Preparation method of vanadium sulfate

Abstract

The invention relates to the technical field of inorganic material synthesis, and discloses a vanadium sulfate preparation method, which comprises: S1, placing raw materials in a closed vessel, adding water, and stirring; s2, introducing protective gas into the closed vessel, dropwise adding sulfuric acid, and stirring; s3, controlling the temperature and the pH value in the closed vessel, so that the sulfuric acid reacts with the raw materials to obtain a reaction solution; and S4, filtering the reaction liquid to obtain a filtrate, adding ethanol into the filtrate, crystallizing, and stirring to obtain a vanadium sulfate product. According to the scheme provided by the invention, a series of problems of high raw material cost, complex process, more byproducts, low reaction efficiency, insufficient product purity and the like in the existing vanadium sulfate preparation process are effectively solved, and the comprehensive technical effects of simplifying the process flow, improving the reaction efficiency and improving the product purity are realized.

Description

Technical Field

[0001] This invention relates to the field of alloy material preparation technology, and in particular to a method for preparing vanadium sulfate. Background Technology

[0002] In the field of vanadium compound preparation, vanadium sulfate, as a product with significant application value, has always been a focus of industry attention in terms of its preparation process. Traditional methods for preparing vanadium sulfate mainly rely on vanadium pentoxide (vanadium sulfate). The methods include reduction or direct acidification of vanadium metal. However, these methods have significant limitations. On the one hand, vanadium pentoxide is a high-cost raw material, and requires multiple reduction or oxidation reactions to achieve valence state transformation, resulting in a complex process, high energy consumption, and the generation of numerous byproducts. On the other hand, while the acidification method of vanadium metal is relatively direct, vanadium metal is expensive, making it less economically viable.

[0003] Vanadium trioxide, as a low-valence vanadium oxide, could theoretically simplify the reaction process if directly used in the preparation of vanadium sulfate, offering potential advantages in cost reduction and operational simplification. In recent years, attempts have been made to simplify the process by using low-valence vanadium trioxide (V2O2). While vanadium trioxide can be used as a raw material to directly prepare barium sulfate, this method still has significant problems in practical applications. Because vanadium in vanadium trioxide is in the +3 oxidation state, it is easily oxidized during the reaction, leading to low reaction efficiency. Simultaneously, the reaction system is prone to generating… The presence of intermediate impurity ions results in insufficient product purity, making it difficult to meet the quality requirements of industrial applications.

[0004] Therefore, there is still a lack of existing technologies for the preparation of vanadium sulfate that can use low-valence vanadium oxides as raw materials and has the advantages of high reaction efficiency, high product purity and simplified process. Summary of the Invention

[0005] In view of this, the present invention proposes a method for preparing vanadium sulfate, which effectively overcomes a series of problems existing in the current vanadium sulfate preparation process, such as high raw material cost, complex process, many by-products, low reaction efficiency and insufficient product purity, and achieves the comprehensive technical effect of simplified process flow, improved reaction efficiency and improved product purity.

[0006] To achieve the above objectives, this invention provides a method for preparing vanadium sulfate, specifically comprising the following steps: S1. Place the raw materials into a sealed container, add water, and stir. S2, after introducing a protective gas into a sealed container, add sulfuric acid dropwise while stirring; S3, control the temperature and pH value inside the sealed container to allow sulfuric acid to react with the raw materials to obtain a reaction solution; S4. Filter the reaction solution to obtain the filtrate. Add ethanol to the filtrate and stir to obtain the vanadium sulfate product.

[0007] According to one embodiment of the present invention, in step S1, the raw material is vanadium trioxide.

[0008] According to one embodiment of the present invention, in step S1, the mixing ratio of raw materials and water is a mass ratio, wherein raw materials:water = (0.5~1):(1.5~2).

[0009] According to one embodiment of the present invention, in step S2, the protective gas is nitrogen.

[0010] According to one embodiment of the present invention, in step S2, the concentration of sulfuric acid is 30% to 50%.

[0011] According to one embodiment of the present invention, in step S3, the temperature range is 30~50℃ and the pH value range is 1.5~2.5.

[0012] According to one embodiment of the present invention, in step S3, the reaction time is 2 to 4 hours.

[0013] According to one embodiment of the present invention, in step S4, the reaction solution is allowed to stand for the first time and then filtered to obtain the filtrate. The first standing time is 30-35 minutes.

[0014] According to one embodiment of the present invention, in step S4, ethanol is added to the filtrate and stirred, and then allowed to stand for a second time for 6 to 12 hours.

[0015] According to one embodiment of the present invention, in step S4, after the second settling is completed, a mixture containing crystals and mother liquor is obtained. The mixture is then centrifuged to obtain vanadium sulfate product.

[0016] The present invention has at least the following beneficial technical effects: This invention provides a method for preparing vanadium sulfate. By using vanadium trioxide as a raw material, the raw material cost is significantly reduced, avoiding the dependence on expensive vanadium pentoxide or metallic vanadium in traditional methods. Conducting the reaction under nitrogen protection effectively inhibits the oxidation of trivalent vanadium, improves reaction efficiency, and reduces side reactions. By controlling key process parameters such as reaction temperature, pH, and reaction time, the reaction process is further optimized, reducing [the risk of side reactions]. The generation of impurity ions significantly improves the purity of the vanadium sulfate product. Furthermore, post-reaction filtration and ethanol crystallization effectively remove impurities from the reaction solution, solving the problem of insufficient product purity in existing methods. This ultimately yields a high-purity vanadium sulfate product that meets the quality requirements of industrial applications. The process ensures high purity and uniformity of the vanadium sulfate product, and its overall simplicity and efficiency make it suitable for large-scale production. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples.

[0018] The terms "comprising" and "having," and any variations thereof, in the specification and claims of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., in the specification and claims of this invention are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0019] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] The present invention provides a method for preparing vanadium sulfate, comprising the following steps: S1. Place the raw materials into a sealed container, add water, and stir. S2, after introducing a protective gas into a sealed container, add sulfuric acid dropwise while stirring; S3, control the temperature and pH value inside the sealed container to allow sulfuric acid to react with the raw materials to obtain a reaction solution; S4. Filter the reaction solution to obtain the filtrate. Add ethanol to the filtrate and stir to obtain the vanadium sulfate product.

[0021] According to one embodiment of the present invention, in step S1, high-purity vanadium trioxide powder is selected as the raw material, with a purity of not less than 99.5% and impurity content meeting the requirements of the reaction system. The vanadium trioxide powder and water are mixed in a sealed container at a mass ratio of (0.5~1):(1.5~2) to form a uniform slurry under stirring conditions.

[0022] According to one embodiment of the present invention, in step S2, nitrogen gas is introduced into a sealed container to maintain an inert atmosphere to prevent the oxidation of trivalent vanadium. Under continuous stirring and nitrogen protection, a sulfuric acid solution with a concentration of 30% to 50% is slowly added dropwise, controlling the dropping rate to avoid local overheating and violent reaction.

[0023] According to one embodiment of the present invention, in step S3, the reaction temperature in the sealed container is controlled within the range of 30~50°C, which can be precisely controlled by a constant temperature water bath. The pH value of the system is maintained between 1.5 and 2.5, and the amount of sulfuric acid added is monitored and adjusted in real time using a pH meter. The reaction continues for 2~4 hours until the solid is completely dissolved and the solution is uniformly blue, indicating that vanadium trioxide has been fully converted into vanadium sulfate. .

[0024] According to one embodiment of the present invention, in step S4, after the reaction is completed, the reaction solution is filtered to remove trace amounts of insoluble matter. Ethanol is added to the filtrate as a crystallization inducer, and the mixture is allowed to stand for 6-12 hours to allow vanadium sulfate crystals to fully precipitate. Finally, a blue solid product is obtained by centrifugation, and after drying, it becomes the final vanadium sulfate product.

[0025] In summary, by selecting high-purity vanadium trioxide as raw material, combining nitrogen protection to prevent vanadium oxidation, controlling reaction temperature and pH to reduce impurity formation, and then purifying the product through filtration, ethanol crystallization, and centrifugation, a complete process for preparing high-purity vanadium sulfate from raw materials has been established. This process eliminates the need for complex reduction or oxidation steps, has low raw material costs, and effectively solves the problems of low reaction efficiency and insufficient product purity in existing methods. This verifies the feasibility of this technical solution in simplifying the process, improving efficiency, and ensuring product quality.

[0026] According to one embodiment of the present invention, in step S1, the raw material is vanadium trioxide. Vanadium trioxide is selected as the core raw material, and high-purity vanadium trioxide powder is chosen. Its impurity content must meet the purity requirements of the subsequent reaction, wherein the total content of impurities other than vanadium does not affect the final purity of vanadium sulfate. The reason for choosing this raw material is that vanadium trioxide, as a low-valence vanadium oxide, can directly participate in the reaction without multiple reduction or oxidation steps. Compared with vanadium pentoxide or metallic vanadium, it can significantly reduce raw material costs and simplify the reaction process.

[0027] According to one embodiment of the present invention, in step S1, the mixing ratio of raw material to water is a mass ratio, wherein raw material:water = (0.5~1):(1.5~2). The above-mentioned vanadium trioxide powder and water are mixed in a certain ratio, such as 1:1.5, and then stirred using a mechanical stirring device until the mixture is uniform. The purpose of stirring is to fully disperse the vanadium trioxide powder, providing a uniform contact environment for the subsequent reaction with sulfuric acid.

[0028] According to one embodiment of the present invention, in step S2, the protective gas is nitrogen. After mixing is completed, nitrogen is introduced into the reaction vessel to create an inert protective atmosphere, and the nitrogen is continuously introduced throughout the reaction process to maintain the inert environment inside the vessel. The purpose of this step is to prevent the +3 valence vanadium in vanadium trioxide from being oxidized by oxygen in the air, and to avoid a decrease in reaction efficiency or the generation of impurities due to abnormal vanadium valence state.

[0029] According to one embodiment of the present invention, in step S2, the concentration of sulfuric acid is 30% to 50%. Under nitrogen protection, sulfuric acid with a concentration of 30% to 50% is slowly added dropwise to the mixture in a sealed container. The dropping rate is controlled to ensure that the sulfuric acid enters the reaction system dropwise, avoiding violent reactions or side reactions caused by excessively high local sulfuric acid concentrations. This concentration range of sulfuric acid is chosen because too low a concentration will reduce the reaction rate, while too high a concentration may lead to excessively strong local acidity in the system, increasing the risk of impurity formation.

[0030] According to one embodiment of the present invention, in step S3, the temperature range is 30~50℃, and the pH range is 1.5~2.5. During and after the addition, the temperature, pH, and reaction time of the reaction system need to be controlled. The temperature is maintained within the set range to avoid abnormal reaction rates caused by temperature fluctuations. The pH value can be monitored in real time using a pH meter. If it deviates from the set range, it can be adjusted by fine-tuning the sulfuric acid addition rate. Maintaining this pH range can suppress the reaction system... The formation of intermediate impurity ions.

[0031] According to one embodiment of the present invention, in step S3, the reaction time is 2-4 hours. The reaction time must ensure that vanadium trioxide fully participates in the reaction, and the reaction can be terminated after confirming that the raw materials have been substantially converted into the target product. The reaction in this stage follows the principle of acid-base neutralization. Vanadium trioxide reacts with sulfuric acid to produce vanadium sulfate and water. The combination of nitrogen protection and parameter control ensures the directional and efficient progress of the reaction, effectively improving the reaction efficiency.

[0032] According to one embodiment of the present invention, in step S4, the reaction solution is allowed to stand for the first time and then filtered to obtain a filtrate. The first standing time is 30-35 minutes. After the reaction is completed, the reaction solution is allowed to stand and then filtered. The purpose of standing and filtering is to remove any unreacted solid impurities that may remain in the reaction solution.

[0033] According to one embodiment of the present invention, in step S4, ethanol is added to the filtrate and stirred, followed by a second settling period of 6-12 hours. Ethanol is then added to the filtrate to induce crystallization. Ethanol, as a poor solvent, reduces the solubility of vanadium sulfate in solution, promoting its precipitation in crystalline form. The need for a settling period after adding ethanol allows for sufficient crystal growth, resulting in uniformly sized crystals and reducing impurity inclusions.

[0034] According to one embodiment of the present invention, in step S4, after the second settling is completed, a mixture containing crystals and mother liquor is obtained. The mixture is then centrifuged to obtain vanadium sulfate product. After settling, the mixture containing crystals and mother liquor is centrifuged. The mother liquor refers to the liquid remaining after crystallization, containing incompletely precipitated vanadium sulfate and a small amount of impurities. Centrifugation is achieved using a centrifuge. Centrifugal force causes the denser crystals to settle to the bottom of the centrifuge tube, and then the upper mother liquor is poured off to obtain blue powdery vanadium sulfate crystals.

[0035] As a feasible embodiment, the method for preparing vanadium sulfate of the present invention fully utilizes the acidity of sulfuric acid and the alkalinity of vanadium trioxide, directly preparing vanadium sulfate from vanadium trioxide under nitrogen protection. The acid-base neutralization reaction formula is as follows: .

[0036] This invention provides a method for preparing vanadium sulfate. By using vanadium trioxide as a raw material, the raw material cost is significantly reduced, avoiding the dependence on expensive vanadium pentoxide or metallic vanadium in traditional methods. Conducting the reaction under nitrogen protection effectively inhibits the oxidation of trivalent vanadium, improves reaction efficiency, and reduces side reactions. By controlling key process parameters such as reaction temperature, pH, and reaction time, the reaction process is further optimized, reducing [the risk of side reactions]. The generation of impurity ions significantly improves the purity of the vanadium sulfate product. Furthermore, post-reaction filtration and ethanol crystallization effectively remove impurities from the reaction solution, solving the problem of insufficient product purity in existing methods. This ultimately yields a high-purity vanadium sulfate product that meets the quality requirements of industrial applications. The process ensures high purity and uniformity of the vanadium sulfate product, and its overall simplicity and efficiency make it suitable for large-scale production.

[0037] The present invention will be further explained below with reference to specific embodiments and comparative examples.

[0038] Example 1 Weigh 200g of high-purity vanadium trioxide (≥99.5%) into a sealed container, add 300ml of water and mix. After stirring evenly, continuously purge the sealed container with nitrogen gas to remove air and maintain an inert atmosphere. Slowly add 400ml of 40% dilute sulfuric acid while stirring to ensure the vanadium trioxide is fully dissolved in the sulfuric acid. Control the temperature in the sealed container between 20~40℃, and monitor and stabilize the pH value at 2.0 using a pH meter. Continue the reaction at this temperature for 2 hours until the solid is completely dissolved, yielding a clear blue solution. After the reaction is complete, let it stand for 30 minutes, then filter to remove trace amounts of insoluble matter. Add ethanol to the filtrate, stir for 30 minutes, and let it stand for 10 hours to crystallize. Separate the precipitated blue crystals by centrifugation to obtain the final vanadium sulfate product.

[0039] Example 2 Weigh 300g of high-purity vanadium trioxide (≥99.5%) into a sealed container, add 450ml of water and mix. After stirring thoroughly, continuously purge the container with nitrogen gas to remove air and maintain an inert atmosphere. Slowly add 600ml of 45% dilute sulfuric acid while stirring to ensure the vanadium trioxide is fully dissolved. Control the temperature in the sealed container between 20~40℃, and monitor the pH value in real time using a pH meter to maintain it at pH=2.5. Continue the reaction at this temperature for 3 hours until the solid is completely dissolved, yielding a clear blue solution. After the reaction is complete, let it stand for 30 minutes, then filter to remove trace amounts of insoluble matter. Add ethanol to the filtrate, stir for 30 minutes, and let it stand for 10 hours to crystallize. Separate the precipitated blue crystals by centrifugation to obtain the final vanadium sulfate product.

[0040] Comparative Example Approximately 89 grams of vanadium pentoxide with a purity ≥99.5% was weighed and placed in a reaction vessel. 300 ml of water was added, and the mixture was stirred and heated to 70°C to partially suspend it. Then, an excess of 40% sulfuric acid solution was slowly added dropwise until the pH of the system was less than 1. After the vanadium pentoxide had completely dissolved to form an orange-red solution, sodium sulfite was slowly added as a reducing agent, maintaining the temperature at 70-80°C. During the reduction process, the color of the system gradually changed from orange-red to blue. Continuous stirring and monitoring were necessary until no more sulfur dioxide gas was emitted, indicating that the reduction reaction was complete. This reduction step took approximately 3 hours. The reduced solution was filtered, and the filtrate was added to ethanol for crystallization. After standing, centrifugation, washing, and drying, the final vanadium sulfate product was obtained.

[0041] As can be seen from the above, the comparative example involves a long process flow, high energy consumption, and the introduction of impurities due to the use of additional reducing agents, potentially leading to the production of harmful gases, resulting in limited product purity, increased production costs, and environmental pollution. In the embodiments of this invention, low-valence vanadium trioxide is directly used as a raw material, and the conversion can be completed in a single neutralization reaction, eliminating the need for expensive reducing agents and complex reduction steps. This not only simplifies the process flow and significantly reduces energy consumption and raw material costs, but also reduces the source of impurities by avoiding the introduction of additional inorganic reducing agent ions. Combined with nitrogen protection and pH control, this comprehensively surpasses the traditional process route using vanadium pentoxide as a raw material in terms of both purity and economic efficiency.

[0042] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0043] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0044] The embodiment numbers disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0045] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for preparing vanadium sulfate, characterized in that, include: S1. Place the raw materials into a sealed container, add water, and stir. S2, after introducing a protective gas into a sealed container, add sulfuric acid dropwise while stirring; S3, control the temperature and pH value inside the sealed container to allow sulfuric acid to react with the raw materials to obtain a reaction solution; S4. Filter the reaction solution to obtain the filtrate. Add ethanol to the filtrate and stir to obtain the vanadium sulfate product.

2. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S1, the raw material is vanadium trioxide.

3. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S1, the mixing ratio of raw materials and water is a mass ratio, wherein raw materials:water = (0.5~1):(1.5~2).

4. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S2, the protective gas is nitrogen.

5. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S2, the concentration of sulfuric acid is 30% to 50%.

6. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S3, the temperature range is 30~50℃ and the pH value range is 1.5~2.

5.

7. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S3, the reaction time is 2 to 4 hours.

8. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S4, the reaction solution is allowed to stand for the first time and then filtered to obtain the filtrate. The first standing time is 30-35 minutes.

9. The method for preparing vanadium sulfate according to claim 1, characterized in that, In step S4, ethanol is added to the filtrate and stirred before a second settling period of 6 to 12 hours.

10. The method for preparing vanadium sulfate according to claim 9, characterized in that, In step S4, after the second settling is completed, a mixture containing crystals and mother liquor is obtained. The mixture is then centrifuged to obtain vanadium sulfate product.