A method and device for preparing niobium pentachloride

Abstract

The invention provides a method and device for preparing niobium pentachloride, and relates to the field of preparing niobium pentachloride. Silicon tetrachloride solution and niobium pentoxide powder are put into a high-pressure reactor in proportion, stirred in a sealed environment, and a uniformly stirred mixture is obtained, wherein the mixture is silicon tetrachloride and niobium pentoxide; under argon protection, the mixture is stirred to heat the high-pressure reactor to 350-600°C, and silicon tetrachloride is fully reacted with niobium pentoxide powder in a liquid or gaseous state in an internal circulation mode, and the reflux reaction is performed for 4-6 hours to obtain gaseous niobium pentachloride; the temperature of the high-pressure reactor is reduced to 100-150°C, and the exhaust valve of the high-pressure reactor is opened to discharge and collect the gaseous silicon tetrachloride in the high-pressure reactor from the exhaust valve; the temperature of the high-pressure reactor is increased to 260°C, and the gaseous niobium pentachloride is collected by a constant temperature condensation trap to obtain liquid niobium pentachloride, and the coagulation time is 30-45min, and the yellow niobium pentachloride powder and crystals are obtained by cooling and crystallization. The present invention effectively improves the production efficiency and purification efficiency of niobium pentachloride production.

Description

Technical Field

[0001] The invention relates to the technical field of preparing niobium pentachloride, and in particular to a method and device for preparing niobium pentachloride. Background Art

[0002] Niobium is a rare metal material, and its compounds have many unique properties. Niobium has a series of excellent characteristics, such as high melting point, low vapor pressure, good cold processing performance, high chemical stability, strong resistance to liquid metal and acid and alkali corrosion, large dielectric constant of surface oxide film, small thermal neutron capture cross section, and good superconductivity. It is an important functional material. Therefore, it is used in optics, electrical engineering, electronics, aerospace, and medical treatment, and is also widely used in superconductivity, atomic energy and other industries.

[0003] The existing processes are as follows: (1) Niobium pentachloride is obtained by reacting metallic niobium with diluted chlorine at 300-350°C and purified by sublimation; (a) In the absence of carbon, niobium pentoxide is directly chlorinated to produce NbOCl3; (b) In the presence of carbon, the reaction produces a mixture of NbCl5 and NbOCl3; (2) Relatively pure niobium pentachloride can be prepared by reacting niobium sulfide with chlorine; (3) Niobium powder is reacted with ammonium oxide to produce ammonium niobate, which is then added with water, filtered and dried to obtain niobic acid; niobial acid is mixed with hydrochloric acid and reacted under certain conditions to obtain niobium pentachloride; the prepared niobium pentachloride needs to be purified and dried. Purification usually adopts sublimation method or cooling crystallization method, while drying requires the use of a high-temperature oven for drying. The above three methods are prone to produce "industrial wastes" such as phosgene, chlorine and waste acid that affect the environment in chemical production, as well as complex production processes and low product quality.

[0004] In view of the defects of the above methods in affecting the environment, it is urgent to provide a preparation technology for producing niobium pentachloride with "high purity, high efficiency, greenness and simple process". Summary of the invention

[0005] In order to solve the above problems, the present invention provides a method and device for preparing niobium pentachloride, which effectively improves the safety of the process, can achieve the purpose of quickly and efficiently preparing niobium pentachloride, is easy to operate, effectively improves the production efficiency and purification efficiency of niobium pentachloride production, reduces dust and waste gas emissions during the production process, and saves resources.

[0006] In order to achieve the above technical purpose, the present invention provides a method for preparing niobium pentachloride, comprising the following steps:

[0007] Step 1: adding silicon tetrachloride solution and niobium pentoxide powder into a high-pressure reactor according to a set ratio, and stirring them with a stirrer in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide;

[0008] Step 2: under the protection of argon, stirring the mixture and heating the autoclave to 350-600° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4-6 hours to obtain gaseous niobium pentachloride;

[0009] Step 3: After lowering the temperature of the autoclave to 100-150° C., the exhaust valve of the autoclave is opened to discharge and collect the gaseous silicon tetrachloride in the autoclave from the exhaust valve;

[0010] Step 4: After the temperature of the high-pressure reactor is increased to 260° C., gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride, with a coagulation time of 30-45 minutes, and finally cooled and crystallized to obtain yellow niobium pentachloride powder and crystals.

[0011] Preferably, the silicon tetrachloride content in the silicon tetrachloride solution is greater than or equal to 99.9%.

[0012] Preferably, the niobium pentoxide content in the niobium pentoxide powder is greater than or equal to 99.8%, and the particle size is 60-100 mesh.

[0013] Preferably, the molar ratio of the silicon tetrachloride to the niobium pentoxide input is (2.5-3):1.

[0014] Preferably, the temperature required for the reaction in the high-pressure reactor is 350-600°C.

[0015] Preferably, the pressure required for the reaction in the high-pressure reactor is 2.0-3.0 MPa.

[0016] Preferably, the time required for the reaction in the high-pressure reactor is 4-6 hours.

[0017] Preferably, the rotation speed of the agitator in step 1 is 50-100 r / min.

[0018] The present invention also provides a niobium pentachloride preparation device, which is applied to the niobium pentachloride preparation method, comprising a high-pressure reactor, wherein the high-pressure reactor comprises a reactor body, an air inlet valve, an exhaust valve, a pressure sensor, a temperature sensor, a temperature controller, an explosion-proof motor, a reducer device, a stirrer, a constant temperature condensation collector, a feed port, a discharge port, a heating component, and a fixing device;

[0019] The kettle body is a hollow cylindrical shape;

[0020] The air inlet valve and the exhaust valve are arranged on the kettle body, and the air inlet valve and the exhaust valve are respectively connected to the reaction chamber surrounded by the kettle body. The air inlet valve is used to pass the protective gas argon into the high-pressure reactor, and the exhaust valve is used to discharge the protective gas argon and the unreacted gaseous silicon tetrachloride out of the high-pressure reactor;

[0021] The temperature sensor is arranged between the inner cylinder and the outer cylinder of the kettle body; the pressure sensor is arranged on the kettle body, and the pressure sensor is connected to the reaction chamber surrounded by the kettle body;

[0022] The temperature controller, the explosion-proof motor, and the reducer device are respectively arranged outside the kettle body, and the stirrer is arranged inside the kettle body;

[0023] The constant temperature condensation collector is arranged on the kettle body, the constant temperature condensation collector is connected to the reaction chamber surrounded by the kettle body, and the constant temperature condensation collector is used to condense and collect gaseous niobium pentachloride;

[0024] The feed inlet is arranged at the high end of the kettle body, and the discharge outlet is arranged at the low end of the kettle body;

[0025] The heating component is connected to the reaction chamber surrounded by the kettle body;

[0026] The fixing devices are respectively arranged at the bottom and the side of the kettle body, and are used to fix the high-pressure reactor.

[0027] Preferably, the heating component includes a heating resistance wire component.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) In the present invention, a slightly excessive amount of silicon tetrachloride and niobium pentoxide are heated and reacted under high pressure. The reaction products are niobium pentachloride and silicon dioxide as well as a small amount of unreacted silicon tetrachloride. Niobium pentachloride with high purity can be separated by simple fractionation and cooling crystallization.

[0030] (2) The present invention does not require the addition of hazardous chemical gases such as chlorine during the production process, and under the protection of argon, the safety of the process is effectively improved;

[0031] (3) The present invention does not require material transfer during the production process, and the input of materials, heating and stirring of the high-pressure reactor, exhaust valve and constant temperature condensation trap and other devices are easy to control during production. The entire device can fully mix the reactants and increase the active components of the reactants, ultimately achieving the purpose of rapidly and efficiently preparing niobium pentachloride. The operation is convenient, and the production efficiency and purification efficiency of niobium pentachloride production are effectively improved.

[0032] (4) The present invention eliminates carbon and chlorine as carbon sources and chlorinating agents and adopts silicon tetrachloride as a chlorine source, which is convenient to purchase, reduces dust and waste gas emissions during the production process, and saves resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 This is a flow chart of the preparation method of niobium pentachloride described in the present invention;

[0035] Figure 2 It is a schematic diagram of the structure of the preparation device of niobium pentachloride described in the present invention.

[0036] In the figure, 1. support; 2. waste residue discharge port; 3. heating component; 4. agitator; 5. outer cylinder; 6. inner cylinder; 7. fixed pipe; 8. protective gas inlet hole; 9. gas control valve; 10. sealing gasket; 11. fixing device; 12. flange; 13. fixing device; 14. pressure gauge; 15. constant temperature condensate collector; 16. frame; 17. explosion-proof motor; 18. reducer device; 19. linkage shaft; 20. double-end mechanical seal; 21. feed port; 22. first sealing gasket and flange; 23. exhaust valve; 24. rotating shaft; 25. temperature controller; 26. second sealing gasket and flange. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0038] like Figure 1 As shown, the present invention proposes a method for preparing niobium pentachloride, which comprises the following steps:

[0039] Step 1: adding silicon tetrachloride solution and niobium pentoxide powder into a high-pressure reactor according to a set ratio, and stirring them with a stirrer in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide;

[0040] Step 2: under the protection of argon, stirring the mixture and heating the autoclave to 350-600° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4-6 hours to obtain gaseous niobium pentachloride;

[0041] Step 3: After lowering the temperature of the autoclave to 100-150° C., the exhaust valve of the autoclave is opened to discharge and collect the gaseous silicon tetrachloride in the autoclave from the exhaust valve;

[0042] Step 4: After the temperature of the high-pressure reactor is increased to 260° C., gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride, with a coagulation time of 30-45 minutes, and finally cooled and crystallized to obtain yellow niobium pentachloride powder and crystals.

[0043] Furthermore, the silicon tetrachloride content in the silicon tetrachloride solution is greater than or equal to 99.9%.

[0044] Furthermore, the niobium pentoxide content in the niobium pentoxide powder is greater than or equal to 99.8%, and the particle size is 60-100 meshes.

[0045] Furthermore, the molar ratio of the silicon tetrachloride to the niobium pentoxide input is (2.5-3):1.

[0046] Furthermore, the temperature required for the reaction in the high-pressure reactor is 350-600°C.

[0047] Furthermore, the pressure required for the reaction in the high-pressure reactor is 2.0-3.0 MPa.

[0048] Furthermore, the time required for the reaction in the high-pressure reactor is 4-6 hours.

[0049] Furthermore, in the step 1, the rotation speed of the agitator is 50-100 r / min.

[0050] like Figure 2 As shown, the present invention also proposes a preparation device of niobium pentachloride, which is applied to the preparation method of niobium pentachloride, including a high-pressure reactor, the high-pressure reactor including a reactor body, an air inlet valve, an exhaust valve 23, a pressure sensor, a temperature sensor, a temperature controller 25, an explosion-proof motor 17, a reducer device 18, a stirrer 4, a constant temperature condensation collector 15, a feed inlet 21, a waste residue discharge port 2, a heating component 3, and a fixing device 13;

[0051] The kettle body is a hollow cylindrical body, and the material of the kettle body is corrosion-resistant Hastelloy;

[0052] The air inlet valve and the exhaust valve 23 are arranged on the kettle body, and the air inlet valve and the exhaust valve 23 are connected to the reaction chamber surrounded by the kettle body. The air inlet valve is used to pass the protective gas argon into the high-pressure reactor; the exhaust valve 23 is used to discharge the protective gas argon and the unreacted gaseous silicon tetrachloride out of the high-pressure reactor;

[0053] The temperature sensor is arranged between the inner cylinder and the outer cylinder of the kettle body; the pressure sensor is arranged on the kettle body, and the pressure sensor is connected to the reaction chamber surrounded by the kettle body;

[0054] The temperature controller 25, the explosion-proof motor 17, and the reducer device 18 are arranged outside the kettle body; the stirrer 4 is arranged inside the kettle body;

[0055] The constant temperature condensation collector 15 is arranged on the kettle body, and the constant temperature condensation collector 15 is connected to the reaction chamber surrounded by the kettle body, and the constant temperature condensation collector 15 is used to condense and collect gaseous niobium pentachloride;

[0056] The feed port 21 is arranged at the high end of the kettle body; the waste residue discharge port 2 is arranged at the low end of the kettle body;

[0057] The heating component 3 is connected to the reaction chamber surrounded by the kettle body;

[0058] The fixing device 13 is arranged at the bottom and side of the reactor body, and is used to fix the high-pressure reactor.

[0059] Furthermore, the heating component 3 includes a heating resistance wire component. Example 4

[0060] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0061] Step 1: 16 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0062] Step 2: under the protection of argon, stirring and heating to 350° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 2.0 MPa, and the speed of the stirrer is 60 r / min;

[0063] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0064] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 16.26 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 80.0%. Example 5

[0065] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0066] Step 1: 16 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0067] Step 2: under the protection of argon, stirring and heating to 400° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 2.0 MPa, and the speed of the stirrer is 60 r / min;

[0068] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0069] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 17.68 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 87.0%. Example 6

[0070] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0071] Step 1: 16 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0072] Step 2: under the protection of argon, stirring and heating to 450° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 3.0 MPa, and the speed of the stirrer is 60 r / min;

[0073] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0074] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 18.70 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 92.0%. Example 7

[0075] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0076] Step 1: 16 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0077] Step 2: under the protection of argon, stirring and heating to 500° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 2.0 MPa, and the speed of the stirrer is 60 r / min;

[0078] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0079] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 19.11 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 94.0%. Example 8

[0080] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0081] Step 1: 19 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0082] Step 2: under the protection of argon, stirring and heating to 500° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 3.0 MPa, and the speed of the stirrer is 60 r / min;

[0083] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0084] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation trap to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 19.311 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 95.0%. Example 9

[0085] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0086] Step 1: 19 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0087] Step 2: under the protection of argon, stirring and heating to 500° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 5 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 3.0 MPa, and the speed of the stirrer is 60 r / min;

[0088] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0089] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 19.52 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 96.0%. Example 10

[0090] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0091] Step 1: 19 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0092] Step 2: under the protection of argon, stirring and heating to 500° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 6 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 3.0 MPa, and the speed of the stirrer is 60 r / min;

[0093] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0094] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 19.92 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 98.0%. Embodiment 11

[0095] A method for preparing niobium pentachloride and a device thereof, comprising the following steps:

[0096] Step 1: 19 kg of silicon tetrachloride solution and 10 kg of niobium pentoxide powder are put into a high-pressure reactor, and stirred in a sealed environment to obtain a uniform mixture, wherein the mixture is silicon tetrachloride and niobium pentoxide, and the speed of the stirrer is 60 r / min;

[0097] Step 2: under the protection of argon, stirring and heating to 600° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 6 hours to obtain gaseous niobium pentachloride, the pressure required for the reaction in the high-pressure reactor is 3.0 MPa, and the speed of the stirrer is 60 r / min;

[0098] Step 3: After lowering the temperature of the autoclave to 120° C., open the exhaust valve to discharge the gaseous silicon tetrachloride in the autoclave from the exhaust valve and collect it;

[0099] Step 4: After raising the temperature of the high-pressure reactor to 260°C, the gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride with high purity. The coagulation time is 45 minutes. Finally, it is cooled and crystallized to obtain 20.125 kg of high-purity niobium pentachloride. The reaction conversion rate is as high as 99.0%.

[0100] The invention heats slightly excess silicon tetrachloride and niobium pentoxide under high pressure to react, and the reaction products are niobium pentachloride and silicon dioxide as well as a small amount of unreacted silicon tetrachloride. Niobium pentachloride with high purity can be separated by simple fractionation and cooling crystallization.

[0101] The present invention does not need to add dangerous chemical gases such as chlorine during the production process, and under the protection of argon, the safety of the process is effectively improved;

[0102] The present invention does not need to transfer materials during the production process, and the input of materials, heating and stirring of the high-pressure reactor, exhaust valve and constant temperature condensation trap and other devices are easy to control during production. The entire device can fully mix the reactants and increase the active components of the reactants, and finally achieve the purpose of quickly and efficiently preparing niobium pentachloride. The operation is convenient, and the production efficiency and purification efficiency of niobium pentachloride production are effectively improved.

[0103] The present invention eliminates carbon and chlorine as carbon sources and chlorinating agents, and adopts silicon tetrachloride as a chlorine source, which is convenient to purchase, reduces dust and waste gas emissions during the production process, and saves resources.

[0104] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0105] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or perform equivalent replacements on some of the technical features thereof; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. They should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing niobium pentachloride, characterized in that: The steps include: Step 1: adding silicon tetrachloride and niobium pentoxide powders according to a set ratio into a high-pressure reactor, stirring with a stirrer in a sealed environment to obtain a uniform mixture, wherein the mixture is a mixture of silicon tetrachloride and niobium pentoxide; Step 2: under the protection of argon, stirring the mixture and heating the autoclave to 350-600° C., allowing silicon tetrachloride to fully react with niobium pentoxide powder in a liquid or gaseous state in an internal circulation manner, and reflux reaction for 4-6 hours to obtain gaseous niobium pentachloride, wherein the pressure required for the reaction in the autoclave is 2.0-3.0 MPa; Step 3: After lowering the temperature of the autoclave to 100-150° C., the exhaust valve of the autoclave is opened to discharge and collect the gaseous silicon tetrachloride in the autoclave from the exhaust valve; Step 4: After the temperature of the high-pressure reactor is increased to 260° C., gaseous niobium pentachloride is collected by a constant temperature condensation collector to obtain liquid niobium pentachloride, with a coagulation time of 30-45 minutes, and finally cooled and crystallized to obtain yellow niobium pentachloride powder and crystals.

2. The method for preparing niobium pentachloride according to claim 1, characterized in that: The purity of the silicon tetrachloride is greater than or equal to 99.9%.

3. The method for preparing niobium pentachloride according to claim 1, characterized in that: The niobium pentoxide powder has a niobium pentoxide content greater than or equal to 99.8% and a particle size of 60-100 meshes.

4. The method for preparing niobium pentachloride according to claim 1, characterized in that: The molar ratio of the silicon tetrachloride to the niobium pentoxide input is (2.5-3):

1.

5. The method for preparing niobium pentachloride according to claim 1, characterized in that: The temperature required for the reaction in the high-pressure reactor is 350-600°C.

6. The method for preparing niobium pentachloride according to claim 1, characterized in that: The time required for the reaction in the high-pressure reactor is 4-6 hours.

7. The method for preparing niobium pentachloride according to claim 1, characterized in that: The rotation speed of the agitator in step 1 is 50-100 r / min.

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