KR102316751B1 - Manufacturing method of needle-typed magnesium sulfate compound - Google Patents

Abstract

The present invention includes the steps of preparing a mixed solution by adding MgO powder and Mg(OH) _{2 powder to a solvent, adding and mixing H 2} SO ₄ solution to the mixed solution, and the H ₂ SO ₄ solution is It relates to a method for producing a needle-shaped magnesium sulfate compound, comprising the steps of hydrothermal reaction of a mixed solution and selectively separating, washing and drying the precipitate formed by the hydrothermal reaction. According to the present invention, _{a needle-like magnesium sulfate compound is prepared through a hydrothermal reaction by providing SO 4} ^2- ions through sulfuric acid and controlling the concentration of magnesium hydroxide and magnesium oxide, and the width (width) of the needle-like type can control

Description

Manufacturing method of needle-type magnesium sulfate compound

The present invention relates to a method for producing a magnesium sulfate compound, and more particularly, needle-shaped sulfuric acid through a hydrothermal reaction by providing _{SO 4} ^{2- ions through sulfuric acid and controlling the concentration of magnesium hydroxide and magnesium oxide.} It relates to a method for manufacturing a needle-shaped magnesium sulfate compound capable of manufacturing a magnesium compound and controlling the width (width) of the needle-shaped type.

Magnesium sulfate compounds can be used in various fields such as fillers, rubber friction materials, building materials, and fireproof materials by replacing the existing asbestos.

The magnesium sulfate compound can be expressed as 5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O (here, n is a natural number less than or equal to 10) in the chemical formula. In particular, magnesium sulfate compound is _{a material that can be used as a flame retardant because the crystal water of H 2} O causes an endothermic reaction to absorb heat as the crystal water is dehydrated during heating.

Magnesium sulfate compound is an eco-friendly composite material used as a high-functional filler for rubber and resin as an alternative to asbestos. .

When synthesizing such a magnesium sulfate compound, NaOH, Mg(OH) ₂ , MgCl ₂ and the like were conventionally synthesized as starting materials. However, NaOH, which is a strong base, causes a rapid change in pH in the solution.

Republic of Korea Patent Publication No. 10-1317675

The problem to be solved by the present invention is _{to provide SO 4} ^2- ions through sulfuric acid and control the concentration of magnesium hydroxide and magnesium oxide to produce a needle-shaped magnesium sulfate compound through a hydrothermal reaction, and To provide a method for producing a needle-shaped magnesium sulfate compound that can control (width).

The present invention, (a) _{preparing a mixed solution by adding MgO powder and Mg(OH) 2} powder to a solvent, (b) _{adding and mixing H 2} SO ₄ solution to the mixed solution, ( c) _{hydrothermal reaction of the solution in which the H 2} SO ₄ solution is mixed, and (d) selectively separating the precipitate formed by the hydrothermal reaction, washing and drying the needle-type sulfuric acid A method for producing a magnesium compound is provided.

In step (a), the MgO powder is preferably added so that the concentration of MgO in the mixed solution is 2-5 M.

In step (a), the Mg(OH) ₂ powder is preferably added so that the concentration of Mg(OH) _{2 in the mixed solution is 0.05 to 2 M.}

In step (a), the concentration of MgO in the mixed solution is preferably set higher than the concentration _{of Mg(OH) 2 in the mixed solution.}

The H ₂ SO ₄ solution preferably has a concentration of 0.1 to 3 M.

It is preferable to set the concentration of MgO in the mixed solution to _{be higher than the concentration of the H 2} SO _{4 solution.}

The concentration of Mg(OH) ₂ in the mixed solution is preferably set to be lower than the concentration of the H ₂ SO _{4 solution.}

The hydrothermal reaction is preferably performed at a temperature of 110 to 200 ℃ higher than the boiling point of the solvent.

The solvent may include distilled water.

By adjusting the ratio of the concentration of Mg(OH) ₂ in the mixed solution and the concentration of MgO in the mixed solution, the width of the needle-like structure of the needle-like magnesium sulfate compound can be controlled.

The ratio of the concentration of Mg(OH) ₂ in the mixed solution and the concentration of MgO in the mixed solution is preferably 1:4 to 1:10.

According to the present invention, it is possible to prepare a needle-shaped magnesium sulfate compound through a hydrothermal reaction by providing _{SO 4} ^{2- ions through sulfuric acid and controlling the concentration of magnesium hydroxide and magnesium oxide.}

According to the present invention, the width (width) of the needle-shaped magnesium sulfate compound can be controlled by adjusting the concentration of magnesium hydroxide and magnesium oxide.

1 is a scanning electron microscope (SEM) photograph showing a needle-shaped magnesium sulfate compound prepared according to Experimental Example 1. FIG.
2 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 2.
3 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 3.
4 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 4.
5 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 5;
6 is a diagram showing X-ray diffraction (XRD) diffraction patterns of needle-shaped magnesium sulfate compounds prepared according to Experimental Examples 1 to 5;

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the following examples are provided so that those of ordinary skill in the art can fully understand the present invention, and may be modified in various other forms, and the scope of the present invention is limited to the examples described below it's not going to be

When it is said that any one component "includes" another component in the detailed description or claims of the invention, it is not construed as being limited to only the component, unless otherwise stated, and other components are further added. It should be understood as being able to include

The method for producing a needle-like magnesium sulfate compound according to a preferred embodiment of the present invention comprises the steps of (a) _{preparing a mixed solution by adding MgO powder and Mg(OH) 2} powder to a solvent, (b) adding to the mixed solution Adding and mixing H ₂ SO ₄ solution, (c) _{hydrothermal reaction of the solution in which the H 2} SO ₄ solution is mixed, and (d) selectively separating the precipitate formed by the hydrothermal reaction, washing and drying.

In step (a), the MgO powder is preferably added so that the concentration of MgO in the mixed solution is 2-5 M.

In step (a), the Mg(OH) ₂ powder is preferably added so that the concentration of Mg(OH) _{2 in the mixed solution is 0.05 to 2 M.}

In step (a), the concentration of MgO in the mixed solution is preferably set higher than the concentration _{of Mg(OH) 2 in the mixed solution.}

The H ₂ SO ₄ solution preferably has a concentration of 0.1 to 3 M.

It is preferable to set the concentration of MgO in the mixed solution to _{be higher than the concentration of the H 2} SO _{4 solution.}

The concentration of Mg(OH) ₂ in the mixed solution is preferably set to be lower than the concentration of the H ₂ SO _{4 solution.}

The hydrothermal reaction is preferably performed at a temperature of 110 to 200 ℃ higher than the boiling point of the solvent.

The solvent may include distilled water.

By adjusting the ratio of the concentration of Mg(OH) ₂ in the mixed solution and the concentration of MgO in the mixed solution, the width of the needle-like structure of the needle-like magnesium sulfate compound can be controlled.

The ratio of the concentration of Mg(OH) ₂ in the mixed solution and the concentration of MgO in the mixed solution is preferably 1:4 to 1:10.

Hereinafter, a method for producing a needle-shaped magnesium sulfate compound according to a preferred embodiment of the present invention will be described in more detail.

Existing needle-type magnesium sulfate compounds have _{been prepared in a basic atmosphere (NH 4} OH, urea, NaOH, etc.) _{using magnesium sulfate and magnesium oxide, but the present invention provides SO 4} ^2- ions through sulfuric acid and immobilized magnesium hydroxide. A method for controlling the concentration of magnesium oxide at the concentration to produce a needle-shaped magnesium sulfate compound through a hydrothermal reaction and to control the width (width) of the needle-type is presented.

A mixed solution (mixture) is prepared by adding MgO powder and Mg(OH) _{2 powder to the solvent.} The MgO powder is preferably added so that the concentration of MgO in the mixed solution (mixture) is 2 to 5 M, more preferably 3.5 to 5 M. The Mg(OH) ₂ powder is preferably added so that the concentration _{of Mg(OH) 2} in the mixed solution (mixture) is 0.05 to 2 M. It is preferable to set the concentration of MgO in the mixed solution (mixture) to _{be higher than the concentration of Mg(OH) 2 in the mixed solution (mixture).} After adding MgO powder and Mg(OH) ₂ powder to the solvent, it is preferably stirred, and the stirring is preferably performed at about 10 to 1000 rpm, more preferably at about 100 to 500 rpm. The solvent may include distilled water.

By adjusting the ratio of the concentration of Mg(OH) ₂ in the mixed solution and the concentration of MgO in the mixed solution, the width of the needle-like structure of the needle-like magnesium sulfate compound can be controlled. The ratio between the concentration of Mg(OH) ₂ in the mixed solution and the concentration of MgO in the mixed solution is 1:4 to 1:10, more preferably 1:7 to 1:10. For example, when the concentration of Mg(OH) ₂ in the mixed solution is 0.8M, the concentration of MgO in the mixed solution is preferably 3.2M or more.

H ₂ SO ₄ solution is added to the mixed solution and mixed. The H ₂ SO ₄ solution serves to provide _{SO 4} ^{2- ions.} The H ₂ SO ₄ solution preferably has a concentration of 0.1 to 3 M. It is preferable to set the concentration of MgO in the mixed solution to _{be higher than the concentration of the H 2} SO _{4 solution.} For example, _{when the concentration of the H 2} SO ₄ solution is 1M, the concentration of MgO in the mixed solution is preferably about 2 to 5 M higher than this. In addition, the concentration of Mg(OH) ₂ in the mixed solution is preferably set to be lower than the concentration of the H ₂ SO _{4 solution.} For example, _{when the concentration of the H 2} SO ₄ solution is 1M, the concentration of Mg(OH) ₂ in the mixed solution is preferably about 0.05 to 0.5 M, which is lower than this.

A solution in which the H ₂ SO ₄ solution is mixed is subjected to a hydrothermal reaction. The solution in which the H ₂ SO ₄ solution is mixed is put in a hydrothermal reactor, completely sealed, and the hydrothermal reactor is placed in a drying oven, and then maintained at a temperature at which the hydrothermal reaction is performed in the drying oven to cause a hydrothermal reaction. The hydrothermal reaction is preferably performed at a temperature of 110 to 200 ℃ higher than the boiling point of the solvent. The hydrothermal reaction is preferably performed for 1 to 48 hours, more preferably 6 to 16 hours.

The precipitate formed by the hydrothermal reaction is selectively separated, washed and dried to obtain a needle-shaped magnesium sulfate compound. For selective separation, a centrifuge or the like may be used. The washing may be performed using distilled water or the like. The drying is preferably performed at a temperature of about 40 to 90 ℃.

Hereinafter, experimental examples according to the present invention are specifically presented, and the present invention is not limited to the experimental examples presented below.

<Experimental Example 1>

MgO powder and Mg(OH) ₂ powder were added to 50 ml of distilled water, and stirred at room temperature (room temperature) for 30 minutes to prepare a mixed solution. The MgO powder was added to achieve a 2.0M concentration of MgO in the mixed solution, the Mg (OH) ₂ powder was added to the concentration of Mg (OH) ₂ to achieve 0.5M in the mixed solution. The stirring was performed at a rotation speed of about 400 rpm.

_{30 ml of a 1M H 2} SO ₄ solution was added to the mixed solution, and the mixture was stirred at room temperature (room temperature) for 30 minutes. The stirring was performed at a rotation speed of about 400 rpm.

The solution in which the H ₂ SO ₄ solution was mixed was put in a hydrothermal reactor, sealed completely, and the hydrothermal reactor was placed in a drying oven, and then maintained in the drying oven at a temperature of 150° C. for 12 hours to perform a hydrothermal reaction. After the hydrothermal reaction, it was cooled to room temperature (room temperature).

The hydrothermal reaction product was centrifuged at 8,000 rpm using a centrifuge to selectively separate the precipitate, and the selectively separated precipitate was washed three times with distilled water and dried at 80 ° C. for 6 hours to obtain needle-like sulfuric acid. A magnesium compound was obtained.

<Experimental Example 2>

MgO powder and Mg(OH) ₂ powder were added to 50 ml of distilled water, and stirred at room temperature (room temperature) for 30 minutes to prepare a mixed solution. The MgO powder was added to achieve a 2.5M concentration of MgO in the mixed solution, the Mg (OH) ₂ powder was added to the concentration of Mg (OH) ₂ to achieve 0.5M in the mixed solution. The stirring was performed at a rotation speed of about 400 rpm.

_{30 ml of a 1M H 2} SO ₄ solution was added to the mixed solution, and the mixture was stirred at room temperature (room temperature) for 30 minutes. The stirring was performed at a rotation speed of about 400 rpm.

The solution in which the H ₂ SO ₄ solution was mixed was put in a hydrothermal reactor, sealed completely, and the hydrothermal reactor was placed in a drying oven, and then maintained in the drying oven at a temperature of 150° C. for 12 hours to perform a hydrothermal reaction. After the hydrothermal reaction, it was cooled to room temperature (room temperature).

The hydrothermal reaction product was centrifuged at 8,000 rpm using a centrifuge to selectively separate the precipitate, and the selectively separated precipitate was washed three times with distilled water and dried at 80 ° C. for 6 hours to obtain needle-like sulfuric acid. A magnesium compound was obtained.

<Experimental Example 3>

MgO powder and Mg(OH) ₂ powder were added to 50 ml of distilled water, and stirred at room temperature (room temperature) for 30 minutes to prepare a mixed solution. The MgO powder was added to achieve a 3.0M concentration of MgO in the mixed solution, the Mg (OH) ₂ powder was added to the concentration of Mg (OH) ₂ to achieve 0.5M in the mixed solution. The stirring was performed at a rotation speed of about 400 rpm.

_{30 ml of a 1M H 2} SO ₄ solution was added to the mixed solution, and the mixture was stirred at room temperature (room temperature) for 30 minutes. The stirring was performed at a rotation speed of about 400 rpm.

The solution in which the H ₂ SO ₄ solution was mixed was put in a hydrothermal reactor, sealed completely, and the hydrothermal reactor was placed in a drying oven, and then maintained in the drying oven at a temperature of 150° C. for 12 hours to perform a hydrothermal reaction. After the hydrothermal reaction, it was cooled to room temperature (room temperature).

The hydrothermal reaction product was centrifuged at 8,000 rpm using a centrifuge to selectively separate the precipitate, and the selectively separated precipitate was washed three times with distilled water and dried at 80 ° C. for 6 hours to obtain needle-like sulfuric acid. A magnesium compound was obtained.

<Experimental Example 4>

MgO powder and Mg(OH) ₂ powder were added to 50 ml of distilled water, and stirred at room temperature (room temperature) for 30 minutes to prepare a mixed solution. The MgO powder was added to achieve a 3.5M concentration of MgO in the mixed solution, the Mg (OH) ₂ powder was added to the concentration of Mg (OH) ₂ to achieve 0.5M in the mixed solution. The stirring was performed at a rotation speed of about 400 rpm.

_{30 ml of a 1M H 2} SO ₄ solution was added to the mixed solution, and the mixture was stirred at room temperature (room temperature) for 30 minutes. The stirring was performed at a rotation speed of about 400 rpm.

The solution in which the H ₂ SO ₄ solution was mixed was put in a hydrothermal reactor, sealed completely, and the hydrothermal reactor was placed in a drying oven, and then maintained in the drying oven at a temperature of 150° C. for 12 hours to perform a hydrothermal reaction. After the hydrothermal reaction, it was cooled to room temperature (room temperature).

The hydrothermal reaction product was centrifuged at 8,000 rpm using a centrifuge to selectively separate the precipitate, and the selectively separated precipitate was washed three times with distilled water and dried at 80 ° C. for 6 hours to obtain needle-like sulfuric acid. A magnesium compound was obtained.

<Experimental Example 5>

MgO powder and Mg(OH) ₂ powder were added to 50 ml of distilled water, and stirred at room temperature (room temperature) for 30 minutes to prepare a mixed solution. The MgO powder was added to achieve a 4.0M concentration of MgO in the mixed solution, the Mg (OH) ₂ powder was added to the concentration of Mg (OH) ₂ to achieve 0.5M in the mixed solution. The stirring was performed at a rotation speed of about 400 rpm.

_{30 ml of a 1M H 2} SO ₄ solution was added to the mixed solution, and the mixture was stirred at room temperature (room temperature) for 30 minutes. The stirring was performed at a rotation speed of about 400 rpm.

The solution in which the H ₂ SO ₄ solution was mixed was put in a hydrothermal reactor, sealed completely, and the hydrothermal reactor was placed in a drying oven, and then maintained in the drying oven at a temperature of 150° C. for 12 hours to perform a hydrothermal reaction. After the hydrothermal reaction, it was cooled to room temperature (room temperature).

The hydrothermal reaction product was centrifuged at 8,000 rpm using a centrifuge to selectively separate the precipitate, and the selectively separated precipitate was washed three times with distilled water and dried at 80 ° C. for 6 hours to obtain needle-type sulfuric acid. A magnesium compound was obtained.

1 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 1, and FIG. 2 is a scanning electron microscope showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 2. (SEM) photograph, FIG. 3 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 3, and FIG. 4 is an injection showing the needle-type magnesium sulfate compound prepared according to Experimental Example 4. It is an electron microscope (SEM) photograph, and FIG. 5 is a scanning electron microscope (SEM) photograph showing the needle-shaped magnesium sulfate compound prepared according to Experimental Example 5.

1 to 5, in the case of preparing a needle-shaped magnesium sulfate compound by setting the concentration of _{Mg(OH) 2} to 0.5M and the concentration of MgO to 2M in the mixed solution according to Experimental Example 1, Mg(OH) _{It was found that two} phases and a needle-shaped magnesium sulfate compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where n is 2 or 3) coexist together. In addition, according to Experimental Example 2, even when the needle-like magnesium sulfate compound was prepared with a _{Mg(OH) 2 concentration of 0.5 M and a MgO concentration of 2.5 M in the mixed solution, Mg(OH) 2} phase and needle-type sulfuric acid Magnesium compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where n is 2 or 3) phases were found to coexist. In addition, even when the needle-like magnesium sulfate compound was prepared by setting the concentration of _{Mg(OH) 2} to 0.5 M and the concentration of MgO to 3.0 M in the mixed solution according to Experimental Example 3 _{, Mg(OH) 2} phase and needle-type sulfuric acid Magnesium compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where n is 2 or 3) phases were found to coexist.

In a mixed solution in accordance with Example 4, the concentration of Mg (OH) ₂ as a 0.5M and the concentration of MgO in the case of preparing the acicular 3.5M magnesium compound is Mg (OH) ₂ phase is not present acicular sulfate It was found that only the magnesium compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where n is 2 or 3) phase was present. In addition, even when the needle-like magnesium sulfate compound was prepared with a _{Mg(OH) 2} concentration of 0.5 M and a MgO concentration of 4.0 M in the mixed solution according to Experimental Example 5 _{, Mg(OH) 2} phase did not exist and needle-like It was found that only the type magnesium sulfate compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where n is 2 or 3) phase was present.

The width (width) of the needle-shaped magnesium sulfate compound prepared according to Experimental Examples 1 to 5 was measured and shown in Table 1 below.

MgO concentration in the mixed solution Width (㎛) of needle structure Experimental Example 1 2.0M 0.716 Experimental Example 2 2.5M 1.432 Experimental Example 3 3.0M 1.718 Experimental Example 4 3.5M 0.77 Experimental Example 5 4.0M 1.307

1 to 5 and Table 1, it was observed that the width (width) of the needle-shaped magnesium sulfate compound increased as the MgO concentration increased. However, when the MgO concentration in the mixed solution was 3.5M, _{there was no Mg(OH) 2} phase and only a pure needle-like magnesium sulfate compound phase was generated, and it was confirmed that the width of the needle-like structure was rapidly reduced to 0.77 μm. When the MgO concentration in the mixed solution was increased from 3.5M to 4.0M, the width of the needle structure increased again to 1.307㎛.

6 is a diagram showing X-ray diffraction (XRD) diffraction patterns of needle-shaped magnesium sulfate compounds prepared according to Experimental Examples 1 to 5; 6, (a) is for the needle-shaped magnesium sulfate compound prepared according to Experimental Example 1, (b) is for the needle-type magnesium sulfate compound prepared according to Experimental Example 2, (c) is Experimental Example 3 For the needle-shaped magnesium sulfate compound prepared according to, (d) is for the needle-shaped magnesium sulfate compound prepared according to Experimental Example 4, (e) is for the needle-type magnesium sulfate compound prepared according to Experimental Example 5 it is about

6, in the specimens prepared according to Experimental Examples 1 to 3, the _{peak corresponding to the Mg(OH) 2} phase and the needle-shaped magnesium sulfate compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where , n is 2 or 3), a peak corresponding to the phase appeared, and in the specimens prepared according to Experimental Examples 4 and 5, needle-shaped magnesium sulfate compound (5Mg(OH) ₂ ·MgSO ₄ ·nH ₂ O, where, Only peaks corresponding to n phase 2 or 3) were observed. As the MgO concentration in the mixed solution increased to 2.0M, 2.5M, 3.0M, 3.5M, and 4.0M, the Mg(OH) ₂ phase decreased and the needle-shaped magnesium sulfate crystal phase increased, and the MgO concentration in the mixed solution increased In the case of 3.5M and 4.0M, it was confirmed that only the needle-shaped magnesium sulfate compound crystal phase was generated.

As mentioned above, although preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various modifications are possible by those skilled in the art.

Claims (11)

(a) preparing a mixed solution by adding MgO powder and Mg(OH) _{2 powder to a solvent;}
(b) mixing _{by adding a H 2} SO ₄ solution to the mixed solution;
(c) hydrothermally reacting the solution in which _{the H 2} SO _{4 solution is mixed;} and
(d) selectively separating the precipitate formed by the hydrothermal reaction, washing and drying;
In step (a),
The concentration of MgO in the mixed solution is set higher than the concentration _{of Mg(OH) 2 in the mixed solution,}
The concentration of MgO in the mixed solution is set higher than the _{concentration of the H 2} SO _{4 solution,}
The concentration of Mg(OH) ₂ in the mixed solution is set to be lower than the concentration of the H ₂ SO _{4 solution,}
Method for producing a needle-shaped magnesium sulfate compound, characterized in that the width of the needle-like structure of the needle-shaped magnesium sulfate compound is controlled by adjusting the ratio of the concentration of Mg(OH) _{2 in the mixed solution and the concentration of MgO in the mixed solution} .
The method of claim 1, wherein in step (a),
The method for producing a needle-shaped magnesium sulfate compound, characterized in that the MgO powder is added so that the concentration of MgO in the mixed solution is 2 to 5 M.
The method of claim 1, wherein in step (a),
The method for producing a needle-shaped magnesium sulfate compound, characterized in that the Mg(OH) ₂ powder is added so that the concentration of Mg(OH) _{2 in the mixed solution is 0.05 to 2 M.}
delete The method of claim 1, wherein the H ₂ SO ₄ solution has a concentration of 0.1 to 3 M.
delete delete The method according to claim 1, wherein the hydrothermal reaction is performed at a temperature of 110 to 200 °C higher than the boiling point of the solvent.
The method according to claim 1, wherein the solvent comprises distilled water.
delete The method according to claim 1, wherein _{the ratio of the concentration of Mg(OH) 2} in the mixed solution to the concentration of MgO in the mixed solution is 1:4 to 1:10. Way.

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