Preparation method of high-nitrogen vanadium-nitrogen alloy and high-nitrogen vanadium-nitrogen alloy

Abstract

The invention relates to the technical field of metallurgy, in particular to a preparation method of a high-nitrogen vanadium-nitrogen alloy and the high-nitrogen vanadium-nitrogen alloy.The preparation method comprises the following steps that 1, wet-based industrial-grade ammonium vanadate, a graphite carbon powder reducing agent, a metal iron powder catalyst and a water-based binder are mixed and stirred according to the mass ratio of 100: (18-22): (0.2-0.5): (8-20), and a mixture is obtained; 2, the mixed material is subjected to compression molding, and a preformed material is obtained; and 3, the preformed material is sequentially subjected to low-temperature pre-sintering dehydration treatment, high-temperature nitridation reduction treatment and cooling annealing treatment, and the high-nitrogen vanadium-nitrogen alloy is obtained. According to the preparation method, industrial-grade wet-based ammonium vanadate is directly adopted as a raw material, pretreatment is not needed, and the production cost is further reduced.

Description

Technical Field

[0001] This disclosure relates to the field of metallurgical technology, and in particular to a method for preparing a high-nitrogen vanadium-nitrogen alloy and the high-nitrogen vanadium-nitrogen alloy itself. Background Technology

[0002] Vanadium-nitrogen alloys are important steel additives, primarily composed of vanadium (V) and nitrogen (N). They possess excellent strengthening and toughening effects, significantly improving the strength, hardness, and wear resistance of steel without reducing its toughness. Therefore, they are widely used in high-end steel production, such as high-strength rebar, automotive beam steel, and high-strength steel for engineering machinery. With the rapid development of my country's high-end manufacturing industry and the transformation and upgrading of the steel industry, the production capacity of high-end steel continues to expand, leading to a steady increase in market demand for vanadium-nitrogen alloys. The industry's need to optimize the preparation process of vanadium-nitrogen alloys is becoming increasingly urgent, with the core objective being to achieve "low-cost, low-energy consumption, short-process, and high-stability" production.

[0003] Currently, the mainstream production processes for vanadium-nitrogen alloys all use high-purity vanadium pentoxide (V₂O₅) or vanadium trioxide (V₂O₃) as vanadium-containing raw materials. Related technologies have been disclosed in numerous patents. For example, CN107673317B discloses a "method for preparing high-nitrogen vanadium-nitrogen alloys," which uses V₂O₅ as a raw material, mixes it with carbon powder and a binder, and then performs nitriding sintering at high temperature to obtain vanadium-nitrogen alloys with high nitrogen content. CN117070780A discloses a "method for preparing vanadium-nitrogen alloys at low temperature and high efficiency," which also uses high-purity V₂O₅ as a raw material and lowers the reaction temperature and shortens the reaction cycle by adding a catalyst. The core limitation of this type of process is: 1. High raw material costs and complex pretreatment processes: The preparation of high-purity V2O5 or V2O3 requires multiple pretreatment processes such as vanadium ore roasting, leaching, purification, refining, and calcination. Not only are the processes lengthy and the equipment investment large, but the procurement cost of high-purity vanadium oxide accounts for more than 60% of the total cost of vanadium-nitrogen alloy products, which directly leads to high overall production costs and restricts the market competitiveness of enterprises.

[0004] 2. High energy consumption and long production cycle: The reaction temperature of the traditional carbothermic reduction nitriding process needs to be maintained above 1500℃, resulting in extremely high energy consumption per unit product, usually exceeding 6000kWh / t; at the same time, the single reaction time is as long as 15-20h, resulting in low production efficiency and difficulty in meeting the needs of large-scale industrial production.

[0005] 3. Significant environmental pressure: The raw material purification and pretreatment process generates a large amount of wastewater and waste gas, requiring additional investment in environmental protection equipment for treatment, which increases the production burden; some processes also generate ammonia-containing flue gas during raw material pretreatment (such as drying and calcination), further exacerbating the environmental pressure.

[0006] To address the aforementioned issues, the industry has undertaken research and development of relevant improvement technologies. Existing optimized preparation technologies are mainly divided into three categories, but all have significant technical limitations and have failed to fundamentally solve the industry's pain points: (1) Improved process using ammonium polyvanadate as raw material: This type of process attempts to use ammonium polyvanadate to replace traditional high-purity vanadium oxide. For example, CN103754839B discloses a "method for preparing vanadium-nitrogen alloy using ammonium polyvanadate as raw material". After drying and calcining to remove ammonia from the ammonium polyvanadate, it is mixed with carbon powder to form a mold and then nitrided and sintered. Although this process has some optimization in raw material cost, it still requires pretreatment steps such as drying and calcining to remove ammonia from the ammonium polyvanadate. The simplification of the process is limited and the pretreatment step cannot be completely eliminated. At the same time, a variety of auxiliary reagents need to be added during the reaction process, which not only increases the reagent cost, but may also lead to an increase in the impurity content of the product. Moreover, the nitrogen content of the finished product is not stable and it is difficult to stably meet the technical requirements of vanadium-nitrogen alloy in the national standard GB / T20567-2020, thus limiting its industrial application.

[0007] (2) Optimization of traditional carbothermic reduction nitriding process: This type of process mainly reduces the reaction temperature and shortens the reaction cycle by adding catalysts and optimizing the reaction atmosphere, such as patents CN101314830A and CN103641080A. However, this type of process still uses high-purity vanadium oxide as raw material, which fails to solve the core pain points of high raw material cost and complex pretreatment process. Moreover, the reaction temperature still needs to be maintained above 1450℃, and the space for optimization of energy consumption and production cycle is limited.

[0008] (3) Other raw material systems and processes: Some patents disclose methods for preparing vanadium-nitrogen alloys using vanadium chloride, vanadate complexes, etc. as vanadium-containing raw materials. However, such processes have obvious shortcomings: vanadium chloride raw materials are scarce and highly corrosive, requiring extremely high corrosion resistance from production equipment, resulting in high equipment investment costs; vanadate complex raw materials are complex to prepare, and impurities are easily generated during the reaction process, leading to substandard purity and nitrogen content of the vanadium-nitrogen alloy, making it difficult to achieve industrial-scale mass production.

[0009] In summary, existing vanadium-nitrogen alloy preparation technologies generally suffer from three major problems: First, they rely on high-purity vanadium oxides as raw materials, resulting in high procurement costs, complex pretreatment processes, and large equipment investments; second, they involve high reaction temperatures, high energy consumption, and long production cycles, leading to low production efficiency and high production costs; and third, although some improved processes attempt to optimize the raw material system, they still cannot get rid of the cumbersome pretreatment process, or have problems such as insufficient product performance stability and excessive impurity content, which cannot meet the needs of large-scale industrial production. Summary of the Invention

[0010] To address the aforementioned technical problems, this disclosure provides a method for preparing a high-nitrogen vanadium-nitrogen alloy and the high-nitrogen vanadium-nitrogen alloy itself, thereby solving the problems of high cost and high energy consumption in the preparation of high-nitrogen vanadium-nitrogen alloys in the prior art.

[0011] To address the aforementioned technical problems, some embodiments of the present invention disclose a method for preparing a high-nitrogen vanadium-nitrogen alloy, comprising the following steps: Step 1: Mix wet-based industrial-grade ammonium vanadate, graphite carbon powder reducing agent, metal iron powder catalyst and water-based binder at a mass ratio of 100:(18~22):(0.2~0.5):(8~20) to obtain a mixture. Step 2: Press the mixture into shape to obtain pre-formed material; Step 3: The preformed material is subjected to low-temperature pre-calcination dehydration treatment, high-temperature nitriding reduction treatment, and cooling annealing treatment in sequence to obtain high-nitrogen vanadium-nitrogen alloy.

[0012] In some embodiments, in step 1, the total vanadium content of wet-based industrial-grade ammonium vanadate is ≥49.5%.

[0013] In some embodiments, in step 1, the carbon content of the graphite carbon powder is ≥98%, the particle size is 100~200 mesh, and the purity of the metallic iron powder is ≥99.5%, the particle size is 200~300 mesh.

[0014] In some embodiments, in step 1, the water-based binder is one or more of starch binder, sodium carboxymethyl cellulose binder, or polyvinyl alcohol binder.

[0015] In some embodiments, the mixing and stirring time in step 1 is 10~30 minutes.

[0016] In some embodiments, in step 2, the pressure for pressing is 2~8 MPa.

[0017] In some embodiments, in step 2, the holding time for pressing is 3 to 8 minutes.

[0018] In some embodiments, in step 2, the preformed material is in the shape of a short cylinder, an ellipsoid, or an octahedron.

[0019] In some embodiments, in step 3 The temperature for low-temperature pre-calcination and dehydration treatment is 400~800℃, and the holding time is 1~2h; The high-temperature nitriding reduction treatment is carried out at a temperature of 1200~1400℃, with a holding time of 2~4h and a nitrogen flow rate of 120~260m³ / h. The cooling rate of the cooling annealing treatment is 5~10℃ / min.

[0020] On the other hand, some embodiments of the present invention also disclose a high-nitrogen vanadium-nitrogen alloy, comprising: being prepared by the above-described method for preparing high-nitrogen vanadium-nitrogen alloys.

[0021] By adopting the above technical solution, the present invention has at least the following beneficial effects: 1. The vanadium-nitrogen alloy product prepared by the method of this invention has a nitrogen content as high as 17.7%~18.6%, which belongs to the high nitrogen content grade. The vanadium content is ≥76.7%, and the impurity content (C≤0.8%, Si≤0.15%, P≤0.03%, S≤0.03%) all meet the technical requirements of the national standard GB / T20567-2020. Some of the products in the embodiments have reached the high quality standard of VN19, and the overall nitrogen content performance is significantly better than that of conventional vanadium-nitrogen alloy products. The nitrogen content of the product fluctuates within a range of ≤0.3%, the performance stability is high, and the product qualification rate can reach more than 99%.

[0022] 2. Using industrial-grade wet ammonium vanadate as raw material, no pretreatment is required, further reducing production costs.

[0023] 3. In the segmented nitriding sintering process, the temperature in the high-temperature stage is controlled at 1200~1400℃, which reduces energy consumption compared with the traditional process (above 1500℃). The entire production process only includes three core links: raw material proportioning, preforming, and segmented sintering, which shortens the production cycle, improves production capacity efficiency, and can meet the needs of large-scale industrial production.

[0024] 4. It eliminates the pretreatment steps of drying and calcining ammonium vanadate to remove ammonia in the traditional process, completely eliminating the ammonia-containing flue gas pollution generated in this step. At the same time, it reduces the generation of wastewater and waste gas during the raw material pretreatment process, reduces environmental pressure, and eliminates the need for additional investment in a large amount of environmental protection equipment, which is in line with the development trend of green metallurgy.

[0025] 5. By adding metallic iron powder catalyst and optimizing the segmented sintering parameters, the nitriding reaction is ensured to be full and uniform. The resulting vanadium-nitrogen alloy has small fluctuations in nitrogen content (fluctuation range ≤0.3%), high purity, and low impurity content. All indicators can stably meet the requirements of national standard GB / T20567-2020, and it can be widely used in the field of high-end steel production.

[0026] 6. The entire process is simple and easy to operate. The raw materials used (industrial-grade ammonium vanadate, graphite carbon powder, etc.) are widely available and readily available. The molding and sintering equipment are all conventional equipment in the vanadium metallurgy industry. No new special equipment is required. It can be directly adapted to existing vanadium-nitrogen alloy production lines, which is convenient for industrial mass production and promotion. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart of a method for preparing a high-nitrogen vanadium-nitrogen alloy according to an embodiment of the present disclosure. Detailed Implementation

[0029] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0030] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0031] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0033] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0034] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0035] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0036] Existing vanadium-nitrogen alloy preparation technologies generally suffer from three major problems: First, they rely on high-purity vanadium oxides as raw materials, resulting in high procurement costs, complex pretreatment processes, and large equipment investments; second, they involve high reaction temperatures, high energy consumption, and long production cycles, leading to low production efficiency and high production costs; and third, although some improved processes attempt to optimize the raw material system, they still cannot get rid of the cumbersome pretreatment process, or have problems such as insufficient product performance stability and excessive impurity content, which cannot meet the needs of large-scale industrial production.

[0037] Therefore, such as Figure 1 As shown, some embodiments of the present invention disclose a method for preparing a high-nitrogen vanadium-nitrogen alloy, comprising the following steps: Step 1: Mix wet-based industrial-grade ammonium vanadate, graphite carbon powder reducing agent, metal iron powder catalyst and water-based binder at a mass ratio of 100:(18~22):(0.2~0.5):(8~20) to obtain a mixture. Step 2: Press the mixture into shape to obtain pre-formed material; Step 3: The preformed material is subjected to low-temperature pre-calcination dehydration treatment, high-temperature nitriding reduction treatment, and cooling annealing treatment in sequence to obtain high-nitrogen vanadium-nitrogen alloy.

[0038] In the above method, in step 1, the total vanadium content of wet-based industrial-grade ammonium vanadate is ≥49.5%.

[0039] In the above method, in step 1, the carbon content of the graphite carbon powder is ≥98% and the particle size is 100~200 mesh, and the purity of the metallic iron powder is ≥99.5% and the particle size is 200~300 mesh.

[0040] In the above method, in step 1, the water-based binder is one or a mixture of starch binder, sodium carboxymethyl cellulose binder, or polyvinyl alcohol binder.

[0041] In the above method, the mixing time in step 1 is 10~30 minutes.

[0042] In the above method, in step 2, the pressing pressure is 2~8MPa.

[0043] In the above method, in step 2, the holding time for pressing is 3~8 minutes.

[0044] In the above method, in step 2, the preformed material is in the shape of a short cylinder, ellipsoid, or octahedron.

[0045] In the above method, in step 3, The temperature for low-temperature pre-calcination and dehydration treatment is 400~800℃, and the holding time is 1~2h; The high-temperature nitriding reduction treatment is carried out at a temperature of 1200~1400℃, with a holding time of 2~4h and a nitrogen flow rate of 120~260m³ / h. The cooling rate of the cooling annealing treatment is 5~10℃ / min.

[0046] Some embodiments of the present invention also disclose a high-nitrogen vanadium-nitrogen alloy, comprising: being prepared by the above-described method for preparing high-nitrogen vanadium-nitrogen alloys.

[0047] The technical solution will be further explained below with reference to specific embodiments.

[0048] Example 1 1. Raw material ratio: Take 100 kg of wet-based industrial grade ammonium vanadate (TV=49.8%), 20 kg of graphite carbon powder (fixed carbon content 98.5%, particle size 150 mesh), 0.3 kg of metallic iron powder (purity 99.6%, particle size 250 mesh), and 12 kg of starch binder, put them into a double helix mixer and stir for 20 min to obtain a uniform mixture.

[0049] 2. Preforming: The mixture is placed in a short cylindrical mold and pressed under a pressure of 5 MPa for 5 minutes to obtain a short cylindrical preform material with a density of 3.0 g / cm³.

[0050] 3. Segmented nitriding sintering: The preformed material is placed in a nitriding kiln and subjected to the following treatments in sequence: (1) Low-temperature pre-calcination dehydration: Nitrogen gas is introduced, the temperature is controlled at 600℃, and the temperature is maintained for 1.5h. The nitrogen flow rate is 80m³ / h. (2) High-temperature nitriding reduction: Stop the nitrogen gas supply and switch to high-purity nitrogen gas (purity 99.99%). Raise the temperature to 1300℃ and keep it at that temperature for 3 hours. The nitrogen gas flow rate is 200 m³ / h. (3) Cooling annealing: Keep nitrogen gas flowing in, control the cooling rate at 8℃ / min, and let it cool naturally to below 50℃ after it drops below 500℃. Take out the material and obtain the vanadium-nitrogen alloy finished product.

[0051] Product performance testing: The vanadium-nitrogen alloy product obtained in this example has a nitrogen content of 18.6%, a vanadium content of 77.2%, and impurity contents of C=0.72%, Si=0.13%, P=0.025%, and S=0.022%. All indicators meet the requirements of the national standard GB / T20567-2020, reaching the high-quality standard of VN19. The nitrogen content fluctuation range is 0.25%, and the product qualification rate is 100%.

[0052] Example 2: 1. Raw material ratio: Take 100 kg of wet-based industrial grade ammonium vanadate (TV=49.5%), 18 kg of graphite carbon powder (fixed carbon content 98.2%, particle size 100 mesh), 0.2 kg of metallic iron powder (purity 99.5%, particle size 200 mesh), and 8 kg of sodium carboxymethyl cellulose binder, put them into a planetary mixer and stir for 10 min to obtain a uniform mixture.

[0053] 2. Preforming: The mixture is placed in an ellipsoidal molding mold and pressed under a pressure of 2MPa for 3 minutes to obtain an ellipsoidal preformed material with a density of 2.8g / cm³.

[0054] 3. Segmented nitriding sintering: The preformed material is placed in a nitriding kiln and subjected to the following treatments in sequence: (1) Low-temperature pre-calcination dehydration: Argon gas is introduced, the temperature is controlled at 400℃, and the temperature is maintained for 2 hours. The argon gas flow rate is 50m³ / h. (2) High-temperature nitriding reduction: Stop the argon gas supply and switch to high-purity nitrogen gas (purity 99.99%). Raise the temperature to 1200℃ and keep it at that temperature for 4 hours. The nitrogen gas flow rate is 120m³ / h. (3) Cooling annealing: Keep nitrogen gas flowing in, control the cooling rate at 5℃ / min, and let it cool naturally to below 50℃ after it drops below 500℃. Take out the material and obtain the vanadium-nitrogen alloy finished product.

[0055] Product performance testing: The vanadium-nitrogen alloy product obtained in this example has a nitrogen content of 17.7%, a vanadium content of 76.8%, and impurity contents of C=0.78%, Si=0.14%, P=0.028%, and S=0.026%. All indicators meet the requirements of the national standard GB / T20567-2020, reaching the high-quality standard of VN19. The nitrogen content fluctuation range is 0.28%, and the product qualification rate is 100%.

[0056] Example 3: 1. Raw material ratio: Take 100 kg of wet-based industrial grade ammonium vanadate (TV=50.2%), 22 kg of graphite carbon powder (fixed carbon content 98.8%, particle size 200 mesh), 0.5 kg of metallic iron powder (purity 99.7%, particle size 300 mesh), and 20 kg of polyvinyl alcohol binder, put them into a twin-screw mixer and stir for 30 min to obtain a uniform mixture.

[0057] 2. Preforming: The mixture is placed in an octahedral molding mold and pressed under a pressure of 8 MPa for 8 minutes to obtain an octahedral preformed material with a density of 3.2 g / cm³.

[0058] 3. Segmented nitriding sintering: The preformed material is placed in a nitriding kiln and subjected to the following treatments in sequence: (1) Low-temperature pre-calcination dehydration: Nitrogen gas is introduced, the temperature is controlled at 800℃, and the temperature is maintained for 1 hour. The nitrogen flow rate is 100m³ / h. (2) High-temperature nitriding reduction: Stop the nitrogen gas supply and switch to high-purity nitrogen gas (purity 99.99%). Raise the temperature to 1400℃ and keep it at that temperature for 2 hours. The nitrogen gas flow rate is 260 m³ / h. (3) Cooling annealing: Keep nitrogen gas flowing in, control the cooling rate at 10℃ / min, and let it cool naturally to below 50℃ after it drops below 500℃. Take out the material and obtain the vanadium-nitrogen alloy finished product.

[0059] Product performance testing: The vanadium-nitrogen alloy product obtained in this example has a nitrogen content of 18.3%, a vanadium content of 77.5%, and impurity contents of C=0.68%, Si=0.12%, P=0.022%, and S=0.020%. All indicators meet the requirements of the national standard GB / T20567-2020, reaching the high-quality standard of VN19. The nitrogen content fluctuation range is 0.22%, and the product qualification rate is 100%.

[0060] Example 4: 1. Raw material ratio: Take 100 kg of wet-based industrial grade ammonium vanadate (TV=49.6%), 19 kg of graphite carbon powder (fixed carbon content 98.3%, particle size 120 mesh), 0.3 kg of metallic iron powder (purity 99.5%, particle size 220 mesh), and 10 kg of starch-carboxymethyl cellulose sodium mixed binder (mass ratio 1:1), put them into a planetary mixer and stir for 15 min to obtain a uniform mixture.

[0061] 2. Preforming: The mixture is placed in a short cylindrical mold and pressed under a pressure of 4 MPa for 4 minutes to obtain a short cylindrical preform material with a density of 2.9 g / cm³.

[0062] 3. Segmented nitriding sintering: The preformed material is placed in a nitriding kiln and subjected to the following treatments in sequence: (1) Low-temperature pre-calcination dehydration: Argon gas is introduced, the temperature is controlled at 500℃, and the temperature is maintained for 1.8h. The argon gas flow rate is 60m³ / h. (2) High-temperature nitriding reduction: Stop the argon gas supply and switch to high-purity nitrogen gas (purity 99.99%). Raise the temperature to 1250℃ and keep it at that temperature for 3.5h. The nitrogen gas flow rate is 150m³ / h. (3) Cooling annealing: Keep nitrogen gas flowing in, control the cooling rate at 6℃ / min, and let it cool naturally to below 50℃ after it drops below 500℃. Take out the material and obtain the vanadium-nitrogen alloy finished product.

[0063] Product index testing: The vanadium-nitrogen alloy product obtained in this example has a nitrogen content of 18.0%, a vanadium content of 77.0%, and impurity contents of C=0.75%, Si=0.13%, P=0.026%, and S=0.

[0064] In summary, the vanadium-nitrogen alloy products prepared by the method of this invention have a nitrogen content as high as 17.7%~18.6%, which belongs to the high nitrogen content grade. The vanadium content is ≥76.7%, and the impurity content (C≤0.8%, Si≤0.15%, P≤0.03%, S≤0.03%) all meet the technical requirements of the national standard GB / T20567-2020. Among them, the products of some embodiments have reached the high-quality standard of VN19 level, and the overall nitrogen content performance is significantly better than that of conventional vanadium-nitrogen alloy products. This invention directly uses industrial-grade wet ammonium vanadate as raw material, without the need for pretreatment, further reducing production costs.

[0065] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0066] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A method for preparing a high-nitrogen vanadium-nitrogen alloy, characterized in that, Includes the following steps: Step 1: Mix wet-based industrial-grade ammonium vanadate, graphite carbon powder reducing agent, metal iron powder catalyst and water-based binder at a mass ratio of 100:(18~22):(0.2~0.5):(8~20) to obtain a mixture. Step 2: Press the mixture into shape to obtain a pre-formed material; Step 3: The preformed material is subjected to low-temperature pre-calcination dehydration treatment, high-temperature nitriding reduction treatment, and cooling annealing treatment in sequence to obtain a high-nitrogen vanadium-nitrogen alloy.

2. The method for preparing the high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 1, the total vanadium content of the wet-based industrial-grade ammonium vanadate is ≥49.5%.

3. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 1, the carbon content of the graphite carbon powder is ≥98% and the particle size is 100~200 mesh, and the purity of the iron powder is ≥99.5% and the particle size is 200~300 mesh.

4. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 1, the water-based binder is one or a mixture of starch binder, sodium carboxymethyl cellulose binder, or polyvinyl alcohol binder.

5. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 1, the mixing and stirring time is 10~30 minutes.

6. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 2, the pressure for pressing and molding is 2~8MPa.

7. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 2, the pressure holding time for pressing and molding is 3 to 8 minutes.

8. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 2, the preformed material is in the shape of a short cylinder, ellipsoid, or octahedron.

9. The method for preparing a high-nitrogen vanadium-nitrogen alloy according to claim 1, characterized in that, In step 3, The temperature of the low-temperature pre-calcination dehydration treatment is 400~800℃, and the holding time is 1~2h; The high-temperature nitriding reduction treatment is performed at a temperature of 1200~1400℃, with a holding time of 2~4h and a nitrogen flow rate of 120~260m³ / h. The cooling rate of the cooling annealing process is 5~10℃ / min.

10. A high-nitrogen vanadium-nitrogen alloy, characterized in that, include: The high-nitrogen vanadium-nitrogen alloy was prepared according to any one of claims 1-9.

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