WO2023277220A1 - Solid binder for refractory material and refractory material comprising same - Google Patents

Abstract

The present invention relates to a solid binder for a refractory material, and a refractory material and a refractory brick comprising same, the solid binder comprising a primary reaction product of: a basic refractory raw material; and an organic acid containing three or more functional groups.

Description

Solid binder for refractory material and refractory material containing the same

The present invention relates to a solid binder for a refractory material capable of producing a refractory material of excellent quality with less generation of harmful gases and a refractory material including the same.

Refractory materials having high heat resistance and high corrosion resistance are used in industries where high-temperature melts are used, such as iron and steel manufacturing. These refractory materials are applied to an electric furnace, a ladle, a converter, a mixed car, etc., and are used in refining processes such as steelmaking and ironmaking. A conventional carbon-containing refractory material includes a carbon-containing refractory material aggregate and a binder. At this time, a phenol resin has been generally used as a binder.

However, the refractory material containing a binder containing an organic material such as phenolic resin is thermally decomposed when exposed to high temperature or fired, resulting in reduced bonding strength, and volatile organic compounds (VOCs) such as phenol are released to the surroundings during the thermal decomposition process. The VOC is a substance that easily volatilizes into the air at room temperature due to its high vapor pressure and causes air pollution. ) and chemical reactivity, and is known to cause odor and some carcinogens. As a result, the health of workers in iron and steel factories and residents living near the factories is threatened.

As an alternative to this, Korean Patent Registration No. 967408 (Patent Document 1) discloses a carbon-containing refractory composition comprising a carbon-containing refractory aggregate and a binder, wherein the binder is composed of magnesium sulfate, lignosulfonate, and water. has been initiated. However, as in Patent Document 1, the refractory material containing magnesium sulfate, lignosulfonate, etc. has thermal decomposition when exposed to high temperatures, resulting in poor physical properties and poor erosion resistance.

Therefore, there is a need for research and development on binders for refractory materials capable of producing refractory materials that generate less harmful gases when exposed to high temperatures and have excellent physical properties such as hot properties, strength, and erosion resistance, and refractory materials including the same.

Accordingly, an object of the present invention is to provide a solid binder for a refractory material capable of producing a refractory material having excellent physical properties such as thermal properties, strength, and erosion resistance with little generation of harmful gases when exposed to high temperatures, and a refractory material including the same.

The present invention is a basic refractory raw material; And an organic acid containing three or more functional groups; it provides a solid binder for fireproof materials, including a primary reactant of.

In addition, the present invention is a solid binder for the fireproof material; And refractory material; to provide a refractory material, including.

In addition, the present invention is a solid binder for fireproof materials; And a refractory material; to provide a refractory brick comprising a.

The solid binder for fireproof materials according to the present invention does not contain organic resins such as phenolic resins, so it is environmentally friendly because it does not generate harmful gases when exposed to high temperatures. In addition, compared to phenolic resins, which are conventionally used binders, the solid binder for refractory materials has excellent kneading properties and shortens kneading time, resulting in excellent economic efficiency. In addition, in the case of phenolic resin, aging time of 3 to 24 hours is required after kneading and drying at high temperature for a long time is required after molding due to the nature of thermosetting resin. And, due to the nature of the water-based binder, the drying time is also shortened, so there is an energy saving effect.

In addition, the refractory material and / or refractory brick containing the solid binder for refractory material has excellent physical properties such as hot properties, strength, and erosion resistance, so that it can be applied to industrial fields in which high-temperature melts such as iron and steel are used. In particular, the refractory materials and/or refractory bricks have excellent fire resistance performance and can be applied in various processes and fields such as electric furnaces, ladles, converters, mixed-line cars, refining processes such as steel making and iron making.

1 is a SEM photograph of a solid binder for fireproof materials according to the binder of Comparative Example 1.

2 is a SEM photograph of a solid binder for fireproof materials according to the binder of Example 1.

3 and 4 are pictures of the reaction temperature measured after adding water to the binder of Example 1 or Comparative Example 1.

5 and 6 are harmful gas analysis results of Example 19 and Comparative Example 1.

7 is a photograph of the residual linear expansion test of the neck region of Comparative Example 1.

8 is a photograph of residual linear expansion of the neck region of Example 25.

Hereinafter, the present invention will be described in detail.

Solid binder for refractory materials

The solid binder for fireproof materials according to the present invention includes a basic fireproof material; and an organic acid containing three or more functional groups.

The solid binder for the refractory material may be in the form of a simple mixture of a refractory raw material and an organic acid, but this may cause problems such as reaction due to moisture in storage and deterioration in hot properties due to unreacted binder after completion of molding. Accordingly, the solid binder for the refractory material includes a primary reactant obtained by reacting a refractory raw material with an organic acid. At this time, the primary reactant is in the form of a hydrate, which can secure storage stability and improve kneadability with refractory materials, thereby preventing problems such as deterioration in hot properties due to unreacted binders during product manufacturing.

basic refractory raw material

The basic refractory raw material reacts with organic acid to impart viscosity to the binder.

The basic refractory raw material may include at least one selected from the group consisting of magnesia, quicklime (CaO), slaked lime (Ca(OH) ₂ ), and calcined dolomite (MgO·CaO). Specifically, the basic refractory raw material may be a product obtained by reacting water with one or more reactants selected from the group consisting of magnesium oxide, quicklime (CaO), slaked lime (Ca(OH) ₂ ), and calcined dolomite (MgO CaO). .

In this case, the magnesia may be at least one selected from the group consisting of acustic calcined magnesia, fused magnesia, sintered magnesia, and dead burned magnesia.

More specifically, the basic refractory raw material may include magnesia and at least one reaction rate regulator selected from the group consisting of quicklime (CaO), slaked lime (Ca(OH) ₂ ), and calcined dolomite (MgO CaO). . In this case, the magnesia and the reaction rate regulator may be included in a weight ratio of 1:0.005 to 1:0.1, or 1:0.01 to 1:0.05. When the weight ratio of magnesia and the reaction rate regulator is within the above range, the reaction rate between the refractory raw material and the organic acid can be appropriately controlled. When the weight ratio of magnesia and the reaction rate regulator exceeds the above range, that is, when the weight of the reaction rate regulator is excessive with respect to the weight of magnesia, the physical properties of the refractory prepared by volume expansion or differentiation during the hydration process are poor, or the binder The properties of the binder may be deteriorated due to precipitation occurring therein.

The content of the reaction rate regulator can be adjusted based on the content of calcium oxide (CaO) contained in magnesia, for example, 0.5 to 10 parts by weight, or 1 to 10 parts by weight based on 100 parts by weight of calcium oxide (CaO) in magnesia. 5 parts by weight.

In addition, the reaction rate regulator may have an average diameter of less than 0.3 mm, 0.045 mm to 0.3 mm, or 0.045 mm to 0.1 mm. When the average diameter of the reaction rate regulator is within the above range, it serves as a catalyst for the reaction through a high specific surface area, thereby reducing the reaction time. In addition, when the average diameter of the reaction rate controller exceeds the above range, the reaction activity is lowered and the reaction rate controller cannot properly perform the role, and the unreacted reaction rate controller adversely affects product properties such as hot strength. can happen

organic acid

The organic acid reacts with the basic refractory raw material to impart viscosity to the binder.

The organic acid contains three or more functional groups. In this case, the functional group may be a carboxyl group (COOH). As described above, when an organic acid containing three or more functional groups is used, strong viscosity can be exhibited by reacting with basic functional groups such as MgOH ⁺ and CaOH ⁺ generated during hydration of a refractory raw material.

Specifically, the organic acid may include at least one selected from the group consisting of citric acid and ethylenediaminetetraacetic acid.

The solid binder for the refractory material may include a refractory raw material and an organic acid at a weight ratio of 1:0.25 to 4.0, 1:0.5 to 2.0, or 1:0.8 to 1.2. When the weight ratio of the refractory raw material to the organic acid is less than the above range, that is, when a small amount of organic acid is included based on the weight of the refractory raw material, it is difficult to express sufficient viscosity conducive to molding after the reaction, and when it exceeds the above range, that is, When an excessive amount of organic acid is included based on the weight of the refractory raw material, deterioration in physical properties may occur due to unreacted organic acid.

Specifically, the solid binder for the refractory material may include a basic refractory material, an organic acid containing three or more functional groups, and a primary reactant in the form of a hydrate reacted with water. At this time, the primary reactant is a refractory raw material, organic acid and water in a weight ratio of 1: 0.25 to 4.0: 0.2 to 1.5, 1: 0.5 to 2.0: 0.3 to 0.9, or 1: 0.8 to 1.2: 0.3 to 0.7. may have reacted with When the weight ratio of the refractory raw material to the water is less than the above range, that is, when a small amount of water is included based on the weight of the refractory raw material, there occurs a problem in that the production of binder hydrate is reduced due to moisture evaporation due to heat generation, and In this case, that is, when an excessive amount of water is included based on the weight of the refractory raw material, a drying process due to residual moisture after the reaction may occur unnecessarily.

The solid binder for fireproof materials may further include at least one selected from the group consisting of a stabilizer and a visible time regulator.

stabilizer

The stabilizer serves to improve the stability of the binder by preventing cracks caused by evaporation of organic acids and/or moisture.

In addition, the stabilizer may include at least one selected from the group consisting of inorganic salts and inorganic acids. Specifically, the stabilizer may include at least one selected from the group consisting of magnesium sulfate, aluminum sulfate, magnesium phosphate, aluminum phosphate, phosphoric acid, and boric acid.

More specifically, the stabilizer is a group consisting of MgSO ₄ , MgSO ₄ 7H ₂ O, Mg ₃ (PO ₄ ) ₂ , H ₃ PO ₄ , Al ₂ (SO ₄ ) ₃ , H ₃ BO ₃ , and AlPO ₄ It may include one or more selected from.

The stabilizer may be included in an amount of 5 to 30% by weight or 7.0 to 20% by weight based on the total weight of the solid binder for fireproof materials. If the content of the stabilizer is less than the above range, cracks may occur on the surface of the binder during the drying process, and if it exceeds the above range, hot strength and forming strength may be reduced.

pot life regulator

The pot life regulator serves to prevent stability deterioration due to moisture evaporation of the solid binder for fireproof materials and to control pot life of the binder by adjusting the water content of the binder.

In addition, the pot life regulator may include at least one selected from the group consisting of glycerin, ethylene glycol, propylene glycol, stearic acid, carbomer, xanthan gum, cellulose, and methyl cellulose.

The pot life regulator may be included in an amount of 0.2 to 5% by weight, or 0.5 to 3.0% by weight based on the total weight of the solid binder for fireproof materials. If the content of the pot life adjuster is less than the above range, it cannot properly function as a pot life adjuster, and if it exceeds the above range, problems such as reduced molding specific gravity and dry strength of the manufactured product may occur.

In addition, the solid binder for fireproof materials according to the present invention as described above may further include coke powder. When coke powder is additionally included as described above, the solid binder may be used as a binder for surface treatment of a refractory material, in particular, a coating binder. At this time, the content of the coke powder may be used without particular limitation as long as it has viscosity and workability suitable for use for surface treatment, particularly for coating.

As described above, the solid binder for refractory materials according to the present invention has excellent kneading properties and shortens kneading time compared to phenolic resins, which are conventionally used binders, and thus has excellent economic efficiency. In addition, in the case of phenolic resin, aging time of 3 to 24 hours is required after kneading, and after molding, due to the nature of thermosetting resin, long drying is required at a high drying temperature, whereas the solid binder for refractories according to the present invention can be molded immediately after kneading Productivity can be improved, and due to the nature of the water-based binder, the drying time is also shortened, so there is an energy saving effect.

fireproof material

A refractory material according to the present invention includes a solid binder for the refractory material; and refractory materials;

The refractory material may be used without particular limitation as long as it is commonly used as a raw material for refractory materials, and includes, for example, at least one selected from the group consisting of magnesia-based, alumina-based, chromium-based, silica-based, and graphite-based refractory materials. can do. In this case, the graphite-based refractory material may include natural graphite, impression graphite, or expanded graphite.

Specifically, the refractory materials include magnesia-carbon refractories, magnesia-alumina-carbon refractories, alumina-magnesia-carbon refractories, magnesia-based refractories, magnesia-chromium refractories, magnesia-spinel refractories, alumina-silicon carbide- It may include at least one selected from the group consisting of carbon-based refractories.

The refractory material may include 100 parts by weight of the refractory material and 1 to 5 parts by weight of a solid binder for the refractory material. When the weight of the solid binder for refractory materials is less than the above range, that is, when a small amount of the solid binder for refractory materials is included based on the refractory material, the erosion resistance of the refractory material is reduced due to a decrease in molding strength, an increase in porosity and an increase in water absorption, When the weight of the solid binder exceeds the above range, that is, when an excessive amount of the solid binder for the refractory material is included based on the refractory material, the durability of the refractory material is reduced due to the volatilization of the binder at high temperature and the increase in porosity, resulting in a decrease in the lifespan of the refractory material (decreased erosion resistance) ) can cause problems.

In addition, the fireproof material may further include at least one selected from the group consisting of a stabilizer and a pot life regulator. In this case, the stabilizer and the pot life regulator are the same as those described in the solid binder for fireproof materials.

The fireproof material may include 100 parts by weight of the fireproof material, 0.1 to 5 parts by weight or 0.1 to 2 parts by weight of a stabilizer, and 0.2 to 5 parts by weight or 0.5 to 3.0 parts by weight of a pot life regulator. When the content of the stabilizer is less than the above range, cracks may occur on the surface of the refractory material during the drying process, and when it exceeds the above range, hot strength and forming strength of the refractory material may be reduced. In addition, when the content of the pot life regulator is less than the above range, the moisture content in the refractory material may be excessive, and when the content exceeds the above range, molding specific gravity and dry strength of the refractory material may be reduced.

The refractory material may further include a hot property improving agent.

Hot property improver

The hot property improver serves to improve the hot strength, erosion resistance, and oxidation resistance of the refractory material.

At this time, the hot property improver may be used without particular limitation as long as it can be added to the refractory material to improve hot property, for example, pitch, silicon nitride (Si ₃ N ₄ ), boron carbide (B ₄ C ) and at least one selected from the group consisting of carbon black.

The hot property improving agent may be included in an amount of 0.1 to 3 parts by weight or 0.1 to 1.0 parts by weight based on 100 parts by weight of the refractory material. If the content of the hot properties improving agent is less than the above range, a problem of not properly expressing the hot property improvement effect occurs, and if it exceeds the above range, the molding strength and dry properties of the refractory material may be reduced or the steel type may be affected.

firebrick

Firebrick according to the present invention includes a solid binder for the refractory material; and refractory materials;

At this time, the refractory material is as described in the refractory material.

The refractory brick may be a magnesia-carbon refractory brick, a magnesia-alumina-carbon refractory brick, an alumina-silica refractory brick, a magnesia-chromium refractory brick, an alumina-carbon refractory brick or a magnesia-based refractory brick.

In addition, the refractory bricks may be reduced-fired bricks, fired bricks, or unfired bricks.

As described above, the refractory material and/or fire brick according to the present invention does not contain organic resins such as phenolic resins, and thus does not generate volatile organic compounds (VOCs) during the manufacturing process, and thus is environmentally friendly. In addition, the refractory materials and/or refractory bricks have excellent physical properties required for refractory materials, such as compressive strength, porosity, erosion resistance, spalling resistance, and the like.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the description by the following examples is only intended to specifically describe specific embodiments of the present invention, and is not intended to limit or limit the scope of the present invention to the content described in these examples.

[Example]

Example 1 and Comparative Example 1. Preparation of solid binder for refractory materials

A solid binder for a refractory material was prepared using each component in an amount as shown in Table 1, and SEM pictures of the prepared solid binder for a refractory material are shown in FIGS. 1 and 2 . 1 is a SEM picture of the binder of Comparative Example 1, and FIG. 2 is a SEM picture of the binder of Example 1.

Specifically, in Comparative Example 1, a solid binder for a refractory material was prepared by simply mixing the refractory raw material and the organic acid. In addition, in Example 1, after mixing the refractory raw material and organic acid, water was added and reacted to obtain a first reactant, and then the first reactant was dried at 80 ± 20 ° C. for 12 hours, and then an impact mill was used as a grinding facility. It was pulverized to prepare a solid binder for fireproof materials having an average particle diameter of 0.074 mm.

Thereafter, 200 parts by weight of water was added to 200 parts by weight of the solid binder for the refractory material, and then the maximum temperature (reaction temperature) was measured using a digital thermometer. At this time, the test results are shown in FIGS. 3 and 4 .

Classification (parts by weight)	Comparative Example 1	Example 1
Light burned magnesia (refractory raw material)	100	100
Citric acid (organic acid)	100	100
water	0	60
Reaction temperature (℃)	60.9	26.7

As shown in Table 1, the binder of Comparative Example 1 prepared by simple mixing reacted with the moisture added for clay and kneading, and increased by 37 ° C compared to the initial temperature of 25 ° C.

On the other hand, the binder of Example 1 prepared by pulverizing the reactants subjected to the first reaction showed no significant change as the initial temperature increased by 2 ° C compared to 25 ° C. In the refractory manufacturing process, the rise in temperature during kneading is a factor that greatly affects the surface drying and formability of the refractory material, and in Example 1 compared to Comparative Example 1, there is little change in temperature to maintain stable mixing and sufficient pot life of the refractory material. can

Examples 2 to 11. Preparation of solid binder for refractory materials

A solid binder for a refractory material was prepared using each component in an amount as shown in Table 2.

Specifically, after mixing the refractory material and the organic acid, water was added and reacted to obtain a primary reactant. Thereafter, the primary reactant was dried at 80 ± 20 ° C. for 12 hours, and then pulverized with an impact mill, which is a grinding facility, to prepare a solid binder for refractories having an average particle diameter of 0.074 mm.

At this time, EDTA in Table 2 is ethylenediaminetetraacetic acid (Ethylenediaminetetraacetic acid), and the reaction temperature and reaction time were measured by using a digital thermometer to measure the maximum temperature, and the reaction time was measured by visually checking the reaction start time.

(parts by weight)		Example
		2	3	4	5	6	7	8	9	10	11
refractory raw materials	full-blown magnesia	100	-	-	-	-	-	-	-	-	-
	calcined magnesia	-	100	-	-	-	-	-	80	50	20
	small and medium magnesia	-	-	100	-	-	-	-	-	-	-
	light burned magnesia	-	-	-	100	-	-	-	20	50	80
	quicklime	-	-	-	-	100	-	-	-	-	-
	slaked lime	-	-	-	-	-	100	-	-	-	-
	calcined dolomite	-	-	-	-	-	-	100	-	-	-
organic acid	citric acid	100	100	100	100	100	100	100	100	100	100
	EDTA	-	-	-	-	-	-	-	-	-	-
water		60	60	60	60	60	60	60	60	60	60
Reaction temperature (℃)		98	97	95	106	120	112	118	98	100	103
Response time (seconds)		510	330	325	30	7	16	12	60	44	36

As shown in Table 2, the reaction rate between the refractory material and the organic acid was in the order of quicklime, slaked lime, calcined dolomite, light-burnt magnesia, small-medium magnesia (DBM), calcined magnesia, and molten magnesia, which is related to the hydration rate of the refractory raw material. was found to be determined by From this, it was also found that the reaction rate can be controlled by adding quicklime, slaked lime, calcined dolomite, etc. to magnesia such as pre-melted magnesia, calcined magnesia, DBM, and light-burnt magnesia.

In addition, it was found that the reaction temperature and reaction time can be controlled by adjusting the mixing ratio of calcined magnesia and light-burnt magnesia, which are refractory raw materials.

Examples 12 to 16. Preparation of refractory materials

A refractory material was prepared using each component in an amount as shown in Table 3.

Specifically, after mixing the refractory material and the organic acid in a weight ratio of 1:1, water was added and reacted to obtain a primary reactant. Thereafter, the primary reactant was dried at 80 ± 20 ° C. for 12 hours, and then a stabilizer was added and pulverized with an impact mill, which is a grinding facility, to prepare a solid binder for refractories having an average particle diameter of 0.074 mm.

Thereafter, refractory materials such as magnesia, aluminum, and impression graphite were mixed, a solid binder for refractories was added, kneaded at 25 to 30 ° C for 15 minutes, molded into a size of 60 mmX60 mm X 60 mm, and dried at 200 ° C for 12 hours to prepare a refractory material. .

Thereafter, the prepared refractory material was subjected to a rapid heating test at 900 ° C. Specifically, the refractory material was charged into an electric furnace at 900 ° C. and rapidly heated for 4 minutes, and then whether or not cracks occurred on the exterior of the refractory material was visually observed.

Classification (parts by weight)		Example
		12	13	14	15	16
fireproof material	magnesia	82	82	82	82	82
	aluminum	3	3	3	3	3
	impression graphite	15	15	15	15	15
Solid binder for refractory materials	Light burned magnesia (refractory raw material)	1.5	1.5	1.5	1.5	1.5
	Citric acid (organic acid)	1.5	1.5	1.5	1.5	1.5
	MgSO 4 (stabilizer)	-	0.45	-	-	0.5
	Al 2 (SO 4 ) 3 (stabilizer)	-	-	0.45	-	-
	H 3 BO 3 (stabilizer)	-	-	-	0.45	0.25
Properties of refractory materials	Bulk Specific Gravity (g/cm 3 )	3	3.01	3	3.01	3.01
	Porosity (%)	4.5	4.2	4.2	4.3	4.1
	Compressive strength (kg/cm 2 )	350	375	372	369	371
	900℃ rapid heating test	surface fine grain	no crack	no crack	no crack	no crack

As shown in Table 3, when the stabilizer MgSO ₄ , Al ₂ (SO ₄ ) ₃ , or H ₃ BO ₃ is added to the refractory binder, surface fine cracks occur during rapid heating compared to Example 12, which is not added. showed a decreasing trend, and overall dry properties were improved.

Examples 17 to 23 and Comparative Examples 2 and 3. Preparation of refractory materials

A refractory material was prepared using each component in an amount as shown in Table 4.

Specifically, after mixing the refractory material and the organic acid, water was added and reacted to obtain a primary reactant. Thereafter, the primary reactant was dried at 80 ± 20 ° C. for 12 hours, and then boric acid (H ₃ BO ₃ ) as a stabilizer was added and pulverized with an impact mill, which is a grinding facility, to prepare a solid binder for refractory materials having a particle size of 0.074 mm.

Thereafter, refractory materials such as magnesia, aluminum, and impression graphite are mixed, a solid binder for refractory materials is added, kneaded at 25 to 35°C for 15 minutes, molded into a size of 60mmX60mmX60mm, dried at 200°C for 12 hours, and then dried at 1000°C for 12 hours. A refractory material was prepared by time firing.

At this time, a product having a bulk specific gravity of 0.98 g/cm ³ , a specific surface area of 1 m ² /g, and an average particle diameter of 350 μm was used as the impression graphite, and a product having an average particle diameter of 4 mm was used as magnesia. In addition, 8027 of Gangnam Hwaseong Co., Ltd. was used as a phenol resin, and molasses from Daesang Co., Ltd. (total solid content: 80% by weight or more) was used as molasses.

The physical properties of the prepared refractory materials were measured in the following manner, and specific gravity after molding, physical properties after drying, physical properties after firing, and erosion resistance were compared as the amount of citric acid added during binder preparation was increased.

1) Volume specific gravity

In accordance with KSL 3114 (2010), the refractory material was put in white kerosene (impregnation liquid), and the bulk specific gravity was calculated after drying or firing using Equation 1 below.

[Equation 1]

ρ _b (volume specific gravity) = m ₁ / (m ₃ -m ₂ ) X ρ _liq

m ₁ : dry mass of refractory material (g)

m ₂ : Apparent mass of impregnated refractory material (g)

m ₃ : Mass of impregnated specimen (g)

ρ _liq : Density of impregnating liquid

2) Compressive strength

The compressive strength of the dried refractory material having a size of 60mmX60mmX60mm was measured using a hydraulic compressive strength tester according to the method described in KS L 3115.

3) Porosity

In accordance with KSL 3114 (2010), the refractory material was put in white kerosene (impregnation liquid), and the apparent porosity after drying or firing was calculated using Equation 2 below.

[Equation 2]

π _a (porosity) = (m ₃ -m ₁ )/(m ₃ -m ₂ ) X 100

m ₁ : dry mass of refractory material (g)

m ₂ : Apparent mass of impregnated refractory material (g)

m ₃ : Mass of impregnated specimen (g)

4) Corrosion resistance

Using a rotary erosion tester, the refractory material was heated to 1,650 ~ 1,700 ° C with a burner, and steel and steelmaking slag as an erosion agent were mixed at a weight ratio of 1: 1 to measure the erosion resistance of the mixture. .

Specifically, the erosion resistance was expressed as a relative erosion index, with the erosion amount of Example 20 being 100. In this case, the lower the erosion index, the better the erosion resistance.

5) Harmful gas analysis

Thermal analysis and mass spectrometry (STA-MS) was used to analyze the components of the gas (decomposition gas) released when the weight is reduced during thermal decomposition analysis of the binder, and the analysis results are shown in FIGS. 5 and 6 . 5 is a gas component analysis result of Comparative Example 2, and FIG. 6 is a gas component analysis result of Example 18.

Classification (parts by weight)			comparative example		Example
			2	3	17	18	19	20	21	22	23
fireproof material		magnesia	82	82	82	82	82	82	82	82	82
		aluminum	3	3	3	3	3	3	3	3	3
		impression graphite	15	15	15	15	15	15	15	15	15
phenolic resin			3	-	-	-	-	-	-	-	-
molasses			-	3	-	-	-	-	-	-	-
bookbinder	calcined magnesia		-	-	2.04	1.608	1.34	1.005	0.67	0.402	0.32
	lightly burned magnesia		-	-	0.51	0.792	0.66	0.495	0.33	0.198	0.08
	Total amount of magnesia		-	-	2.55	2.4	2	1.5	One	0.6	0.4
	Citric acid (organic acid)		-	-	0.45	0.6	One	1.5	2	2.4	2.6
	H 3 BO 3 (stabilizer)				0.45	0.45	0.45	0.45	0.45	0.45	0.45
specific gravity after molding			3	2.98	2.97	2.99	3	3.01	2.99	2.99	2.99
after drying	Bulk Specific Gravity (g/cm 3 )		2.98	2.97	2.96	2.98	2.99	2.99	2.97	2.98	2.97
	Porosity (%)		4.7	5.6	6.2	4.9	4.8	4.2	4.9	4.6	5.2
	Compressive strength (kg/cm 2 )		370	315	294	362	371	392	366	374	325
after firing	Bulk Specific Gravity (g/cm 3 )		2.96	2.94	2.94	2.96	2.95	2.97	2.96	2.95	2.94
	Porosity (%)		9.5	13.6	16.2	9.6	9.4	9.2	9.8	9.7	10.5
	Compressive strength (kg/cm 2 )		343	214	198	331	329	352	331	338	254
erosion resistance			115	135	140	150	110	100	110	120	140

As shown in Table 4, Examples 18 to 22 exhibited the molding specific gravity, physical properties after drying, and physical properties after firing at the same level as those of Comparative Examples 2 and 3. In particular, Example 20 in which the weight ratio of the refractory raw material to citric acid was 1:1 was excellent in corrosion resistance compared to Comparative Example 2 using a phenol resin.

In Example 17, the organic acid content compared to the total amount of refractory raw materials was low, resulting in poor binder properties. In addition, in Example 23, due to the excessive amount of organic acid compared to the content of the refractory material, it reacted with the clay and caused surface drying, resulting in a decrease in the molding strength of the refractory material.

As shown in FIG. 5, in Comparative Example 2, benzene (C ₆ H ₆ ), toluene (C ₇ H ₈ ), and phenol (C ₆ H ₅ OH) were released. On the other hand, as shown in FIG. 6, the binder of Example 18 is environmentally friendly because no harmful substances such as benzene (C ₆ H ₆ ), toluene (C ₇ H ₈ ), and phenol (C ₆ H ₅ OH) are emitted. did.

Examples 24 to 28. Preparation of refractory materials

A refractory material was prepared using each component in an amount as shown in Table 5.

Specifically, after mixing 34 parts by weight of calcined magnesia, 16 parts by weight of calcined magnesia, and 50 parts by weight of citric acid, water was added and reacted to obtain a primary reactant. Then, after drying at 80 ± 20 ° C. for 12 hours, 10 parts by weight of boric acid and 5 parts by weight of magnesium sulfate were added to the primary reactant as a stabilizer, and pulverized with an impact mill, an average particle diameter of 0.074 mm. did

Thereafter, refractory materials such as magnesia, aluminum, and impression graphite were mixed, solid binder-1 for refractory materials was added, kneaded at 25 to 30°C for 15 minutes, molded into a size of 60mmX60mmX60mm, dried at 200°C for 12 hours, and then dried at 1000°C. It was fired for 12 hours to prepare a refractory material.

At this time, pitch (pitch) of CABORES-P of RUTGERS was used as a hot property improving agent, and carbon black having an average diameter of 0.01 mm was used. In addition, phenol resin 8027 of Gangnam Chemical Co., Ltd. was used.

Physical properties after drying, physical properties after firing, and erosion resistance of the prepared refractory material were measured in the same manner as in Example 17, and spalling resistance and residual linear expansion were measured in the following manner.

1) Spalling resistance

After making molten steel by melting metal at 1,650℃ using a high-frequency induction furnace, refractory material of size 230mmX40mmX40mm is immersed in molten steel for 60 seconds and then cooled in air for 5 minutes, which is a cycle until spalling (crack) occurs in the refractory material. number was recorded. The greater the number of cycles measured, the better the spalling resistance.

2) Residual linear expansion

After firing, the linear change rate of the refractory material was measured. A refractory material with a size of 50mmX40mmX60mm was charged into a crucible filled with coke to induce a reducing atmosphere, fired at 1,500℃ for 5 hours, cooled to room temperature, and then compared to the initial length of the refractory material. The linear change rate was measured by measuring the changed length. At this time, pictures of the refractory material before and after firing are shown in FIGS. 7 and 8, FIG. 7 is a picture of the refractory material of Comparative Example 2, and FIG. 8 is a picture of the refractory material of Example 24.

Classification (parts by weight)		comparative example	Example
		2	24	25	26	27	28
fireproof material	magnesia	82	82	82	82	82	82
	aluminum	3	3	3	3	3	3
	impression graphite	15	15	15	15	15	15
Solid binder for refractory material-1		-	3	3	3	3	3
phenolic resin		3	-	-	-	-	-
Hot property improver	pitch	-	-	0.4	-	-	-
	carbon black	-	-	-	0.4	-	-
	B4C	-	-	-	-	0.4	-
	Si 3 N 4	-	-	-	-	-	0.4
molding specific gravity		3.00	2.99	3.00	3.00	3.01	3.01
after drying	Bulk Specific Gravity (g/cm 3 )	2.98	2.98	2.99	2.99	3.00	2.99
	Porosity (%)	4.70	4.80	4.20	4.30	4.10	4.20
	Compressive strength (kg/cm 2 )	370	371	391	389	381	379
after firing	Bulk Specific Gravity (g/cm 3 )	2.96	2.96	2.98	2.97	2.98	2.98
	Porosity (%)	9.50	10.10	8.90	9.40	9.40	9.20
	Compressive strength (kg/cm 2 )	343	331	344	351	337	334
erosion resistance		115	100	97	98	94	91
resistance to spalling		14	13	15	16	14	14
Residual linear expansion		0.43%	0.74%	0.65%	0.61%	0.69%	0.51%

As shown in Table 5, the refractory materials of Examples 26 to 30 to which a hot property improver such as pitch or carbon black was added improved molding specific gravity, physical properties after drying, and physical properties after firing than Example 25 without a hot property improver. . In particular, Examples 25 to 28 were superior in erosion resistance and spalling resistance to Comparative Example 2. In addition, Example 28 including silicon nitride (Si ₃ N ₄ ) has improved corrosion resistance by 10% or more compared to Comparative Example 2, and residual linear expansion is greatly improved compared to Comparative Example 2 using the existing phenolic resin.

As shown in FIGS. 7 and 8 and Table 5, the refractory material of Example 24 compared to the refractory material of Comparative Example 2 to which a phenolic resin, a conventional binder, was applied had excellent residual linear expansion property, preventing penetration of molten steel in the wood paper (brick bonding) part, Erosion of the site was prevented.

Claims (20)

1. basic refractory raw materials; And an organic acid containing three or more functional groups; comprising a primary reactant, a solid binder for fireproof materials.
2. The method of claim 1,

   The refractory raw material includes at least one selected from the group consisting of magnesia, quicklime (CaO), slaked lime (Ca(OH) ₂ ) and calcined dolomite (MgO CaO).
3. The method of claim 2,

   The magnesia is at least one selected from the group consisting of acustic calcined magnesia, fused magnesia, sintered magnesia, and dead burned magnesia.
4. The method of claim 1,

   The organic acid is a solid binder for fireproof materials comprising at least one selected from the group consisting of citric acid and ethylenediaminetetraacetic acid.
5. The method of claim 1,

   A solid binder for fireproof materials comprising a refractory raw material and an organic acid in a weight ratio of 1:0.25 to 4.0.
6. The method of claim 1,

   A solid binder for fireproof materials, further comprising at least one selected from the group consisting of a stabilizer and a pot life regulator.
7. The method of claim 6,

   The stabilizer comprises at least one selected from the group consisting of inorganic salts and inorganic acids, a solid binder for fireproof materials.
8. The method of claim 6,

   A solid binder for fireproof materials comprising a stabilizer of 5 to 20% by weight based on the total weight of the solid binder for fireproof materials.
9. The method of claim 6,

   The pot life regulator includes at least one selected from the group consisting of glycerin, ethylene glycol, propylene glycol, stearic acid, carbomer, xanthan gum, cellulose, and methyl cellulose.
10. A solid binder for fireproof materials according to any one of claims 1 to 9; and

    A refractory material comprising; a refractory material.
11. The method of claim 10,

    The refractory material includes at least one selected from the group consisting of magnesia-based, alumina-based, chromium-based, silica-based, and graphite-based refractory materials.
12. The method of claim 10,

    A fireproof material further comprising at least one selected from the group consisting of a stabilizer and a pot life regulator.
13. The method of claim 12,

    The stabilizer includes at least one selected from the group consisting of inorganic salts and inorganic acids.
14. The method of claim 12,

    The visible time regulator includes at least one selected from the group consisting of glycerin, ethylene glycol, propylene glycol, stearic acid, carbomer, xanthan gum, cellulose, and methyl cellulose.
15. The method of claim 12,

    A fire resistant material comprising 100 parts by weight of a fire resistant material, 5 to 20 parts by weight of a stabilizer and 0.2 to 5 parts by weight of a pot life regulator.
16. The method of claim 10,

    A refractory material comprising 100 parts by weight of a refractory material and 1 to 5 parts by weight of a solid binder for the refractory material.
17. A solid binder for fireproof materials according to any one of claims 1 to 9; And a refractory material; including, refractory bricks.
18. The method of claim 17

    The refractory material includes at least one selected from the group consisting of magnesia-based, alumina-based, chromium-based, silica-based, and graphite-based refractory materials.
19. The method of claim 17

    Refractory brick, which is a magnesia-carbonaceous refractory brick, a magnesia-alumina-carbonaceous refractory brick, an alumina-silica refractory brick, a magnesia-chromium refractory brick, an alumina-carbonaceous refractory brick or a magnesia-based refractory brick.
20. The method of claim 17

    Refractory bricks, which are reduced fired bricks, fired bricks or unfired bricks.

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