Preparation method of vanadium tetrachloride

Abstract

The invention relates to the technical field of chemical metallurgy, and discloses a method for preparing vanadium tetrachloride, which comprises the following steps: S1, fully mixing vanadium oxide with carbon; s2, water is added into the mixture of vanadium oxide and carbon, and briquetting, drying and crushing are carried out after sufficient wetting; s3, carrying out carbonization reaction on the crushed material in a protective atmosphere; s4, crushing and screening the materials after the carbonization reaction; s5, carrying out chlorination reaction on the carbonized material obtained by screening, and collecting a chlorinated product; and S6, distilling and condensing the chlorinated product to obtain a vanadium tetrachloride product. According to the method, the preparation process of the high-purity vanadium tetrachloride is simplified, the production period is remarkably shortened, the cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical metallurgy, and in particular to a method for preparing vanadium tetrachloride. Background Art

[0002] As an important strategic metal resource, vanadium is widely used in many fields such as metallurgy, chemical industry, energy storage and aerospace. At present, about 90% of the world's vanadium resources are concentrated in the form of intermediate alloys such as ferrovanadium and vanadium-nitrogen alloys for use in the steel industry, and only a small amount of vanadium resources are used in the non-steel field in the form of high-purity vanadium pentoxide, vanadium electrolyte, vanadium-aluminum alloy and high-purity metallic vanadium. This excessive concentration in the steel industry has restricted the rapid development of the global vanadium industry and led to a gradual decrease in product added value. As the vanadium industry develops in the direction of green, high efficiency and high value, it will inevitably promote the wider application of vanadium in the non-steel field and promote the development of high-value-added vanadium intermediate chemical products. This will be an inevitable trend in the future of the vanadium industry.

[0003] Vanadium chloride is an important type of high-value-added vanadium-based fine chemical products, mainly including vanadium dichloride, vanadium trichloride and vanadium tetrachloride. Among them, vanadium tetrachloride shows broad application prospects due to its stable chemical properties. It is a bright red liquid at room temperature, with a melting point of about -28°C and a boiling point of about 150°C. As a key raw material for the preparation of high-purity metallic vanadium, vanadium tetrachloride can also be used as a catalyst for olefin polymerization in the rubber industry, and can be used to produce functional materials such as high-purity vanadium dioxide. With the rapid development of high-purity metallic vanadium and organic catalysis, the demand for high-purity vanadium tetrachloride will continue to grow. Therefore, the development of high-purity vanadium tetrachloride preparation technology has important strategic and practical significance.

[0004] In the prior art, the relevant documents on the preparation process of high-purity vanadium tetrachloride are as follows: Patent CN202311428612.6 discloses a preparation process and system of vanadium tetrachloride, which mainly includes the following steps: under heating conditions, chlorine gas is mixed with a vanadium powder raw material to react to obtain a crude vanadium tetrachloride product, and the crude vanadium tetrachloride product is distilled to obtain a vanadium tetrachloride product.

[0005] Patent CN202111511867.X discloses a method for preparing vanadium tetrachloride using ferrovanadium fine powder, which includes: spreading ferrovanadium fine powder and petroleum coke in a crucible, and the mass ratio of ferrovanadium fine powder to petroleum coke is 1:4-10; placing a corundum crucible in a quartz reactor, and then placing the quartz reactor in a heating furnace, passing chlorine and nitrogen for chlorination reaction, condensing the gas product, centrifugal separation, and obtaining crude vanadium tetrachloride; placing the crude vanadium tetrachloride product in a polytetrafluoroethylene distillation condensation device and adding distilled water, stirring the reaction; performing a primary distillation at 130-140°C, when the mass of the condensed product is 5-10% of the mass of the crude vanadium tetrachloride product, performing a secondary distillation at 150-160°C, when the mass of the condensed product is 50-75% of the mass of the crude vanadium tetrachloride product, the condensed product is the vanadium tetrachloride product. The above method has the advantages of simple operation and high product purity.

[0006] However, the above patents all use metallic vanadium or ferrovanadium as raw materials. To obtain metallic vanadium or ferrovanadium, vanadium oxide needs to be subjected to metal thermal reduction, crushing and screening. This not only increases the cost, but also easily generates new impurities during the metal thermal reduction process, making the purification of vanadium tetrachloride difficult and costly.

[0007] Therefore, there is still room for improvement in the existing high-purity vanadium tetrachloride preparation process. Summary of the invention

[0008] In view of this, an object of the embodiments of the present invention is to provide a method for preparing vanadium tetrachloride.

[0009] Based on the above purpose, an embodiment of the present invention provides a method for preparing vanadium tetrachloride, comprising: S1, thoroughly mixing vanadium oxide and carbon; S2, adding water to the mixture of vanadium oxide and carbon, briquetting, drying and crushing after fully wetting; S3, subjecting the crushed materials to carbonization reaction under a protective atmosphere; S4, crushing and screening the materials after the carbonization reaction; S5, subjecting the sieved carbonized material to a chlorination reaction, and collecting the chlorination product; S6, distilling and condensing the chlorinated product to obtain a vanadium tetrachloride product.

[0010] According to one embodiment of the present invention, in step S1, the vanadium oxide is one or more of vanadium pentoxide, vanadium trioxide, vanadium dioxide, etc., the titanium content in the vanadium oxide is less than 1%, and the purity of the vanadium oxide is not less than 95%.

[0011] According to one embodiment of the present invention, in step S1, the carbon includes at least one of graphite, activated carbon, petroleum coke and carbon black, the carbon content is not less than 85%, and the amount of carbon added is 1 to 3 times the mass of oxygen element in vanadium oxide. According to one embodiment of the present invention, in step S2, the water is tap water or distilled water, and the amount of water added is 2% to 5% of the mass of the solid material.

[0012] According to one embodiment of the present invention, in step S2, the briquetting pressure is 10-50 MPa, the drying temperature is 100-200° C., and the particle size of the crushed particles is ≤10 mm.

[0013] According to one embodiment of the present invention, in step S3, the protective atmosphere includes at least one of argon, nitrogen and helium, the volume purity of the protective atmosphere is ≥99.9%, the temperature of the carbonization reaction is 1200~1700°C, and the time of the carbonization reaction is 2~10h.

[0014] According to an embodiment of the present invention, in step S4, the particle size of the carbide obtained by screening is 20-1000 μm.

[0015] According to one embodiment of the present invention, in step S5, the temperature of the chlorination reaction is 200~500°C, the time of the chlorination reaction is 30~240min, the atmosphere of the chlorination reaction is chlorine, the volume purity of the atmosphere is ≥99.9%, and the chloride is collected by condensation, and the condensation temperature is -10~-30°C.

[0016] According to one embodiment of the present invention, in step S6, the distillation method is multi-stage distillation, and the multi-stage distillation includes primary distillation and secondary distillation; The primary distillation temperature is 120~130℃, the condensation temperature is -10~-30℃, and the primary distillation ends when the fraction mass accounts for 5%~10%. The bottom product is the raw material for the next distillation. The secondary distillation temperature is 135~140℃, the condensation temperature is -10~-30℃, the secondary distillation ends when the fraction mass accounts for 1%~5%, and the bottom product is vanadium tetrachloride product; The primary distillation and the secondary distillation are respectively carried out once or multiple times.

[0017] According to one embodiment of the present invention, in step S6, the distillation process is protected by an inert gas, and the inert gas includes at least one of argon, helium and nitrogen with a volume purity of more than 99.9%.

[0018] The present invention has at least the following beneficial technical effects: The invention uses vanadium oxide as a raw material and carbon as a deoxidizer, converts vanadium oxide into vanadium carbide through a carbonization process, then converts vanadium carbide into crude vanadium tetrachloride through low-temperature chlorination, and finally prepares a high-purity vanadium tetrachloride product with a purity of more than 99.9% through distillation. The carbonization-chlorination-distillation steps are adopted, which simplifies the preparation process of high-purity vanadium tetrachloride, significantly shortens the production cycle, reduces costs, improves production efficiency, and has broad application prospects and potential economic value. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments.

[0020] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0021] 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.

[0022] The percentages or % (percent sign) in the present invention are all based on mass percentage unless otherwise specified.

[0023] The content in the present invention refers to mass percentage.

[0024] One or more embodiments of the present invention will be described in detail below.

[0025] The present invention provides a method for preparing vanadium tetrachloride, comprising the following steps: S1, thoroughly mixing vanadium oxide and carbon; S2, adding water to the mixture of vanadium oxide and carbon, briquetting, drying and crushing after fully wetting; S3, subjecting the crushed materials to carbonization reaction under a protective atmosphere; S4, crushing and screening the materials after the carbonization reaction; S5, subjecting the sieved carbonized material to a chlorination reaction, and collecting the chlorination product; S6, distilling and condensing the chlorinated product to obtain a vanadium tetrachloride product.

[0026] In some embodiments, in step S1, the vanadium oxide is one or more of vanadium pentoxide, vanadium trioxide, vanadium dioxide, etc., the titanium content in the vanadium oxide is less than 1%, and the purity of the vanadium oxide is not less than 95%. Vanadium pentoxide is preferably used as the vanadium oxide.

[0027] In some embodiments, in step S1, the carbon includes at least one of graphite, activated carbon, petroleum coke and carbon black, the carbon content is not less than 85%, and the amount of carbon added is 1 to 3 times the mass of oxygen in the vanadium oxide. Preferably, petroleum coke is added to the vanadium oxide as carbon.

[0028] In some embodiments, in step S2, the water is tap water or distilled water, and the amount of water added is 2% to 5% of the mass of the solid material.

[0029] In some embodiments, in step S2, the briquetting pressure is 10-50 MPa, the drying temperature is 100-200° C., and the particle size of the crushed particles is ≤10 mm.

[0030] In some embodiments, in step S3, the protective atmosphere includes at least one of argon, nitrogen and helium, the volume purity of the protective atmosphere is ≥99.9%, the temperature of the carbonization reaction is 1200-1700°C, and the carbonization reaction time is 2-10 hours. Nitrogen is preferably used as the protective atmosphere.

[0031] In some embodiments, in step S4, the particle size of the carbide obtained by screening is 20-1000 μm.

[0032] In some embodiments, in step S5, the temperature of the chlorination reaction is 200~500°C, the time of the chlorination reaction is 30~240min, the atmosphere of the chlorination reaction is chlorine, the volume purity of the atmosphere is ≥99.9%, and the chloride is collected by condensation, and the condensation temperature is -10~-30°C.

[0033] In some embodiments, in step S6, the distillation method is multi-stage distillation, and the multi-stage distillation includes primary distillation and secondary distillation; The primary distillation temperature is 120~130℃, the condensation temperature is -10~-30℃, and the primary distillation ends when the fraction mass accounts for 5%~10%. The bottom product is the raw material for the next distillation. The secondary distillation temperature is 135~140℃, the condensation temperature is -10~-30℃, the secondary distillation ends when the fraction mass accounts for 1%~5%, and the bottom product is vanadium tetrachloride product; The primary distillation and the secondary distillation are respectively carried out once or multiple times.

[0034] In some embodiments, in step S6, the distillation process is protected by an inert gas, and the inert gas includes at least one of argon, helium, and nitrogen with a volume purity of 99.9% or more. Preferably, argon with a volume purity of 99.9% or more is used as the inert gas.

[0035] In some embodiments, the method can be implemented in the following manner during production: vanadium pentoxide with a purity of 95% or more and a titanium content of ≤1% and petroleum coke with a carbon content of 85% or more are fully mixed, wherein the mass of petroleum coke is added according to 1 to 3 times the mass of oxygen in vanadium pentoxide, and 2% to 5% of the mass of distilled water is added to the mixture, and after being fully moistened, the mixture is pressed into blocks at a pressure of 10 to 50 MPa, and the material blocks obtained after the pressing are fully dried at a temperature of 100 to 200°C, and the dried material blocks are crushed into materials with a particle size of ≤10 mm, and the materials are placed in an atmosphere furnace, and carbonized at a temperature of 1200 to 1700°C for 2 to 10 hours under a nitrogen protective atmosphere with a volume purity of 99.9% or more. The materials after the carbonization reaction are crushed and sieved, and then the materials with a particle size of 20 to 1000 μm are taken for the next chlorination reaction. The material with a particle size of 20~1000μm is placed in a chlorination furnace, and chlorine with a volume purity of more than 99.9% is used as the reaction gas. The chlorination is carried out at a temperature of 200~500℃ for 30~240min. During the chlorination process, the gaseous chlorination products are condensed at a temperature of -10~-30℃. The collected condensed product is first distilled at a temperature of 120-130° C. under an argon protective atmosphere with a volume purity of more than 99.9%, and the volatile matter is condensed and collected at -10--30° C. The distillation is stopped when the mass of the volatile matter accounts for 5%-10% of the mass of the initial material. The remaining bottom material is the raw material for the next distillation. In order to ensure the purity of the product, this step can be repeated multiple times; the bottom material is further subjected to secondary distillation at a temperature of 135-140° C. under an argon protective atmosphere with a volume purity of more than 99.9%, and the volatile matter is condensed and collected at -10--30° C. The distillation is stopped when the mass of the volatile matter accounts for 1%-5% of the mass of the initial material. The remaining bottom material is the final vanadium tetrachloride product. In order to ensure the purity of the product, this step can be repeated multiple times.

[0036] The invention uses vanadium oxide as a raw material and carbon as a deoxidizer, converts vanadium oxide into vanadium carbide through a carbonization process, then converts vanadium carbide into crude vanadium tetrachloride through low-temperature chlorination, and finally prepares a high-purity vanadium tetrachloride product with a purity of more than 99.9% through distillation. The carbonization-chlorination-distillation steps are adopted, which simplifies the preparation process of high-purity vanadium tetrachloride, significantly shortens the production cycle, reduces costs, improves production efficiency, and has broad application prospects and potential economic value.

[0037] The present invention is further explained below in conjunction with specific embodiments and comparative examples.

[0038] Example 1 Weigh 1000g of vanadium pentoxide and 453g of petroleum coke with a carbon content of more than 95%, and mix them evenly. The purity of vanadium pentoxide is 98%, the mass of oxygen is 430.8g, and the titanium content is 0.5%. Add 29g of distilled water to the mixture, and after fully wetting, press the mixture under a pressure of 10MPa, and fully dry the material blocks obtained after pressing at a temperature of 100℃, and break the dried material blocks into carbonized materials with a particle size of about 5~10mm. Weigh 1000g of carbonized materials with a particle size of about 5~10mm, place them in an atmosphere furnace, and carbonize them at a temperature of 1700℃ for 2h in a nitrogen protective atmosphere with a volume purity of more than 99.9%. The material after the carbonization reaction is crushed and sieved, and then 300g of the material with a particle size of 20-1000μm is taken and placed in a chlorination furnace, and chlorine gas with a volume purity of more than 99.9% is used as the reaction gas, and chlorination is carried out at 200℃ for 240min. During the chlorination reaction, the gaseous chlorination product is condensed at -10℃, and 739g of liquid crude vanadium tetrachloride is collected, wherein the content of titanium tetrachloride is 0.60% and the content of vanadium trichloride is 2.07%. 300g of crude vanadium tetrachloride is first distilled at 127℃ under the protection of argon with a volume purity of more than 99.9%, and the volatile matter is condensed and collected at -10℃. When the mass of the volatile matter reaches 15g, the distillation is stopped, and the above distillation operation is repeated twice. Finally, the remaining bottom material of the kettle is 256g, and its vanadium trichloride content is 0.12% and the titanium tetrachloride content is 0.32%. Take 200g of the bottom product of the first-level distillation, distill it at 137°C under the protection of argon with a volume purity of more than 99.9%, condense the volatile matter at -10°C and collect it, stop distillation when the mass of the volatile matter reaches 2g, repeat the above distillation operation 3 times, and finally the remaining bottom material is 180g, with a vanadium trichloride content of 0.03%, a titanium tetrachloride content of 0.05%, and a vanadium tetrachloride content of 99.90%.

[0039] Example 2 Weigh 1000g of vanadium pentoxide and 907g of petroleum coke with a carbon content of more than 95%, and mix them evenly, wherein the purity of vanadium pentoxide is 98%, the mass of oxygen element is 430.8g, and the titanium content is 0.5%. Add 57g of distilled water to the mixture, and after fully wetting, press the mixture into blocks at a pressure of 30MPa, and fully dry the material blocks obtained after briquetting at a temperature of 150°C, and crush the dried material blocks into carbonized materials with a particle size of about 5-10mm; weigh 1000g of carbonized materials with a particle size of about 5-10mm, place them in an atmosphere furnace, and heat them at a volume of 1000g. The method comprises the following steps: carbonizing the raw material at 1500°C for 6 hours under a nitrogen protective atmosphere with a purity of more than 99.9%. The raw material after the carbonization reaction is crushed and sieved. Then, 300 g of the raw material with a particle size of 20-1000 μm is taken and placed in a chlorination furnace. Chlorine with a volume purity of more than 99.9% is used as the reaction gas. The raw material is chlorinated at 300°C for 120 minutes. During the chlorination reaction, the gaseous chlorination product is condensed at -20°C. 480 g of crude liquid vanadium tetrachloride is collected, in which the content of titanium tetrachloride is 0.82% and the content of vanadium trichloride is 2.86%. 300g of crude vanadium tetrachloride was first distilled at 127°C under the protection of argon with a volume purity of more than 99.9%, and the volatile matter was condensed and collected at -20°C. The distillation was stopped when the mass of the volatile matter reached 20g. The above distillation operation was repeated 3 times. Finally, 227g of the remaining bottom material was obtained, and the vanadium trichloride content was 0.07% and the titanium tetrachloride content was 0.21%. 150g of the bottom product of the first-level distillation was taken and distilled at 137°C under the protection of argon with a volume purity of more than 99.9%, and the volatile matter was condensed and collected at -20°C. The distillation was stopped when the mass of the volatile matter reached 5g. The above distillation operation was repeated 3 times. Finally, 121g of the remaining bottom material was obtained, and the vanadium trichloride content was 0.02%, the titanium tetrachloride content was 0.04%, and the vanadium tetrachloride content was 99.92%.

[0040] Example 3 Weigh 1000g of vanadium pentoxide and 1360g of petroleum coke with a carbon content of more than 95%, and mix them evenly. The purity of vanadium pentoxide is 98%, the mass of oxygen is 430.8g, and the titanium content is 0.5%. Add 118g of distilled water to the mixture, and after fully wetting, press the mixture under a pressure of 50MPa, and fully dry the material blocks obtained after pressing at a temperature of 200℃, and break the dried material blocks into carbonized materials with a particle size of about 5~10mm. Weigh 1000g of carbonized materials with a particle size of about 5~10mm, place them in an atmosphere furnace, and carbonize them at a temperature of 1200℃ for 10h under a nitrogen protective atmosphere with a volume purity of more than 99.9%. The material after the carbonization reaction is crushed and sieved, and then 300g of the material with a particle size of 20-1000μm is taken and placed in a chlorination furnace, and chlorine gas with a volume purity of more than 99.9% is used as the reaction gas, and chlorination is carried out at a temperature of 500°C for 30min. During the chlorination reaction, the gaseous chlorination product is condensed at a temperature of -30°C, and 401g of liquid crude vanadium tetrachloride is collected, wherein the content of titanium tetrachloride is 0.87% and the content of vanadium trichloride is 3.13%. 300g of crude vanadium tetrachloride is first distilled at a temperature of 127°C under the protection of argon gas with a volume purity of more than 99.9%, and the volatile matter is condensed and collected at a temperature of -30°C. When the mass of the volatile matter reaches 30g, the distillation is stopped, and the above distillation operation is repeated 3 times. Finally, the remaining bottom material of the kettle is 198g, and the content of vanadium trichloride is 0.05% and the content of titanium tetrachloride is 0.16%. Take 150g of the bottom product of the first-stage distillation, distill it at 137°C under the protection of argon with a volume purity of more than 99.9%, condense and collect the volatile matter at -30°C, stop distillation when the mass of the volatile matter reaches 8g, repeat the above distillation operation 3 times, and finally the remaining bottom material is 105g, with a vanadium trichloride content of 0.01%, a titanium tetrachloride content of 0.02%, and a vanadium tetrachloride content of 99.95%.

Claims

1. A method for preparing vanadium tetrachloride, characterized in that: include: S1, thoroughly mixing vanadium oxide and carbon; S2, adding water to the mixture of vanadium oxide and carbon, briquetting, drying and crushing after fully wetting; S3, subjecting the crushed materials to carbonization reaction under a protective atmosphere; S4, crushing and screening the materials after the carbonization reaction; S5, subjecting the sieved carbonized material to a chlorination reaction, and collecting the chlorination product; S6, distilling and condensing the chlorinated product to obtain a vanadium tetrachloride product.

2. The method according to claim 1, characterized in that In step S1, the vanadium oxide is one or more of vanadium pentoxide, vanadium trioxide, vanadium dioxide, etc., the titanium content in the vanadium oxide is less than 1%, and the purity of the vanadium oxide is not less than 95%.

3. The method according to claim 1, characterized in that: In step S1, the carbon includes at least one of graphite, activated carbon, petroleum coke and carbon black, the carbon content is not less than 85%, and the amount of carbon added is 1 to 3 times the mass of oxygen element in vanadium oxide.

4. The method according to claim 1, characterized in that: In step S2, the water is tap water or distilled water, and the amount of water added is 2% to 5% of the mass of the solid material.

5. The method according to claim 1, characterized in that In step S2, the briquetting pressure is 10-50 MPa, the drying temperature is 100-200°C, and the particle size of the crushed particles is ≤10 mm.

6. The method according to claim 1, characterized in that In step S3, the protective atmosphere includes at least one of argon, nitrogen and helium, the volume purity of the protective atmosphere is ≥99.9%, the temperature of the carbonization reaction is 1200~1700°C, and the time of the carbonization reaction is 2~10h.

7. The method according to claim 1, characterized in that In step S4, the particle size of the carbide obtained by screening is 20-1000 μm.

8. The method according to claim 1, characterized in that In step S5, the temperature of the chlorination reaction is 200-500°C, the time of the chlorination reaction is 30-240 minutes, the atmosphere of the chlorination reaction is chlorine, the volume purity of the atmosphere is ≥99.9%, and the chloride is collected by condensation, and the condensation temperature is -10--30°C.

9. The method according to claim 1, characterized in that: In step S6, the distillation method is multi-stage distillation, and the multi-stage distillation includes primary distillation and secondary distillation; The primary distillation temperature is 120~130℃, the condensation temperature is -10~-30℃, and the primary distillation ends when the fraction mass accounts for 5%~10%. The bottom product is the raw material for the next distillation. The secondary distillation temperature is 135~140℃, the condensation temperature is -10~-30℃, the secondary distillation ends when the fraction mass accounts for 1%~5%, and the bottom product is vanadium tetrachloride product; The primary distillation and the secondary distillation are respectively carried out once or multiple times.

10. The method according to claim 1, characterized in that In step S6, the distillation process is protected by an inert gas, wherein the inert gas includes at least one of argon, helium and nitrogen with a volume purity of more than 99.9%.