Iodination deposition method of high-purity metal vanadium

Abstract

The invention relates to an iodination deposition method of high-purity metal vanadium. According to the technical scheme, a high-purity vanadium metal iodination deposition furnace is adopted for iodination deposition of vanadium metal; the method comprises the following steps: uniformly paving metal vanadium in a charging tray (18), and when the charging tray (18) is heated to 600-1000 DEG C, adjusting the vacuum degree of a vacuum chamber (9) to 1 * 10 <-2 >-1 * 10 <-4 > Pa every time the charging tray (18) is heated to 100-200 DEG C; raising the temperature of the deposition cylinder (10) to 1200-1500 DEG C, and adding iodine when the temperature of the charging tray (18) is stable; performing iodination deposition for 3-24 hours; turning off the power supply, and recovering the vacuum chamber (9) to normal temperature and normal pressure to obtain a high-purity metal vanadium product; a small amount of metal vanadium which is not iodized is recycled after being subjected to acid leaching treatment, ultrasonic cleaning and drying. The method has the advantages of being simple in process, low in raw material loss, small in deposition temperature error, high in deposition efficiency, free of pollution and wide in deposition base material application range.

Description

Technical Field

[0001] This invention belongs to the field of iodide deposition technology for metallic vanadium. Specifically, it relates to a method for iodide deposition of high-purity metallic vanadium. Background Technology

[0002] High-purity metallic vanadium (purity ≥99.95%) is an important strategic advanced functional material with key application value in high-tech fields such as nuclear reactor structural materials, aerospace high-temperature components, high-temperature superconducting systems, and special corrosion-resistant alloys. Currently, the mainstream industrial process for preparing metallic vanadium is still aluminothermic reduction combined with electron beam melting, with the final product typically having a vanadium purity between 98% and 99%. Due to the difficulty in effectively removing interstitial non-metallic impurities, the products cannot meet the technical requirements for 3N-grade (≥99.9%) and higher-purity metallic vanadium, severely restricting its large-scale application in high-end fields. Iodide deposition purification is effective in removing non-metallic elements such as oxygen and nitrogen. Developing an efficient, stable, and repeatable high-purity metallic vanadium preparation technology system based on iodide deposition purification is of great significance for overcoming the bottleneck in the industrial production of 3N-grade metallic vanadium.

[0003] A method for preparing high-purity metallic vanadium (CN 112725641A) uses a commonly used heating wire as the deposition substrate to prepare high-purity metallic vanadium crystal rods. The equipment employed is an iodination furnace with an existing heating wire deposition structure. The deposition temperature is controlled by adjusting the voltage and current values ​​on the deposition substrate to change the K value. However, this method, relying on manual adjustment of electrical parameters, results in an extremely cumbersome temperature control process and a large range of deposition temperature errors, making it difficult to achieve precise and constant temperature control, thus affecting the quality of the final product. Furthermore, the heating wire, as the deposition substrate, has a limited deposition area and low deposition efficiency.

[0004] A method for producing high-purity metallic vanadium (CN 118272654 A) involves a vacuum aluminothermic reaction of high-purity vanadium oxide and aluminum powder to produce a crude vanadium-aluminum alloy. This alloy is then mixed with aluminum, vacuum induction melted, and sodium carbonate is added to obtain a refined vanadium-aluminum alloy. Finally, a high-purity metallic vanadium product is obtained through two melting processes in an electron beam furnace. This process requires three types of high-vacuum equipment: a vacuum reactor, an induction melting furnace, and an electron beam furnace. The process is complex and demands high levels of sealing, control precision, and operational skills. While adding sodium carbonate can reduce silicon content, it introduces the risk of sodium contamination, limiting its application in high-end fields. At high temperatures, metallic vanadium is prone to volatilization during electron beam melting, leading to a decrease in the yield of high-purity metallic vanadium. Although the two melting processes enhance the purification effect, they also exacerbate vanadium loss and increase energy consumption.

[0005] A method for refining high-carbon crude vanadium into high-purity metallic vanadium (CN 110079833A) combines constant-current pre-electrolysis salt preparation with constant-voltage electrolytic refining. After pretreatment to prepare the anode from crude metallic vanadium, high-purity metallic vanadium is obtained by electrolysis at the cathode using an externally applied constant current. However, this method generates chlorine gas when using a chloride molten salt system, which is toxic and corrosive, and the electrolysis process also produces solid waste such as waste electrolyte.

[0006] In summary, current methods for preparing high-purity metallic vanadium suffer from problems such as cumbersome operation, complex process, large range of deposition temperature error, low deposition efficiency, easy loss of metallic vanadium, and pollution of waste gas and residue. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of existing technologies and provides an iodination deposition method for high-purity vanadium metal that is easy to operate, has a simple process, a small deposition temperature error range, high deposition efficiency, low vanadium metal loss, no pollution, and a wide range of applicable deposition substrate materials. The high-purity vanadium metal prepared by this method meets the purity requirements of 3N grade high-purity vanadium metal.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The technical solution employs a "high-purity vanadium iodide deposition furnace" to perform iodide deposition on vanadium metal. The specific steps are as follows: Step 1, Loading The upper insulation cover of the high-purity metal iodide deposition furnace is lifted by a hook, and the ratio of vanadium mass to vacuum chamber volume is 0.01~0.1:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray and close the upper heat preservation cover; open the iodine stopper and add elemental iodine into the iodine addition container.

[0009] The purity of the vanadium metal is 95~99wt%, and the particle size of the vanadium metal is 0.1~5cm.

[0010] Step 2, Iodide deposition Use a vacuum pump to evacuate the vacuum chamber to a vacuum level of 1×10⁻⁶. -2 ~1×10 -4 Pa, and then the resistance wire of the electric heating layer raises the temperature of the material tray to 600~1000℃; during the heating process of the material tray, the vacuum degree is adjusted to 1×10 by a vacuum pump every 100~200℃ increase. -2 ~1×10 -4 Pa; then the deposition cylinder is heated to 1200~1500℃ by a graphite heating rod.

[0011] When the temperature in the material tray area stabilizes at 600~1000℃, the mass ratio of elemental iodine to the volume of the vacuum chamber is 0.001~0.01:1 (kg / m³). 3Open the iodine container and add elemental iodine.

[0012] Iodide deposition was carried out for 3~24 hours. The power supply to the resistance wire and graphite heating rod was disconnected, and the gas nozzle of the vacuum tube was slowly opened to restore the pressure of the vacuum chamber to normal pressure. After natural cooling, high-purity metallic vanadium product was obtained.

[0013] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was treated with acid leaching, ultrasonically cleaned with deionized water and vacuum dried, and then subjected to iodide deposition.

[0014] In this technical solution: The high-purity vanadium metal iodide deposition furnace consists of an iodide deposition furnace body, an intermediate heating device, an iodine addition and vacuum system, and a temperature measurement system.

[0015] The iodide deposition furnace body consists of a furnace body and a furnace cover. The furnace body is composed of a furnace shell, a furnace body insulation layer, an electric heating layer, and a furnace body lining, which are symmetrically arranged from the outside to the inside. An upper insulation cover and a lower insulation cover are fixed to the furnace body accordingly. A resistance wire is installed inside the electric heating layer.

[0016] The intermediate heating device has the following structure: a material tray is provided at the bottom of the vacuum chamber, a deposition cylinder is coaxially mounted on the upper surface of the material tray, and a graphite heating rod is inserted into the deposition cylinder; an upper heat insulation rod and a lower heat insulation rod are coaxially positioned on the upper and lower end faces of the graphite heating rod; the upper end of the upper heat insulation rod passes through the heat insulation rod through-hole of the upper insulation cover and is tightly attached to the upper heat insulation rod fixing plate, and the upper electrode connected to the external power supply passes through the upper heat insulation rod fixing plate and the central hole of the upper heat insulation rod and is connected to the upper end face of the graphite heating rod; the lower end of the lower heat insulation rod passes through the material tray and the central through-hole of the lower heat insulation rod and is tightly attached to the lower heat insulation rod fixing plate, and the lower electrode connected to the external power supply passes through the lower heat insulation rod fixing plate and the central hole of the lower heat insulation rod and is connected to the lower end face of the graphite heating rod. The upper heat insulation rod fixing plate and the lower heat insulation rod fixing plate are disc-shaped, and the upper heat insulation rod fixing plate and the lower heat insulation rod are pressed together by bolts; both the upper heat insulation rod fixing plate and the lower heat insulation rod fixing plate are provided with electrode through holes in the center.

[0017] The iodine addition and vacuum system consists of: a vacuum tube through hole on one side of the center of the upper insulation cover; the lower end of the vacuum tube passes through the through hole and communicates with the vacuum chamber; a branch pipe is horizontally installed on the upper part of the vacuum tube; a vacuum valve, a gas nozzle, and a pressure gauge are installed in sequence from the outer end of the branch pipe; the outer end of the branch pipe is connected to the vacuum pump; and an iodine addition container is installed at the upper end of the vacuum tube.

[0018] The temperature measurement system consists of: a graphite heating rod temperature probe located in the middle of the graphite heating rod; a deposition cylinder temperature probe located at the bottom of the deposition cylinder; a raw material temperature probe located in the middle of the material tray; and an electric heating layer temperature probe located at the contact surface between the electric heating layer and the lower insulation cover. The four temperature probes are connected to corresponding external temperature displays via their respective cables.

[0019] The upper insulation cover has the following structure: from the outside to the inside, it consists of a furnace cover shell, a furnace cover insulation layer, and a furnace cover lining. The furnace cover shell, furnace cover insulation layer, and furnace cover lining are fixedly connected by bolts. The upper insulation cover has a heat insulation rod through hole in the center. The lower insulation cover has the same structure as the upper insulation cover.

[0020] The vacuum chamber is a cylindrical sealed cavity formed by the distance between the upper and lower insulation covers and the furnace lining, and the diameter-to-length ratio of the vacuum chamber is 1:1 to 2.

[0021] The outer diameter of the graphite heating rod is the same as the nominal size of the inner diameter of the deposition cylinder; the height of the graphite heating rod is 0.9 to 0.95 times the height of the deposition cylinder.

[0022] The deposition cylinder is a cylindrical structure with a wall thickness of 0.5 to 3 cm and a height of 0.1 to 0.5 times the height of the furnace lining.

[0023] The inner diameter of the iodine addition container is 1.2 to 1.5 times the diameter of the vacuum tube, and the height of the iodine addition container is 0.1 to 0.5 times the height of the vacuum tube. The valve stem of the iodine addition valve passes through the upper and lower holes of the iodine addition container coaxially. The valve disc at the lower end of the valve stem seals the lower hole of the iodine addition container. An iodine addition plug is provided on one side of the center of the upper surface of the iodine addition container.

[0024] The resistance wire is spirally embedded in the inner wall of the electric heating layer from bottom to top. The electric heating layer wire is in close contact with the inner lining of the furnace body, and the two ends of the resistance wire are connected to an external power source through cables.

[0025] The height of the material tray is 0.1 to 0.5 times the height of the vacuum chamber, and the outer diameter of the material tray is the same as the nominal size of the inner diameter of the vacuum chamber.

[0026] The height of the iodide deposition furnace body is the same as the sum of the heights of the upper heat insulation rod, the lower heat insulation rod, and the graphite heating rod, and the iodide deposition furnace body is supported by a base.

[0027] The upper and lower insulation covers are fitted with heat-insulating and anti-loosening gaskets on the contact surfaces with the furnace body lining; the upper and lower insulation rod fixing plates are fitted with flat gaskets on the contact surfaces with the furnace cover shell; and a tubular heat insulation ring is provided between the through hole of the vacuum tube and the vacuum tube.

[0028] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. Simple operation. Compared with existing electric heating wire iodization furnaces that require frequent adjustment of voltage and current to maintain stable deposition temperature, this invention is not affected by the deposition of high-purity vanadium metal products and can maintain stable temperature without real-time control, significantly reducing the difficulty and labor intensity of operation, and making it simple to operate.

[0029] 2. Small deposition temperature error range. This invention maintains the deposition cylinder temperature stably at a certain point within the high-temperature range of 1200~1500℃ by adjusting the heating power of the graphite heating rod. This provides a crucial constant thermal environment for the decomposition of vanadium iodide and the uniform deposition of high-purity vanadium crystals, reducing the impact of temperature fluctuations on the deposition results and resulting in a small deposition temperature error range.

[0030] 3. High deposition efficiency. Compared with the existing iodination furnace using heating wire as the deposition substrate, the deposition cylinder structure of this invention significantly increases the deposition area and the vanadium iodide cracking temperature range, thereby accelerating the deposition rate of high-purity metallic vanadium and achieving high deposition efficiency.

[0031] 4. Simple process flow. The iodination deposition refining process of this invention is completed in one step in a high-purity vanadium metal iodination deposition furnace, and there is no intermediate product transfer between various equipment, which greatly reduces the manual operation links and simplifies the process flow.

[0032] 5. Low raw material loss. In this invention, a small amount of metallic vanadium that has not been deposited by iodide is recovered after acid leaching, ultrasonic cleaning with deionized water, and vacuum drying, and then subjected to iodide deposition again; from elemental iodine to vanadium iodide and back to elemental iodine, a closed-loop reaction is formed, realizing the recycling of elemental iodine; the closed-loop design of the entire process achieves efficient conversion and high utilization of metallic vanadium, significantly reducing the waste of metallic vanadium.

[0033] 6. Clean and pollution-free process. This invention produces no harmful gases and leaves no waste electrolyte solids during the iodination deposition refining process, making the process clean and pollution-free.

[0034] 7. Wide range of applicable deposition substrate materials. This invention supports the use of various high-temperature resistant and iodide-resistant materials as deposition substrates (such as metallic molybdenum, boron nitride, ceramics, etc.), breaking the limitation of the insulating material of the heating wire and providing convenience for studying the preparation of high-purity metallic vanadium on different deposition substrates.

[0035] Therefore, this invention has the advantages of simple operation, simple process, small deposition temperature error range, high deposition efficiency, low vanadium metal loss, no pollution and wide applicability of deposition substrate materials. The high-purity vanadium metal prepared by this method meets the purity requirements of 3N grade high-purity vanadium metal. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a high-purity vanadium iodide deposition furnace used in this invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of protection thereof.

[0038] An iodide deposition method for high-purity metallic vanadium. The iodide deposition method employs a high-purity metallic vanadium iodide deposition furnace to deposit metallic vanadium using iodide deposition. The specific steps are as follows: Step 1, Loading The upper insulation cover 2 of the high-purity vanadium iodide deposition furnace is lifted by hook 26, with the vanadium mass to vacuum chamber 9 volume ratio being 0.01~0.1:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray 18 and close the upper heat preservation cover 2; open the iodine plug 32 and add elemental iodine into the iodine addition tank 31.

[0039] The purity of the vanadium metal is 95~99wt%, and the particle size of the vanadium metal is 0.1~5cm.

[0040] Step 2, Iodide deposition Vacuum pump 27 was used to evacuate vacuum chamber 9 to a vacuum level of 1×10⁻⁶. -2 ~1×10 -4 Pa, and then the resistance wire 11 of the electric heating layer 7 heats the material tray 18 to 600~1000℃. During the heating process of the material tray 18, the vacuum degree is adjusted to 1×10 by the vacuum pump 27 every 100~200℃ increase. -2 ~1×10 -4 Pa; then the deposition cylinder 10 is heated to 1200~1500℃ by the graphite heating rod 22.

[0041] When the temperature of zone 18 of the material tray stabilizes at 600~1000℃, the mass ratio of elemental iodine to the volume ratio of vacuum chamber 9 is 0.001~0.01:1 (kg / m³). 3 Open the iodine addition container 31 and add elemental iodine.

[0042] Iodide deposition for 3~24 hours, disconnect the power supply to the resistance wire 11 and graphite heating rod 22, slowly open the gas nozzle 29 of the vacuum tube 25 to restore the pressure of the vacuum chamber 9 to normal pressure, and allow it to cool naturally to obtain a high-purity metallic vanadium product.

[0043] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was treated with acid leaching, ultrasonically cleaned with deionized water and vacuum dried, and then subjected to iodide deposition.

[0044] In this specific implementation: The high-purity metal vanadium iodide deposition furnace, such as Figure 1 As shown, the high-purity vanadium metal iodide deposition furnace consists of an iodide deposition furnace body, an intermediate heating device, an iodine addition and vacuum system, and a temperature measurement system.

[0045] The iodide deposition furnace body consists of a furnace body and a furnace cover. The furnace body is composed of a furnace shell 24, a furnace insulation layer 6, an electric heating layer 7, and a furnace lining 8, arranged symmetrically from the outside to the inside. An upper insulation cover 2 and a lower insulation cover 17 are fixed to the upper and lower ends of the furnace body, respectively, and are bolted to the furnace body. A resistance wire 11 is installed inside the electric heating layer 7.

[0046] The structure of the intermediate heating device is as follows: a material tray 18 is provided at the bottom of the vacuum chamber 9, and a deposition cylinder 10 is coaxially mounted on the upper surface of the material tray 18. A graphite heating rod 22 is installed inside the deposition cylinder 10. An upper heat insulation rod 23 and a lower heat insulation rod 13 are coaxially arranged on the upper and lower end faces of the graphite heating rod 22. The upper end of the upper heat insulation rod 23 passes through the heat insulation rod through hole of the upper heat insulation cover 2 and is tightly attached to the upper heat insulation rod fixing plate 34. The upper electrode 1, which is connected to an external power source, passes through the upper heat insulation rod fixing plate 34 and the central hole of the upper heat insulation rod 23 and is connected to the upper end face of the graphite heating rod 22. The lower end of the lower heat insulation rod 13 passes through the material tray 18 and the central through hole of the lower heat insulation rod 13 and is tightly attached to the lower heat insulation rod fixing plate 14. The lower electrode 15, which is connected to an external power source, passes through the lower heat insulation rod fixing plate 14 and the central hole of the lower heat insulation rod 13 and is connected to the lower end face of the graphite heating rod 22. The upper heat insulation rod fixing plate 34 and the lower heat insulation rod fixing plate 14 are disc-shaped. The upper heat insulation rod fixing plate 34 and the lower heat insulation rod fixing plate 14 are fastened to the upper heat insulation rod 23 and the lower heat insulation rod 13 by bolts. The upper heat insulation rod fixing plate 34 and the lower heat insulation rod fixing plate 14 are both provided with electrode through holes in the center.

[0047] The iodine addition and vacuum system is as follows: a vacuum tube 25 is provided on one side of the center of the upper heat preservation cover 2. The lower end of the vacuum tube 25 passes through the through hole of the vacuum tube 25 and communicates with the vacuum chamber 9. A branch pipe is provided horizontally on the upper part of the vacuum tube 25. A vacuum valve 28, a gas nozzle 29 and a pressure gauge 30 are provided in sequence from the outer end of the branch pipe. The outer end of the branch pipe is connected to the vacuum pump 27. An iodine addition container 31 is provided at the upper end of the vacuum tube 25.

[0048] The temperature measurement system consists of: a graphite heating rod temperature probe 21 located in the middle of the graphite heating rod 22; a deposition cylinder temperature probe 20 located at the bottom of the deposition cylinder 10; a raw material temperature probe 19 located in the middle of the material tray; and an electric heating layer temperature probe 12 located at the contact surface between the electric heating layer 7 and the lower insulation cover 17. The above four temperature probes are connected to the corresponding external temperature displays via their respective cables.

[0049] The upper insulation cover 2 has the following structure: from the outside to the inside, there are furnace cover shell 3, furnace cover insulation layer 4 and 5, which are fixedly connected by bolts. The upper insulation cover 2 has a heat insulation rod through hole in the center. The lower insulation cover 17 has the same structure as the upper insulation cover 2.

[0050] The upper insulation cover 2 is equipped with a lifting ring 26.

[0051] The vacuum chamber 9 is a cylindrical sealed cavity formed by the distance between the upper insulation cover 2 and the lower insulation cover 17 and the furnace body lining 8. The diameter-to-length ratio of the vacuum chamber 9 is 1:1~2.

[0052] The outer diameter of the graphite heating rod 22 is the same as the nominal size of the inner diameter of the deposition cylinder 10; the height of the graphite heating rod 22 is 0.9 to 0.95 times the height of the deposition cylinder 10.

[0053] The deposition cylinder 10 has a cylindrical structure with a wall thickness of 0.5 to 3 cm and a height of 0.1 to 0.5 times that of the furnace lining 8.

[0054] The inner diameter of the iodine addition container 31 is 1.2 to 1.5 times the diameter of the vacuum tube 25, and the height of the iodine addition container 31 is 0.1 to 0.5 times the height of the vacuum tube 25. The valve stem of the iodine addition valve 33 passes through the upper and lower holes of the iodine addition container 31 coaxially, and the valve disc at the lower end of the valve stem seals the lower hole of the iodine addition container 31. An iodine addition plug 32 is provided on one side of the center of the upper surface of the iodine addition container 31.

[0055] The resistance wire 11 is spirally embedded in the inner wall of the electric heating layer 7 from bottom to top. The electric heating layer wire 11 is in close contact with the furnace body lining 8. The two ends of the resistance wire 11 are connected to an external power source via cables. The height of the material tray 18 is 0.1 to 0.5 times the height of the vacuum chamber 9, and the outer diameter of the material tray 18 is the same as the nominal size of the inner diameter of the vacuum chamber 9.

[0056] The height of the iodide deposition furnace body is the same as the sum of the heights of the upper heat insulation rod 23, the lower heat insulation rod 13 and the graphite heating rod 22, and the iodide deposition furnace body is supported by the base 16.

[0057] The upper insulation cover 2, the lower insulation cover 17 and the furnace body lining 8 are provided with heat-insulating loosening gaskets on their contact surfaces; the upper heat insulation rod fixing plate 34, the lower heat insulation rod fixing plate 14 and the furnace cover shell 3 are provided with flat gaskets on their contact surfaces; a tubular heat insulation ring is provided between the through hole of the vacuum tube 25 and the vacuum tube.

[0058] Example 1 An iodide deposition method for high-purity metallic vanadium. The iodide deposition method described in this embodiment uses a "high-purity metallic vanadium iodide deposition furnace" to deposit metallic vanadium using iodide deposition. The specific steps are as follows: Step 1, Loading The upper insulation cover 2 of the high-purity vanadium iodide deposition furnace is lifted by hook 26, with the mass ratio of vanadium metal to the volume ratio of the vacuum chamber 9 being 0.01:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray 18 and close the upper heat preservation cover 2; open the iodine plug 32 and add elemental iodine into the iodine addition tank 31.

[0059] The purity of the vanadium metal is 95 wt%, and the particle size of the vanadium metal is greater than or equal to 0.1 cm and less than 1.0 cm.

[0060] Step 2, Iodide deposition Vacuum pump 27 was used to evacuate vacuum chamber 9 to a vacuum level of 1×10⁻⁶. -2 Pa, and then the resistance wire 11 of the electric heating layer 7 heats the material tray 18 to 600°C. During the heating process of the material tray 18, the vacuum degree is adjusted to 1×10 by the vacuum pump 27 every 100°C increase. -2 Pa; then the deposition cylinder 10 is heated to 1200°C by the graphite heating rod 22.

[0061] When the temperature of zone 18 of the material tray stabilizes at 600℃, the mass ratio of elemental iodine to the volume ratio of vacuum chamber 9 is 0.001:1 (kg / m³). 3 Open the iodine addition container 31 and add elemental iodine.

[0062] After iodination deposition for 3 hours, the power supply to the resistance wire 11 and graphite heating rod 22 is disconnected. The gas nozzle 29 of the vacuum tube 25 is slowly opened to restore the pressure of the vacuum chamber 9 to normal pressure. After natural cooling, a high-purity metallic vanadium product is obtained.

[0063] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was treated with acid leaching, ultrasonically cleaned with deionized water and vacuum dried, and then subjected to iodide deposition.

[0064] In this embodiment 1, the high-purity vanadium iodide deposition furnace is the same as the specific implementation method except for the following technical parameters: The diameter-to-length ratio of the vacuum chamber 9 is 1:2; The height of the graphite heating rod 22 is 0.95 times the height of the deposition cylinder 10; The wall thickness of the deposition cylinder 10 is 3cm, and the height of the deposition cylinder 10 is 0.5 times the height of the furnace lining 8; The inner diameter of the iodine addition container 31 is 1.5 times the diameter of the vacuum tube 25, and the height of the iodine addition container 31 is 0.5 times the height of the vacuum tube 25. The height of the material tray 18 is 0.5 times the height of the vacuum chamber 9.

[0065] Example 2 An iodide deposition method for high-purity metallic vanadium. The iodide deposition method described in this embodiment uses a "high-purity metallic vanadium iodide deposition furnace" to deposit metallic vanadium using iodide deposition. The specific steps are as follows: Step 1, Loading The upper insulation cover 2 of the high-purity vanadium iodide deposition furnace is lifted by hook 26, with the vanadium mass to vacuum chamber 9 volume ratio being 0.03:1 (kg / m³). 3Spread metallic vanadium evenly in the material tray 18 and close the upper heat preservation cover 2; open the iodine plug 32 and add elemental iodine into the iodine addition tank 31.

[0066] The purity of the vanadium metal is 96.1 wt%, and the particle size of the vanadium metal is greater than or equal to 1.0 cm and less than 2.0 cm.

[0067] Step 2, Iodide deposition Use vacuum pump 27 to evacuate the vacuum chamber 9 to a vacuum level of 5×10⁻⁶. -3 Pa, and then the resistance wire 11 of the electric heating layer 7 heats the material tray 18 to 700°C. During the heating process of the material tray 18, the vacuum degree is adjusted to 5×10 by the vacuum pump 27 every 130°C increase. -3 Pa; then the deposition cylinder 10 is heated to 1280°C by the graphite heating rod 22.

[0068] When the temperature of zone 18 of the material tray stabilizes at 700℃, the mass ratio of elemental iodine to the volume ratio of vacuum chamber 9 is 0.003:1 (kg / m³). 3 Open the iodine addition container 31 and add elemental iodine.

[0069] After iodination deposition for 8 hours, the power supply to the resistance wire 11 and graphite heating rod 22 is disconnected. The gas nozzle 29 of the vacuum tube 25 is slowly opened to restore the pressure of the vacuum chamber 9 to normal pressure. After natural cooling, a high-purity metallic vanadium product is obtained.

[0070] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was treated with acid leaching, ultrasonically cleaned with deionized water and vacuum dried, and then subjected to iodide deposition.

[0071] In this embodiment 2, the high-purity vanadium iodide deposition furnace is the same as the specific implementation method except for the following technical parameters: The diameter-to-length ratio of the vacuum chamber 9 is 1:1.5; The height of the graphite heating rod 22 is 0.93 times the height of the deposition cylinder 10; The wall thickness of the deposition cylinder 10 is 1.5 cm, and the height of the deposition cylinder 10 is 0.3 times the height of the furnace lining 8; The inner diameter of the iodine addition container 31 is 1.3 times the diameter of the vacuum tube 25, and the height of the iodine addition container 31 is 0.3 times the height of the vacuum tube 25. The height of the material tray 18 is 0.3 times the height of the vacuum chamber 9.

[0072] Example 3 An iodide deposition method for high-purity metallic vanadium. The iodide deposition method described in this embodiment uses a "high-purity metallic vanadium iodide deposition furnace" to deposit metallic vanadium using iodide deposition. The specific steps are as follows: Step 1, Loading The upper insulation cover 2 of the high-purity vanadium iodide deposition furnace is lifted by hook 26, with the mass ratio of vanadium metal to the volume ratio of the vacuum chamber 9 being 0.05:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray 18 and close the upper heat preservation cover 2; open the iodine plug 32 and add elemental iodine into the iodine addition tank 31.

[0073] The purity of the vanadium metal is 97.3 wt%, and the particle size of the vanadium metal is greater than or equal to 2.0 cm and less than 3.0 cm.

[0074] Step 2, Iodide deposition Vacuum pump 27 was used to evacuate vacuum chamber 9 to a vacuum level of 1×10⁻⁶. -3 Pa, and then the resistance wire 11 of the electric heating layer 7 heats the material tray 18 to 800°C. During the heating process of the material tray 18, the vacuum degree is adjusted to 1×10 by the vacuum pump 27 every 150°C increase. -3 Pa; then the deposition cylinder 10 is heated to 1360°C by the graphite heating rod 22.

[0075] When the temperature of zone 18 of the material tray stabilizes at 800℃, the mass ratio of elemental iodine to the volume ratio of vacuum chamber 9 is 0.005:1 (kg / m³). 3 Open the iodine addition container 31 and add elemental iodine.

[0076] After iodination deposition for 12 hours, the power supply to the resistance wire 11 and graphite heating rod 22 is disconnected. The gas nozzle 29 of the vacuum tube 25 is slowly opened to restore the pressure of the vacuum chamber 9 to normal pressure. After natural cooling, a high-purity metallic vanadium product is obtained.

[0077] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was treated with acid leaching, ultrasonically cleaned with deionized water and vacuum dried, and then subjected to iodide deposition.

[0078] In this embodiment 3: Except for the following technical parameters, the high-purity vanadium iodide deposition furnace is the same as the specific implementation method: The diameter-to-length ratio of the vacuum chamber 9 is 1:1; The height of the graphite heating rod 22 is 0.9 times the height of the deposition cylinder 10; The wall thickness of the deposition cylinder 10 is 0.5 cm, and the height of the deposition cylinder 10 is 0.1 times the height of the furnace lining 8; The inner diameter of the iodine addition container 31 is 1.2 times the diameter of the vacuum tube 25, and the height of the iodine addition container 31 is 0.1 times the height of the vacuum tube 25. The height of the material tray 18 is 0.1 times the height of the vacuum chamber 9.

[0079] Example 4 An iodide deposition method for high-purity metallic vanadium. The iodide deposition method described in this embodiment uses a "high-purity metallic vanadium iodide deposition furnace" to deposit metallic vanadium using iodide deposition. The specific steps are as follows: Step 1, Loading The upper insulation cover 2 of the high-purity vanadium iodide deposition furnace is lifted by hook 26, with the mass ratio of vanadium metal to the volume ratio of the vacuum chamber 9 being 0.08:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray 18 and close the upper heat preservation cover 2; open the iodine plug 32 and add elemental iodine into the iodine addition tank 31.

[0080] The purity of the vanadium metal is 98.5 wt%, and the particle size of the vanadium metal is greater than or equal to 3.0 cm and less than 4.0 cm.

[0081] Step 2, Iodide deposition Use vacuum pump 27 to evacuate the vacuum chamber 9 to a vacuum level of 5×10⁻⁶. -4 Pa, and then the resistance wire 11 of the electric heating layer 7 heats the material tray 18 to 900°C. During the heating process of the material tray 18, the vacuum degree is adjusted to 5×10 by the vacuum pump 27 every 180°C increase. -4 Pa; then the deposition cylinder 10 is heated to 1440°C by the graphite heating rod 22.

[0082] When the temperature of zone 18 of the material tray stabilizes at 900℃, the mass ratio of elemental iodine to the volume ratio of vacuum chamber 9 is 0.008:1 (kg / m³). 3 Open the iodine addition container 31 and add elemental iodine.

[0083] After iodination deposition for 18 hours, the power supply to the resistance wire 11 and graphite heating rod 22 is disconnected. The gas nozzle 29 of the vacuum tube 25 is slowly opened to restore the pressure of the vacuum chamber 9 to normal pressure. After natural cooling, a high-purity metallic vanadium product is obtained.

[0084] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was treated with acid leaching, ultrasonically cleaned with deionized water and vacuum dried, and then subjected to iodide deposition.

[0085] In this embodiment 4: Except for the following technical parameters, the high-purity vanadium iodide deposition furnace is the same as the specific implementation method: The diameter-to-length ratio of the vacuum chamber 9 is 1:1.2; The height of the graphite heating rod 22 is 0.92 times the height of the deposition cylinder 10; The wall thickness of the deposition cylinder 10 is 1.0 cm, and the height of the deposition cylinder 10 is 0.2 times the height of the furnace lining 8; The inner diameter of the iodine addition container 31 is 1.4 times the diameter of the vacuum tube 25, and the height of the iodine addition container 31 is 0.2 times the height of the vacuum tube 25. The height of the material tray 18 is 0.2 times the height of the vacuum chamber 9.

[0086] Example 5 An iodide deposition method for high-purity metallic vanadium. The iodide deposition method described in this embodiment uses a "high-purity metallic vanadium iodide deposition furnace" to deposit metallic vanadium using iodide deposition. The specific steps are as follows: Step 1, Loading The upper insulation cover 2 of the high-purity vanadium iodide deposition furnace is lifted by hook 26, with the vanadium mass to vacuum chamber 9 volume ratio being 0.1:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray 18 and close the upper heat preservation cover 2; open the iodine plug 32 and add elemental iodine into the iodine addition tank 31.

[0087] The vanadium metal has a purity of 99 wt% and a particle size of 4.0 cm or less than or equal to 5.0 cm.

[0088] Step 2, Iodide deposition Vacuum pump 27 was used to evacuate vacuum chamber 9 to a vacuum level of 1×10⁻⁶. -4 Pa, and then the resistance wire 11 of the electric heating layer 7 heats the material tray 18 to 1000℃. During the heating process of the material tray 18, the vacuum degree is adjusted to 1×10 by the vacuum pump 27 every 200℃ increase. - 4 Pa; then the deposition cylinder 10 is heated to 1500°C by the graphite heating rod 22.

[0089] When the temperature of zone 18 of the material tray stabilizes at 1000℃, the mass ratio of elemental iodine to the volume ratio of vacuum chamber 9 is 0.01:1 (kg / m³). 3 Open the iodine addition container 31 and add elemental iodine.

[0090] After iodination deposition for 24 hours, the power supply to the resistance wire 11 and graphite heating rod 22 is disconnected, and the gas nozzle 29 of the vacuum tube 25 is slowly opened to restore the pressure of the vacuum chamber 9 to normal pressure. After natural cooling, a high-purity metallic vanadium product is obtained.

[0091] Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was subjected to acid leaching, ultrasonic cleaning with deionized water, and vacuum drying before iodide deposition. This specific embodiment has the following advantages compared to the prior art: In this embodiment 5: Except for the following technical parameters, the high-purity vanadium iodide deposition furnace is the same as the specific implementation method: The diameter-to-length ratio of the vacuum chamber 9 is 1:1.8; The height of the graphite heating rod 22 is 0.94 times the height of the deposition cylinder 10; The wall thickness of the deposition cylinder 10 is 2.0 cm, and the height of the deposition cylinder 10 is 0.4 times the height of the furnace lining 8; The inner diameter of the iodine addition container 31 is 1.4 times the diameter of the vacuum tube 25, and the height of the iodine addition container 31 is 0.4 times the height of the vacuum tube 25. The height of the material tray 18 is 0.4 times the height of the vacuum chamber 9.

[0092] This specific implementation method has the following advantages compared with the prior art: 1. Simple operation. Compared with existing electric heating wire iodization furnaces that require frequent adjustment of voltage and current to maintain stable deposition temperature, this specific implementation method is not affected by the deposition of high-purity vanadium metal products, and can maintain stable temperature without real-time control, significantly reducing the difficulty and labor intensity of operation, and making it simple to operate.

[0093] 2. Small deposition temperature error range. This specific embodiment maintains the deposition cylinder temperature stably at a certain point within the high-temperature range of 1200~1500℃ by adjusting the heating power of the graphite heating rod. This provides a crucial constant thermal environment for the decomposition of vanadium iodide and the uniform deposition of high-purity vanadium crystals, reducing the impact of temperature fluctuations on the deposition results and resulting in a small deposition temperature error range.

[0094] 3. High deposition efficiency. Compared with the existing iodination furnace using heating wire as the deposition substrate, the deposition tube structure in this specific embodiment significantly increases the deposition area and the vanadium iodide cracking temperature range, thereby accelerating the deposition rate of high-purity metallic vanadium and achieving high deposition efficiency.

[0095] 4. Simple process flow. In this specific embodiment, the iodination deposition refining process is completed in one step in a high-purity vanadium metal iodination deposition furnace, and there is no intermediate product transfer between various equipment, which greatly reduces the manual operation links and simplifies the process flow.

[0096] 5. Low raw material loss. In this specific embodiment, a small amount of metallic vanadium that has not been deposited by iodide is recovered after acid leaching, ultrasonic cleaning with deionized water, and vacuum drying, and then subjected to iodide deposition again; from elemental iodine to vanadium iodide and back to elemental iodine, a closed-loop reaction is formed, realizing the recycling of elemental iodine; the closed-loop design of the entire process achieves efficient conversion and high utilization of metallic vanadium, significantly reducing the waste of metallic vanadium.

[0097] 6. Clean and pollution-free process. This specific implementation method produces no harmful gases and leaves no waste electrolyte solids during the iodination deposition refining process, resulting in a clean and pollution-free process.

[0098] 7. Wide range of applicable deposition substrate materials. This specific embodiment supports the use of various high-temperature resistant and iodide-resistant materials as deposition substrates (such as metallic molybdenum, boron nitride, ceramics, etc.), breaking the limitation of the insulating material of the heating wire and providing convenience for studying the preparation of high-purity metallic vanadium on different deposition substrates.

[0099] Therefore, this specific implementation method has the characteristics of simple operation, simple process, small deposition temperature error range, high deposition efficiency, low vanadium metal loss, no pollution and wide applicability of deposition substrate materials. The high-purity vanadium metal prepared by this method meets the purity requirements of 3N grade high-purity vanadium metal.

Claims

1. A method for iodide deposition of high-purity metallic vanadium, characterized in that, The preparation method involves iodizing vanadium metal using a "high-purity vanadium iodide deposition furnace," and the specific steps are as follows: Step 1, Loading Open the heat preservation cover (2) on the high-purity metal iodide deposition furnace, and adjust the volume ratio of vanadium metal mass to vacuum chamber (9) to be 0.01~0.1:1 (kg / m³). 3 Spread metallic vanadium evenly in the material tray (18), and close the upper heat preservation cover (2); add elemental iodine to the iodine addition tank (31); The purity of the vanadium metal is 95~99wt%, and the particle size of the vanadium metal is 0.1~5cm; Step 2, Iodide deposition The vacuum level of the vacuum chamber (9) was evacuated to 1×10⁻⁶. -2 ~1×10 -4 Pa, then heat the material tray (18) to 600~1000℃. During the heating process of the material tray (18), use a vacuum pump (27) to adjust the vacuum degree to 1×10 for every 100~200℃ increase. -2 ~1×10 -4 Pa; then the deposition cylinder (10) is heated to 1200~1500℃; When the temperature of the material tray (18) area stabilizes at 600~1000℃, the mass ratio of elemental iodine to the volume ratio of the vacuum chamber (9) is 0.001~0.01:1 (kg / m³). 3 ), open the iodine addition container (31) and add elemental iodine; Iodide deposition for 3~24h, disconnect the power supply of resistance wire (11) and graphite heating rod (22), slowly open the gas nozzle (29) of vacuum tube (25) to restore the pressure of vacuum chamber (9) to normal pressure, and cool naturally to obtain high-purity metallic vanadium product; Step 3: Raw material recycling A small amount of metallic vanadium that was not deposited by iodide was recovered after acid leaching, ultrasonic cleaning with deionized water, and vacuum drying.

2. The iodide deposition method for high-purity metallic vanadium according to claim 1, characterized in that, The "high-purity metal vanadium iodide deposition furnace" consists of an iodide deposition furnace body, an intermediate heating device, an iodine addition and vacuum system, and a temperature measurement system. The iodide deposition furnace body consists of a furnace body and a furnace cover: the furnace body is composed of a furnace body shell (24), a furnace body insulation layer (6), an electric heating layer (7) and a furnace body lining (8) arranged symmetrically from the outside to the inside. The upper insulation cover (2) and the lower insulation cover (17) are fixed on the furnace body respectively; the electric heating layer (7) is provided with a resistance wire (11). The structure of the intermediate heating device is as follows: a material tray (18) is provided at the bottom of the vacuum chamber (9), and the deposition cylinder (10) is coaxially mounted on the upper surface of the material tray (18). A graphite heating rod (22) is installed inside the deposition cylinder (10). An upper heat insulation rod (23) and a lower heat insulation rod (13) are coaxially positioned on the upper and lower end faces of the graphite heating rod (22). The upper end of the upper heat insulation rod (23) passes through the heat insulation rod through hole of the upper insulation cover (2) and is tightly attached to the upper heat insulation rod fixing plate (34). The upper electrode (1) connected to the external power supply passes through the center hole of the upper heat insulation rod fixing plate (34) and the upper heat insulation rod (23) and connects to the upper end face of the graphite heating rod (22); the lower end of the lower heat insulation rod (13) passes through the material tray (18) and the center through hole of the lower heat insulation rod (13) and is closely attached to the lower heat insulation rod fixing plate (14); the lower electrode (15) connected to the external power supply passes through the center hole of the lower heat insulation rod fixing plate (14) and the lower heat insulation rod (13) and connects to the lower end face of the graphite heating rod (22); The iodine addition and vacuum system is as follows: a vacuum tube (25) is provided on one side of the center of the upper heat preservation cover (2). The lower end of the vacuum tube (25) passes through the vacuum tube (25) and communicates with the vacuum chamber (9). A branch pipe is provided horizontally on the upper part of the vacuum tube (25). A vacuum valve (28), a gas nozzle (29) and a pressure gauge (30) are provided in sequence from the outer end of the branch pipe. The outer end of the branch pipe is connected to the vacuum pump (27). An iodine addition tank (31) is provided at the upper end of the vacuum tube (25). The temperature measurement system is as follows: a graphite heating rod temperature probe (21) is provided at the middle position of the graphite heating rod (22), a deposition cylinder temperature probe (20) is provided at the lower part of the deposition cylinder (10), a raw material temperature probe (19) is provided at the middle position of the material tray, and an electric heating layer temperature probe (12) is provided at the contact surface between the electric heating layer (7) and the lower insulation cover (17); the above four temperature probes are connected to the corresponding external temperature display through their respective cables.

3. The iodide deposition method for high-purity metallic vanadium according to claim 1 or 2, characterized in that, The structure of the upper heat insulation cover (2) is as follows: from the outside to the inside, there are furnace cover shell (3), furnace cover insulation layer (4) and furnace cover lining (5). The furnace cover shell (3), furnace cover insulation layer (4) and furnace cover lining (5) are fixedly connected by bolts. The upper heat insulation cover (2) has a heat insulation rod through hole in the center. The lower heat insulation cover (17) has the same structure as the upper heat insulation cover (2).

4. The iodide deposition method for high-purity metallic vanadium according to claim 1 or 2, characterized in that, The vacuum chamber (9) is a cylindrical sealed cavity formed by the distance between the upper insulation cover (2) and the lower insulation cover (17) and the furnace body lining (8). The diameter-to-length ratio of the vacuum chamber (9) is 1:1~2.

5. The iodide deposition method for high-purity metallic vanadium according to claim 1 or 2, characterized in that, The outer diameter of the graphite heating rod (22) is the same as the nominal size of the inner diameter of the deposition cylinder (10); the height of the graphite heating rod (22) is 0.9 to 0.95 times the height of the deposition cylinder (10).

6. The iodide deposition method for high-purity metallic vanadium according to claim 1 or 2, characterized in that, The deposition cylinder (10) is a cylindrical structure with a wall thickness of 0.5~3cm and a height of 0.1~0.5 times that of the furnace lining (8).

7. The iodide deposition method for high-purity metallic vanadium according to claim 1 or 2, characterized in that, The inner diameter of the iodine addition vessel (31) is 1.2 to 1.5 times the diameter of the vacuum tube (25), and the height of the iodine addition vessel (31) is 0.1 to 0.5 times the height of the vacuum tube (25). The valve stem of the iodine addition valve (33) passes through the upper and lower holes of the iodine addition vessel (31) coaxially, and the valve disc at the lower end of the valve stem seals the lower hole of the iodine addition vessel (31). An iodine addition plug (32) is provided on one side of the center of the upper surface of the iodine addition vessel (31).

8. The iodide deposition method for high-purity metallic vanadium according to claim 1, characterized in that, The resistance wire (11) is spirally embedded in the inner wall of the electric heating layer (7) from bottom to top. The resistance wire (11) is close to the inner lining (8) of the furnace body. The two ends of the resistance wire (11) are connected to the external power supply through cables.

9. The iodide deposition method for high-purity metallic vanadium according to claim 1, characterized in that, The height of the tray (18) is 0.1 to 0.3 times the height of the vacuum chamber (9), and the outer diameter of the tray (18) is the same as the nominal size of the inner diameter of the vacuum chamber (9).

10. The iodide deposition method for high-purity metallic vanadium according to claim 1, characterized in that, The height of the iodide deposition furnace body is the same as the sum of the heights of the upper heat insulation rod (23), the lower heat insulation rod (13) and the graphite heating rod (22), and the iodide deposition furnace body is supported by the base (16).

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