CN111003696B - Preparation method of nano zirconium nitride powder - Google Patents

Abstract

A preparation method of nano zirconium nitride powder relates to the technical field of preparation of high melting point nitride powder. The zirconium dioxide is pretreated, the zirconium nitride is prepared by chemical vapor deposition, and finally the nano-zirconium nitride powder is obtained by grinding and classifying. Before the preparation of zirconium nitride, zirconium dioxide needs to be pretreated, and the surface of the zirconium dioxide powder is polished with the silica sol obtained by the reaction, which can obtain a relatively smooth surface and improve its reactivity, which is more conducive to the subsequent Generation of high-purity zirconium nitride powder. The invention realizes the preparation of high-purity nano-zirconium nitride powder, has the advantages of simple process, low cost, uniform product particle size distribution and high product purity, and can be used for large-scale production.

Description

A kind of preparation method of nanometer zirconium nitride powder

technical field

The invention relates to the technical field of preparation of high melting point nitride powder, in particular to a preparation method of nano zirconium nitride powder.

Background technique

Nitride powders with high melting point, high hardness, high chemical stability and excellent electrical and optical properties have attracted widespread attention. The unique physical and chemical properties make these nitrides have a wide range of applications in semiconductor devices, microelectronics, porous ceramics and other fields.

ZrN is a refractory hard compound with high decomposition temperature and good chemical stability, so it has good high temperature resistance, corrosion resistance and wear resistance. It is a good high temperature structural material, superhard tool material and surface protection material. ZrN films have a favored lower-brightness golden color and are suitable for applications where titanium nitride is less suitable for coating, with high corrosion resistance, good smooth surface, and ductility. Widely used in hardware, building materials, sanitary ware and other daily hardware workpieces. It has been widely used in architectural decoration, home appliances, watches, jewelry, mobile phones and other fields, so it has become a research object that the decorative coating industry attaches great importance to.

At present, the preparation of zirconium nitride powder mainly includes conventional methods for synthesizing nitrides such as solid-phase reaction synthesis and gas-phase reaction synthesis, among which reduction nitridation method and chemical vapor deposition (CVD) method are commonly used preparation methods. The reductive nitridation method uses ammonia gas and metal oxides as the main raw materials to prepare nitride powder. Chemical vapor deposition (CVD) is to introduce metals and metal volatile compounds (halides or alkyl compounds) from _N2 atmosphere into the reaction chamber and react with _NH3 to obtain nitride crystal grains from the vapor phase, and then aggregate into nitrogen. Compound powder. However, the zirconium nitride powder prepared by the above method also has many shortcomings and defects, such as the need to prepare reactant precursors with suitable size and structure, the purity of the powder obtained by the reaction is not high, and environmental problems are easy to occur.

SUMMARY OF THE INVENTION

In view of the above-mentioned shortcomings such as impure product, difficult reaction control, and uneven particle size distribution in the preparation of zirconium nitride powder, the present invention provides a preparation method of nano-zirconium nitride powder, which has the advantages of simple operation, small product size and the like. It has the advantages of controllable diameter distribution and high purity.

In order to achieve the above purpose, the technical scheme adopted in the present invention is as follows: a preparation method of nanometer zirconium nitride powder, pretreatment of zirconium dioxide, preparation of zirconium nitride by chemical vapor deposition method, and finally obtaining nanometer zirconium nitride by grinding and classification Zirconium nitride powder.

As a preferred technical solution of the present invention, the step of pre-processing the zirconium dioxide is as follows:

First, add absolute ethanol to the zirconium dioxide, and ultrasonically disperse; the weight ratio of zirconium dioxide and absolute ethanol is 1:15-25; then add silane coupling agent KH-792 and polyvinyl alcohol, and heat up to 40- The reaction is stirred at 80°C for 10 to 30 hours; the weight ratio of zirconium dioxide, silane coupling agent KH-792 and polyvinyl alcohol is 1:2 to 5:1 to 3; after the reaction, it is left to stand for 10 to 30 hours. , solid-liquid separation and drying to obtain pretreated zirconium dioxide.

As a preferred technical solution of the present invention, the step of preparing zirconium nitride by chemical vapor deposition is as follows:

The reactor is divided into a heating zone, a high temperature zone and a cooling zone. The temperatures of the heating zone and the high temperature zone are respectively: 200-500°C and 800-1100°C; the heating zone, the high temperature zone and the cooling zone are continuously fed with argon. Ammonia gas is introduced into the zone; the mixed powder of zirconium dioxide and magnesium powder enters the heating zone of the reactor through automatic feeding equipment, and stays for 1 to 5 minutes, and then continues to advance to the high temperature zone, and stays for 10 to 30 minutes; After the reaction is completed, leave the high temperature zone and enter the cooling zone to cool down; after cooling to room temperature, a mixture of zirconium nitride and magnesium nitride is obtained; the mixture is washed with acid and alcohol to remove magnesium nitride, and then dried to obtain zirconium nitride powder body.

Further, the weight ratio of ammonia gas to zirconium dioxide is 4-10:1.

Further, the weight ratio of zirconium dioxide and magnesium powder is 1:2-5.

As a preferred technical solution of the present invention, the steps of obtaining nano-zirconium nitride powder by grinding and classifying are as follows:

Add the zirconium nitride powder to the grinding machine, add grinding balls, solvents and grinding aids; first control the stirring shaft of the stirring mill to keep the same direction and run at high speed for 10 to 20 minutes, so that the materials collide violently, and then change The rotation direction of the stirring shaft is reversed for 15-25 minutes, so that the zirconium nitride powder is further ground, and then classified to obtain nano-zirconium nitride powder with uniform particle size distribution.

Further, the solvent and grinding aid added in the grinding machine are ethanol and quartz sand respectively.

Further, the weight ratio of material balls in the grinding machine is 1:3-5, and the weight ratio of zirconium nitride powder, solvent and grinding aid is 1:3-5:2-6.

Compared with the prior art, the beneficial effects of the present invention are shown in:

1) The preparation of high-purity nano-zirconium nitride powder is realized, which has the advantages of simple process, low cost, uniform product particle size distribution and high product purity, and can be used for large-scale production.

2) Before preparing zirconium nitride, zirconium dioxide needs to be pretreated, and the surface of the zirconium dioxide powder can be polished by the silica sol obtained by the reaction, which can obtain a relatively smooth surface, improve its reactivity, and thus improve the efficiency of the reaction. It is beneficial to the subsequent generation of high-purity zirconium nitride powder. Completing the nitridation reduction reaction in an inert atmosphere can completely eliminate the influence of oxygen or air on the reaction process, and the sufficient amount of ammonia makes the zirconium dioxide react completely.

Description of drawings

Fig. 1 is the XRD pattern (a) and SEM pattern (b) of preparing zirconium nitride before grinding;

FIG. 2 is an SEM image of the prepared zirconium nitride after grinding.

Detailed ways

The invention provides a preparation method of nano-zirconium nitride powder. The zirconium dioxide is pretreated, the zirconium nitride is prepared by a chemical vapor deposition method, and finally the zirconium nitride powder is obtained by grinding and classifying. The steps are as follows:

1. The steps of pretreatment of zirconium dioxide are:

First, add anhydrous ethanol to the zirconium dioxide, and disperse by ultrasonic. The added weight ratio of zirconium dioxide and absolute ethanol is 1:15-25. Then, silane coupling agent KH-792 and polyvinyl alcohol were added, and the temperature was raised to 40-80° C. and stirred for reaction for 10-30 hours. Wherein, the added weight ratio of zirconium dioxide, silane coupling agent KH-792 and polyvinyl alcohol is 1:2-5:1-3. After the reaction is completed, it is left to stand for 10-30 hours, and the pretreated zirconium dioxide is obtained by drying after solid-liquid separation.

In order to improve the quality of the zirconium nitride preparation, the raw material, zirconium dioxide, needs to be pretreated before the preparation of zirconium nitride. surface, improving its reactivity, which is more conducive to the subsequent generation of high-purity zirconium nitride powder.

2. The steps of preparing zirconium nitride by chemical vapor deposition are:

The reactor is divided into a heating zone, a high temperature zone and a cooling zone, and the temperature of the heating zone and the high temperature zone are respectively 200-500°C and 800-1100°C. Argon gas is continuously fed into the heating zone, high temperature zone and cooling zone, while ammonia gas is fed into the high temperature zone.

The mixed powder of zirconium dioxide and magnesium powder enters the heating zone of the reactor through automatic feeding equipment, and stays for 1-5 minutes, and then continues to advance to the high-temperature zone, and stays for 10-30 minutes. The weight ratio of ammonia gas to zirconium dioxide is 4-10:1. The weight ratio of zirconium dioxide and magnesium powder is 1:2-5.

After the reaction, leave the high temperature zone and enter the cooling zone to cool down. After cooling to room temperature, a mixture of zirconium nitride and magnesium nitride is obtained. The mixture is washed with acid and alcohol to remove magnesium nitride, and then dried to obtain zirconium nitride powder.

It should be noted here that the reaction is a nitridation reduction reaction completed in an inert atmosphere, which can completely eliminate the influence of oxygen or air on the reaction process, and the ammonia gas is sufficient to make the zirconium dioxide react completely.

Fig. 1a is an XRD spectrum of the prepared zirconium nitride powder, and analysis shows that the reaction product is ZrN (XRD standard spectrum: ZrN standard spectrum). Figure 1b is the overall SEM image of the zirconium nitride powder. It can be seen that the powder exists in the form of a block, with a particle size exceeding 100 nm and an uneven distribution.

3. The steps of obtaining nano-zirconium nitride powder by grinding and grading are:

Add the zirconium nitride powder to the grinding machine, add the grinding ball, solvent and grinding aid. First, control the stirring shaft of the stirring mill to run at high speed in the same direction for 10 to 20 minutes, so that the materials collide violently, then change the rotation direction of the stirring shaft and run in reverse for 15 to 25 minutes, so that the zirconium nitride powder can be further Grinding and classifying to obtain nano-zirconium nitride powder with uniform particle size distribution.

The solvent and grinding aid added in the grinding machine are ethanol and quartz sand respectively. The weight ratio of material balls in the grinding machine is 1:3-5, and the weight ratio of zirconium nitride powder, solvent and grinding aid is 1:3-5:2-6.

Figure 2 is the SEM image of the zirconium nitride powder after grinding. It can be seen that the particle size distribution of the zirconium nitride powder after grinding is relatively uniform, and the average particle size is about 30 nm. After testing, the purity of the prepared nano-zirconium nitride powder reaches more than 99%.

The preparation method of the nano-zirconium nitride powder of the present invention is further described below with reference to the examples.

Example 1

The preparation of nano-zirconium nitride powder, the steps are as follows:

1. The steps of pretreatment of zirconium dioxide are:

First, add anhydrous ethanol to the zirconium dioxide, and disperse by ultrasonic. The added weight ratio of zirconium dioxide and absolute ethanol was 1:18. Next, silane coupling agent KH-792 and polyvinyl alcohol were added, and the temperature was raised to 75° C. and stirred for reaction for 15 hours. Among them, the added weight ratio of zirconium dioxide, silane coupling agent KH-792 and polyvinyl alcohol is 1:3:3. After the reaction was completed, it was allowed to stand for 15 hours, and the pretreated zirconium dioxide was obtained by drying after solid-liquid separation.

2. The steps of preparing zirconium nitride by chemical vapor deposition are:

The reactor is divided into a heating zone, a high temperature zone and a cooling zone. The temperature of the heating zone and the high temperature zone are respectively 500°C and 1000°C. Argon gas is continuously fed into the heating zone, high temperature zone and cooling zone, while ammonia gas is fed into the high temperature zone. The mixed powder of zirconium dioxide and magnesium powder enters the heating zone of the reactor through automatic feeding equipment, and stays for 3 minutes, and then continues to advance to the high temperature zone, and stays for 10 minutes. The weight ratio of ammonia gas to zirconium dioxide was 8:1. The weight ratio of zirconium dioxide and magnesium powder is 1:3. After the reaction, leave the high temperature zone and enter the cooling zone to cool down. After cooling to room temperature, a mixture of zirconium nitride and magnesium nitride is obtained. The mixture is washed with acid and alcohol to remove magnesium nitride, and then dried to obtain zirconium nitride powder.

3. The steps to obtain zirconium nitride powder by grinding and grading are:

Add the zirconium nitride powder to the grinding machine, add the grinding ball, solvent and grinding aid. First, control the stirring shaft of the stirring mill to run at high speed in the same direction for 15 minutes, so that the materials collide violently, then change the rotation direction of the stirring shaft and run in reverse for 15 minutes to further grind the zirconium nitride powder, and then classify A zirconium nitride powder with uniform particle size distribution was obtained. The solvent and grinding aid added in the grinding machine are ethanol and quartz sand respectively. The weight ratio of material balls in the grinding machine is 1:4, and the weight ratio of zirconium nitride powder, solvent and grinding aid is 1:5:3.

Example 2

The preparation of nano-zirconium nitride powder, the steps are as follows:

1. The steps of pretreatment of zirconium dioxide are:

First, add anhydrous ethanol to the zirconium dioxide, and disperse by ultrasonic. The added weight ratio of zirconium dioxide and absolute ethanol was 1:22. Next, silane coupling agent KH-792 and polyvinyl alcohol were added, and the temperature was raised to 55° C. and stirred for reaction for 25 hours. The added weight ratio of zirconium dioxide, silane coupling agent KH-792 and polyvinyl alcohol is 1:2:1. After the reaction was completed, it was left to stand for 20 hours, and the pretreated zirconium dioxide was obtained by drying after solid-liquid separation.

2. The steps of preparing zirconium nitride by chemical vapor deposition are:

The reactor is divided into a heating zone, a high temperature zone and a cooling zone. The temperature of the heating zone and the high temperature zone are respectively 400°C and 800°C. Argon gas is continuously fed into the heating zone, high temperature zone and cooling zone, while ammonia gas is fed into the high temperature zone. The mixed powder of zirconium dioxide and magnesium powder enters the heating zone of the reactor through automatic feeding equipment, and stays for 5 minutes, and then continues to advance to the high temperature zone and stays for 30 minutes. The weight ratio of ammonia gas to zirconium dioxide was 5:1. The weight ratio of zirconium dioxide and magnesium powder is 1:5. After the reaction, leave the high temperature zone and enter the cooling zone to cool down. After cooling to room temperature, a mixture of zirconium nitride and magnesium nitride is obtained. The mixture is washed with acid and alcohol to remove magnesium nitride, and then dried to obtain zirconium nitride powder.

3. The steps to obtain zirconium nitride powder by grinding and grading are:

Add the zirconium nitride powder to the grinding machine, add the grinding ball, solvent and grinding aid. First, control the stirring shaft of the stirring mill to run at high speed in the same direction for 10 minutes, so that the materials collide violently, then change the rotation direction of the stirring shaft and run in reverse for 20 minutes to further grind the zirconium nitride powder, and then classify A zirconium nitride powder with uniform particle size distribution was obtained. The solvent and grinding aid added in the grinding machine are ethanol and quartz sand respectively. The weight ratio of material balls in the grinding machine is 1:5, and the weight ratio of zirconium nitride powder, solvent and grinding aid is 1:3:6.

Example 3

The preparation of nano-zirconium nitride powder, the steps are as follows:

1. The steps of pretreatment of zirconium dioxide are:

First, add anhydrous ethanol to the zirconium dioxide, and disperse by ultrasonic. The added weight ratio of zirconium dioxide and absolute ethanol is 1:20. Next, silane coupling agent KH-792 and polyvinyl alcohol were added, and the temperature was raised to 45° C. and stirred for reaction for 30 hours. Among them, the added weight ratio of zirconium dioxide, silane coupling agent KH-792 and polyvinyl alcohol is 1:5:1. After the reaction was completed, it was allowed to stand for 30 hours, and the pretreated zirconium dioxide was obtained by drying after solid-liquid separation.

2. The steps of preparing zirconium nitride by chemical vapor deposition are:

The reactor is divided into a heating zone, a high temperature zone and a cooling zone. The temperature of the heating zone and the high temperature zone are respectively 300°C and 900°C. Argon gas is continuously fed into the heating zone, high temperature zone and cooling zone, while ammonia gas is fed into the high temperature zone. The mixed powder of zirconium dioxide and magnesium powder was introduced into the heating zone of the reactor through automatic feeding equipment, and stayed for 4 minutes, and then continued to advance to the high temperature zone and stayed for 25 minutes. The weight ratio of ammonia gas to zirconium dioxide was 10:1. The weight ratio of zirconium dioxide and magnesium powder is 1:2. After the reaction, leave the high temperature zone and enter the cooling zone to cool down. After cooling to room temperature, a mixture of zirconium nitride and magnesium nitride is obtained. The mixture is washed with acid and alcohol to remove magnesium nitride, and then dried to obtain zirconium nitride powder.

3. The steps to obtain zirconium nitride powder by grinding and grading are:

Add the zirconium nitride powder to the grinding machine, add the grinding ball, solvent and grinding aid. First, control the stirring shaft of the stirring mill to run at high speed in the same direction for 10 minutes, so that the materials collide violently, then change the rotation direction of the stirring shaft and run in reverse for 25 minutes to further grind the zirconium nitride powder, and then classify A zirconium nitride powder with uniform particle size distribution was obtained. The solvent and grinding aid added in the grinding machine are ethanol and quartz sand respectively. The weight ratio of material balls in the grinding machine is 1:3, and the weight ratio of zirconium nitride powder, solvent and grinding aid is 1:4:4.

The above content is only an example and description of the concept of the present invention. Those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them in a similar manner, as long as they do not deviate from the concept of the invention. Or beyond the scope defined by the claims, all belong to the protection scope of the present invention.

Claims (1)

1. A process for preparing zirconium nitride nanoparticles includes such steps as pretreating zirconium dioxide, preparing zirconium nitride by chemical gas-phase deposition, grinding and classifying,

the pretreatment of zirconium dioxide comprises the following steps:

firstly, adding absolute ethyl alcohol into zirconium dioxide, and performing ultrasonic dispersion; the weight ratio of the added zirconium dioxide to the absolute ethyl alcohol is 1: 15-25; then adding a silane coupling agent KH-792 and polyvinyl alcohol, heating to 40-80 ℃, and stirring for reaction for 10-30 hours; wherein the adding weight ratio of the zirconium dioxide to the silane coupling agent KH-792 to the polyvinyl alcohol is 1: 2-5: 1-3; standing and aging for 10-30 h after the reaction is finished, and drying after solid-liquid separation to obtain pretreated zirconium dioxide;

preparing zirconium nitride by a chemical vapor deposition method, which comprises the following steps:

the reactor is divided into a heating area, a high-temperature area and a cooling area, wherein the temperatures of the heating area and the high-temperature area are respectively as follows: 200-500 ℃ and 800-1100 ℃; continuously introducing argon into the heating area, the high-temperature area and the cooling area, and simultaneously introducing ammonia gas into the high-temperature area; enabling the mixed powder of zirconium dioxide and magnesium powder to enter a heating area of a reactor through automatic feeding equipment, staying for 1-5 minutes, then continuing to advance to a high-temperature area, and staying for 10-30 minutes; leaving the high-temperature area after the reaction is finished, and entering a cooling area for cooling; cooling to room temperature to obtain a mixture of zirconium nitride and magnesium nitride; removing magnesium nitride from the mixture through acid washing and alcohol washing, and then drying to obtain zirconium nitride powder;

the weight ratio of the ammonia gas to the zirconium dioxide is 4-10: 1, the weight ratio of zirconium dioxide to magnesium powder is 1: 2-5;

the step of obtaining the nano zirconium nitride powder by grinding and grading comprises the following steps:

adding zirconium nitride powder into a grinding machine, and adding a grinding ball, a solvent and a grinding aid; firstly, controlling a stirring shaft of a stirring mill to keep high-speed running for 10-20 minutes in the same direction, so that violent collision is generated between materials, then changing the rotating direction of the stirring shaft, reversely running for 15-25 minutes at high speed, further grinding zirconium nitride powder, and then grading to obtain nano zirconium nitride powder with uniform particle size distribution;

the solvent and the grinding aid added into the grinding machine are respectively ethanol and quartz sand, and the weight ratio of material balls in the grinding machine is 1: 3-5, wherein the weight ratio of the zirconium nitride powder, the solvent and the grinding aid is 1: 3-5: 2 to 6.

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