A method for producing vanadium-nitrogen alloy by utilizing vanadium oxynitride

Abstract

The present invention discloses a method for producing a vanadium-nitrogen alloy using vanadium oxynitride, comprising the following steps: a. mixing graphite powder and vanadium oxynitride in a mass percentage ratio of K:1 to obtain a mixture, wherein the oxygen content of the vanadium oxynitride is 4% to 20%, and the oxygen content is divided into n intervals, wherein the K value is proportional to the oxygen content in each interval; b. adding the mixture to a wet mixer, spraying atomized water into the wet mixer, and mixing the mixture to obtain a water-containing mixture; c. pressing the water-containing mixture into a raw material block in a high-pressure briquetting machine; d. drying the raw material block in a drying kiln to obtain a dried raw material block; e. calcining the dried raw material block in a calcining kiln under a nitrogen atmosphere, and cooling to obtain a vanadium-nitrogen alloy. The present invention utilizes brand-new raw materials to prepare the vanadium-nitrogen alloy and innovates process parameters such as the batching method, temperature control, and calcination time, thereby achieving the goals of reducing carbon content and carbon emissions, lowering reaction temperature and energy consumption, and increasing the processing capacity of a single kiln.

Description

Technical Field

[0001] The present invention relates to the field of metallurgy, and in particular to a method for producing a vanadium-nitrogen alloy by utilizing vanadium nitrogen oxide. Background Art

[0002] Vanadium-nitrogen alloys are the most important and widely used vanadium alloy additives in the steel industry. Their addition improves the overall performance of steel. Currently, vanadium-nitrogen alloys are primarily produced domestically and internationally using a normal-pressure, one-step process involving carbothermal reduction and nitridation of vanadium pentoxide or vanadium trioxide as raw materials. This production method requires the addition of a large amount of a carbonaceous reducing agent for deoxidation, producing carbon monoxide during the reaction. This elevated carbon monoxide partial pressure within the kiln is detrimental to the carbothermal reduction reaction. Therefore, during production, the kiln temperature must be raised or the nitrogen flow rate increased to reduce the carbon monoxide concentration within the kiln. The higher the oxygen content in the vanadium-containing raw materials used to produce vanadium-nitrogen alloys, the greater the carbon content, the greater the burnout during calcination, and the lower the per-kiln output for the same kiln charge. The production of vanadium-nitrogen alloys using vanadium pentoxide or vanadium trioxide as raw materials suffers from a low per-kiln output. Therefore, there is a need to further develop a vanadium-nitrogen alloy production method that requires a low carbon content, low reaction temperature, short reaction time, and high per-kiln output.

[0003] Therefore, there is a need in the prior art for an improved method for producing vanadium nitrogen alloys. Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present invention is to propose a method for producing vanadium-nitrogen alloy using vanadium nitrogen oxide, which uses new raw materials to prepare vanadium-nitrogen alloy and innovates in process parameters such as batching method, temperature control, and calcination time, thereby achieving the purpose of reducing carbon content and carbon emissions, reducing reaction temperature and energy consumption, and increasing the processing capacity of a single kiln.

[0005] Based on the above objectives, an embodiment of the present invention provides a method for producing a vanadium-nitrogen alloy by using vanadium oxynitride, comprising the following steps:

[0006] a. Graphite powder and vanadium oxynitride are mixed in a ratio of K:1 by mass to obtain a mixture, wherein the oxygen content of the vanadium oxynitride is 4% to 20%. The oxygen content is divided into n intervals, and within each interval, the K value is proportional to the oxygen content.

[0007] b. adding the mixture to a wet mixer, spraying atomized water into the wet mixer and mixing the mixture to obtain an aqueous mixture;

[0008] c. Pressing the water-containing mixture into raw material blocks in a high-pressure pelletizing machine;

[0009] d. drying the raw material block in a drying kiln to obtain a dry raw material block;

[0010] e. Calcine the dried raw material block in a calcining kiln under a nitrogen atmosphere and cool it to obtain a vanadium-nitrogen alloy.

[0011] In some embodiments, in step a, n is 4, wherein:

[0012] In the first interval, the oxygen content (O%) in the vanadium oxynitride is 4% to 8%, and K = (0.780 to 0.785) O%;

[0013] In the second interval, the oxygen content (O%) in the vanadium oxynitride is 8% to 12%, and K = (0.775 to 0.780) O%;

[0014] In the third interval, the oxygen content (O%) in the vanadium oxynitride is 12% to 16%, and K = (0.765 to 0.775) O%;

[0015] In the fourth range, the oxygen content (O%) in the vanadium oxynitride is 16% to 20%, and K=(0.755 to 0.765)O%.

[0016] In some embodiments, in step a, vanadium oxynitride is prepared by reducing vanadium oxide with ammonia gas, and has a particle size of less than 125 μm. In terms of mass percentage, the vanadium oxynitride comprises 65-76% V, 10-20% N, and 4-20% O.

[0017] In some embodiments, in step a, the fixed carbon content in the graphite powder is ≥98%, and the particle size is less than 125 μm.

[0018] In some embodiments, in step b, the mixture is added to a wet mixer, the mixing is started, and atomized water is sprayed into the wet mixer until the moisture content in the mixture reaches 4% to 9%. The spraying of atomized water is stopped, and the mixing is continued for 15 to 25 minutes. The wet mixer is then turned off to obtain a water-containing mixture.

[0019] In some embodiments, in step c, the pressure in the high-pressure pelletizing machine is 6 to 30 MPa.

[0020] In some embodiments, in step d, the temperature of the drying kiln is 120-260° C., and the raw material blocks are dried until the moisture content of the raw material blocks is less than 0.6% to obtain dried raw material blocks.

[0021] In some embodiments, in step e, after calcining in a high temperature constant temperature zone of 930° C. to 1280° C. in a calcining kiln for 50 to 210 minutes, the dried raw material block is cooled to 50° C. to 160° C. before being taken out of the kiln to obtain a vanadium-nitrogen alloy.

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

[0023] This invention proposes a method for producing a vanadium-nitrogen alloy using vanadium oxynitride. This method utilizes a novel raw material for preparing the vanadium-nitrogen alloy. The vanadium oxynitride contains 65-76% V and 4-20% O. Compared to vanadium pentoxide and vanadium trioxide, vanadium oxynitride has a lower oxygen content and requires less carbon to prepare the vanadium-nitrogen alloy using this raw material. This reduces the carbon monoxide concentration in the kiln during calcination, allowing the reduction nitridation reaction to be completed at a lower temperature and in a shorter time. Furthermore, the calcination process for preparing the vanadium-nitrogen alloy using vanadium oxynitride reduces burnout, increasing kiln output while maintaining the same loading. While utilizing novel raw materials, this invention further innovates process parameters such as the batching method, temperature control, and calcination time, achieving the goals of reducing carbon content and carbon emissions, lowering reaction temperature and energy consumption, and increasing the processing capacity of a single kiln. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments.

[0025] The terms "including," "having," and any variations thereof, in the specification and claims of the present invention are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the specification and claims of the present invention are used to distinguish between different items, not to describe a particular order. "Multiple" means two or more, unless otherwise expressly specified.

[0026] Furthermore, references herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] The present invention provides a method for producing a vanadium-nitrogen alloy by utilizing vanadium oxynitride, comprising the following steps:

[0028] a. Graphite powder and vanadium oxynitride are mixed in a ratio of K:1 by mass to obtain a mixture, wherein the oxygen content of the vanadium oxynitride is 4% to 20%. The oxygen content is divided into n intervals, and within each interval, the K value is proportional to the oxygen content.

[0029] b. adding the mixture to a wet mixer, spraying atomized water into the wet mixer and mixing the mixture to obtain an aqueous mixture;

[0030] c. Pressing the water-containing mixture into raw material blocks in a high-pressure pelletizing machine;

[0031] d. drying the raw material block in a drying kiln to obtain a dry raw material block;

[0032] e. Calcine the dried raw material block in a calcining kiln under a nitrogen atmosphere and cool it to obtain a vanadium-nitrogen alloy.

[0033] Furthermore, in step a, the oxygen content is divided into four levels, i.e., n=4, specifically:

[0034] In the first interval, the oxygen content (O%) in the vanadium oxynitride is 4% to 8%, and K = (0.780 to 0.785) O%;

[0035] In the second interval, the oxygen content (O%) in the vanadium oxynitride is 8% to 12%, and K = (0.775 to 0.780) O%;

[0036] In the third interval, the oxygen content (O%) in the vanadium oxynitride is 12% to 16%, and K = (0.765 to 0.775) O%;

[0037] In the fourth range, the oxygen content (O%) in the vanadium oxynitride is 16% to 20%, and K=(0.755 to 0.765)O%.

[0038] The vanadium oxynitride used in the embodiment of the present invention has a low oxygen content, and is used as a vanadium raw material to prepare a vanadium-nitrogen alloy, and different carbon content is set based on the specific oxygen content range. Compared with traditional preparation methods, the method of the present invention has a low carbon content and small burn-off during the preparation process, which effectively increases the single kiln preparation output.

[0039] Furthermore, in step a, vanadium oxynitride is prepared by reducing vanadium oxide with ammonia gas, and has a particle size of less than 125 μm. The vanadium oxynitride comprises, by mass percentage, 65-76% V, 10-20% N, and 4-20% O. The graphite powder has a fixed carbon content of ≥98% and a particle size of less than 125 μm.

[0040] Furthermore, in step b, the mixture is added to a wet mixer, the mixing is started, and atomized water is sprayed into the wet mixer until the moisture content in the mixture reaches 4% to 9%. The spraying of atomized water is stopped, and the mixing is continued for 15 to 25 minutes, and then the wet mixer is turned off to obtain a water-containing mixture.

[0041] Furthermore, in step c, the pressure in the high-pressure ball press is 6 to 30 MPa.

[0042] Furthermore, in step d, the temperature of the drying kiln is 120-260° C., and the raw material blocks are dried until the moisture content of the raw material blocks is less than 0.6% to obtain dried raw material blocks.

[0043] Furthermore, in step e, after calcining in a high temperature constant temperature zone of 930° C. to 1280° C. in a calcining kiln for 50 to 210 minutes, the dried raw material block is cooled to 50° C. to 160° C. and then discharged from the kiln to obtain a vanadium-nitrogen alloy.

[0044] The specific implementation of the present invention is further described below based on specific examples.

[0045] Example 1

[0046] Vanadium-nitrogen alloys are produced using vanadium oxynitride containing 70.3% V, 14.8% N, and 14.1% O as raw material. Graphite powder and vanadium oxynitride are mixed in a mass ratio of 0.108:1 to produce a mixture. The mixture is then added to a wet mixer, which is then operated. Atomized water is sprayed into the mixer until the moisture content reaches 6%. The spraying of atomized water is stopped, and mixing is continued for 18 minutes. The wet mixer is then closed to produce a wet mixture. The wet mixture is then pressed into a briquette using a high-pressure briquette press at 15 MPa to form a raw material. The raw material is then dried in a drying kiln at 160°C to a moisture content of 0.4%, producing dried raw material. The dried raw material is then transferred to a calcining kiln, where it is calcined in a nitrogen atmosphere at a high-temperature constant temperature zone of 1070°C for 120 minutes. After cooling to 83°C, the vanadium-nitrogen alloy is produced.

[0047] Example 2

[0048] Vanadium-nitrogen alloys are produced using vanadium oxynitride containing 74.8% V, 16.3% N, and 8.2% O as raw material. Graphite powder and vanadium oxynitride are mixed in a mass ratio of 0.0636:1 to produce a mixture. The mixture is then added to a wet mixer, which is then operated. Atomized water is sprayed into the mixer until the moisture content reaches 8%. The spraying of atomized water is stopped, and mixing is continued for 22 minutes. The wet mixer is then closed to produce a wet mixture. The wet mixture is then pressed into a briquette using a high-pressure briquette press at 23 MPa to form a raw material. The raw material is then dried in a drying kiln at 210°C to a moisture content of 0.5%, producing dried raw material. The dried raw material is then transferred to a calcining kiln, where it is calcined in a nitrogen atmosphere at a high-temperature constant temperature zone of 980°C for 95 minutes. After cooling to 57°C, the vanadium-nitrogen alloy is produced.

[0049] Example 3

[0050] Vanadium-nitrogen alloys are produced using vanadium oxynitride containing 68.7% V, 12.6% N, and 17.9% O as raw material. Graphite powder and vanadium oxynitride are mixed in a mass ratio of 0.136:1 to produce a mixture. The mixture is then added to a wet mixer, which is then turned on and atomized water is sprayed into the mixer until the moisture content reaches 5%. The spraying of atomized water is then stopped, and mixing is continued for 23 minutes. The wet mixer is then turned off to produce a wet mixture. The wet mixture is then pressed into a briquette using a high-pressure briquette press at a pressure of 10 MPa to form a raw material. The raw material is then dried in a drying kiln at 140°C to a moisture content of 0.4%, producing dried raw material. The dried raw material is then transferred to a calcining kiln, where it is calcined in a nitrogen atmosphere at a high-temperature constant temperature zone of 1230°C for 150 minutes. After cooling to 130°C, the vanadium-nitrogen alloy is produced.

[0051] 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 of the embodiments disclosed 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 expressly limited to the singular.

[0052] It should be understood that, as used herein, the singular forms "a" and "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" is intended to include any and all possible combinations of one or more of the associated listed items.

[0053] 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.

[0054] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative 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. Within the spirit of the embodiments of the present invention, the technical features of the above embodiments or different embodiments may be combined, and there are many other variations of different aspects of the above embodiments of the present invention, 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 scope of protection of the embodiments of the present invention.

Claims

1. A method for producing a vanadium-nitrogen alloy by using vanadium oxynitride, characterized in that: include: a. In percentage by mass, the graphite powder and vanadium oxynitride were mixed in a ratio of K: 1 to obtain a mixture, wherein the oxygen content of the vanadium oxynitride was 4% to 20%, and the oxygen content was divided into n intervals. Within each interval, the K value was proportional to the oxygen content. b. adding the mixture to a wet mixer, spraying atomized water into the wet mixer and mixing to obtain an aqueous mixture; c. pressing the aqueous mixture into raw material blocks in a high-pressure pelletizing machine; d. drying the raw material block in a drying kiln to obtain a dry raw material block; e. calcining the dried raw material block in a calcining kiln under a nitrogen atmosphere and cooling to obtain a vanadium-nitrogen alloy; In step a, n is 4, wherein: In the first interval, the oxygen content (O%) in the vanadium oxynitride is 4% to 8%, and K=(0.780 to 0.785)0%; In the second range, the oxygen content (O%) in the vanadium oxynitride is 8% to 12%, and K=(0.775 to 0.780)O%; In the third range, the oxygen content (O%) in the vanadium oxynitride is 12% to 16%, and K=(0.765 to 0.775)O%; In the fourth range, the oxygen content (0%) in the vanadium oxynitride is 16%-20%, and K=(0.755-0.765)0%.

2. The method for producing a vanadium-nitrogen alloy by utilizing vanadium oxynitride according to claim 1, wherein: In step a, the vanadium oxynitride is prepared by reducing vanadium oxide with ammonia gas, and has a particle size of less than 125 μm. In terms of mass percentage, the vanadium oxynitride comprises 65-76% of V, 10-20% of N, and 4-20% of O.

3. The method for producing vanadium-nitrogen alloy by utilizing vanadium oxynitride according to claim 1, characterized in that: In step a, the fixed carbon content in the graphite powder is ≥98%, and the particle size is less than 125 μm.

4. The method for producing vanadium-nitrogen alloy by utilizing vanadium oxynitride according to claim 1, characterized in that: In step b, the mixture is added to the wet mixer, mixing is started, and atomized water is sprayed into the wet mixer until the moisture content of the mixture reaches 4% to 9%. Then, the spraying of the atomized water is stopped, mixing is continued for 15 to 25 minutes, and the wet mixer is turned off to obtain a water-containing mixture.

5. The method for producing vanadium-nitrogen alloy by utilizing vanadium oxynitride according to claim 1, characterized in that: In step c, the pressure in the high-pressure ball press is 6~30MPa.

6. The method for producing vanadium-nitrogen alloy by utilizing vanadium oxynitride according to claim 1, characterized in that: In step d, the temperature of the drying kiln is 120-260° C., and the raw material blocks are dried until the moisture content of the raw material blocks is less than 0.6% to obtain dried raw material blocks.

7. The method for producing vanadium-nitrogen alloy by utilizing vanadium oxynitride according to claim 1, characterized in that: In step e, after calcining in a high temperature constant temperature zone of 930° C. to 1280° C. in the calcining kiln for 50 to 210 minutes, the dried raw material block is cooled to 50° C. to 160° C. and then taken out of the kiln to obtain a vanadium-nitrogen alloy.