilled in the art without creative labor based on these drawings.

[0018] Figure 1 The flow chart of the preparation method of high-purity vanadium pentoxide provided by the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will be further described in detail with reference to the drawings.

[0020] It should be noted that all the expressions of "first" and "second" in the embodiments of the present application are used to distinguish two same name different entities or different parameters. It can be seen that "first" and "second" are only for the convenience of description, and should not be understood as a limitation of the embodiments of the present application. The subsequent embodiments will not be described one by one.

[0021] The present application provides a preparation method of high-purity vanadium pentoxide. The preparation method of high-purity vanadium pentoxide comprises the following steps: S1, adding aluminum salt to the raw material for reaction and standing, and then filtering to obtain a filtrate; S2, heating the filtrate and adjusting the pH value of the filtrate, and adding a precipitant to the filtrate; S3, continuing to heat the filtrate and adjust the pH value of the filtrate, and then performing liquid-solid separation to obtain a first precipitate; S4, performing alkali dissolution reaction on the first precipitate to obtain a vanadium-containing solution, adjusting the pH value and temperature of the vanadium-containing solution, adding a chromium removal agent to the vanadium-containing solution for reaction to obtain a chromium removal liquid; S5, performing sedimentation and liquid-solid separation on the chromium removal liquid to obtain a second precipitate, and drying and calcining the second precipitate to prepare vanadium pentoxide product.

[0022] According to one embodiment of the present application, in step S1, a sodiumized vanadium-containing leaching solution is used as raw material, which can be obtained by sodiumizing roasting or water leaching of vanadium slag or vanadium-containing materials through conventional processes. The reaction temperature is controlled in the range of 50-70°C by using the waste heat of the leaching process. The aluminum salt is preferably aluminum sulfate octadecahydrate (Al2(SO4)3·18H2O). The amount of aluminum salt added is controlled such that the molar ratio of aluminum (Al) to silicon (Si) in the raw material is n(Al):n(Si) = 0.8-1.2. The reaction is carried out under stirring, and the reaction time is controlled in the range of 1-2 hours. After the reaction is completed, the reaction solution is allowed to stand for not less than 24 hours to allow the precipitate to fully grow, and then filtration is performed, and the obtained filtrate is subjected to the subsequent step. The main principle of this step is that Al 3+ SiO3 2- The reaction generates a silico-aluminate precipitate, and the excess aluminum ions are hydrolyzed to generate an aluminum hydroxide precipitate, thereby achieving co-precipitation removal of Si and Al and preliminary removal of Cr, and the formed precipitate has large particles and is easy to separate from the liquid.

[0023] According to one embodiment of the present application, in step S2, the filtrate obtained in S1 is heated to 60-80°C. Then, sulfuric acid is added to the hot filtrate to adjust the pH value of the system to the weakly acidic range of 5-6. Then, a precipitant is added to the system, which is an ammonium salt, such as ammonium sulfate.

[0024] According to one embodiment of the present application, in step S3, the system after step S2 is continuously heated to a high temperature condition of 90-95°C, and sulfuric acid is again added to the system to adjust the pH value to the strongly acidic range of 2-3. The system is kept at this condition for about 30 minutes to promote the precipitation of ammonium polyvanadate (APV). After the reaction is completed, liquid-solid separation is performed, and the obtained solid is the first precipitate, i.e., ammonium polyvanadate. This step takes advantage of the difference in the precipitation behavior of vanadium and impurity elements under acidic conditions, so that vanadium is selectively precipitated in the form of ammonium polyvanadate, while most of the Cr, Al, Si and other impurities remain in the mother liquor, thereby achieving preliminary deep impurity removal.

[0025] According to one embodiment of the present application, in step S4, the first precipitate is subjected to alkali dissolution transformation. Sodium hydroxide solution and pure water are added to the first precipitate, and the conditions are controlled to completely dissolve the first precipitate to obtain a vanadium-containing solution. The pH value of the vanadium-containing solution is adjusted to an alkaline range of 9-10.5, and the temperature is maintained at 50-70°C by heating. Subsequently, a chromium removal agent is added to the vanadium-containing solution under the above conditions for reaction. The chromium removal agent includes magnesium salt and barium salt. The magnesium salt is first added for the first stage reaction, and the reaction is performed for 10-30 minutes. Then, the barium salt is added, and the second stage reaction is continued for 30-60 minutes. The molar ratio of Mg element in the magnesium salt to Cr element in the raw material is controlled to n(Mg):n(Cr)=0.2-0.5. The molar ratio of Ba element in the barium salt to Cr element in the raw material is controlled to n(Ba):n(Cr)=1-1.5. The magnesium salt plays a role of co-precipitation, and Mg 2+ can neutralize the negative charge of CrO4 2- , reduce the colloidal stability, form fine flocs, provide crystal nuclei for subsequent barium salt precipitation, and improve the particle size and filtration performance of the precipitate. The barium salt reacts with chromate to form insoluble barium chromate precipitate, thereby achieving deep Cr removal.

[0026] According to one embodiment of the present application, in step S5, the chromium removal solution obtained in step S4 is subjected to long-time sedimentation, and the sedimentation time is not less than 24 hours to ensure that the barium chromate and other precipitates are fully settled. After the sedimentation is completed, liquid-solid separation is performed, a precipitant is added to the supernatant for precipitation, and the obtained solid is the second precipitate, i.e., ammonium metavanadate. After drying and calcination of the second precipitate, high-purity vanadium pentoxide product can be prepared. After the above process, the impurity content in the solution can be significantly reduced to Si≤0.005 g / L, Cr≤0.003 g / L, and Al≤0.001 g / L. The final vanadium pentoxide product has extremely high purity, and the impurity content satisfies Si≤0.01%, Cr≤0.005%, and Al≤0.005%.

[0027] In summary, the preparation method of high-purity vanadium pentoxide according to the present application effectively solves the problems of long impurity removal process, high cost, and insufficient product purity in the traditional method. The method integrates the steps of aluminum salt silicon removal, ammonium polyvanadate precipitation for initial impurity removal, and magnesium-barium salt synergistic deep chromium removal, and has smooth process flow, strong operability, high impurity removal efficiency, and small environmental pollution. The purity of the obtained vanadium pentoxide product can meet the stringent requirements of high-end application fields.

[0028] According to one embodiment of the present application, in step S1, the raw material is sodiumized vanadium-containing leaching solution, and the temperature of the raw material is 60-70°C.

[0029] According to one embodiment of the present application, in step S4, the magnesium salt is magnesium sulfate, and the barium salt is barium sulfate.

[0030] According to one embodiment of the present application, in step S5, the settling time is ≥24h, the second precipitate is ammonium metavanadate, the content of Si in the vanadium pentoxide product is ≤0.01%, the content of Al is ≤0.005%, and the content of Cr is ≤0.005%.

[0031] In summary, by introducing aluminum salt to remove Si in the sodium-containing vanadium leaching solution, and using the waste heat of the leaching solution to carry out the reaction, the efficient and selective removal of Si is achieved. Not only the content of Si in the solution is effectively reduced, but also the excess aluminum is hydrolyzed to form a precipitate that is easy to separate, avoiding the introduction of new impurities. The precipitate has large particles and is easy to separate, thereby significantly improving the impurity removal efficiency, simplifying the subsequent processing difficulty, and reducing the requirements of the process on equipment, which is highly consistent with industrial production. The differences in the precipitation behaviors of vanadium and impurity elements at a specific acidity are utilized. By accurately controlling the pH value and temperature, vanadium is efficiently precipitated in the form of ammonium polyvanadate, while most of the Cr, aluminum and residual Si impurities remain in the mother liquor and are separated. This step realizes the preliminary and cooperative removal of multiple impurities, lays a foundation for obtaining high-purity intermediate products, and effectively reduces the load of subsequent deep purification. A deep Cr removal strategy of adding magnesium salt and barium salt in stages is adopted. First, the colloidal stability of chromate ions is destroyed by using the electro-neutralization and coagulation aid of magnesium ions to form small flocs that can act as "seeds". Then, stable precipitates are formed by the reaction of barium ions with chromate ions. The synergistic effect of the two-step reaction significantly improves the physical properties of the precipitate, making it easier to settle and filter, greatly improving the efficiency and depth of Cr removal, and completely solving the industry problem of difficult deep removal of Cr impurities. Through the synergistic effect and process integration of the above steps, the present application successfully obtains high-purity vanadium pentoxide products with extremely low impurity content, and the purity fully meets the stringent requirements of high-end application fields. The whole process layout is reasonable, the operability is strong, the production efficiency is high, the environmental pollution is small, and it has broad industrial application prospects and economic benefits.

[0032] The present application will be further explained in conjunction with specific examples and comparative examples.

[0033] Example 1 Take 1 L of sodiumized vanadium-containing leaching solution as raw material, wherein the V content is 45 g / L, the Si content is 1.36 g / L, and the Cr content is 3.5 g / L. Heat the leaching solution to 60°C, and add 14 g of aluminum sulfate octadecahydrate under stirring condition, and keep the reaction at 60°C for 1 h. After the reaction is completed, stand for 24 h, filter to obtain a Si-removed filtrate. Heat the obtained filtrate to 60-80°C, and add sulfuric acid under stirring condition to adjust the pH value to 5-6. Then, add 54 g of ammonium sulfate as a precipitant, and the addition amount is calculated according to the ratio of V mass to ammonium sulfate mass, m(V):m((NH4)2SO4) is about 1:1.2. After that, continue to heat to above 90°C, supplement sulfuric acid to adjust the pH value to 2-2.5, and keep the reaction under the condition for 30 min. Perform liquid-solid separation to obtain ammonium polyvanadate. Use sodium hydroxide and pure water to perform alkali dissolution on the obtained ammonium polyvanadate, and control the solution pH value to maintain between 9-10.5 to obtain a vanadium-containing solution. The Cr content in the vanadium-containing solution is measured to be 0.08 g / L. Warm the back-dissolution solution to 50°C, first add 0.08 g of magnesium sulfate heptahydrate to perform first-stage reaction, and the reaction time is 30 min. Then, add 0.43 g of barium sulfate to perform second-stage reaction, and the reaction time is 30 min. After the reaction is completed, stand the obtained Cr-removed solution for 24 h, and perform liquid-solid separation. The obtained clear liquid is used for precipitating ammonium metavanadate. After the ammonium metavanadate is dried and calcined, high-purity vanadium pentoxide product is prepared. The Cr content in the high-purity vanadium pentoxide product is measured to be 0.004%, the Si content is 0.008%, and the Al content is 0.002%.

[0034] Example 2 Take 1 L of sodiumized vanadium-containing leaching solution as raw material, wherein the V content is 45 g / L, the Si content is 1.36 g / L, and the Cr content is 3.5 g / L. Heat the leaching solution to 60°C, and add 17.8 g of aluminum sulfate octadecahydrate under stirring condition, and keep the reaction at 60°C for 1 h. After the reaction is completed, stand for 24 h, filter to obtain a Si-removed filtrate. Heat the obtained filtrate to 60-80°C, and add sulfuric acid under stirring condition to adjust the pH value to 5-6. Then add 54 g of ammonium sulfate as a precipitant, and the addition amount is calculated according to the ratio of V mass to ammonium sulfate mass, m(V):m((NH4)2SO4) is about 1:1.2. After that, continue to heat to above 90°C, supplement sulfuric acid to adjust the pH value to 2-2.5, and keep the reaction under the condition for 30 min. Perform liquid-solid separation to obtain ammonium polyvanadate. Use sodium hydroxide and pure water to perform alkali dissolution on the obtained ammonium polyvanadate, and control the solution pH value to maintain between 9-10.5 to obtain a vanadium-containing solution. The Cr content in the vanadium-containing solution is measured to be 0.08 g / L. Warm the back-dissolution solution to 50°C, first add 0.133 g of magnesium sulfate heptahydrate to perform first-stage reaction, and the reaction time is 30 min. Then add 0.5 g of barium sulfate to perform second-stage reaction, and the reaction time is 30 min. After the reaction is completed, stand the obtained Cr-removed solution for 24 h, and perform liquid-solid separation. The obtained clear solution is used for precipitating ammonium metavanadate. After the ammonium metavanadate is dried and calcined, high-purity vanadium pentoxide product is prepared. The Cr content in the high-purity vanadium pentoxide product is measured to be 0.003%, the Si content is 0.007%, and the Al content is 0.002%.

[0035] Example 3 Take 1 L of sodium containing vanadium leaching solution as raw material, wherein V content is 45 g / L, Si content is 1.36 g / L, and Cr content is 3.5 g / L. Heat the leaching solution to 60℃, and add 21.4 g of aluminum sulfate octadecahydrate under stirring condition, and keep the reaction at 60℃ for 1 h. After the reaction is completed, stand for 24 h, filter to obtain a silicon-removed filtrate. Heat the obtained filtrate to 60-80℃, and add sulfuric acid under stirring condition to adjust the pH value to 5-6. Then add 54 g of ammonium sulfate as a precipitant, and the addition amount is calculated according to the mass ratio of V to ammonium sulfate, m(V):m((NH4)2SO4) is about 1:1.2. After that, continue to heat to above 90℃, and supplement sulfuric acid to adjust the pH value to 2-2.5, and keep the reaction under the condition for 30 min, and perform liquid-solid separation to obtain ammonium polyvanadate. The obtained ammonium polyvanadate is subjected to alkali dissolution with sodium hydroxide and pure water, and the pH value of the solution is controlled to maintain at 9-10.5 to obtain a vanadium-containing solution. The Cr content in the vanadium-containing solution is measured to be 0.08 g / L. The resolvent is heated to 50℃, 0.19 g of magnesium sulfate heptahydrate is first added for first-stage reaction, and the reaction time is 30 min, and then 0.54 g of barium sulfate is added for second-stage reaction, and the reaction time is 30 min. After the reaction is completed, the obtained Cr-removed solution is settled for 24 h, and liquid-solid separation is performed, and the obtained clear liquid is used for precipitating ammonium metavanadate. After the ammonium metavanadate is dried and calcined, high-purity vanadium pentoxide product is prepared. The Cr content in the high-purity vanadium pentoxide product is 0.002%, the Si content is 0.006%, and the Al content is 0.003%.

[0036] Comparative Example Take 1 L of sodium containing vanadium leaching solution as raw material, wherein V content is 45 g / L, Si content is 1.36 g / L, and Cr content is 3.5 g / L. Heat the sodium containing vanadium leaching solution to 60-80℃, and add sulfuric acid under stirring condition to adjust the pH value to 5-6. Then add 54 g of ammonium sulfate, and continue to heat the system to above 90℃, supplement sulfuric acid to adjust the pH value to 2-2.5, and keep the reaction under the condition for 30 min, and perform liquid-solid separation to obtain ammonium polyvanadate precipitate. The obtained ammonium polyvanadate is subjected to alkali dissolution with sodium hydroxide and pure water, and the pH value of the solution is controlled to maintain at 9-10.5 to obtain a vanadium-containing resolvent. Then ammonium sulfate is directly added to the resolvent to precipitate ammonium metavanadate, and vanadium pentoxide product is prepared after drying and calcining. The Cr content in the vanadium pentoxide product prepared by the traditional redissolution and crystallization process is 0.15%, the Si content is 0.09%, and the Al content is 0.05%.

[0037] The results show that, compared with the traditional re-dissolution and crystallization process, the core step of introducing aluminum salt to remove silicon and magnesium barium salt to remove Cr in depth can significantly reduce the content of key impurities such as Cr, Si and Al in the product, effectively improve the purity of the vanadium pentoxide product, and solve the problem of low product purity caused by the limited impurity removal capacity of the traditional process.

[0038] The above are exemplary embodiments disclosed by the present application, but it should be noted that various changes and modifications can be made without departing from the scope of the embodiments disclosed by the present application defined by the claims. The functions, steps and / or actions of the method claims described in the embodiments disclosed herein need not be performed in any particular order. In addition, although the elements of the embodiments disclosed by the present application can be described or claimed in individual form, they can also be understood as plural unless explicitly limited to singular.

[0039] It should be understood that, as used herein, the singular forms "a", "an" and "the" are intended to include plural forms, unless the context clearly dictates otherwise. It should also be understood that "and / or" as used herein refers to any and all possible combinations of one or more of the associated listed items.

[0040] The above embodiment number of the embodiments disclosed by the present application is only for description, not representing the advantages and disadvantages of the embodiments.

[0041] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary, and is not intended to imply that the scope of the embodiments disclosed by the present application (including claims) is limited to these examples; under the idea of the embodiments of the present application, the above embodiments or technical features in different embodiments can also be combined, and there are many other changes of the different aspects of the embodiments of the present application as above. In order to be brief, they are not provided in details. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principles of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A method for preparing high-purity vanadium pentoxide, characterized in that, The method comprises the following steps: S1, adding an aluminum salt into a raw material to react and stand, and then filtering to obtain a filtrate; S2, heating the filtrate and adjusting the pH value of the filtrate, and adding a precipitant into the filtrate; S3, continuing to heat the filtrate and adjust the pH value of the filtrate, and then performing liquid-solid separation to obtain a first precipitate; S4, performing alkali dissolution reaction on the first precipitate to obtain a vanadium-containing solution, adjusting the pH value and temperature of the vanadium-containing solution, adding a chromium removal agent into the vanadium-containing solution to react, and obtaining a chromium removal liquid; S5, performing sedimentation and liquid-solid separation on the chromium removal liquid to obtain a second precipitate, and performing drying and calcination on the second precipitate to obtain a vanadium pentoxide product.

2. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In step S1, the raw material is a sodiumized vanadium-containing leaching solution, and the temperature of the raw material is 60-70℃. ​ 3. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In step S1, the adding amount of the aluminum salt is calculated according to the molar ratio of Al element to Si element in the raw material, the molar ratio is n(Al):n(Si)=0.8-1.2, the reaction time is 1-2h, the reaction temperature is 50-70℃, and the standing time is ≥24h. ​ 4. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In step S2, the heating temperature ranges from 60 to 80℃, sulfuric acid is added into the filtrate to adjust the pH value of the filtrate, the pH value is adjusted to 5-6, and the precipitant is an ammonium salt. ​ 5. The method for preparing high-purity vanadium pentoxide according to claim 1, characterized in that, In step S3, the heating temperature ranges from 90 to 95℃, sulfuric acid is added into the filtrate to adjust the pH value of the filtrate, and the pH value is adjusted to 2-3.

6. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In step S3, a heat preservation reaction is performed before the solid-liquid separation, the heat preservation reaction time is 30min, and the first precipitate is ammonium polyvanadate. ​ 7. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In step S4, sodium hydroxide and water are added into the first precipitate to perform alkali dissolution reaction, the pH value is adjusted to 9-10.5, and the temperature is adjusted to 50-70℃. ​ 8.The method for preparing high-purity vanadium pentoxide according to claim 1, characterized in that, In step S4, the chromium removal agent is a magnesium salt and a barium salt, the magnesium salt is added into the vanadium-containing solution to perform a first stage reaction, the barium salt is added into the vanadium-containing solution to perform a second stage reaction after the first stage reaction is completed, the first stage reaction time is 10-30min, and the second stage reaction time is 30-60min. 9.The method for preparing high-purity vanadium pentoxide according to claim 8, characterized in that, In step S4, the adding amount of the magnesium salt is calculated according to the molar ratio of Mg element to Cr element in the raw material, the molar ratio is n(Mg):n(Cr)=0.2-0.5, and the adding amount of the barium salt is calculated according to the molar ratio of Ba element to Cr element in the raw material, the molar ratio is n(Ba):n(Cr)=1-1.

5.

10. The method of claim 1, wherein the high purity vanadium pentoxide is prepared by the steps of: In step S5, the sedimentation time is ≥24h, the second precipitate is ammonium metavanadate, the content of Si in the vanadium pentoxide product is ≤0.01%, the content of Al is ≤0.005%, and the content of Cr is ≤0.005%. ​

Images