KR101494611B1 - Manufacturing method of basic magnesium sulfate compound - Google Patents

Abstract

The present invention relates to a method for producing magnesium sulfate, which comprises mixing magnesium sulfate (MgSO ₄ .7H ₂ O), magnesium oxide (MgO) and a solvent, reflowing a mixture of magnesium sulfate, Magnesium sulfate, and a precipitate obtained from the reaction product by using a centrifugal separator or a filter unit. The precipitate is dried to obtain a needle-like basic magnesium sulfate compound (5Mg (OH) ₂ .MgSO ₄ .3H ₂ O) To obtain a basic magnesium sulfate compound. According to the present invention, it is possible to produce an acicular basic magnesium sulfate compound through a simple process at a lower cost than a method of synthesizing in a hydrothermal reactor by using a reflux method at normal pressure.

Description

Technical Field [0001] The present invention relates to a basic magnesium sulfate compound,

The present invention relates to a process for producing a basic magnesium sulfate compound, and more particularly, to a process for producing a basic magnesium sulfate compound by a simple process at a lower cost than a synthesis process in a hydrothermal reactor by using a reflux process at normal pressure. And a method for manufacturing the same.

The basic magnesium sulfate compound can be used in various fields such as filler, rubber friction material, building material, refractory material, etc. in place of existing asbestos.

The basic magnesium sulfate compound can be represented by the formula 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O. In particular, the basic magnesium sulfate compound is a material which can be used as a flame retardant because the endothermic reaction in which the crystal water is dehydrated and absorbs heat occurs upon heating due to the crystal water of 3H ₂ O.

5Mg (OH) ₂ · MgSO ₄ · 3H ₂ O is an environmentally friendly composite material that is used as a high performance filler for rubber and resin as a substitute for asbestos. It has shapes such as needle shape, plate shape and spherical shape. The application field varies depending on the thermal properties.

In order to synthesize acicular basic magnesium sulfate compound, acicular structure could be obtained by hydrothermal reaction using high pressure formed at 170 ~ 180 ℃. The hydrothermal reaction is an easy way to synthesize the needle-shaped structure, but it has difficulties in mass production of the basic magnesium sulfate compound due to the high process cost. Also, since the precursor is stirred at room temperature and then transferred to the hydrothermal reactor, it is difficult to process the precursor.

A problem to be solved by the present invention is to provide a method for producing a needle-shaped basic magnesium sulfate compound through a simple process at a lower cost than a synthesis method using a reflux method at atmospheric pressure by a hydrothermal reactor.

(A) mixing magnesium sulfate (MgSO ₄ .7H ₂ O), magnesium oxide (MgO) and a solvent; and (b) refluxing the mixture of magnesium sulfate, magnesium oxide and the solvent (C) obtaining a precipitate from the reaction product by using a centrifugal separator or a filter, and (d) drying the precipitate to obtain an acicular magnesium sulfate basic compound (5Mg OH) ₂ .MgSO ₄ .3H ₂ O). The present invention also provides a process for producing a basic magnesium sulfate compound.

In the step (a), it is preferable that the magnesium sulfate and the magnesium oxide are mixed in a molar ratio of 7: 1 to 10: 1.

In the step (b), a vessel containing the magnesium sulfate, the magnesium oxide and the solvent is placed in an oil bath, refluxed in the vessel using a bar, and the magnesium sulfate And reacting the magnesium oxide.

The reaction is preferably carried out at a temperature of 100-110 < 0 > C.

It is preferable to use distilled water as the solvent.

According to the present invention, a basic magnesium sulfate compound can be synthesized by a simple process of refluxing a solution containing magnesium oxide and magnesium sulfate at a temperature above the boiling point of the solvent.

An acicular basic magnesium sulfate compound (5Mg (OH) ₂ .MgSO ₄ .3H ₂ O) can be synthesized by a reflux method other than hydrothermal method.

The process cost can be lowered by using the reflux method at normal pressure instead of the high pressure reaction.

1 is a schematic view of an apparatus for synthesizing a basic magnesium sulfate compound using a three neck flask.
2 is an X-ray diffraction pattern of 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder synthesized according to Example 1.
3 is a scanning electron microscope (SEM) image of 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder synthesized according to Example 1.
4 is a scanning electron microscope (SEM) image of 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder synthesized according to Example 2. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not.

A method for producing a basic magnesium sulfate compound according to a preferred embodiment of the present invention comprises the steps of: (a) mixing magnesium sulfate (MgSO ₄ .7H ₂ O), magnesium oxide (MgO) and a solvent; and (b) Reacting the magnesium sulfate with the magnesium oxide while refluxing the mixture of magnesium oxide and the solvent; (c) obtaining a precipitate from the reaction product by using a centrifugal separator or a filter unit; and (d) To obtain an acicular basic magnesium sulfate compound (5Mg (OH) ₂ .MgSO ₄ .3H ₂ O). In the step (a), it is preferable that the magnesium sulfate and the magnesium oxide are mixed in a molar ratio of 7: 1 to 10: 1. In the step (b), a vessel containing the magnesium sulfate, the magnesium oxide and the solvent is placed in an oil bath, refluxed in the vessel using a bar, and the magnesium sulfate And reacting the magnesium oxide. The reaction is preferably carried out at a temperature of 100 to 110 DEG C, which is not lower than the boiling point of the solvent. It is preferable to use distilled water as the solvent.

Specifically, a method of synthesizing a basic magnesium sulfate compound (5Mg (OH) ₂ .MgSO ₄ .3H ₂ O) is as follows. Magnesium sulfate (MgSO ₄ .7H ₂ O) and magnesium oxide (MgO) (For example, from 7: 1 to 10: 1), and the mixture of magnesium sulfate, magnesium oxide and solvent is transferred into a container such as a three neck flask, (For example, 2 to 120 hours) while refluxing the inside of the vessel using a bar at a temperature higher than the boiling point of the solvent (for example, 100 to 110 ° C).

There is a method of synthesizing a basic magnesium compound _{(5Mg (OH) 2 · MgSO} 4 · 3H 2 O) using a MgCl ₂ and ammonia, in the method NH is used when changing the MgCl ₂ with Mg (OH) _{2 4} OH and NaOH are regenerated in the reaction bed due to the regeneration of Mg (OH) ₂ (plate phase), which is an element that interferes with the synthesis of the acicular basic magnesium sulfate compound.

However, MgO changes to Mg (OH) ₂ when it comes into contact with water, but it exists in MgOH ⁺ state and binds to MgSO ₄ to form acicular compound. The molar ratio of MgSO ₄ to MgO is an important factor. When the ratio of MgSO ₄ and MgO is 7 or more, basic magnesium sulfate is produced. When the ratio of MgO to MgO is less than 7, a plate-like Mg (OH) ₂ is produced have.

The basic magnesium sulfate compound can be synthesized at normal pressure. Can be synthesized at normal pressure to form an acicular structure with an appropriate concentration of MgOH ⁺ formation and a sufficient amount of SO ₄ ^{2 -} feed. This allows a single process to be performed at a low cost even in the case of a large reaction.

The following Reaction Schemes 1 to 3 show the reaction in which a basic magnesium sulfate compound (5Mg (OH) ₂ .MgSO ₄ .3H ₂ O) is synthesized.

[Reaction Scheme 1]

MgO + H ₂ O - > Mg ² + 2OH ^-

[Reaction Scheme 2]

MgSO _{4 -} > Mg ^{2 +} + SO ₄ ^{2 -}

[Reaction Scheme 3]

6Mg ^{2 +} + 10OH ^- + SO ₄ ^{2 -} + 3H ₂ O -> 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O

The Mg ^{2 +} ion reacts with OH ^- to form Mg (OH) ₂ and is ionized to Mg ^{2 +} and MgOH ⁺ . It generates a Mg ^{2 +} and SO ₄ ^2- ions in the Mg-O bond (bond) ^- proper amount of SO ₄ ^2. Further, when ^4- pieces of Mg (OH) ₆ are produced, SO ₄ ^{2 -} is connected in the direction of the B axis and grows one-dimensionally to produce acicular particles. At this time, when the amount of SO ₄ ^{2 -} is small, the acicular magnesium sulfate compound is not formed but becomes Mg (OH) ₂ . At too high a pH (a large amount of OH ^- ions present), formation of basic magnesium sulfate compounds is inhibited due to thermodynamically forming a plate - like Mg (OH) ₂ . In addition, MgO can be easily ionized into MgOH ⁺ and OH ^- even at a boiling temperature, and can be synthesized in a reflux reaction. When the MgSO ₄ and MgO molar ratio are appropriately controlled, the whiskers of acicular shape are synthesized even at normal pressure. Since a single process and a temperature can be synthesized at a temperature slightly over 100 ° C., simplification of the process and low-cost process become possible.

The basic magnesium sulfate compound (5Mg (OH) ₂ .MgSO ₄ .3H ₂ O) can be synthesized at atmospheric pressure according to the above reaction schemes 1 to 3, and the bed length can be controlled by increasing the reaction time.

The precipitate is selectively separated from the reaction product by using a centrifuge or a filter, and the precipitate is washed several times (for example, 2 to 10 times) with distilled water or the like. The precipitate is dried in a drying oven at 80 to 100 DEG C for 10 minutes to 48 hours.

EXAMPLES Hereinafter, examples according to the present invention will be specifically shown, and the present invention is not limited to the following examples.

≪ Example 1 >

1 schematically shows an apparatus for synthesizing a basic magnesium sulfate compound using a three neck flask. 1, numeral 110 denotes a three-way flask, numeral 120 denotes a mixture of magnesium sulfate, magnesium oxide and distilled water, numeral 130 denotes a thermocouple, numeral 140 denotes a condenser, numeral 150 denotes an oil bath, numeral 160 Is a magnetic stirrer.

0.35 mol (86.3 g) of magnesium sulfate (MgSO ₄ .7H ₂ O), 0.05 mol (2 g) of magnesium oxide (MgO) and 30 mL of distilled water were mixed in a 50 mL round three-necked flask .

The mixture of magnesium sulfate, magnesium oxide and distilled water was reacted at 100 ° C for 6 hours while refluxing using a magnetic bar, and then cooled to room temperature.

The solution cooled to room temperature was filtered using a filter paper and washed three times with distilled water to obtain a reaction product. The obtained reaction product was dried to obtain an acicular 5Mg OH) ₂ .MgSO ₄ .3H ₂ O powder was obtained.

≪ Example 2 >

0.35 mol (86.3 g) of magnesium sulfate (MgSO ₄ .7H ₂ O), 0.05 mol (2 g) of magnesium oxide (MgO) and 30 mL of distilled water were mixed in a 50 mL round three-necked flask .

The mixture of magnesium sulfate, magnesium oxide and distilled water was reacted at 100 ° C for 72 hours while refluxing using a magnetic bar, and then cooled to room temperature.

The solution cooled to room temperature was filtered using a filter paper and washed three times with distilled water to obtain a reaction product. The obtained reaction product was dried to obtain an acicular 5Mg OH) ₂ .MgSO ₄ .3H ₂ O powder was obtained.

So 5Mg of the resulting acicular _{(OH) 2 · MgSO 4 ·} 3H 2 O with respect to the powder X- ray diffraction; were measured (X-ray diffraction XRD), 5Mg (OH) of the needle shape ₂ · MgSO ₄ · 3H ₂ O powder was redispersed in distilled water, dropped onto a silicon wafer, and observed with a scanning electron microscope (SEM).

2 shows an X-ray diffraction pattern of 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder synthesized according to Example 1.

Referring to FIG. 2, the synthesized 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder can be confirmed to be free of impurities.

3 is a scanning electron microscope (SEM) image of 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder synthesized by reflux reaction according to Example 1.

Referring to FIG. 3, it can be confirmed that the synthesized 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder has an acicular type structure and an average length of about 30 μm.

4 is a scanning electron microscope (SEM) image of 5Mg (OH) ₂ .MgSO ₄ .3H ₂ O powder synthesized according to Example 2. FIG.

Referring to FIG. 4, it was confirmed that when the reaction was carried out for 72 hours (in the case of Example 2), the bed length was about twice as long as that in the case of the reaction for 6 hours (in the case of Example 1).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, This is possible.

110: triple flask
120: a mixture of magnesium sulfate, magnesium oxide and distilled water
130: Thermocouple
140: condenser
150: Oil bath
160: magnetic stirrer

Claims (5)

(a) mixing magnesium sulfate (MgSO ₄ .7H ₂ O), magnesium oxide (MgO) and a solvent;
(b) reacting the magnesium sulfate with the magnesium oxide while refluxing the mixture of the magnesium sulfate, the magnesium oxide and the solvent at normal pressure;
(c) obtaining a precipitate from the reaction product using a centrifugal separator or a filter unit; And
(d) drying the precipitate to obtain an acicular basic magnesium sulfate compound (5 Mg (OH) ₂ MgSO ₄ .3H ₂ O)
In the step (a)
The magnesium sulfate and magnesium oxide are mixed so as to have a molar ratio of 7: 1 to 10: 1,
The step (b)
Placing the vessel containing the magnesium sulfate, magnesium oxide and the solvent in an oil bath and reacting the magnesium sulfate with the magnesium oxide while refluxing the vessel using a bar Lt; / RTI >
The reaction is carried out at a temperature of 100-110 < 0 > C,
Distilled water is used as the solvent,
(5Mg (OH) ₂ .MgSO ₄ .3H ₂ O) of the needle-shaped basic magnesium sulfate compound is controlled by controlling the time of the reaction. delete delete delete delete

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