Method for preparing vanadium nitride from organic amine vanadium precipitation product

Abstract

The invention provides a method for preparing vanadium nitride from an organic amine vanadium precipitation product, which comprises the following steps: S1) placing the organic amine vanadium precipitation product in heating equipment, continuously introducing nitrogen to enable the interior of the heating equipment to be in a nitrogen atmosphere, heating the heating equipment to a first temperature, carrying out heat preservation, and collecting and drying tail gas generated in the heat preservation process; s2) heating the heating equipment to a second temperature, preserving heat, and introducing mixed gas of nitrogen source gas and carbonaceous reducing gas or mixed gas of the nitrogen source gas, the carbonaceous reducing gas and the tail gas in the step S1) in the heat preservation process for reaction; and S3) stopping heating, and continuously introducing nitrogen into the heating equipment until cooling to obtain vanadium nitride. Vanadium nitride is directly prepared from the organic amine vanadium precipitation product, compared with an existing vanadium precipitation product-vanadium oxide-vanadium nitride preparation route, the preparation process can be shortened, meanwhile, carbon elements and nitrogen elements in the organic amine vanadium precipitation product can be effectively utilized for reduction and nitridation, and the purpose of reducing environmental pollution is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgy, and particularly relates to a method for preparing vanadium nitride from vanadium precipitation product of organic amine. BACKGROUND

[0002] Vanadium nitride is an important steel additive, mainly used in the production of microalloyed steel, which can improve the strength, toughness, wear resistance and corrosion resistance of steel. The most commonly used vanadium source for preparing vanadium nitride is vanadium oxide, including vanadium trioxide and vanadium pentoxide. Vanadium oxide is usually prepared by solution vanadium precipitation and calcination of the precipitate. When preparing vanadium nitride, vanadium oxide needs to be placed in a high-temperature environment again, and then reacts with carbon source and nitrogen source to obtain vanadium nitride. The whole reaction process is long, and the energy consumption is large. From vanadium solution to vanadium precipitate, to vanadium oxide, and finally to vanadium nitride, the whole reaction process is long, and the energy consumption is large.

[0003] In order to shorten the preparation process of vanadium nitride and improve the production efficiency, researchers have proposed a method for directly using vanadium precipitation product to prepare vanadium nitride, for example, using ammonium metavanadate to prepare vanadium nitride. A method for preparing vanadium nitride using ammonium metavanadate as vanadium source is disclosed in Chinese patent CN114231781A. The ammonium metavanadate is first dried and mixed with part of the carbonaceous reducing agent and finely ground to obtain a mixture A. Then, the remaining part of the carbonaceous reducing agent, water and catalyst are added to the mixture A to obtain a mixture B. Finally, high-nitrogen vanadium nitride is prepared from the mixture B in an oxygen-poor nitrogenization tunnel kiln. In Chinese patent CN105063398A, coarse ammonium metavanadate is used as raw material, mixed with graphite powder as a deceleration agent, and hydrogen is introduced to successfully prepare vanadium nitride products by using self-propagating high-temperature synthesis technology.

[0004] The ammonium metavanadate used in the above-mentioned patents is obtained by vanadium precipitation of inorganic ammonium salt. In addition to inorganic ammonium salt, some organic amines are also effective vanadium precipitants, such as patents CN116462227A and CN118957306A which use ethylenediamine and melamine for vanadium precipitation, respectively. The method for treating such organic amine vanadium precipitation products is generally oxidation and calcination, which oxidizes carbon and nitrogen elements in the precipitate into carbon dioxide and nitrogen oxides, and at the same time obtains vanadium pentoxide products. At present, there is no related report on directly preparing vanadium nitride from organic amine vanadium precipitation products. According to the existing technology, if organic amine vanadium precipitation products are used to prepare vanadium nitride, vanadium oxide needs to be prepared by calcination first, and then reduction and nitriding to prepare vanadium nitride. The process is long, and the emission of carbon dioxide and nitrogen oxides not only causes waste of carbon and nitrogen elements, but also easily leads to environmental pollution.

[0005] Therefore, from the perspective of shortening the preparation process and reducing air pollution, it is of great significance to provide a method for preparing vanadium nitride from organic amine vanadium precipitation products. SUMMARY

[0006] The application provides a method for preparing vanadium nitride from an organic amine vanadium precipitation product.

[0007] Therefore, the application provides a method for preparing vanadium nitride from an organic amine vanadium precipitation product, which comprises the following steps:

[0008] S1) placing the organic amine vanadium precipitation product in a heating device, continuously introducing nitrogen gas to make the heating device have a nitrogen atmosphere, heating the heating device to a first temperature, keeping the temperature, collecting and drying tail gas generated in the keeping process;

[0009] S2) heating the heating device to a second temperature, keeping the temperature, and introducing a mixture of nitrogen source gas and carbonaceous reducing gas or a mixture of nitrogen source gas, carbonaceous reducing gas and the tail gas in step S1) for reaction in the keeping process;

[0010] S3) stopping heating and continuously introducing nitrogen gas into the heating device until cooling, to obtain vanadium nitride.

[0011] In some specific embodiments, the organic amine vanadium precipitation product is a primary amine, secondary amine, tertiary amine or quaternary ammonium salt vanadium precipitation product.

[0012] In some specific embodiments, the organic amine vanadium precipitation product is an ethylenediamine vanadium precipitation product.

[0013] In some specific embodiments, the first temperature is 600-650 DEG C, and the keeping time is 1-2 h.

[0014] In some specific embodiments, the second temperature is 1050-1250 DEG C, and the keeping time is 1-3 h.

[0015] In some specific embodiments, in step S2), the nitrogen source gas comprises one or both of ammonia and nitrogen.

[0016] In some specific embodiments, in step S2), the carbonaceous reducing gas comprises one or more of methane, ethane, ethylene, acetylene, propane, propylene and propyne.

[0017] In some specific embodiments, in step S2), when the mixture gas is nitrogen source gas, carbonaceous reducing gas and the tail gas in step S1), the ratio of the total volume of the nitrogen source gas and the tail gas to the volume of the carbonaceous reducing gas is 1:1-3:1.

[0018] In some specific embodiments, in step S2), when the mixture gas is nitrogen source gas and carbonaceous reducing gas, the volume ratio of the nitrogen source gas to the carbonaceous reducing gas is 1:1-3:1.

[0019] In some embodiments, the vanadium content of the vanadium nitride is 76-81 wt%, and the nitrogen content is 14-20 wt%.

[0020] The present application provides a method for preparing vanadium nitride from organic amine vanadium precipitation product, which first pyrolyzes the organic amine vanadium precipitation product at high temperature in a nitrogen atmosphere, converts the organic part of the organic amine vanadium precipitation product into tail gas including carbonaceous reducing gas and nitrogen source gas, and decomposes the inorganic part into intermediate product vanadium oxide, and then reduces and nitridizes the intermediate product in a mixed gas of carbonaceous reducing gas and nitrogen source gas or a mixed gas of the above tail gas, carbonaceous reducing gas and nitrogen source gas to obtain vanadium nitride product. The present application directly prepares vanadium nitride from organic amine vanadium precipitation product, and compared with the conversion route of organic amine vanadium precipitation product-vanadium pentoxide-vanadium nitride, the route of organic amine vanadium precipitation product-vanadium nitride of the present application shortens the preparation process, and the carbon element in the organic amine vanadium precipitation product is converted into small molecules of reducing carbonaceous gas, and the nitrogen element is converted into nitrogen source gas, which can be recycled, thereby reducing environmental pollution, saving production cost, and ensuring the quality of vanadium nitride. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The figure is a flowchart of the method for preparing vanadium nitride from organic amine vanadium precipitation product of the present application. DETAILED DESCRIPTION

[0022] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, and are not limitations on the claims of the present application.

[0023] In view of the problems of long route and environmental pollution caused by the existing technology for preparing vanadium nitride from organic amine vanadium precipitation product-vanadium pentoxide-vanadium nitride, the present application provides a method for preparing vanadium nitride from organic amine vanadium precipitation product, as shown in the flowchart Figure 1 , that is, the organic amine vanadium precipitation product is incubated at a first temperature in a nitrogen atmosphere to obtain intermediate product and tail gas, and then the intermediate product is incubated at a second temperature under the action of mixed gas to perform reduction and nitridization reaction and obtain vanadium nitride. The above method directly prepares vanadium nitride from organic amine vanadium precipitation product, shortens the preparation process, and converts the carbon element in the organic amine vanadium precipitation product into small molecules of reducing carbonaceous gas, and converts the nitrogen element into nitrogen source gas (nitrogen and ammonia), which can be recycled, thereby reducing environmental pollution. Specifically, the present application discloses a method for preparing vanadium nitride from organic amine vanadium precipitation product, which comprises the following steps:

[0024] S1) placing the organic amine vanadium precipitation product in a heating device, continuously introducing nitrogen to make the heating device be in a nitrogen atmosphere, heating the heating device to a first temperature, incubating, collecting and drying the tail gas generated in the incubation process;

[0025] S2) heating the heating device to a second temperature, holding the temperature, and introducing a mixture of a nitrogen source gas and a carbonaceous reducing gas or a mixture of a nitrogen source gas, a carbonaceous reducing gas, and the tail gas in step S2) into the heating device during the holding;

[0026] S3) stopping heating and continuously introducing nitrogen into the heating device until cooling, to obtain vanadium nitride. In the process of preparing vanadium nitride from an organic amine vanadium precipitation product, the present application relates to step S1:

[0027] The organic amine vanadium precipitation product is placed in a heating device, nitrogen is continuously introduced to make the heating device in a nitrogen atmosphere, the heating device is heated to a first temperature, and the tail gas generated during the holding is collected and dried.

[0028] The organic amine vanadium precipitation product is a primary amine, secondary amine, tertiary amine, or quaternary ammonium salt vanadium precipitation product, preferably, the organic amine vanadium precipitation product is an ethylenediamine vanadium precipitation product. Taking ethylenediamine vanadium precipitation as an example, under neutral and weakly basic conditions, vanadium in the solution exists in the form of VO3 - , and ethylenediamine vanadium precipitation obtains a complex product of C2H8N2, H + , VO3 - ; under acidic conditions, vanadium exists in the form of V 10 O 28 6- , and ethylenediamine vanadium precipitation obtains a complex of C2H8N2, H + , V 10 O 28 6- .

[0029] The first temperature is 600-650°C, and the holding time of the first temperature is 1-2h; preferably, the first temperature is 620-630°C, and the holding time of the first temperature is 1.5-2h.

[0030] In this step, the organic amine vanadium precipitation product is placed in a heating device, nitrogen is introduced to first remove the original gas in the heating device, and nitrogen is continuously introduced to make the subsequent reaction in a nitrogen atmosphere; under a nitrogen atmosphere, the organic amine vanadium precipitation product, i.e., the complex of the organic amine and the vanadate, undergoes thermal decomposition at a temperature in the range of 600-650°C, wherein the inorganic part H + and VO3 - (or H + , V 10 O 28 6-) into water vapor and V2O5, and the organic part, i.e. C2H8N2, is decomposed to produce small molecule gases such as C3H8, C2H4, CH4, NH3, N2, etc., wherein C3H8, C2H4, CH4 are carbonaceous reducing gases, and NH3, N2 are nitrogen sources for the production of vanadium nitride; that is, the organic amine vanadium precipitation product is thermally decomposed at a temperature range of 600-650°C to obtain intermediate products, carbonaceous reducing gases and nitrogen source gases, wherein the carbonaceous reducing gases and nitrogen source gases are collected as tail gas for reuse.

[0031] Regarding step S2:

[0032] The heating device is heated to a second temperature and kept at the second temperature, and a mixed gas of nitrogen source gas and carbonaceous reducing gas or a mixed gas of nitrogen source gas, carbonaceous reducing gas and tail gas in step S1) is introduced into the heating device for reaction during the keeping at the second temperature.

[0033] The second temperature is 1050-1250°C, and the keeping time is 1-3h; preferably, the second temperature is 1150-1200°C, and the keeping time is 2-3h. The intermediate product in the heating device is heated to the second temperature and kept at the second temperature, and a mixed gas is introduced into the heating device for reduction and nitriding reaction during the keeping at the second temperature, so as to reduce and nitride the intermediate product produced by the decomposition of the complex into vanadium oxide into vanadium nitride.

[0034] The mixed gas comprises nitrogen source gas and carbonaceous reducing gas, or comprises nitrogen source gas, carbonaceous reducing gas and tail gas; preferably, the nitrogen source gas comprises one or both of ammonia and nitrogen, and the carbonaceous reducing gas comprises one or more of methane, ethane, ethylene, acetylene, propane, propylene and propyne; further, when the mixed gas is selected from nitrogen source gas and carbonaceous reducing gas, the volume ratio of the nitrogen source gas to the carbonaceous reducing gas is 1:1-3:1; since the tail gas after drying is mostly nitrogen, the volume fraction of the carbonaceous reducing gas is low, and sufficient carbonaceous reducing gas needs to be added when the mixed gas is introduced, i.e. the volume of the gas in the mixed gas needs to satisfy V(nitrogen source gas + tail gas):V(carbonaceous reducing gas) = 1:1-3:1 (V in the above formula represents the volume of the gas), so as to ensure that V can be fully reduced.

[0035] In the present application, the tail gas in step S1) can be used as nitrogen source gas and carbonaceous reducing gas for reduction and nitriding of the intermediate product; the tail gas in step S1) can also not be used for the reduction and nitriding reaction of the intermediate product, and the tail gas can be used for metal smelting.

[0036] Regarding step S3:

[0037] After stopping heating, nitrogen is continuously introduced into the heating device until cooling, to obtain vanadium nitride.

[0038] In this step, nitrogen is continuously introduced to avoid oxygen entering to oxidize the vanadium nitride, and the vanadium nitride product can be collected after natural cooling to a temperature at which oxygen cannot oxidize the vanadium nitride.

[0039] After the above process, the vanadium content in the vanadium nitride is 76-81wt%, and the nitrogen content is 14-20wt%; specifically, the vanadium content in the vanadium nitride is 78.0-79.5wt%, and the nitrogen content is 15.5-16.5wt%.

[0040] The present application provides a method for preparing vanadium nitride from vanadium precipitation product of organic amine, which directly prepares vanadium nitride from vanadium precipitation product of organic amine. Compared with the material conversion route of vanadium precipitation product of organic amine-vanadium pentoxide-vanadium nitride, the route provided by the present application shortens the preparation process, and the carbon element in the vanadium precipitation product of organic amine is converted into a reducing carbon gas small molecule, and the nitrogen element is converted into nitrogen and ammonia, which can be recycled, and at the same time, the purpose of reducing environmental pollution and saving production cost is achieved, and the quality of vanadium nitride can also be guaranteed.

[0041] In order to further understand the present application, the method for preparing vanadium nitride from vanadium precipitation product of organic amine provided by the present application is described in detail below, and the protection scope of the present application is not limited by the following examples.

[0042] The vanadium content in the vanadium precipitation product of ethylenediamine in the following examples and comparative examples is 40.1wt%.

[0043] Example 1

[0044] S1, the vanadium precipitation product of ethylenediamine is placed in a reaction furnace, and nitrogen is introduced into the furnace to remove the original gas in the furnace;

[0045] The nitrogen is kept flowing in the reaction furnace, and the reaction furnace is slowly heated to 620℃ and kept for 1.5h, and the tail gas generated after keeping is collected and dried;

[0046] S2, the reaction furnace is heated to 1150℃ and kept for 2h, and a mixed gas of nitrogen, methane and the dried tail gas of S1 is introduced during the keeping process, and the volume ratio of the mixed gas is controlled to be V(nitrogen+tail gas):V(methane)=2:1;

[0047] S3, stop heating, continuously introduce nitrogen into the reaction furnace until natural cooling, and obtain vanadium nitride product, wherein the V content is 78.6wt%, and the N content is 16.4wt%.

[0048] Example 2

[0049] S1, the vanadium precipitation product of ethylenediamine is placed in a reaction furnace, and nitrogen is introduced into the furnace to remove the original gas in the furnace;

[0050] Keeping nitrogen flowing in the reactor, slowly heat the reactor to 600℃ and keep for 2h, collect and dry the tail gas produced after keeping;

[0051] S2, heat the reactor to 1050℃ and keep for 3h, keep flowing in the mixed gas of ammonia, methane and the dried tail gas of S1 in the process of keeping, control the gas volume ratio in the mixed gas as V(ammonia+tail gas):V(methane)=1:1;

[0052] S3, stop heating, keep flowing in nitrogen into the reactor until natural cooling, obtain the vanadium nitride product, wherein the V content is 78.0wt%, the N content is 16.2wt%.

[0053] Example 3

[0054] S1, put the vanadium precipitation product of ethylenediamine into the reactor, flow in nitrogen into the reactor to discharge the original gas in the reactor;

[0055] Keeping nitrogen flowing in the reactor, slowly heat the reactor to 650℃ and keep for 1h, collect and dry the tail gas produced after keeping;

[0056] S2, heat the reactor to 1250℃ and keep for 1h, keep flowing in the mixed gas of ammonia, nitrogen, methane and the dried tail gas of S1 in the process of keeping, control the gas volume ratio in the mixed gas as V(ammonia+nitrogen+tail gas):V(methane)=1:1, and V(ammonia):V(nitrogen)=1:1;

[0057] S3, stop heating, keep flowing in nitrogen into the reactor until natural cooling, obtain the vanadium nitride product, wherein the V content is 79.2wt%, the N content is 15.8wt%.

[0058] Example 4

[0059] S1, put the vanadium precipitation product of ethylenediamine into the reactor, flow in nitrogen into the reactor to discharge the original gas in the reactor;

[0060] Keeping nitrogen flowing in the reactor, slowly heat the reactor to 630℃ and keep for 2h, collect and dry the tail gas produced after keeping (the tail gas is retained and does not enter the next reaction);

[0061] S3, heat the reactor to 1180℃ and keep for 2h, keep flowing in the mixed gas of nitrogen and methane in the process of keeping, control the gas volume ratio in the mixed gas as V(nitrogen):V(methane)=3:1;

[0062] S4, stop heating, keep flowing in nitrogen into the reactor until natural cooling, obtain the vanadium nitride product, wherein the V content is 78.8wt%, the N content is 16.5wt%.

[0063] Comparative Example 1

[0064] The vanadium-precipitated ethylenediamine product was placed in a reaction furnace, and nitrogen was introduced into the furnace to remove the original gas in the furnace; the reaction furnace was heated to 1150°C and kept for 2 h, and a mixed gas of nitrogen and methane with a volume ratio of V(nitrogen):V(methane)=2:1 was introduced into the furnace during the keeping process; heating was stopped, and nitrogen was continuously introduced into the reaction furnace until natural cooling, to obtain a vanadium nitride product, wherein the content of V was 76.5wt%, and the content of N was 13.8wt%.

[0065] The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0066] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing vanadium nitride from organic amine vanadium precipitation products, comprising the following steps: S1) Place the organic amine vanadium precipitation product in a heating device, continuously introduce nitrogen gas to make the heating device a nitrogen atmosphere, heat the heating device to the first temperature, keep it at the temperature, and collect and dry the tail gas generated during the holding process. S2) Heat the heating equipment to the second temperature and keep it at that temperature. During the heat preservation process, a mixture of nitrogen source gas and carbonaceous reducing gas or a mixture of nitrogen source gas, carbonaceous reducing gas and the tail gas mentioned in step S1) is introduced to react. S3) Stop heating and continuously introduce nitrogen gas into the heating equipment until cooling is achieved, thus obtaining vanadium nitride.

2. The method according to claim 1, characterized in that, The vanadium precipitation product of the organic amine is a primary amine, secondary amine, tertiary amine or quaternary ammonium salt vanadium precipitation product.

3. The method according to claim 1 or 2, characterized in that, The organic amine vanadium precipitation product is an ethylenediamine vanadium precipitation product.

4. The method according to claim 1, characterized in that, The first temperature is 600-650℃, and the heat preservation time is 1-2 hours.

5. The method according to claim 1, characterized in that, The second temperature is 1050-1250℃, and the heat preservation time is 1-3 hours.

6. The method according to claim 1, characterized in that, In step S2), the nitrogen source gas includes one or both of ammonia and nitrogen.

7. The method according to claim 1, characterized in that, In step S2), the carbonaceous reducing gas includes one or more of methane, ethane, ethylene, acetylene, propane, propylene, and propyne.

8. The method according to claim 1 or 7, characterized in that, In step S2), when the mixed gas is a nitrogen source gas, a carbonaceous reducing gas, and the tail gas mentioned in step S1), the ratio of the total volume of the nitrogen source gas and the tail gas to the volume of the carbonaceous reducing gas is 1:1 to 3:

1.

9. The method according to claim 1 or 7, characterized in that, In step S2), when the mixed gas is a nitrogen source gas and a carbonaceous reducing gas, the volume ratio of the nitrogen source gas to the carbonaceous reducing gas is 1:1 to 3:

1.

10. The method according to any one of claims 1 to 9, characterized in that, The vanadium nitride contains 76–81 wt% vanadium and 14–20 wt% nitrogen.

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