阅读说明：本技术 一种纳米晶氮化钒粉体的制备方法 (Preparation method of nanocrystalline vanadium nitride powder ) 是由 张春雨 于 2019-12-19 设计创作，主要内容包括：一种纳米晶氮化钒粉体的制备方法,该方法是通过将钒源氢化后,然后用机械破碎方法将氢化后的钒源破碎成到一定的粒度,通过等离子雾化制粉设备的高温条件下进行脱氢和气化,然后在液氩的急冷作用下迅速冷凝成纳米钒粉,接着在氮气环境下进行钝化反应,最后生产出纳米晶氮化钒粉体。整个工艺生产成本低,工艺时间短,易于实现工业化生产。(A process for preparing the nano-crystal vanadium nitride powder includes such steps as hydrogenating the vanadium source, mechanical breaking to a certain granularity, dehydrogenating and gasifying at high temp by plasma atomizing powder preparing apparatus, quickly condensing under the action of liquid argon to obtain nano-crystal vanadium nitride powder, passivating in nitrogen atmosphere, and finally preparing the nano-crystal vanadium nitride powder. The whole process has low production cost and short process time, and is easy to realize industrial production.)

1. A preparation method of nanocrystalline vanadium nitride powder is characterized by comprising the following steps:

the method comprises the following steps: adding a vanadium source into a vacuum hydrogenation furnace, vacuumizing the vacuum hydrogenation furnace to 10Pa, introducing hydrogen into the vacuum hydrogenation furnace, heating to 450-580 ℃, controlling the pressure of the hydrogen in the furnace to be 0.1-0.12 Mpa all the time, and carrying out hydrogenation treatment for 3-5 hours to obtain vanadium hydride;

step two: crushing the vanadium hydride prepared in the step one by using mechanical crushing equipment under the protection of inert gas atmosphere, and then sieving the crushed vanadium hydride by using a 325-mesh sieve to prepare-325-mesh vanadium hydride powder;

step three: introducing the-325-mesh vanadium hydride powder prepared in the step two into 100KW plasma atomization powder making equipment by taking argon as carrier gas, controlling the feeding speed to be 2-5KG/H, introducing the argon as protective gas into an atomization chamber of the plasma atomization powder making equipment, generating a plasma torch by taking the argon as plasma generating gas by the plasma atomization powder making equipment, and instantly dehydrogenating the-325-mesh vanadium hydride powder at the high temperature of the plasma torch and quickly gasifying the powder to form vanadium steam; then introducing liquid argon into the atomizing chamber, and instantly condensing and crystallizing vanadium steam under the rapid cooling of the liquid argon to form nano vanadium powder, and dropping the nano vanadium powder into a powder collecting cylinder at the lower end of the plasma atomization powder-making equipment; the average particle size of the formed vanadium powder is 30-100 nm;

step four: and (3) taking down the powder collecting cylinder in the third step, continuously introducing nitrogen from the bottom of the powder collecting cylinder to ensure that the nano vanadium powder in the cylinder is always in a boiling rolling state under the flushing of nitrogen airflow, controlling the pressure of the nitrogen in the cylinder to be 0.1-0.15 Mpa, and finally passivating the nano vanadium powder by the nitrogen after 2-4 hours to form nano-crystal vanadium nitride powder, then packaging the nano-crystal vanadium nitride powder, and introducing the nitrogen as protective gas.

2. The method for preparing the nanocrystalline vanadium nitride powder of claim 1, wherein in the first step, the vanadium source is at least one of sponge vanadium, vanadium lumps, and vanadium filaments.

3. The method for preparing the nanocrystalline vanadium nitride powder according to claim 1 or 2, wherein in the second step, the mechanical crushing method is one of ball milling crushing and airflow crushing.

4. The method for preparing the nanocrystalline vanadium nitride powder according to claim 1 or 2, wherein in the third step, the plasma atomization powder manufacturing device is one of a radio frequency plasma atomization powder manufacturing device, a microwave plasma atomization powder manufacturing device and a high-frequency induction plasma atomization powder manufacturing device.

5. The method for preparing the nanocrystalline vanadium nitride powder according to claim 1 or 2, wherein in the fourth step, the temperature of the introduced nitrogen is 0-200 ℃.

6. The method for preparing the nanocrystalline vanadium nitride powder according to claim 1 or 2, wherein the powder collecting barrel in the fourth step is fixed on a rolling device, and the powder collecting barrel is continuously rolled.

7. The method for preparing the nanocrystalline vanadium nitride powder according to claim 1 or 2, wherein in the second step, the inert gas is argon.

Technical Field

The invention relates to a preparation method of nanocrystalline vanadium nitride powder, belonging to the technical field of vanadium-nitrogen alloys and the field of nano materials.

Background

Vanadium Nitride (VN), also known as vanadium-nitrogen alloy, belongs to a novel alloy, and as a transition metal nitride, it has unique advantages in the aspects of theoretical specific capacity, electronic conductivity, chemical stability, anti-poisoning performance, electrochemical potential window range, comprehensive mechanical properties, and the like, and is widely applied to the fields of supercapacitors, catalysis, lithium electrochemistry, and the like.

Compared with micron-sized vanadium nitride, the nano vanadium nitride has the following advantages: 1. the sintering temperature of some materials can be reduced, and the sintering performance is improved; 2. the reinforcing phase can effectively improve the strength and the wear resistance of metal and ceramic matrixes; 3. as a catalyst, the catalyst has higher catalytic activity; 4. as a superconducting material, the superconducting material has higher superconducting performance. Therefore, the nano vanadium nitride has wide application prospect.

The traditional nitriding process of the metal vanadium is extremely complex, the metal powder needs to be ground to be less than 300 meshes and reacts for a long time at high temperature, and even if a microwave plasma combined method is applied, after the reaction is carried out for 3 hours, the reactants need to be ground and then react for 3 hours, so that the phase-pure vanadium nitride can be obtained. In industry, vanadium nitride usually adopts V2O5 and carbon as raw materials, and micron-sized vanadium nitride can be obtained by carrying out reduction nitridation reaction at 1250 ℃ in a nitrogen atmosphere. Impure vanadium nitrides can only be obtained by reacting metallic vanadium powder with Li3N, Ca3N2 or Mg3N2 in a nitrogen atmosphere. By applying the alkali metal or alkaline earth metal nitrifying agent and VCl2 or VCl3 to carry out solid-solid double decomposition reaction under the vacuum condition or carrying out liquid-solid double decomposition reaction by using VCl4, VN can be prepared under the mild condition (400-900 ℃), but the reaction raw materials are expensive and only micron-sized vanadium nitride can be obtained.

Disclosure of Invention

The invention aims to solve the technical problems, overcomes the defects of low yield, complex process, harsh preparation conditions and the like in the process of preparing the nanocrystalline vanadium nitride powder in the prior art, and provides the method for preparing the nanocrystalline vanadium nitride powder, which has the advantages of low production cost, short process time and easy realization of industrial production.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the preparation method of the nanocrystalline vanadium nitride powder comprises the following steps:

the method comprises the following steps: adding a vanadium source into a vacuum hydrogenation furnace, vacuumizing the vacuum hydrogenation furnace to 10Pa, introducing hydrogen into the vacuum hydrogenation furnace, heating to 450-580 ℃, controlling the pressure of the hydrogen in the vacuum hydrogenation furnace to be 0.1-0.12 Mpa all the time, carrying out hydrogenation treatment for 3-5 hours, and obtaining vanadium hydride after the reaction is finished;

step two: crushing the vanadium hydride prepared in the step one by using a mechanical crushing device under the protection of inert gas atmosphere, and then sieving the crushed vanadium hydride by using a 325-mesh sieve to prepare-325-mesh vanadium hydride powder (namely the particle size is smaller than 325 meshes);

step three: introducing the-325-mesh vanadium hydride powder prepared in the step two into 100KW plasma atomization powder making equipment by taking argon as carrier gas, controlling the feeding speed to be 2-5KG/H, introducing the argon as protective gas into an atomization chamber of the plasma atomization powder making equipment, generating a plasma torch by taking the argon as plasma generating gas by the plasma atomization powder making equipment, and instantly dehydrogenating the-325-mesh vanadium hydride powder at the high temperature of the plasma torch and quickly gasifying the powder to form vanadium steam; and then introducing liquid argon into the atomizing chamber, and under the rapid cooling of the liquid argon, instantly condensing and crystallizing the vanadium steam to form nano vanadium powder, and falling into a powder collecting cylinder at the lower end of the plasma atomization powder preparation device. Through detection, the average particle size of the formed vanadium powder is 30-100 nm;

step four: and (3) taking down the powder collecting cylinder in the third step, continuously introducing nitrogen from the bottom of the powder collecting cylinder to ensure that the nano vanadium powder in the cylinder is always in a boiling rolling state under the flushing of nitrogen airflow, controlling the pressure of the nitrogen in the cylinder to be 0.1-0.15 Mpa, and finally completely passivating the nano vanadium powder by the nitrogen after 2-4 hours to form nano-crystal vanadium nitride powder, then packaging the nano-crystal vanadium nitride powder, and introducing the nitrogen as protective gas.

The obtained nano vanadium powder has very small particles and large specific surface area, the surface of the nano vanadium powder is converted into vanadium nitride by absorbing nitrogen, and the vanadium nitride is generated by completely absorbing nitrogen by utilizing the active property of the nano powder.

Preferably, in the first step, the vanadium source is at least one of sponge vanadium, vanadium block and vanadium wire.

Preferably, in the second step, the mechanical crushing method is one of ball milling and airflow crushing.

Preferably, in step two, the inert gas is argon.

Preferably, in the third step, the plasma atomization powder making device is one of a radio frequency plasma atomization powder making device, a microwave plasma atomization powder making device and a high-frequency induction plasma atomization powder making device.

Preferably, in the fourth step, the temperature of the nitrogen gas is 0-200 ℃.

Preferably, the powder collecting cylinder in the fourth step is fixed on a rolling device, and the powder collecting cylinder is continuously rolled.

The invention has the beneficial effects that:

according to the preparation method of the nanocrystalline vanadium nitride powder, the hydrogen brittleness characteristic of vanadium is utilized, a vanadium source absorbing hydrogen easily forms micron-sized vanadium hydride powder under a mechanical crushing method, then the vanadium hydride powder is easily dehydrogenated and gasified at the high temperature of a plasma torch, and the nano vanadium powder is formed under the cooling of liquid argon, and finally the nano vanadium powder is easily passivated by nitrogen to form the nanocrystalline vanadium nitride powder due to larger specific surface area and larger activity. The preparation method of the nanocrystalline vanadium nitride powder has the advantages of low production cost, short process time and easy realization of industrial production.

Detailed Description

The present invention will be described in further detail with reference to specific examples.