Method for preparing high-quality vanadium oxide

Abstract

The invention relates to the technical field of vanadium, and provides a method for preparing high-quality vanadium oxide.The method comprises the steps that S1, solid ammonium salt is dissolved in water, and a solution is obtained; s2, adding ammonium vanadate produced by a first process and ammonium vanadate produced by a second process into the solution, and stirring to obtain mixed slurry; s3, carrying out solid-liquid separation on the mixed slurry to obtain ammonium vanadate solid and filtrate; s4, the ammonium vanadate solid is subjected to dehydration and deamination, and vanadium oxide is obtained. The method comprises the following steps: mixing ammonium vanadate (ammonium polyvanadate, ammonium metavanadate and the like) obtained by two different vanadium extraction processes according to different proportions, pulping, mixing, washing, carrying out solid-liquid separation, and carrying out dehydration, deamination, oxidation or reduction according to different process routes. And corresponding process routes are selected according to different product requirements to produce different high-quality vanadium oxide and other products, so that the urgent requirement of the market on the high-quality vanadium oxide can be effectively met, and the market development and social application of vanadium resources are accelerated.

Description

Technical Field

[0001] The present invention relates to the field of vanadium technology, and more particularly to a method for preparing high-quality vanadium oxide. Background Art

[0002] At present, the vanadium extraction process of vanadium slag mostly adopts the "sodium roasting + water leaching" process, and there are also two processes that adopt both "sodium roasting + water leaching" (hereinafter referred to as sodium) and "calcification roasting + acid leaching" (hereinafter referred to as calcification). Restricted by the defects of the two different process routes, the ammonium vanadate and vanadium oxide produced by the sodium process have high impurity contents such as Cr, K, Na, and Si, and the ammonium vanadate and vanadium oxide produced by the calcification process have high impurity contents such as Mn and P. In addition, the production of high-quality vanadium oxide by each single process route will bring about problems such as difficulty in impurity removal, long process route, low vanadium yield, high production cost, low production efficiency (long deammoniation time, small feed amount), and poor production operating environment, which in turn results in the market demand for high-quality vanadium oxide being hindered, insufficient market development of vanadium resources, and insufficient social application. Summary of the invention

[0003] In view of this, the present invention proposes a method for preparing high-quality vanadium oxide, which effectively solves the problems of difficulty in impurity removal, long process route, low vanadium yield, high production cost, low production efficiency (long deamination time, small feed amount), poor production environment, and unmet market demand brought about by the production of high-quality vanadium oxide via a single process route.

[0004] Based on the above purpose, the present invention proposes a method for preparing high-quality vanadium oxide, comprising the following steps: S1, dissolving a solid ammonium salt in water to obtain a solution; S2, adding the ammonium vanadate produced by the first process and the ammonium vanadate produced by the second process to the solution, stirring to obtain a mixed slurry; S3, performing solid-liquid separation on the mixed slurry to obtain ammonium vanadate solid and filtrate; S4, dehydrating and deammoniating the ammonium vanadate solid to obtain vanadium oxide.

[0005] In some embodiments, the vanadium oxide includes vanadium pentoxide and vanadium trioxide, the solid ammonium salt includes solid ammonium sulfate or solid ammonium carbonate, the first process is a calcification process, and the second process is a sodiumization process.

[0006] In some embodiments, the method described in the present invention further comprises: S51, continuously keeping or melting the powdered vanadium obtained after dehydration and deammoniation in step S4 at the first temperature or the second temperature and in an oxidizing atmosphere to obtain powdery or flaky vanadium pentoxide.

[0007] In some embodiments, the method of the present invention further comprises: S52, continuously keeping or calcining the powdered vanadium obtained after dehydration and deammoniation in step S4 in a third temperature and reducing atmosphere, introducing an inert gas for cooling, and obtaining vanadium trioxide at room temperature.

[0008] In some embodiments, in step S4, the ammonium vanadate filtrate is subjected to stepwise dehydration and deammoniation or continuous dehydration and deammoniation.

[0009] In some embodiments, in step S1, the solid ammonium salt is added in an amount less than 5% in concentration.

[0010] In some embodiments, in step S1, the pH range of the solution is 2.0-7.0.

[0011] In some embodiments, in step S3, the method of the present invention further includes: During solid-liquid separation, a 0.8% concentration of ammonium sulfate solution is added to the mixed slurry for washing to obtain a filtrate; The vanadium concentration in the filtrate is detected and the vanadium loss is calculated.

[0012] In some embodiments, the concentration of vanadium in the filtrate ranges from 0.1 g / l to 0.5 g / l; The range of vanadium loss is 0.1%-0.5%.

[0013] In some embodiments, in the laboratory, industrial step-by-step dehydration and deamination, and industrial continuous dehydration and deamination, the temperature range of dehydration is 100°C-200°C, and the temperature range of deamination is 300°C-600°C; in the laboratory continuous dehydration and deamination, the temperature is controlled at 300-600°C, allowing dehydration and deamination to proceed simultaneously.

[0014] The present invention has at least the following beneficial technical effects: The present invention provides a method for preparing high-quality vanadium oxide, which comprises: S1, dissolving a solid ammonium salt in water to obtain a solution; S2, adding ammonium vanadate produced by a first process and ammonium vanadate produced by a second process to the solution, and stirring to obtain a mixed slurry; S3, performing solid-liquid separation on the mixed slurry to obtain ammonium vanadate solid and a filtrate; S4, dehydrating and deammonifying the ammonium vanadate solid to obtain vanadium oxide.

[0015] The present invention makes it possible to mix the ammonium vanadate (ammonium polyvanadate, ammonium metavanadate, etc.) obtained by two different vanadium extraction processes of sodiumization and calcification in different proportions, and then carry out dehydration, deammoniation, oxidation or reduction according to different process routes after pulping, mixing, washing and solid-liquid separation, and select the corresponding process route according to different product requirements to produce different high-quality vanadium oxide and other products, which can effectively meet the urgent market demand for high-quality vanadium oxide and accelerate the market development and social application of vanadium resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 A flow chart of a method for preparing high-quality vanadium oxide according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0018] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0019] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as in the embodiments of this application.

[0020] The present invention proposes a method for preparing high-quality vanadium oxide. Figure 1 , including the following steps: S1, dissolving a solid ammonium salt in water to obtain a solution; S2, adding the ammonium vanadate produced by the first process and the ammonium vanadate produced by the second process to the solution, stirring to obtain a mixed slurry; S3, performing solid-liquid separation on the mixed slurry to obtain ammonium vanadate solid and filtrate; S4, dehydrating and deammoniating the ammonium vanadate solid to obtain vanadium oxide.

[0021] The solution can be prepared using different ammonium vanadates, the specific usage is as follows: Solution preparation (ammonium polyvanadate + ammonium polyvanadate): Prepare the solution with production water or domestic water. First add a certain amount of water (liquid-to-solid ratio of 1:1-5:1) to a beaker or material tank and other containers. The amount of water should be sufficient to ensure that the materials added later can be fully stirred and mixed, and some impurity elements can be properly washed. It can be adjusted according to the actual situation. The water temperature is controlled within 50°C (the higher the water temperature, the greater the vanadium loss dissolved in the liquid later); add a certain amount of solid ammonium salt (the purpose of adding ammonium salt: it can effectively reduce the dissolution of ammonium vanadate in water and reduce vanadium loss. Ammonium salts such as ammonium sulfate and ammonium carbonate can be used. The amount of ammonium salt added can be ≤5%; the more ammonium salt is added, the higher the ammonium salt consumption, but the vanadium loss decreases accordingly. When the ammonium salt concentration is 1%, the vanadium loss can be controlled within 0.3%; if no ammonium salt is added, the ammonium vanadate is easily soluble in water and causes a large vanadium loss), stir until all dissolved; add sulfuric acid to adjust the solution pH to 2.0-7.0 (it can also be not adjusted. The purpose of adding is to reduce the dissolution rate of ammonium vanadate and increase the vanadium yield).

[0022] Solution preparation (ammonium polyvanadate + ammonium metavanadate): Use production water or domestic water to prepare the solution. First add a certain amount of water to a beaker or material tank (the amount of water is sufficient to ensure that the materials added later can be fully stirred and mixed, and some impurity elements can be properly washed, which can be adjusted according to actual conditions), and the water temperature is controlled within 50°C (the higher the water temperature, the greater the loss of vanadium dissolved in the liquid later); add a certain amount of solid ammonium salt (ammonium sulfate, ammonium carbonate and other ammonium salts can be used, and the amount of ammonium salt added can be ≤5%; the more ammonium salt is added, the higher the ammonium salt consumption, but the vanadium loss decreases accordingly. When the ammonium salt concentration is 1%, the vanadium loss can be controlled within 0.3%; if no ammonium salt is added, the vanadium solubility in water will increase, resulting in greater vanadium loss), and stir until all dissolved.

[0023] After the solution is prepared, first add an appropriate amount of ammonium vanadate (ammonium polyvanadate, ammonium metavanadate, etc.) produced by one process into the solution. After adding, stir until the slurry is stable, and then continue to add ammonium vanadate (ammonium polyvanadate, ammonium metavanadate, etc.) produced by another process. In order to improve production efficiency, stirring can be carried out during the addition process. After the materials are added and stirred evenly, the next step of solid-liquid separation can be carried out.

[0024] Prepare washing water according to the above solution preparation method, control the water temperature within 50℃ (the higher the water temperature, the greater the vanadium loss), and the water volume can be adjusted at will.

[0025] The present invention adopts the method of mixing ammonium vanadate (ammonium polyvanadate, ammonium metavanadate, etc.) obtained by two different vanadium extraction processes of sodiumization and calcification in different proportions, and then dehydrating, deammonifying, oxidizing or reducing according to different process routes after pulping, mixing, washing and solid-liquid separation, and selecting corresponding process routes according to different product requirements to produce different high-quality vanadium oxide and other products, which can effectively meet the urgent market demand for high-quality vanadium oxide and accelerate the market development and social application of vanadium resources.

[0026] In some embodiments, see Figure 1 The vanadium oxide includes vanadium pentoxide and vanadium trioxide, the solid ammonium salt includes solid ammonium sulfate or solid ammonium carbonate, and the first process is a calcification process, and the second process is a sodiumization process.

[0027] Vanadium pentoxide is an important raw material for the preparation of vanadium alloys. Vanadium pentoxide has stable chemical properties and can provide a stable supply of vanadium to meet the demand for vanadium in various industrial fields. When used as a catalyst, vanadium pentoxide can significantly improve the efficiency and yield of chemical reactions.

[0028] Vanadium trioxide has a specific crystal structure and electronic arrangement, which makes it exhibit unique properties in conductivity regulation and magnetic applications, and is of great significance to the production of vanadium alloys.

[0029] In some embodiments, see Figure 1 The method described in the present invention further comprises: S51, continuously keeping or melting the powdered vanadium obtained after dehydration and deammoniation in step S4 at the first temperature or the second temperature and in an oxidizing atmosphere to obtain powdery or flaky vanadium pentoxide.

[0030] Preparation of powdered vanadium pentoxide (laboratory): The deaminated material (vanadium powder) is kept at 500-600℃ in an oxidizing atmosphere (air environment or a small amount of oxygen) for a period of time (the temperature can be adjusted appropriately so that the vanadium powder does not sinter or melt).

[0031] Preparation of powdered vanadium pentoxide (industrialization): The deaminated material (vanadium powder) is transported to a rotary kiln or other high-temperature equipment and kept at 500-600°C in an oxidizing atmosphere (air environment or a small amount of oxygen) for a period of time (the temperature can be adjusted appropriately so that the vanadium powder does not sinter or melt).

[0032] Preparation of flake vanadium pentoxide (laboratory): The deaminated material (vanadium powder) is placed in a crucible or other container and placed in a high-temperature device such as a muffle furnace. It is melted at 600-900°C in an oxidizing atmosphere (air environment or a small amount of oxygen) for a period of time (the temperature can be adjusted appropriately to reduce the melting and burning of vanadium).

[0033] Preparation of flake vanadium pentoxide (industrialization): The deaminated material (vanadium powder) is transported to a high-temperature equipment such as a melting furnace, and melted at 600-900°C in an oxidizing atmosphere (air environment or a small amount of oxygen) for a period of time (the temperature can be adjusted appropriately to reduce the melting and burning of vanadium).

[0034] Under high temperature and oxidizing atmosphere, impurities in the material are more easily oxidized or volatilized, thereby improving the purity of vanadium pentoxide. Appropriate insulation and melting conditions are conducive to the growth and arrangement of vanadium pentoxide crystals and improve their crystallinity. Vanadium pentoxide with good crystallinity has better physical and chemical properties, such as higher melting point, better thermal stability and chemical stability. Combining the steps of deamination, insulation and melting can reduce the number of process conversions and material handling in the production process, thereby improving production efficiency and reducing production costs. Under high temperature and oxidizing atmosphere, the vanadium element in the material is more easily oxidized to vanadium pentoxide, thereby increasing the yield of vanadium. This is of great significance for improving resource utilization and reducing production costs.

[0035] In some embodiments, see Figure 1 The method of the present invention further comprises: S52, the powdered vanadium obtained after dehydration and deammoniation in step S4 is continuously kept warm or calcined in an environment of a third temperature and a reducing atmosphere, an inert gas is introduced to cool it down, and vanadium trioxide is obtained at room temperature.

[0036] Preparation of powdered vanadium trioxide (laboratory): The dehydrated or deaminated material is placed in a crucible or other container and placed in a closed muffle furnace or other high-temperature equipment at 600-900℃ and a reducing atmosphere (vacuum environment or a small amount of Keep warm for a while until the material is completely gray and black, then pass in The process is completed by adding inert gas and cooling to room temperature (to prevent oxidation).

[0037] Preparation of powdered vanadium trioxide (industrialization): The dehydrated or deaminated materials are transported to high-temperature equipment such as rotary kilns, and calcined at 600-900℃ in a reducing atmosphere (with coke oven gas or other reducing gases) for a period of time until the materials turn gray and black, and then introduced The process is completed by adding inert gas and cooling down to near room temperature (to prevent oxidation).

[0038] The material obtained after deammoniation is continuously kept warm or calcined in a high temperature and reducing atmosphere, and inert gas is introduced to cool it down, and vanadium trioxide is obtained at room temperature. The heat preservation or calcination process under high temperature and reducing atmosphere is conducive to the growth and arrangement of vanadium trioxide crystals, forming products with specific crystal structure and morphology. These factors directly affect the physical and chemical properties of vanadium trioxide, such as density, hardness, thermal stability, etc. In a reducing atmosphere, harmful substances in the material (such as ammonia, etc.) are more easily decomposed or converted into harmless substances, thereby reducing the emission of harmful gases and environmental pollution. In addition, by recovering and utilizing resources such as heat in flue gas, energy consumption and emissions in the production process can be further reduced.

[0039] In some embodiments, see Figure 1 In step S4, the ammonium vanadate filtrate is subjected to step-by-step dehydration and deammoniation or continuous dehydration and deammoniation.

[0040] Dehydration and deammoniation control can be carried out in the laboratory or in industrialization. Dehydration and deammoniation can be carried out step by step or simultaneously, and can be adjusted according to the actual situation. Whether it is step-by-step dehydration and deammoniation or continuous dehydration and deammoniation, it can effectively remove water and ammonia in the filtrate, thereby improving the purity of the final product. By optimizing the dehydration and deammoniation process, the waste and by-products generated in the production process can be reduced.

[0041] In some embodiments, see Figure 1 In step S1, the amount of solid ammonium salt added is less than 5% in concentration.

[0042] Appropriate ammonium salt concentration can reduce the dissolution loss of vanadium during solution treatment (inhibiting the dissolution of ammonium vanadate). High concentrations of ammonium salts will increase production costs such as ammonium salt consumption and subsequent filtrate (wastewater) treatment, or form complexes with other substances that are difficult to separate. By controlling the ammonium salt concentration at a lower level, more vanadium can be ensured to exist in solid form, which is convenient for subsequent recovery and treatment. Under conditions of low ammonium salt concentration, other reaction conditions (such as temperature, pH value, etc.) can be more easily adjusted and optimized to achieve a higher vanadium recovery rate. These optimization measures help ensure the effective extraction and separation of vanadium and reduce unnecessary losses in the process. Appropriate ammonium salt concentration and vanadium loss can be fully combined with the disposal and production costs of subsequent filtrate.

[0043] In some embodiments, see Figure 1 In step S1, the pH range of the solution is 2.0-7.0.

[0044] Under acidic conditions (low pH), ammonium polyvanadate is more easily converted into insoluble vanadium compounds; under weakly alkaline conditions, ammonium metavanadate is more easily converted into insoluble vanadium compounds. These insoluble compounds are easy to precipitate from the solution, thereby increasing the precipitation rate of vanadium. Adjusting the pH value to an appropriate range can effectively reduce the possibility of the precipitated ammonium vanadate dissolving back into the solution again, ensuring that more vanadium exists in solid form and is recovered. Reducing dissolution losses helps to keep the impurity content in the solution low, thereby improving the purity of the final product. Under appropriate pH conditions, the vanadium precipitate may form a tighter and more regular crystal structure, which helps to improve the physical and chemical properties of the product.

[0045] In some embodiments, see Figure 1 In step S3, the method of the present invention further includes: During solid-liquid separation, a 0.8% concentration of ammonium sulfate solution is added to the mixed slurry for washing to obtain ammonium vanadate solid and filtrate; The vanadium concentration in the filtrate is detected and the vanadium loss is calculated.

[0046] The mixed slurry is pumped into a solid-liquid separation device (plate and frame filter press, belt filter, centrifuge, etc.) for solid-liquid separation. In the laboratory, it is directly poured into a vacuum separator for solid-liquid separation. During the solid-liquid separation process, an appropriate amount of prepared washing water can be added to further reduce the impurity elements in the mixed material and control and reduce vanadium loss. The amount of washing water can be adjusted according to the actual product quality requirements.

[0047] Washing with ammonium sulfate solution can effectively remove impurities attached to the surface of ammonium vanadate particles, such as unreacted raw materials, by-products, other metal ions, etc. The presence of these impurities may reduce the purity of ammonium vanadate and affect its subsequent processing and application effects. The addition of ammonium sulfate solution may help improve the filtration performance of the mixed slurry, making it easier to separate the ammonium vanadate particles from the liquid phase and improving the efficiency of solid-liquid separation. The appropriate ammonium sulfate concentration helps maintain the stability of ammonium vanadate and reduce its dissolution loss during the washing process. Too high a concentration may increase the risk of dissolution, while too low a concentration may result in poor washing effect. The 0.8% ammonium sulfate solution concentration is optimized and can reduce the amount of washing liquid and washing time while ensuring the washing effect, thereby improving the washing efficiency.

[0048] In some embodiments, see Figure 1 , the vanadium concentration of the ammonium vanadate filtrate is in the range of 0.1 g / l-0.5 g / l; The range of vanadium loss is 0.1%-0.5%.

[0049] The smaller the proportion of vanadium loss obtained in this method, the better. Lower vanadium loss means less loss of vanadium element during the production process, thereby improving the utilization rate of raw materials. Low vanadium loss helps to maintain the purity of vanadium in the product and reduce the content of impurities and undesirable substances. Low vanadium loss means that the vanadium content in pollutants such as wastewater and waste slag generated during the production process is lower, reducing the risk of pollution to the environment.

[0050] In some embodiments, see Figure 1 In the laboratory, industrial step-by-step dehydration and deammoniation, and industrial continuous dehydration and deammoniation, the dehydration temperature range is 100℃-200℃, and the deammoniation temperature range is 300℃-600℃; in the laboratory continuous dehydration and deammoniation, the temperature is controlled at 300-600℃, allowing dehydration and deammoniation to proceed simultaneously.

[0051] Step-by-step method: Dehydration and deamination steps (laboratory): Place the ammonium vanadate separated by solid-liquid separation in a baking tray or crucible, and control the drying temperature at 100-200°C. The drying and dehydration time is directly related to its water content. After the dehydration is completed, adjust the temperature to 300-600°C for deamination. The deamination time is significantly affected by the proportion of ammonium metavanadate and the temperature. The higher the proportion of ammonium metavanadate and the lower the temperature, the longer the deamination time.

[0052] Dehydration and deammoniation step by step (industrialization): the mixed ammonium vanadate after solid-liquid separation is sent to the dryer for dehydration, and the drying temperature is controlled at 100-200℃. The drying and dehydration time is directly related to the moisture content and the amount of material; after dehydration, it is sent to the calcining furnace for deammoniation, and the deammoniation temperature is controlled at 300-600℃. The deammoniation time is significantly affected by the proportion of ammonium metavanadate and the temperature. The higher the proportion of ammonium metavanadate and the lower the temperature, the longer the deammoniation time.

[0053] Continuous method: Continuous dehydration and deamination (laboratory): Place the ammonium vanadate separated by solid-liquid separation in a baking tray or crucible and other objects, control the temperature at 300-600℃, and allow dehydration and deamination to proceed simultaneously. The drying, dehydration and deamination time is directly related to its water content, ammonium metavanadate ratio and temperature; the higher the water content, the more ammonium metavanadate ratio and the lower the temperature, the longer the deamination time.

[0054] Continuous dehydration and deammoniation (industrialization): The mixed ammonium vanadate after solid-liquid separation is sent to the dryer for dehydration. The drying temperature is controlled at 100-200℃. The drying and dehydration time is directly related to the moisture content and the amount of material. After dehydration, it is sent to the calcining furnace for deammoniation. The deammoniation temperature is set at 300-600℃. The deammoniation time is significantly affected by the proportion of ammonium metavanadate and the temperature. The higher the proportion of ammonium metavanadate and the lower the temperature, the longer the deammoniation time.

[0055] In some embodiments, see Figure 1 The operating procedures for preparing powdered and flake vanadium pentoxide in both laboratory and industrial applications are as follows.

[0056] Example 1 Preparation of powdered vanadium pentoxide (laboratory): Take 400 ml of room temperature water and add it to a 500 ml beaker; weigh 6.4 g of ammonium sulfate and add it to the beaker and stir thoroughly; add sulfuric acid to adjust the pH value to 2.5; weigh 80 g of ammonium polyvanadate (calcification process) and add it to the beaker; weigh another 80 g of ammonium polyvanadate (sodiumization process) and add it to the beaker, stir and mix well.

[0057] The mixed materials are poured into a vacuum filter for solid-liquid separation. During the filtration process, 0.8% ammonium sulfate solution can be added for washing (freely adjustable). After filtration, the V concentration and impurity content of the filtrate are tested. The filtrate [V] is 0.22 g / l, and the vanadium loss is calculated to be 0.15%. Other impurity elements such as Mn, Mg, Ca, and P are reduced to varying degrees.

[0058] Pour all the ammonium vanadate mixture obtained above (containing 25% water) into a baking tray and place it on a resistance wire heating furnace for one-step dehydration and deammoniation. The temperature is set at 550°C and the dehydration and deammoniation process is stirred several times. The dehydration and deammoniation process is completed after 15 minutes. At this time, the vanadium powder is golden yellow and uniform in color. Sampling and testing of each component meet the technical requirements of powdered vanadium pentoxide of more than 99.0%.

[0059] Example 2 Preparation of powdered vanadium pentoxide (laboratory): Take 400ml of room temperature water and add it to a 500ml beaker; weigh 6.4g of ammonium sulfate and add it to the beaker and stir thoroughly; weigh 80g of ammonium polyvanadate (calcification process) and add it to the beaker; weigh 80g of ammonium metavanadate (sodiumization process) and add it to the beaker, stir and mix well.

[0060] The mixed materials are poured into a vacuum filter for solid-liquid separation. During the filtration process, 0.8% ammonium sulfate solution can be added for washing (freely adjustable). After filtration, the V concentration and impurity content of the filtrate are tested. The filtrate [V] is 0.22 g / l, and the vanadium loss is calculated to be 0.15%. Other impurity elements such as Mn, Mg, Ca, and P are reduced to varying degrees.

[0061] Pour all the ammonium vanadate mixture obtained above (containing 25% water) into a baking tray and place it on a resistance wire heating furnace for one-step dehydration and deammoniation. The temperature is set at 550°C and the dehydration and deammoniation process is stirred several times. The dehydration and deammoniation process is completed after 20 minutes. At this time, the color of the vanadium powder is golden yellow and uniform. Sampling and testing of each component meet the technical requirements of powdered vanadium pentoxide of more than 99.0%.

[0062] Example 3 Preparation of powdered vanadium pentoxide (laboratory): Take 400ml of room temperature water and add it to a 500ml beaker; weigh 4.8g of ammonium sulfate and add it to the beaker and stir thoroughly; weigh 80g of ammonium polyvanadate (calcification process) and add it to the beaker; weigh 80g of ammonium metavanadate (sodiumization process) and add it to the beaker, stir and mix well.

[0063] The mixed materials are poured into a vacuum filter for solid-liquid separation. During the filtration process, 0.8% ammonium sulfate solution can be added for washing (freely adjustable). After filtration, the V concentration and impurity content of the filtrate are tested. The filtrate [V] is 0.31 g / l, and the vanadium loss is calculated to be 0.22%. Other impurity elements such as Mn, Mg, Ca, and P have decreased to varying degrees.

[0064] Pour all the ammonium vanadate mixture (containing 25% water) obtained above into a crucible and place it in a muffle furnace for multi-step dehydration, deamination and oxidation. The temperatures are set at 150°C, 350°C and 550°C respectively (the temperature can be adjusted appropriately so that the powdered vanadium does not sinter or melt). The door of the muffle furnace is half open (when closed, an appropriate amount of oxygen needs to be introduced to ensure an oxidizing atmosphere). After 3 hours, dehydration, deamination and oxidation can be basically completed. At this time, the color of the powdered vanadium is golden yellow and uniform. Sampling and testing of each component meets the technical requirements of powdered vanadium pentoxide of more than 99.0%.

[0065] Example 4 Preparation of powdered vanadium pentoxide (laboratory): Take 400ml of room temperature water and add it to a 500ml beaker; weigh 3.2g of ammonium sulfate and add it to the beaker and stir thoroughly; weigh 80g of ammonium polyvanadate (calcification process) and add it to the beaker; weigh 80g of ammonium metavanadate (sodiumization process) and add it to the beaker, stir and mix well.

[0066] The mixed materials are poured into a vacuum filter for solid-liquid separation. During the filtration process, 0.8% ammonium sulfate solution can be added for washing (freely adjustable). After filtration, the V concentration and impurity content of the filtrate are tested. The filtrate [V] is 0.46 g / l, and the vanadium loss is calculated to be 0.35%. Other impurity elements such as Mn, Mg, Ca, and P have decreased to varying degrees.

[0067] Pour all the ammonium vanadate mixture (containing 25% water) obtained above into a crucible and place it in a muffle furnace for one-step dehydration, deamination and oxidation. The temperature is set at 550°C, and the door of the muffle furnace is half open. After 3 hours, the dehydration, deamination and oxidation can be basically completed. If the color of the powdered vanadium is black and uneven, it means that the oxidation is not sufficient. It is necessary to continue oxidation for a period of time until it is golden and uniform. Samples are taken to test each component to meet the technical requirements of powdered vanadium pentoxide of more than 99.0%.

[0068] Example 5 Preparation of flake vanadium pentoxide (laboratory): Take 400ml of room temperature water and add it to a 500ml beaker; weigh 3.2g of ammonium sulfate and add it to the beaker and stir thoroughly; weigh 80g of ammonium polyvanadate (produced by calcification process) and add it to the beaker; weigh another 80g of ammonium polyvanadate (produced by sodium process) and add it to the beaker, stir and mix well.

[0069] The mixed materials are poured into a vacuum filter for solid-liquid separation. During the filtration process, 0.8% ammonium sulfate solution can be added for washing (freely adjustable). After filtration, the V concentration and impurity content of the filtrate are tested. The filtrate [V] is 0.43 g / l, and the vanadium loss is calculated to be 0.34%. Other impurity elements such as Mn, Mg, Ca, and P have decreased to varying degrees.

[0070] The ammonium vanadate mixture obtained above (containing 25% water) was poured into a crucible and placed in a muffle furnace for one-step dehydration and deamination. The temperature was set at 550°C, and the muffle furnace door was half open. The dehydration and deamination were basically completed after 3 hours. The temperature was then set at 850°C, and the muffle furnace door was half open. The melting was completed after 10 minutes. At this time, the color of the solid vanadium was gray-black. Sampling and testing of each component met the technical requirements of flaky vanadium pentoxide of more than 99.0%.

[0071] Example 6 Preparation of vanadium pentoxide flakes (industrialization): first add 10 Produce water at room temperature; then add 100kg of solid ammonium sulfate (ammonium sulfate concentration 1%) and stir until it is completely dissolved; then add 2.5 tons of ammonium polyvanadate (produced by calcification process) into the material tank; then continue to add 2.5 tons of ammonium metavanadate or other ammonium vanadate (produced by sodium process), and the mixer must be turned on during the feeding process.

[0072] After 1 minute, the mixed material slurry is pumped into the plate and frame filter press for solid-liquid separation; the agitator should be turned on as much as possible during the process of the material being pumped into the plate and frame filter press to prevent the material from sinking to the bottom; during the filtration process, 1% ammonium sulfate solution prepared with normal temperature production water can be appropriately added for washing (optional or free adjustment), and the V concentration and impurity content in the filtrate are tested after filtration. The filtrate [V] is 0.40 g / l, and the vanadium loss is calculated to be 0.32%. Other impurity elements such as Mn, Mg, Ca, and P have decreased to varying degrees.

[0073] The ammonium vanadate mixture (containing 25% water) obtained above is sent to a melting furnace for one (or more) steps of dehydration, deammoniation and melting. The drying, calcination and melting temperatures are set at 150°C, 500°C and 850°C respectively. After the material is melted, the molten iron flows through a water-cooled granulator and forms flakes. The sampling and testing of each component meets the technical requirements of flake vanadium pentoxide of more than 99.0%.

[0074] Example 7 Preparation of powdered vanadium trioxide (laboratory): Take 400ml of room temperature water and add it to a 500ml beaker; weigh 3.2g of ammonium sulfate and add it to the beaker and stir thoroughly; weigh 80g of ammonium polyvanadate (calcification process) and add it to the beaker; weigh 80g of ammonium metavanadate (sodiumization process) and add it to the beaker, stir and mix well.

[0075] The mixed materials are poured into a vacuum filter for solid-liquid separation. During the filtration process, 0.8% ammonium sulfate solution can be added for washing (freely adjustable). After filtration, the V concentration and impurity content of the filtrate are tested. The filtrate [V] is 0.46 g / l, and the vanadium loss is calculated to be 0.35%. Other impurity elements such as Mn, Mg, Ca, and P have decreased to varying degrees.

[0076] The ammonium vanadate mixture (containing 25% water) obtained above is poured into a crucible and placed in a muffle furnace for one-step dehydration, deamination and reduction. The temperature is set at 600℃-900℃, and the muffle furnace door is sealed. After 3 hours, the dehydration, deamination and reduction can be basically completed. Samples are taken to test that each component meets the technical requirements of powdered vanadium trioxide of more than 66.0%.

[0077] Example 8 Preparation of powdered vanadium trioxide (industrialization): First add 10 Produce water at room temperature; then add 100kg of solid ammonium sulfate (ammonium sulfate concentration 1%) and stir until it is completely dissolved; then add 2.5 tons of ammonium polyvanadate (produced by calcification process) into the material tank; then continue to add 2.5 tons of ammonium metavanadate or other ammonium vanadate (produced by sodium process), and the mixer must be turned on during the feeding process.

[0078] After 1 minute, the mixed material slurry is pumped into the plate and frame filter press for solid-liquid separation; the agitator should be turned on as much as possible during the process of the material being pumped into the plate and frame filter press to prevent the material from sinking to the bottom; during the filtration process, 1% ammonium sulfate solution prepared with normal temperature production water can be appropriately added for washing (optional or free adjustment), and the V concentration and impurity content in the filtrate are tested after filtration. The filtrate [V] is 0.40 g / l, and the vanadium loss is calculated to be 0.32%. Other impurity elements such as Mn, Mg, Ca, and P have decreased to varying degrees.

[0079] The ammonium vanadate mixture obtained above (containing 25% water) is sent to a rotary kiln for one (or more) steps of dehydration and deammoniation, and calcined at 600°C-900°C. Reducing gas is introduced into the rotary kiln, and the material turns gray-black. Inert gas is introduced and waited to cool to room temperature for sampling. The components are tested to meet the technical requirements of powdered vanadium trioxide of more than 66.0%.

[0080] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0081] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0082] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing high-quality vanadium oxide, characterized in that: The following steps are involved: S1, dissolving a solid ammonium salt in water to obtain a solution; S2, adding the ammonium vanadate produced by the first process and the ammonium vanadate produced by the second process to the solution, stirring to obtain a mixed slurry; S3, performing solid-liquid separation on the mixed slurry to obtain ammonium vanadate solid and filtrate; S4, dehydrating and deammoniating the ammonium vanadate solid to obtain vanadium oxide.

2. The method for preparing high-quality vanadium oxide according to claim 1, characterized in that: The vanadium oxide includes vanadium pentoxide and vanadium trioxide, the solid ammonium salt includes solid ammonium sulfate or solid ammonium carbonate, the first process is a calcification process, and the second process is a sodiumization process.

3. The method for preparing high-quality vanadium oxide according to claim 2, characterized in that: Further including: S51, the powdered vanadium obtained after dehydration and deammoniation in step S4 is continuously kept warm or melted at the first temperature or the second temperature in an oxidizing atmosphere to obtain powdery or flaky vanadium pentoxide.

4. The method for preparing high-quality vanadium oxide according to claim 2, characterized in that: Further including: S52, the vanadium powder obtained after dehydration and deammoniation in step S4 is continuously kept warm or calcined in a reducing atmosphere at the third temperature, and an inert gas is introduced to cool it down, so as to obtain vanadium trioxide at room temperature.

5. The method for preparing high-quality vanadium oxide according to claim 1, characterized in that: In step S4, the ammonium vanadate solid is subjected to step-by-step dehydration and deammoniation or continuous dehydration and deammoniation.

6. The method for preparing high-quality vanadium oxide according to claim 1, characterized in that: In step S1, the solid ammonium salt is added in an amount with a concentration of less than 5%.

7. The method for preparing high-quality vanadium oxide according to claim 1, characterized in that: In step S1, the pH range of the solution is 2.0-7.

0.

8. The method for preparing high-quality vanadium oxide according to claim 1, characterized in that: In step S3, it also includes: During solid-liquid separation, a 0.8% concentration of ammonium sulfate solution is added to the mixed slurry for washing to obtain ammonium vanadate solid and filtrate; The vanadium concentration in the filtrate is detected and the vanadium loss is calculated.

9. The method for preparing high-quality vanadium oxide according to claim 8, characterized in that: The vanadium concentration of the ammonium vanadate filtrate is in the range of 0.1 g / l to 0.5 g / l; The range of vanadium loss is 0.1%-0.5%.

10. The method for preparing high-quality vanadium oxide according to claim 5, characterized in that: In the laboratory, industrial step-by-step dehydration and deammoniation, and industrial continuous dehydration and deammoniation, the temperature range of dehydration is 100℃-200℃, and the temperature range of deammoniation is 300℃-600℃; in the laboratory continuous dehydration and deammoniation, the temperature is controlled at 300-600℃, allowing dehydration and deammoniation to proceed simultaneously.

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