KR102114106B1 - Preparation of tungsten nanoparticles - Google Patents

Abstract

The present invention relates to a method for producing tungsten nanoparticles, which includes a tungsten precursor synthesis step of preparing tungsten precursor by adding tungsten to a strong acid solution; A mixing step of mixing sodium oleate with a tungsten precursor; A drying step of drying the mixed material; A heating step of heating the dried mixture; And washing and filtration steps of washing and filtering using distilled water.

Description

Manufacturing method of tungsten nanoparticles {Preparation of tungsten nanoparticles}

The present invention relates to a method for producing tungsten nanoparticles, and more particularly, to a method for producing tungsten nanoparticles capable of efficiently extracting tungsten from semiconductor waste.

Since a high temperature process is required in a semiconductor process, tungsten that is resistant to high temperatures is often used. However, due to the short lifespan of high-temperature process equipment, there are many waste equipment.

On the other hand, tungsten-based nanoparticles of uniform size and tungsten-based compound-carbon nanocomposites containing tungsten-based nanoparticles have been actively studied for their synthesis methods due to various industrial applications such as battery electronics, mechanical processes, and catalysts. Is going on. In addition, the development of tungsten-based nanoparticles containing tungsten-based nanoparticles and tungsten-based nanoparticles of various sizes for various industrial applications such as uniform battery electronics, mechanical processes, and catalysts is actively underway.

Recently, these tungsten-based nanoparticles have electrical explosion of wires method, high energy ball milling method using WO3 and Mg as starting materials, molten salt assisted self-propagating high frequency heating method, physical vapor deposition method, gas phase combustion synthesis method, WCl6 and Si There is a method of synthesizing a sealed tube using a chemical reduction method. The size and shape of the particles can be controlled by adjusting synthetic parameters such as the molar ratio of stabilizer to metal precursor, heating time and temperature.

However, these methods are difficult to control the size of the nanoparticles, and because of the high temperature heat treatment process, crystal growth and agglomeration of the nanomaterial based on the tans occur, thus showing limitations in the production of uniform size particles, as well as the multi-step process. It is pointed out that there is a disadvantage in that the manufacturing cost is high because it is manufactured through and is unsuitable for mass synthesis.

In order to prevent such side effects, a wrap-bake-peel method was recently devised to prevent the nanoparticles from agglomerating during the heat treatment process. However, since the method is also manufactured through a complicated process, problems that are time-consuming and high in manufacturing cost still remain.

The present invention is to provide a manufacturing process capable of manufacturing tungsten-based nanoparticles by recycling tungsten in a waste equipment, in order to solve the problems of the prior art described above.

In addition, an object of the present invention is to provide tungsten-based nanoparticles having a uniform size of nanopowders having excellent properties such as structure and catalytic activity.

According to an aspect of the present invention, a tungsten precursor synthesis step of preparing a tungsten precursor by adding tungsten to a strong acid solution; A mixing step of mixing sodium oleate with a tungsten precursor; A drying step of drying the mixed material; A heating step of heating the dried mixture; And washing and filtration steps of washing and filtering using distilled water.

In addition, according to the present invention, in the step of synthesizing the tungsten precursor, the strong acid solution provides a method for producing tungsten nanoparticles, which is produced by mixing hydrochloric acid and nitric acid.

In addition, according to the present invention, by adding water in the mixing step to provide a method for producing tungsten nanoparticles, characterized in that to help the combination of tungsten ions and sodium oleate.

In addition, according to the present invention, drying in the drying step provides a method for producing tungsten nanoparticles, characterized in that drying at 90 to 100°C.

In addition, according to the present invention, in the heating step Na ₂ SO ₄ , K ₂ SO ₄ , NaCl, KCl, Na ₂ CO ₃ , Li ₂ CO ₃ , K ₂ CO ₃ , any one salt of CaCl ₂ (Salt) It provides a method for producing tungsten nanoparticles characterized by mixing.

In addition, according to the present invention, by providing the salt (Salt) is mixed tungsten nanoparticles to provide a method for producing tungsten nanoparticles, characterized in that produced in a thin two-dimensional form.

In addition, according to the present invention, there is provided a method for producing tungsten nanoparticles characterized in that it is carried out in any one of a nitrogen atmosphere, a reducing atmosphere and an air atmosphere in the heating step.

In addition, according to the present invention, there is provided a method for producing tungsten nanoparticles, characterized in that tungsten oxide-carbon nanoparticles under the nitrogen atmosphere, tungsten-carbon nanoparticles under the reducing atmosphere, and tungsten oxide particles are produced under the air atmosphere.

According to an embodiment of the present invention, by manufacturing tungsten-based nanoparticles by recycling tungsten in the waste equipment, it is possible to reduce manufacturing cost and enable mass synthesis.

In addition, according to an embodiment of the present invention, tungsten in a waste equipment is recycled to synthesize precursors and heat treatment to produce tungsten-based nanoparticles having excellent crystallinity and uniform size. This not only synthesizes tungsten nanoparticles, but also simultaneously carbonizes a surfactant of sodium oleate to produce carbon nanocomposites, and can be mass-produced to apply to various industrial applications such as actual battery electronics, mechanical processes, and catalysts. This is possible.

In addition, when the mixture of tungsten precursor and sodium oleate is heat-treated with a salt, a carbon composite material in the form of a thin paper can be produced. It is expected that such a thin paper-like composite material has excellent properties such as structure and catalytic activity.

1 shows a tungsten nanoparticle manufacturing process diagram according to an embodiment of the present invention.
Figure 2 schematically shows a tungsten nanoparticle manufacturing process according to an embodiment of the present invention.
3 shows the chemical formula of tungsten-oleate.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be interpreted as being limited to the following embodiments. This embodiment is provided to more fully describe the present invention to those skilled in the art. Therefore, the shape of the elements in the drawings has been exaggerated to emphasize a clearer explanation.

1 shows a tungsten nanoparticle manufacturing process diagram according to an embodiment of the present invention, and FIG. 2 schematically shows a tungsten nanoparticle manufacturing process according to an embodiment of the present invention.

The present invention relates to a method for recovering tungsten from used semiconductor equipment to produce tungsten nanoparticles, a tungsten precursor synthesis step of preparing tungsten precursor by adding tungsten to a strong acid solution; A mixing step of mixing sodium oleate with the liquefied material; A drying step of drying the mixed material; A heating step of heating the dried mixture; And washing and filtration steps of washing and filtering using distilled water, and a method of manufacturing nanoparticles step by step with reference to FIGS. 1 and 2 will be described.

(1) Tungsten precursor synthesis step

Tungsten obtained from semiconductor equipment is synthesized as a tungsten precursor.

Tungsten obtained from semiconductor equipment is a metal-type tungsten that has a high melting point, which makes it difficult to separate it. Accordingly, it can be obtained by converting to tungsten nanomaterial through a simple process through a chemical reaction. To this end, the tungsten metal obtained from the used semiconductor equipment is first liquefied.

For the liquefaction of tungsten, tungsten can be ionized using a strong acid solution. That is, the tungsten of the metal can be changed to an ionized state.

The strong acid solution used at this time is used by mixing hydrochloric acid and nitric acid at a mass ratio of about 3:1.

The liquefied material is dried by vacuum drying in an oven, etc., and the tungsten ion reacts with the strong acid solution material to synthesize the tungsten precursor material.

When drying in an oven vacuum, the powder is tungsten precursor is synthesized by removing moisture while drying at a temperature of about 100°C.

(2) Mixing step

In the mixing step, sodium oleate is mixed with the synthesized tungsten precursor material.

The tungsten ion in the tungsten precursor is mixed with sodium oleate to combine with it to produce tungsten-oleate.

In addition, in the mixing step, water may be additionally mixed, and water may be mixed so that sodium oleate is well mixed with tungsten ions by making it a liquid phase.

The water acts as a solvent so that tungsten ions and sodium oleate are mixed well in the liquid phase.

The amount of water to be mixed can be mixed with a weight of about twice the amount of the tungsten precursor.

When the tungsten precursor and sodium oleate are mixed, the tungsten ion of the tungsten precursor is combined with the oleate of sodium oleate to form tungsten-oleate.

3 shows the chemical formula of tungsten-oleate.

3 may be formed of tungsten-oleate, which may be formed in a small size in nano form.

The amount of sodium oleate to be mixed may be mixed with the tungsten precursor material and sodium oleate in a weight ratio of about 1:2.

(3) Drying step

In the drying step, the tungsten ion in the tungsten precursor and sodium oleate are dried at a high temperature in order to bond well.

The drying temperature is desirably dried at 90 to 100°C. To this end, it is dried while maintaining a temperature of 90 to 100°C through a heating device such as an oven.

Drying does not completely dry the remaining material, but it is dried to a viscous state. Through drying, the strong acid solution material mixed in the tungsten precursor synthesis step may be removed.

The reason for drying at a high temperature of 90 to 100°C is to increase the solubility of sodium oleate and increase the binding force with tungsten ions.

In addition, water that has been mixed in the mixing step can be removed by maintaining it at a high temperature in the drying step.

(4) Heating step

After the drying step, there is a process of heating.

Tungsten nanoparticles may be produced by transforming them into two-dimensional shapes such as thin paper rather than nanoparticles.

To this end, a salt is mixed before heating, and one of Na ₂ SO ₄ , K ₂ SO ₄ , NaCl, KCl, Na ₂ CO ₃ , Li ₂ CO ₃ , K ₂ CO ₃ , and CaCl ₂ ( Salt) can be mixed and heated.

When the salt is mixed before the heating step, tungsten-oleate is coated on the salt to form tungsten-oleate in the form of nanoparticles, and when heated, the oleate is removed and tungsten in the form of nanoparticles Only a thin sheet is formed in a two-dimensional form.

When the salt (Salt) is mixed and heated together with tungsten-oleate, the tungsten of the nanoparticles does not stick or clump together, and thus has the advantage of being useful when recycling tungsten.

On the other hand, in the heating step, an atmosphere of any one of a nitrogen atmosphere, a reducing atmosphere, and an air atmosphere can be created to produce different types of tungsten. Heating temperature can be heated to 550 ~ 650 ℃.

When heated under a nitrogen atmosphere (N ₂ ), tungsten-oleate is formed of tungsten-carbon nanocomposites. Specifically, tungsten ions become tungsten oxide (WO ₃ ) and oleate groups are carbonized, leaving only carbon as a result. In addition, tungsten oxide (WO ₃ ) becomes a form in which carbon remaining in the oleate group is wrapped to form tungsten oxide-carbon nanoparticles. In this case, a two-dimensional sheet may be formed.

In addition, when heated in a reducing atmosphere, tungsten ions become tungsten metal (W), and oleate groups are carbonized, leaving only carbon. Tungsten-carbon particles surrounding the carbon remaining in the oleate group of tungsten metal (W) are formed, and a two-dimensional sheet is formed. The reducing atmosphere may be composed of, for example, 95% argon (Ar) and 5% hydrogen (H ₂ ).

In addition, when heated under an air atmosphere, oleate is removed, leaving only tungsten nanoparticles. That is, the tungsten ion becomes tungsten oxide (WO ₃ ) and the oleate group is carbonized, and then carbon and oxygen in the air combine to burn and disappear as CO ₂ . Therefore, only tungsten oxide remains as particles.

(5) Cleaning and filtration steps

After the heating step, a washing and filtering step may be performed.

Washing can be done through distilled water. When washed with distilled water, the tungsten nanoparticles remain solid and the rest are dissolved in distilled water. This can be filtered through only filtration of filter paper, such as tungsten nanoparticles.

On the other hand, when heated under a nitrogen atmosphere (N ₂ ) in the heating step, tungsten-carbon nanocomposites are formed, and when washed with distilled water, the tungsten-carbon nanocomposites remain in a solid state and the rest are dissolved in distilled water and filtered. Only tungsten-carbon nanocomposites can be filtered.

The filtered material is tungsten nanoparticles. Here, drying to remove water is additionally performed to obtain tungsten nanoparticles in powder form.

Hereinafter, embodiments of the present invention will be described in detail.

Example 1

After obtaining tungsten from the semiconductor waste equipment, it is dissolved in an acidic solution. The acidic solution is mixed with hydrochloric acid and nitric acid at a mass ratio of about 3:1 to melt tungsten and liquefy it.

The liquefied material is dried in an oven to remove moisture from the acidic solution to synthesize tungsten precursor.

Water and sodium oleate are mixed with the synthesized tungsten precursor, and the tungsten precursor, water, and sodium oleate are mixed in a weight ratio of 1:2:2.

After mixing and drying, it is put in an oven at 95°C and dried. After drying to a viscous state, it is heated. The heating condition is heated to about 600° C. for 3 hours under a nitrogen atmosphere.

After heating, it is washed with distilled water to acquire a solid material, which is obtained by filtering on filter paper.

In addition, when moisture is removed through drying, a powder in the form of nanoparticles is obtained.

When heated in a nitrogen atmosphere, tungsten oxide carbon atoms in the oleate remain and tungsten oxide-carbon nanoparticles are formed.

Example 2

It was carried out in the same manner as in Example 1,

When heating, heating was carried out in a reducing atmosphere (argon 95%, hydrogen 5%), not a nitrogen atmosphere.

When heated in a reducing atmosphere, a structure is formed in which a carbon atom in oleate wraps tungsten metal to form a two-dimensional tungsten gold-carbon nanoparticle.

Example 2

It was carried out in the same manner as in Example 1,

When heating, heating was performed in an air atmosphere rather than a nitrogen atmosphere.

When heated in an air atmosphere, tungsten oxide remains, and the carbon atom in oleate is burned in combination with oxygen in the air, resulting in only tungsten oxide particles.

The above detailed description is to illustrate the present invention. In addition, the above-described content is to describe and describe preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications and environments. That is, it is possible to change or modify the scope of the concept of the invention disclosed herein, the scope equivalent to the disclosed contents, and/or the scope of the art or knowledge in the art. The embodiments described describe the best state for implementing the technical spirit of the present invention, and various changes required in specific application fields and uses of the present invention are possible. Therefore, the detailed description of the above invention is not intended to limit the present invention to the disclosed embodiments. In addition, the appended claims should be construed to include other embodiments.

Claims (8)

A tungsten precursor synthesis step of preparing a tungsten precursor by adding tungsten to a strong acid solution;
A mixing step of mixing sodium oleate with a tungsten precursor;
A drying step of drying the mixed material;
A heating step of heating the dried mixture; And
Includes; washing and filtration step of washing and filtering using distilled water,
The tungsten precursor synthesis step,
Tungsten metal obtaining step of obtaining tungsten metal in used semiconductor equipment,
A liquefaction step of adding tungsten metal to a strong acid solution to change the tungsten of the metal to an ionized state; And
A synthetic step of synthesizing a tungsten precursor material by vacuum drying the liquefied material containing tungsten ions to remove moisture and reacting the tungsten ion with a strong acid solution material; Method for producing tungsten nanoparticles comprising a.
According to claim 1,
In the step of synthesizing the tungsten precursor, the strong acid solution is prepared by mixing hydrochloric acid and nitric acid.
According to claim 1,
A method of preparing tungsten nanoparticles, characterized in that water is added and mixed in the mixing step to help the combination of tungsten ions and sodium oleate.
According to claim 1,
The drying in the drying step is tungsten nanoparticle manufacturing method characterized in that drying at 90 ~ 100 ℃.
According to claim 1,
In the heating step, any one of Na ₂ SO ₄ , K ₂ SO ₄ , NaCl, KCl, Na ₂ CO ₃ , Li ₂ CO ₃ , K ₂ CO ₃ , and CaCl ₂ is mixed. Method for manufacturing tungsten nanoparticles.
The method of claim 5,
A method of manufacturing tungsten nanoparticles, characterized in that the salt (Salt) is mixed to form tungsten nanoparticles in a thin two-dimensional form.
According to claim 1,
Method of producing tungsten nanoparticles, characterized in that carried out in any one of a nitrogen atmosphere, a reducing atmosphere and an air atmosphere in the heating step.
The method of claim 7,
Tungsten oxide-carbon nanoparticles under the nitrogen atmosphere, tungsten-carbon nanoparticles under the reducing atmosphere, tungsten oxide particles are produced under the air atmosphere.

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