Method for recycling gas medium in the process of preparing vanadium-nitrogen alloy

Abstract

The invention discloses a method for recycling gas medium in the process of preparing vanadium nitrogen alloy, comprising: heating ammonium vanadate salt in a first rotary kiln to deaminate to obtain hot vanadium oxide 1 and mixed gas 1, drying and feeding into a second rotary kiln for reduction nitridation reaction to obtain vanadium oxide and mixed gas 2, mixing and forming the vanadium oxide to obtain dry raw material blocks, feeding into a calcining kiln and introducing dry mixed gas 2 and purified nitrogen, controlling the flow of the purified nitrogen, performing carbon thermal reduction nitridation to obtain vanadium nitrogen alloy and mixed gas 3, introducing the mixed gas 3 into a third rotary kiln for heating and reduction to obtain hot vanadium oxide 2 and mixed gas 4, circulating the hot vanadium oxide 2 into the second rotary kiln, absorbing the mixed gas 4 with alkali to obtain purified nitrogen and absorption liquid, and circulating the purified nitrogen into the calcining kiln. The invention realizes the online recycling of gas medium in the process of preparing vanadium nitrogen alloy, greatly improving the utilization rate of gas medium.

Description

Technical Field

[0001] The invention relates to the field of metallurgy, and in particular to a method for recycling gas medium in a vanadium-nitrogen alloy preparation process. Background Art

[0002] Vanadium-nitrogen alloy is the most important and widely used vanadium alloy additive in the steel industry. The addition of vanadium-nitrogen alloy can improve the comprehensive performance of steel. At present, the preparation method of vanadium-nitrogen alloy is to use vanadium oxide and carbonaceous reducing agent as raw materials to carry out carbon thermal reduction nitridation reaction in nitrogen atmosphere. In this production method, a large amount of carbonaceous reducing agent must be added for deoxidation. Carbon monoxide is produced during the reaction. The increase of carbon monoxide partial pressure in the kiln is not conducive to the carbon thermal reduction reaction. Therefore, the kiln temperature must be increased or the nitrogen flow rate must be increased to reduce the carbon monoxide concentration in the kiln during production. However, the nitrogen utilization rate of the nitrogen introduced into the kiln that actually enters the vanadium-nitrogen alloy is only 5% to 10%, which has the problem of low nitrogen utilization rate.

[0003] Therefore, there is a need in the prior art for improving the method of recycling the gas medium during the preparation of vanadium-nitrogen alloy. Summary of the invention

[0004] In view of this, the purpose of an embodiment of the present invention is to propose a method for recycling gas media in the preparation process of vanadium-nitrogen alloy, and proposes a method for recycling gas media such as ammonia and nitrogen in the preparation process of vanadium-nitrogen alloy, which can realize the online recycling of gas media in the preparation process of vanadium-nitrogen alloy and greatly improve the utilization rate of gas media.

[0005] Based on the above purpose, an embodiment of the present invention provides a method for recycling gas medium in a vanadium-nitrogen alloy preparation process, comprising the following steps:

[0006] a. adding ammonium vanadate salt to a first rotary kiln and heating to remove ammonia to obtain hot vanadium oxide 1 and a mixed gas 1;

[0007] b. The mixed gas 1 is dried and dehydrated to obtain a dry mixed gas 1;

[0008] c. feeding the hot vanadium oxide 1 into the second rotary kiln, and introducing the dry mixed gas 1 into the second rotary kiln for reduction nitridation reaction to obtain vanadium oxynitride and the mixed gas 2;

[0009] d. The mixed gas 2 is dried and dehydrated to obtain a dry mixed gas 2;

[0010] e. The vanadium oxynitride is mixed and formed and dried to obtain a dry raw material block, and the dry raw material block is fed into a calcining kiln, and a dry mixed gas 2 and purified nitrogen are introduced, and the flow rate of the purified nitrogen is controlled to perform carbon thermal reduction nitridation to obtain a vanadium nitrogen alloy and a mixed gas 3;

[0011] f. The mixed gas 3 is completely introduced into the third rotary kiln, and vanadium pentoxide is added to the third rotary kiln for heating and reduction to obtain hot vanadium oxide 2 and a mixed gas 4;

[0012] g. The hot vanadium oxide 2 is circulated and added into the second rotary kiln. The mixed gas 4 is absorbed by alkali to obtain purified nitrogen and absorption liquid. The purified nitrogen is circulated and introduced into the calcining kiln.

[0013] In some embodiments, mixed gas 1 includes ammonia, nitrogen, hydrogen and water vapor, mixed gas 2 includes unreacted ammonia, nitrogen, hydrogen and water vapor, mixed gas 3 includes carbon monoxide and nitrogen, and mixed gas 4 includes nitrogen and carbon dioxide.

[0014] In some embodiments, in step c, the amount of dry mixed gas 1 introduced per kilogram of hot vanadium oxide 2 is 0.8 to 1.6 m 3 .

[0015] In some embodiments, in step a, the reaction temperature of heating deamination is 330-390° C., and the reaction time is 40-70 min.

[0016] In some embodiments, in step b and step d, the drying and dehydration is carried out by absorbing water with calcium oxide, and the volume fraction of water in the dry mixed gas 1 and the dry mixed gas 2 is less than or equal to 0.15%.

[0017] In some embodiments, in step c, the reduction nitridation reaction comprises reacting at 470° C. to 630° C. for 40 to 80 min, and then reacting at 740° C. to 860° C. for 50 to 130 min.

[0018] In some embodiments, in step e, during the mixing and molding, vanadium oxynitride and graphite powder are mixed in a weight ratio of ((0.755-0.785)*oxygen content in vanadium oxynitride): 1 to obtain a mixture, and then atomized water is sprayed until the moisture content in the mixture reaches 4%-9%, and then mixing is continued for 15-25 minutes to obtain a water-containing mixture. The water-containing mixture is pressed into blocks at a pressure of 6-30 MPa using a high-pressure ball press to obtain raw blocks. The raw blocks enter a drying kiln and are dried at a temperature of 120-260° C. to a moisture content of less than 0.6%, thereby obtaining dry raw blocks.

[0019] In some embodiments, in step e, in the calcining kiln, the carbon thermal reduction nitriding is calcined in a high temperature constant temperature zone of 930° C. to 1280° C. for 50 to 210 min, and the flow rate of the purified nitrogen is controlled so that the amount of purified nitrogen introduced per kilogram of dry raw material block is 1.2 to 2.4 m 3 .

[0020] In some embodiments, in step f, the amount of vanadium pentoxide added to the third rotary kiln is 32.2 to 65 times the mass of carbon monoxide in the mixed gas 3, the thermal reduction reaction temperature is 350° C. to 650° C., and the reaction time is 70 min to 130 min.

[0021] In some embodiments, in step g, the alkali absorption is performed using sodium hydroxide.

[0022] The present invention has at least the following beneficial technical effects:

[0023] The present invention is based on a new process of preparing vanadium oxide by deammoniation of ammonium vanadate - preparing vanadium oxide by ammonia medium reduction of vanadium oxide - preparing vanadium oxide by carbon thermal reduction of vanadium oxide to prepare vanadium-nitrogen alloy. A method for recycling gaseous media such as ammonia and nitrogen in the preparation process of vanadium-nitrogen alloy is proposed. The method can realize the online recycling of gaseous media in the preparation process of vanadium-nitrogen alloy, and greatly improve the utilization rate of gaseous media. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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 or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of an embodiment of a method for recycling gas medium in a vanadium-nitrogen alloy preparation process provided by the present invention. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0027] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0028] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] like Figure 1 The figure shows a schematic diagram of an embodiment of a method for recycling gas medium in a vanadium-nitrogen alloy preparation process provided by the present invention, the method comprising the following steps:

[0030] a. adding ammonium vanadate salt to a first rotary kiln and heating to remove ammonia to obtain hot vanadium oxide 1 and a mixed gas 1;

[0031] b. The mixed gas 1 is dried and dehydrated to obtain a dry mixed gas 1;

[0032] c. feeding the hot vanadium oxide 1 into the second rotary kiln, and introducing the dry mixed gas 1 into the second rotary kiln for reduction nitridation reaction to obtain vanadium oxynitride and the mixed gas 2;

[0033] d. The mixed gas 2 is dried and dehydrated to obtain a dry mixed gas 2;

[0034] e. The vanadium oxynitride is mixed and formed and dried to obtain a dry raw material block, and the dry raw material block is fed into a calcining kiln, and a dry mixed gas 2 and purified nitrogen are introduced, and the flow rate of the purified nitrogen is controlled to perform carbon thermal reduction nitridation to obtain a vanadium nitrogen alloy and a mixed gas 3;

[0035] f. The mixed gas 3 is completely introduced into the third rotary kiln, and vanadium pentoxide is added to the third rotary kiln for heating and reduction to obtain hot vanadium oxide 2 and a mixed gas 4;

[0036] g. The hot vanadium oxide 2 is circulated and added into the second rotary kiln. The mixed gas 4 is absorbed by alkali to obtain purified nitrogen and absorption liquid. The purified nitrogen is circulated and introduced into the calcining kiln.

[0037] Furthermore, in step a, the reaction temperature during heating and deammoniation in the first rotary kiln is 330-390° C., the reaction time is 40-70 min, and the obtained mixed gas 1 mainly contains ammonia and water vapor, and a small amount of ammonia decomposes to generate nitrogen and hydrogen.

[0038] Furthermore, in step b, the mixed gas 1 is dried to remove water, the desiccant is calcium oxide, and the volume fraction of water in the dried mixed gas 1 is less than or equal to 0.15%.

[0039] Furthermore, in step c, the amount of dry mixed gas 1 introduced is adjusted according to the mass of the hot vanadium oxide 1. Specifically, the amount of dry mixed gas 1 introduced per kilogram of hot vanadium oxide 1 is 0.8 to 1.6 m 3 The mixed gas 2 includes water vapor, nitrogen and unreacted ammonia.

[0040] Since the water vapor concentration is high, ammonia reduction nitriding is not used. Therefore, the mixed gas 2 can be used for ammonia reduction nitriding after drying.

[0041] Furthermore, in step d, the mixed gas 2 is dried to remove water, the desiccant is calcium oxide, and the volume fraction of water in the dried mixed gas 2 is less than or equal to 0.15%.

[0042] Furthermore, in step e, during the mixing and forming, vanadium oxynitride and graphite powder are mixed in a weight ratio of ((0.755-0.785)*oxygen content in vanadium oxynitride): 1 to obtain a mixture, and then atomized water is sprayed until the moisture content in the mixture reaches 4%-9%, and then the mixture is mixed for 15-25 minutes to obtain a water-containing mixture. The water-containing mixture is pressed into a block shape by a high-pressure ball press at a pressure of 6-30 MPa to obtain a raw material block. The raw material block enters a drying kiln and is dried at a temperature of 120-260°C to a moisture content of less than 0.6%, thereby obtaining a dry raw material block. In the calcining kiln, carbon thermal reduction nitriding is calcined in a high temperature constant temperature zone of 930°C-1280°C for 50-210 minutes, and the flow rate of purified nitrogen is controlled so that the amount of purified nitrogen introduced per kilogram of dry raw material block is 1.2-2.4 m 3 The mixed gas 3 formed in the carbon thermal reduction nitriding step includes nitrogen and carbon monoxide. If the mixed gas 3 is directly returned to this step, the carbon monoxide concentration gradually increases without utilizing the carbon thermal reduction reaction. Therefore, the mixed gas of nitrogen and carbon monoxide reacts with vanadium pentoxide.

[0043] Further, in step f, vanadium pentoxide is reduced by carbon monoxide to convert it into carbon dioxide and low-valent vanadium oxides, and the low-valent vanadium oxides can be returned for the ammonia reduction nitriding step, and the mixed gas 4 includes nitrogen and carbon dioxide. In some embodiments, the amount of vanadium pentoxide added to the third rotary kiln is 32.2 to 65 times the mass of carbon monoxide in the mixed gas 3, the temperature of the heat reduction reaction is 350°C to 650°C, and the reaction time is 70min to 130min.

[0044] Furthermore, in step g, the mixed gas 4 is subjected to alkaline absorption to remove carbon dioxide to obtain purified nitrogen. In some embodiments, the alkaline solution used in the alkaline absorption is sodium hydroxide.

[0045] According to the characteristics of the reactions in each step, the present invention can be recycled by simply treating the gas medium, so it has good feasibility and broad prospects for promotion and application.

[0046] The specific implementation manner of the present invention is further described below based on specific examples.

[0047] Example 1

[0048] The ammonium vanadate salt was calcined in the first rotary kiln at 347°C for 62 minutes to heat and deaminate to obtain hot vanadium oxide 1 and mixed gas 1. The mixed gas 1 was dried and dehydrated to obtain a water volume fraction of 0.09% to obtain dry mixed gas 1. The hot vanadium oxide 1 and the hot vanadium oxide 2 were sent to the second rotary kiln. The dry mixed gas 1 was introduced into the second rotary kiln and the ammonia flow rate was adjusted so that the total air flow rate in the kiln was 1.3m 3 / kg vanadium oxide is first reacted at 526℃ for 74min; then reacted at 806℃ for 79min to undergo ammonia reduction nitridation reaction to obtain vanadium oxynitride and mixed gas 2. The mixed gas 2 is dried twice to remove water so that the water volume fraction is 0.11% to obtain dry mixed gas 2. Vanadium oxynitride and graphite powder are mixed in a weight ratio of (0.763*oxygen content in vanadium oxynitride): 1 to obtain a mixture, and then atomized water is sprayed until the moisture content in the mixture reaches 7% and then the mixture is mixed for 22min to obtain a water-containing mixture. The water-containing mixture is pressed into a block shape by a high-pressure ball press at a pressure of 18MPa to obtain a raw material block. The raw material block enters a drying kiln and is dried at a temperature of 234℃ to a moisture content of 0.3% to obtain a dry raw material block. The dry raw material block is sent to a calcining kiln, and dry mixed gas 2 and purified nitrogen are introduced into the calcining kiln, and the nitrogen flow rate is adjusted so that the total air intake flow rate in the calcining kiln is 1.7m 3 / kg dry raw material block, calcined in a high temperature constant temperature zone at 990°C for 137min for carbon thermal reduction nitridation to obtain vanadium nitrogen alloy and mixed gas 3. All the mixed gas 3 is introduced into the third rotary kiln, and vanadium pentoxide in an amount 44 times the mass of carbon monoxide in the mixed gas 3 is added into the third rotary kiln, and then heated and reduced at a temperature of 583°C for a reaction time of 95min to obtain hot vanadium oxide 2 and mixed gas 4, vanadium oxide 2 returns to vanadium oxide 1, and mixed gas 4 is absorbed by alkali to obtain purified nitrogen and absorption liquid, and the purified nitrogen is introduced into the calcining kiln.

[0049] Example 2

[0050] The ammonium vanadate salt was calcined in the first rotary kiln at 351°C for 55 minutes to heat and deaminate to obtain hot vanadium oxide 1 and mixed gas 1. The mixed gas 1 was dried and dehydrated to reduce the water volume fraction to 0.1% to obtain dry mixed gas 1. The hot vanadium oxide 1 and the hot vanadium oxide 2 were sent to the second rotary kiln. The dry mixed gas 1 was introduced into the second rotary kiln and the ammonia flow rate was adjusted so that the total air flow rate in the kiln was 1.5m 3 / kg vanadium oxide is first reacted at 484℃ for 58min; then reacted at 765℃ for 102min to perform ammonia reduction nitridation reaction to obtain vanadium oxynitride and mixed gas 2. The mixed gas 2 is dried twice to remove water so that the water volume fraction is 0.13% to obtain dry mixed gas 2. Vanadium oxynitride and graphite powder are mixed in a weight ratio (0.771*oxygen content in vanadium oxynitride): 1 to obtain a mixture, and then atomized water is sprayed until the moisture content in the mixture reaches 5% and then the mixture is mixed for 17min to obtain a water-containing mixture. The water-containing mixture is pressed into a block shape by a high-pressure ball press at a pressure of 6-30MPa to obtain a raw material block. The raw material block enters a drying kiln and is dried at a temperature of 180℃ to a moisture content of 0.2% to obtain a dry raw material block. The dry raw material block is sent to a calcining kiln, and dry mixed gas 2 and purified nitrogen are introduced into the calcining kiln and the nitrogen flow rate is adjusted so that the total air intake flow rate in the calcining kiln is 1.4m 3 / kg dry raw material block, calcined in a high temperature constant temperature zone at 1150°C for 201min for carbon thermal reduction nitridation to obtain vanadium nitrogen alloy and mixed gas 3. All the mixed gas 3 is introduced into the third rotary kiln, and vanadium pentoxide 37 times the mass of carbon monoxide in the mixed gas 3 is added into the third rotary kiln, and then heated and reduced at a temperature of 454°C for a reaction time of 129min to obtain hot vanadium oxide 2 and mixed gas 4, vanadium oxide 2 returns to vanadium oxide 1, and mixed gas 4 is absorbed by alkali to obtain purified nitrogen and absorption liquid, and the purified nitrogen is introduced into the calcining kiln.

[0051] Example 3

[0052] The ammonium vanadate salt was calcined in the first rotary kiln at 365°C for 51 minutes to heat and deaminate to obtain hot vanadium oxide 1 and mixed gas 1. The mixed gas 1 was dried and dehydrated to reduce the water volume fraction to 0.14% to obtain dry mixed gas 1. The hot vanadium oxide 1 and the hot vanadium oxide 2 were sent to the second rotary kiln. The dry mixed gas 1 was introduced into the second rotary kiln and the ammonia flow rate was adjusted so that the total air flow rate in the kiln was 1.2m 3 / kg vanadium oxide is first reacted at 470℃~630℃ for 40~80min; then reacted at 740℃~860℃ for 50~130min to perform ammonia reduction nitridation reaction to obtain vanadium oxynitride and mixed gas 2. The mixed gas 2 is dried and dehydrated twice to make the water volume fraction 0.03% to obtain dry mixed gas 2. Vanadium oxynitride and graphite powder are mixed and mixed according to the weight ratio (0.781*oxygen content in vanadium oxynitride): 1 to obtain a mixture, and then sprayed with atomized water until the water content in the mixture reaches 6% and continued to mix for 24min to obtain a water-containing mixture. The water-containing mixture is pressed into a block shape by a high-pressure ball press at a pressure of 9MPa to obtain a raw material block. The raw material block enters a drying kiln and is dried at a temperature of 154℃ to a water content of 0.1% to obtain a dry raw material block. The dry raw material block is sent to a calcining kiln, and dry mixed gas 2 and purified nitrogen are introduced into the calcining kiln and the nitrogen flow rate is adjusted so that the total air intake flow rate in the calcining kiln is 1.6m 3 / kg dry raw material block, calcined in a high temperature constant temperature zone at 1030°C for 140min for carbon thermal reduction nitridation to obtain vanadium nitrogen alloy and mixed gas 3. All the mixed gas 3 is introduced into the third rotary kiln, and vanadium pentoxide 61 times the mass of carbon monoxide in the mixed gas 3 is added into the third rotary kiln, and then heated and reduced at a temperature of 396°C for a reaction time of 88min to obtain hot vanadium oxide 2 and mixed gas 4, vanadium oxide 2 returns to vanadium oxide 1, and mixed gas 4 is absorbed by alkali to obtain purified nitrogen and absorption liquid, and the purified nitrogen is introduced into the calcining kiln.

[0053] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0054] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0055] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0056] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for recycling gas medium in the process of preparing vanadium nitrogen alloy, characterized in that: include: a. adding ammonium vanadate salt to a first rotary kiln for heating and deamination to obtain hot vanadium oxide 1 and a mixed gas 1, wherein the heating and deamination reaction temperature is 330 to 390°C and the reaction time is 40 to 70 min; b. The mixed gas 1 is dried and dehydrated to obtain a dry mixed gas 1; c. feeding the hot vanadium oxide 1 into a second rotary kiln, introducing the dry mixed gas 1 into the second rotary kiln for reduction nitridation reaction to obtain vanadium oxynitride and mixed gas 2, wherein the reduction nitridation reaction comprises reacting at 470°C to 630°C for 40 to 80 minutes, and then reacting at 740°C to 860°C for 50 to 130 minutes; d. The mixed gas 2 is dried to obtain a dry mixed gas 2 after removing water; e. The vanadium oxynitride is mixed and formed and dried to obtain a dry raw block, the dry raw block is fed into a calcining kiln, and a dry mixed gas 2 and purified nitrogen are introduced, the flow rate of the purified nitrogen is controlled, and carbon thermal reduction nitridation is performed to obtain a vanadium nitrogen alloy and a mixed gas 3, the carbon thermal reduction nitridation is calcined in a high temperature constant temperature zone of 930°C to 1280°C for 50 to 210 minutes; f. The mixed gas 3 is completely introduced into the third rotary kiln, and vanadium pentoxide is added to the third rotary kiln for heating and reduction to obtain hot vanadium oxide 2 and a mixed gas 4, wherein the heating and reduction reaction temperature is 350°C to 650°C, and the reaction time is 70min to 130min; g. The hot vanadium oxide 2 is circulated into the second rotary kiln, the mixed gas 4 is absorbed by the base to obtain purified nitrogen and an absorbing liquid, and the purified nitrogen is circulated into the calcining kiln; The mixed gas 1 includes ammonia, nitrogen, hydrogen and water vapor, the mixed gas 2 includes unreacted ammonia, nitrogen, hydrogen and water vapor, the mixed gas 3 includes carbon monoxide and nitrogen, and the mixed gas 4 includes nitrogen and carbon dioxide.

2. The method for recycling gas medium in the process of preparing vanadium-nitrogen alloy according to claim 1, characterized in that: In step c, the amount of dry mixed gas 1 introduced per kilogram of the hot vanadium oxide 2 is 0.8-1.6 m 3 .

3. The method for recycling gas medium in the process of preparing vanadium-nitrogen alloy according to claim 1, characterized in that: In step b and step d, the drying and dehydration adopts calcium oxide absorption and dehydration, and the volume fraction of water in the dry mixed gas 1 and the dry mixed gas 2 is less than or equal to 0.15%.

4. The method for recycling gas medium in the process of preparing vanadium-nitrogen alloy according to claim 1, characterized in that: In step e, during the mixing and molding, the vanadium oxynitride and graphite powder are mixed in a weight ratio of ((0.755-0.785)*oxygen content in vanadium oxynitride): 1 to obtain a mixture, and then atomized water is sprayed until the moisture content in the mixture reaches 4%-9%, and then the mixing is continued for 15-25 minutes to obtain a water-containing mixture. The water-containing mixture is pressed into a block shape by a high-pressure ball press at a pressure of 6-30 MPa to obtain a raw material block. The raw material block enters a drying kiln and is dried at a temperature of 120-260° C. to a moisture content of less than 0.6%, thereby obtaining the dried raw material block.

5. The method for recycling gas medium in the process of preparing vanadium-nitrogen alloy according to claim 1, characterized in that: In step e, in the calcining kiln, the flow rate of the purified nitrogen is controlled so that the amount of the purified nitrogen introduced per kilogram of the dried raw material block is 1.2-2.4 m 3 .

6. The method for recycling gas medium in the process of preparing vanadium-nitrogen alloy according to claim 1, characterized in that: In step f, the amount of vanadium pentoxide added to the third rotary kiln is 32.2 to 65 times the mass of carbon monoxide in the mixed gas 3.

7. The method for recycling gas medium in the process of preparing vanadium nitrogen alloy according to claim 1, characterized in that: In step g, the alkali absorption is carried out using sodium hydroxide.

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