Liquid binder for refractory materials and refractory bricks containing the same

Abstract

The present invention relates to a liquid binder for refractory materials, which contains a reaction product of a basic compound containing one or more selected from the group consisting of alkali metals and alkaline earth metals; and an organic acid containing three or more functional groups, and a refractory brick containing the same.

Description

Technical Field

[0001] The present invention relates to a liquid binder for refractory bricks having excellent environmental friendliness and refractory bricks containing the same, since it is possible to produce refractory bricks with less generation of harmful gases and excellent quality.

Background Art

[0002] Generally, refractory bricks used in the iron and / or steel manufacturing process require high corrosion resistance and high heat resistance, and such refractory bricks are mainly used in electric furnaces, converters, ladles, hot metal cars, etc. Conventionally, refractory bricks were manufactured using a phenolic resin as a binder, but refractory bricks manufactured using a phenolic resin are thermally decomposed by the heat generated during iron and steel manufacturing operations to generate various decomposition gases. Since such decomposition gases contain a large amount of aromatic organic compounds, they are known to have an adverse effect on the human body. In particular, phenol, cresol, xylenol, etc. in the decomposition gases have a strong pungent odor and generate a serious foul odor, polluting the working environment and the surrounding environment.

[0003] Conventionally, as a method for improving such problems, the refractory bricks were preheated and used until the thermal decomposition of the phenolic resin was completed. However, such a method has a limited effect of reducing foul odor and has a limit in that it adversely affects the physical properties of the refractory bricks. In addition, since harmful gases are generated not only at the use site but also at the manufacturing site in the preheating method, this was not a fundamental solution.

[0004] As an alternative to this, Korean Registered Patent No. 967408 (Patent Document 1) discloses a carbon-containing refractory material composition containing a carbon-containing refractory aggregate and a binder, wherein the binder is a carbon-containing refractory material composition composed of magnesium sulfate, lignosulfonate and water. However, like Patent Document 1, refractory bricks containing magnesium sulfate, lignosulfonate, etc. have problems such as thermal decomposition occurring during high-temperature exposure and insufficient hot physical properties and insufficient erosion resistance.

[0005] Therefore, there is a need for research and development on a refractory binder for producing refractory materials with less generation of harmful gases during high-temperature exposure and excellent physical properties such as hot properties, strength, and erosion resistance, and refractory bricks containing the same.

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, the present invention aims to provide a liquid binder for refractory materials that can produce refractory materials with less generation of harmful gases during high-temperature exposure and excellent physical properties such as hot properties, strength, and erosion resistance, and refractory bricks containing the same.

Means for Solving the Problems

[0007] The present invention provides a liquid binder for refractory materials, which contains a reaction product of a basic compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals; and an organic acid containing three or more functional groups.

[0008] In addition, the present invention provides a refractory material containing the liquid binder for refractory materials and a refractory material.

[0009] In addition, the present invention provides refractory bricks containing the liquid binder for refractory materials and a refractory material.

Effects of the Invention

[0010] The liquid binder for refractories according to the present invention is environmentally friendly because it does not emit aromatic organic compounds generated while being thermally decomposed by heating, which is a problem of conventional phenolic resin binders. In addition, while phenolic resin requires a curing time of 3 to 24 hours after kneading, the liquid binder for refractories according to the present invention can be molded immediately after kneading, so it is excellent in productivity and kneadability and can shorten the kneading time. Furthermore, thermoplastic resins such as phenolic resin require heat treatment at a certain temperature or higher to develop strength after molding, while the liquid binder for refractories according to the present invention is an aqueous binder, so it can significantly shorten the drying time and reduce energy costs.

[0011] In addition, the refractory and / or refractory brick containing the liquid binder for refractories is excellent in physical properties such as hot properties, strength, and erosion resistance, so it is applicable to industrial fields where high-temperature melts such as ironmaking and steelmaking are used. In particular, since the refractory and / or refractory brick has excellent refractory performance, it can be applied to various fields such as refining processes in electric furnaces, ladles, converters, hot metal cars, steelmaking, and ironmaking.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described in detail.

[0014] Liquid binder for refractories The liquid binder for refractories of the present invention contains a basic compound and a reaction product of an organic acid containing 3 or more functional groups.

[0015] Since the liquid binder for refractory materials is in a liquid form, it has excellent storage stability, excellent kneadability with refractory materials, and no emission of harmful gases, which is a problem of phenolic resins, so it has the effect of being excellent in environmental friendliness.

[0016] Basic compound The basic compound plays a role of reacting with an organic acid to impart viscosity to the binder.

[0017] The basic compound contains one or more selected from the group consisting of alkali metals and alkaline earth metals.

[0018] The alkali metal can contain one or more selected from the group consisting of one or more metals selected from the group consisting of sodium (Na) and potassium (K), its oxides, hydrates, halides, sulfides, nitrides, oxygen acid salts, carbonates and organic acid salts. Specifically, the alkali metal can contain one or more selected from the group consisting of NaOH, NaCl, Na2O, Na2CO3, NaHCO3, 2Na2CO3·3H2O2, K2O, KOH, KCl, K2S and KNH2.

[0019] The alkaline earth metal can contain one or more selected from the group consisting of one or more metals selected from the group consisting of magnesium (Mg) and calcium (Ca), its oxides, hydrates, halides, sulfides, nitrides, oxygen acid salts, carbonates and organic acid salts. Specifically, the alkaline earth metal consists of MgO, Mg(OH)2, MgCO3, MgO·CaO, MgCO3·CaCO3, CaO, CaCO3, and Ca ( OH ) 2 and can contain one or more selected from the group selected therefrom. At this time, the magnesium oxide (MgO) may be one or more selected from the group consisting of lightly calcined magnesia, fused magnesia, sintered magnesia and dead burned magnesia.

[0020] The basic compound may have an average diameter of 5.0 mm or less, from 0.01 mm to 5.0 mm, from 0.01 to 1.0 mm, from 0.01 mm to 0.3 mm, or from 0.01 mm to 0.045 mm. When the average diameter of the basic compound is within the above range, due to the high specific surface area, the reactivity with the organic acid is high, so a reaction product with high purity can be produced. On the other hand, when the average diameter of the basic compound exceeds the above range, the reactivity with the organic acid is insufficient, and there may be problems such as a longer reaction time required to exhibit sufficient viscosity in the binder and the unreacted components affecting the homogeneity of the binder and thus the physical properties of the manufactured product such as the hot strength.

[0021] organic acid The organic acid plays a role of reacting with the basic compound to impart viscosity to the binder.

[0022] The organic acid contains 3 or more functional groups. At this time, the functional group may be a carboxy group (COOH). As described above, when an organic acid containing 3 or more functional groups is used, there is an effect of reacting with the basic compound to exhibit strong viscosity.

[0023] Specifically, the organic acid can include one or more selected from the group consisting of citric acid and ethylenediaminetetraacetic acid.

[0024] The organic acid and the basic compound can be included in a weight ratio of 5 to 100:1.0, 5 to 50:1.0, or 5 to 25:1.0. When the weight ratio of the organic acid to the basic compound is less than the above range, that is, when a small amount of organic acid is included based on the weight of the basic compound, the basic compound remaining after reacting with the organic acid may react further with the reaction product, resulting in the loss of the binder's viscosity, precipitation in the binder, or a decrease in the strength of the manufactured refractory material. Also, when the weight ratio of the organic acid to the basic compound exceeds the above range, that is, when an excessive amount of organic acid is included based on the weight of the basic compound, there are not enough positive (+) ions of the basic compound that can react with the organic acid, so the viscosity of the binder becomes insufficient, and unreacted organic acid remains in the binder and reacts with the refractory material during product manufacturing, generating heat, shortening the pot life, or causing surface drying of the product and a decrease in strength.

[0025] The liquid binder for the refractory material can further contain water.

[0026] Water For example, the liquid binder can contain a reaction product in which a basic compound is added to an aqueous organic acid solution containing an organic acid and water, and the positive (+) ions of the basic compound react with the organic acid.

[0027] Water and the organic acid can be included in a weight ratio of 1.0:0.2 to 0.8, 1.0:0.3 to 0.8, or 1.0:0.33 to 0.75. At this time, when the content ratio of water 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 water, there may be a problem that the strength of the manufactured refractory material decreases due to a decrease in the binder concentration. Also, when the content ratio of water to the organic acid exceeds the above range, that is, when an excessive amount of organic acid is included based on the weight of water, precipitation occurs in the binder, resulting in a decrease in the binder's viscosity and a possible decrease in the strength of the manufactured refractory material.

[0028] The liquid binder can contain water, an organic acid, and a basic compound in a weight ratio of 1:0.3 to 1.0:0.01 to 0.20, a weight ratio of 1:0.3 to 0.75:0.02 to 0.17, or a weight ratio of 1:0.33 to 0.75:0.025 to 0.15.

[0029] In addition, the binder for refractory materials can further contain one or more selected from the group consisting of a stabilizer and a viscosity enhancer.

[0030] Stabilizer The stabilizer plays a role in preventing the shortening of the pot life due to unreacted organic acid by reacting the unreacted organic acid with the excess basic compound, and preventing the occurrence of precipitation of the binder due to the excess basic compound.

[0031] In addition, the stabilizer may be an organic acid or an inorganic salt, and specifically, can contain one or more selected from the group consisting of tartaric acid, lactic acid, phosphoric acid, oxalic acid, boric acid, and phosphorous acid.

[0032] The stabilizer may be contained in an amount of 0.1 to 15% by weight, or 1 to 8% by weight based on the total weight of the binder for refractory materials. If the content of the stabilizer is less than the above range, the pot life of the binder may be shortened or precipitation may occur, resulting in a decrease in the strength and hot strength of the manufactured refractory material. If it exceeds the above range, the occurrence of precipitation of the binder due to the excess stabilizer and the decrease in viscosity may cause a decrease in the strength and / or hot strength of the manufactured refractory material.

[0033] Viscosity enhancer The viscosity enhancer plays a role in increasing the viscosity of the liquid binder for refractory materials, preventing a decrease in stability due to water evaporation, and improving the kneadability with the refractory material.

[0034] In addition, the viscosity enhancer can contain one or more selected from the group consisting of, for example, corn starch, potato starch, carbomer, xanthan gum, methyl cellulose, methymethyl cellulose, and molasses.

[0035] The tackifier may be contained in an amount of 0.1 to 10% by weight, or 0.5 to 5.0% by weight, based on the total weight of the liquid binder for refractory materials. When the content of the tackifier is less than the above range, it is difficult to obtain the effect of adding the tackifier. When it exceeds the above range, aggregation of the binder may occur due to an excessive amount of the tackifier, resulting in a decrease in the kneading homogeneity during kneading with the refractory material, and a decrease in physical properties such as the specific gravity and dry strength of the manufactured product may occur.

[0036] In addition, the liquid binder for refractory materials according to the present invention as described above may further contain coke powder. When coke powder is further contained in this way, the liquid binder may be used as a binder for surface treatment of refractory materials, particularly for coating. At this time, the content of the coke powder can be used without particular limitation as long as it has appropriate viscosity and workability for use as a surface treatment, particularly for coating.

[0037] The liquid binder for refractory materials according to the present invention as described above is excellent in kneadability, shortening the kneading time, and is excellent in economy, compared with the phenolic resin which is a conventionally commonly used binder. In addition, in the case of phenolic resin, a ripening time of 3 to 24 hours is required after kneading. On the other hand, the liquid binder for refractory materials according to the present invention can be molded immediately after kneading, so the productivity can also be improved, the drying time is shortened, and there is also an effect of energy saving.

[0038] Refractory The refractory material according to the present invention includes the liquid binder for refractory materials as described above; and refractory materials.

[0039] The refractory material can be used without special restrictions as long as it is usually used as a raw material for refractory materials. For example, it can include one or more selected from the group consisting of magnesia-based, alumina-based, chrome-based, dolomite-based, and graphite-based refractory materials. Specifically, the refractory material can include one or more selected from the group consisting of magnesia-carbon-based, magnesia-alumina-carbon-based, alumina-silica-based, magnesia-chrome-based, magnesia-spinel-based, alumina-silicon carbide-carbon-based, alumina-carbon-based, and magnesia-based refractory materials. Examples of the graphite-based refractory material can include natural graphite, flake graphite, or expanded graphite.

[0040] Also, the refractory material can contain 1 to 10 parts by weight or 1 to 5 parts by weight of a liquid binder for refractory materials with respect to 100 parts by weight of the refractory material. When the parts by weight of the refractory material and the liquid binder are less than the above range, that is, when a small amount of the liquid binder is contained with respect to the weight of the refractory material, a decrease in the erosion resistance of the refractory material due to a decrease in the forming strength and hot strength occurs. When the parts by weight of the refractory material and the liquid binder exceed the above range, that is, when an excessive amount of the liquid binder is contained with respect to the weight of the refractory material, problems such as an agglomeration phenomenon during kneading, a cracking phenomenon during pressing, and a decrease in strength due to the volatilization of the binder at high temperature and a decrease in life (a decrease in erosion resistance) due to an increase in porosity may occur.

[0041] Also, the refractory material can further include one or more selected from the group consisting of a stabilizer and a viscosity enhancer. At this time, the stabilizer and the viscosity enhancer are as described for the liquid binder.

[0042] The refractory material can further include a hot property improver.

[0043] Hot property improver The hot property improver plays a role in improving the hot strength, erosion resistance, oxidation resistance, etc. of the refractory material.

[0044] At this time, the hot property improver can generally be used without special limitation as long as it can be added to the refractory material for improving the hot properties. For example, it can contain one or more selected from the group consisting of pitch, silicon nitride (Si3N4), boron carbide (B4C), and carbon black.

[0045] The hot property improver may be contained in an amount of 0.1 to 3.0 parts by weight or 0.1 to 1.0 parts by weight based on 100 parts by weight of the refractory material. When the content of the hot property improver is less than the above range, the effect of improving the hot properties of the refractory material cannot be fully exhibited. When it exceeds the above range, the molding strength and drying physical properties of the refractory material may decrease or may affect the steel type.

[0046] Refractory brick In addition, the refractory brick according to the present invention includes the binder for the refractory material; and the refractory material.

[0047] At this time, the refractory material is as described for the refractory material.

[0048] The refractory brick may be a magnesia-carbon refractory brick, a magnesia-alumina-carbon refractory brick, an alumina-silica refractory brick, a magnesia-chrome refractory brick, a magnesia-spinel refractory brick, an alumina-silicon carbide-carbon refractory brick, an alumina-carbon refractory brick, an alumina-silicon carbide-magnesia refractory brick, or a magnesia refractory brick.

[0049] In addition, the refractory brick may be a reduced-fired brick, a fired brick, or an unfired brick.

[0050] The refractory material and / or refractory brick according to the present invention as described above do not contain organic resins such as phenolic resins and are environmentally friendly because volatile organic compounds (VOCs) are not generated during the manufacturing process. Further, the refractory material and / or refractory brick are excellent in the required physical properties of refractory materials, such as compressive strength, porosity, erosion resistance, spalling resistance, etc., and thus can be applied to industrial fields where high-temperature melts such as iron and steel production are used. In particular, since the refractory material and / or refractory brick are excellent in refractory performance, they can be applied to various fields such as refining processes in electric furnaces, ladles, converters, hot metal cars, steelmaking, and ironmaking.

Example

[0051] Hereinafter, the present invention will be described more specifically with reference to the following examples. However, the description according to the following examples is only intended to specify and describe specific embodiments of the present invention, and is not intended to limit or interpret the scope of the rights of the present invention to the contents described in these examples.

[0052] [Example] Examples 1 to 8. Production of Liquid Binder for Refractory Material A liquid binder for refractory material was produced using each component in the content as described in Table 1.

[0053] Specifically, after mixing water and an organic acid, a basic compound was added to react basic positive (+) ions with the organic acid to produce a liquid binder for refractory material. During the production of the liquid binder, the reaction temperature, reaction time, and viscosity were measured. For the reaction temperature and reaction time, the maximum value of the temperature value was measured using a digital thermometer, and for the reaction time, the time when the reaction temperature reached the highest point was measured. Also, the viscosity of the liquid binder was measured by classifying it as high, medium, and low by touch.

[0054]

Table 1

[0055] As shown in Table 1, the reaction rates of the basic compounds and the organic acids appeared in the order of KOH, NaOH, Na2O, K2O, 2Na2CO3·3H2O2, NaHCO3, KCl, and NaCl. Also, regardless of the reaction temperature and reaction rate, the binder viscosities were strong for the binders produced using NaOH, NaHCO3, and 2Na2CO3·3H2O2, and the binders produced using K2O, KOH, KCl, Na2O, and NaCl showed relatively low viscosities.

[0056] Examples 9 to 13. Production of a liquid binder for refractories A liquid binder for refractories was produced using each component in the contents as described in Table 2.

[0057] Specifically, water and an organic acid were mixed at a weight ratio of 2:1, sodium hydroxide (NaOH) was added as a basic compound, and then the reaction temperature, reaction time, and viscosity were measured in the same manner as in Example 1.

[0058]

Table 2

[0059] As shown in Table 2, the reaction temperature, reaction time, and viscosity due to the addition amount of NaOH, which is a basic compound, were shown. As the addition amount of the basic compound increased from 3 to 15 parts by weight, the reaction temperature increased, but the viscosity appeared strongly at 5 to 7.5 parts by weight. Also, in Examples 9 and 10 where the addition amount of NaOH was 10% by weight or more, precipitates were formed during storage at room temperature for 5 hours or more, and the viscosity tended to decrease in the state where precipitates were formed.

[0060] Examples 14 to 25. Production of a liquid binder for refractories A liquid binder for refractories was produced using each component in the contents as described in Table 3.

[0061] Specifically, water and an organic acid were mixed at a weight ratio of 2:1. After adding a basic compound, the reaction temperature, reaction time, and viscosity of the binder were measured during the production of the binder. At this time, for the reaction temperature, the maximum value of the temperature was measured using a digital thermometer, and for the reaction time, the time when the reaction temperature reached the highest point was measured. The viscosity of the binder was measured by categorizing it as upper, middle, and lower by touch.

[0062]

Table 3

[0063] As shown in Table 3, the reaction rates of the basic compounds of alkaline earth metals and the organic acid are presented in the order of CaO, calcined dolomite, Ca ( OH ) 2, light-burned magnesia, CaCO3, MgCO3·CaCO3, Mg(OH)2, dead-burned magnesia (DBM), calcined magnesia, MgCO3, MgCl, and fused magnesia, and the viscosity of the binder appears in the order of light-burned magnesia, dead-burned magnesia, calcined magnesia, Mg(OH)2, fused magnesia, MgCO3, MgCO3·CaCO3, CaCO3, Ca(OH)2, MgCl, calcined dolomite, and CaO, regardless of the reaction rate and reaction temperature.

[0064] Examples 26 to 33. Production of a liquid binder for refractories A liquid binder for refractories was produced using each component in the contents as described in Table 4.

[0065] Specifically, water and an organic acid were mixed at a weight ratio of 2:1. While adjusting the addition amount of light-burned magnesia or CaO as the basic compound, the reaction time, reaction temperature, and viscosity of the binder were measured during production, and the reaction time, reaction temperature, and viscosity of the binder were measured in the same manner as in Example 14.

[0066]

Table 4

[0067] As shown in Table 4, when the addition amount of light-burned magnesia was increased from 3 to 10 parts by weight, the viscosity of the binder also increased. However, in Example 26 where 10 parts by weight of light-burned magnesia was added, precipitation occurred 5 hours after the production of the binder, resulting in a decrease in viscosity.

[0068] Also, in Examples 30 to 33 where the addition amount of CaO was changed from 1 to 5 parts by weight, the viscosity of the binder in Example 32 where the addition amount of CaO was 2 parts by weight was the highest. In Examples 30 and 31 containing 3 to 5 parts by weight of CaO, precipitation occurred and a decrease in viscosity was observed.

[0069] Examples 34 to 39. Production of liquid binder for refractory A liquid binder for refractory was produced using each component in the content as described in Table 5.

[0070] Specifically, while fixing the amount of the basic compound and adjusting the weight ratio of the organic acid to water, the reaction temperature, reaction time, and the viscosity of the binder during production were measured in the same manner as in Example 14.

[0071]

Table 5

[0072] As shown in Table 5, as the ratio of water to organic acid was 1.5:1, 2:1, 3:1 and the concentration increased, the reaction temperature during binder production increased, and the viscosity of the binder also increased.

[0073] As shown in Tables 1 to 5, when the addition amount of the basic compound increases or the content of the organic acid relative to water increases, the viscosity of the binder increases. As the addition amount of the basic compound increases, the amount of the basic compound in the eluted cationic (+) ion form increases, and the reaction product of the basic compound and the organic acid undergoes an additional reaction, which may form precipitation in the binder and cause a decrease in viscosity. Since such an additional reaction does not have a rapid reaction rate, it proceeds gradually after the production of the binder, resulting in precipitation in the binder and affecting the storage stability and quality stability of the binder.

[0074] Examples 40 to 44. Production of Liquid Binder for Refractory A liquid binder for refractory was produced using each component in the content as described in Table 6. At this time, as tartaric acid, L(+)-Tartaric acid (solid content: 99.5% by weight) of SAMCHUN pure chemical was used, and as lactic acid, Lactic acid (solid content: 88 ± 3% by weight) of SAMCHUN pure chemical was used.

[0075] Specifically, the storage stability and quality stability of the binder after adding the stabilizer to produce the binder were measured by the following methods and shown in Table 6.

[0076] 1) Storage stability 2 L of the liquid binder for refractory was put into a 2 L beaker, the upper part was sealed, and while storing for 2 months, the deterioration state of the binder and the presence or absence of precipitation were visually measured.

[0077] 2) Quality stability: Pot life 82 parts by weight of magnesia, 3 parts by weight of aluminum, and 15 parts by weight of flake graphite were mixed as refractory materials, 2 parts by weight of the liquid binder for refractory was added, kneaded at 25 to 35 °C for 15 minutes, and then molded into 60 mm × 60 mm × 60 mm at 1-hour intervals to produce a refractory. The pot life was defined as the time when the molding specific gravity of the produced refractory reached 3.0.

[0078] [Table 6]

[0079] As shown in Table 6, the addition of highly reactive tartaric acid and lactic acid, and phosphoric acid and boric acid which are inorganic acids improved the storage stability and quality stability of the binder. Also, since the stabilizer collects unreacted organic acids and basic compounds, it did not significantly affect the binder properties.

[0080] In addition, the stabilizer reacted with the unreacted organic acid, indicating an increase in the pot life. Furthermore, when the stabilizer is added in an amount of 9% by weight or more based on the total weight of the binder, precipitation may occur in the binder due to the excessive stabilizer. Therefore, it can be said that it is preferably used within the range of 3 to 9% by weight.

[0081] In addition, when the content of the organic acid in water increases, the viscosity of the binder is enhanced. However, when it reacts with MgO in the refractory material during product manufacturing, surface drying of the refractory material before molding may occur. Through the addition of the stabilizer, the reactivity with the refractory material and the pot life can also be ensured.

[0082] Examples 45 to 52. Production of liquid binder for refractory A liquid binder for refractory was produced using each component in the contents as described in Table 7.

[0083] Specifically, since the liquid binder for refractory according to the present invention is an aqueous binder, there may be a decrease in characteristics due to moisture evaporation during storage, and a decrease in quality stability due to moisture evaporation caused by heat generation during kneading. Therefore, after adding a viscosity enhancer to produce the binder, the viscosity, uniaxial molding strength, and moisture evaporability were measured by the following methods.

[0084] At this time, as the corn starch, maltodextrin of Dosan Co., Ltd. was used, as the potato starch, potato starch powder of Demyon Co., Ltd. was used, as the carbomer, carbomer of Jason CnT Co., Ltd. was used, as the xanthan gum, Xantan Gum of DEOSEN BIOCHEMICAL was used, and as the molasses, molasses of Dosan Co., Ltd. (total solid content: 80% by weight or more) was used.

[0085] 1) Viscosity It was measured at 25°C using a Brookfield viscometer by the method described in KS M ISO2555.

[0086] 2) Uniaxial molding strength 82 parts by weight of magnesia, 3 parts by weight of aluminum, and 15 parts by weight of flake graphite were mixed as refractory materials, and 2 parts by weight of a liquid binder for refractories was added to produce a refractory composition. Then, 300 g of the refractory composition was put into a mold of 40 mm × 70 mm (width × length), and 2 it was pressed at a pressure of 5 t / cm for 1 minute to produce a specimen. Then, after drying at 200 °C for 12 hours, the compressive strength was measured using a compression strength meter (Kumkang Equipment Co., Ltd.) and taken as the uniaxial forming strength.

[0087] 3) Moisture evaporability 100 g of the liquid binder for refractories was accurately weighed to measure the initial mass, and after being treated in a dryer at 40 °C for 1 hour, the mass (mass after heat treatment) was measured. Then, the mass reduction rate (weight %) of the mass after heat treatment with respect to the initial mass was measured.

[0088]

Table 7

[0089] As shown in Table 7, compared with the binder of Example 45 that does not contain a tackifier, the viscosity at 25 °C of the binders of Examples 46 to 51 that contain a tackifier increased to 300 - 370 cps. Also, compared with the binder of Example 46 that does not contain a tackifier, the specimens produced from the binders of Examples 47 to 52 had a 5 - 32% improvement in forming strength. Furthermore, compared with Example 45, in Examples 46 to 51, the weight reduction due to moisture evaporation was suppressed by 50% or more.

[0090] Also, the phenolic resin, which is a conventional binder, has a high viscosity of 400 cps at 25 °C and agglomeration occurs during kneading, but for the binder of the present invention, it was possible to ensure the pot life and improve the kneadability by controlling the addition amount and type of the tackifier.

[0091] Examples 52 to 57 and Comparative Examples 1 and 2. Production of magnesia - carbon (MgO - C) refractory bricks Using each component in the content as described in Table 8, a liquid binder for refractory materials was manufactured.

[0092] Specifically, after mixing water and an organic acid, a basic compound was added and reacted, and then a stabilizer and a viscosity enhancer were added to manufacture a liquid binder for refractory materials.

[0093] [Table 8]

[0094] Thereafter, using each component in the content as described in Table 9, refractory bricks, which are refractory materials, were manufactured. At this time, as the refractory materials, magnesia, aluminum, and flake graphite were mixed, a liquid binder for refractory materials was added, kneaded at 25 to 35°C for 15 minutes, then formed into 60 mm × 60 mm × 60 mm, dried at 200°C for 12 hours, and fired at 1000°C for 12 hours to manufacture the refractory materials.

[0095] At this time, as the flake graphite, a product with a bulk specific gravity of 0.98 g / cm 3 , a specific surface area of 1 m 2 / g, and an average particle size of 350 μm was used, and for magnesia, a product with an average particle size of 4 mm was used. Also, as the phenolic resin, 8027 (product number) of Konoike Chemical was used, and as the molasses, molasses of Desan Co., Ltd. (total solid content of 80% or more) was used.

[0096] The physical properties of the manufactured refractory materials were measured by the following method, and the molding specific gravity, physical properties after drying, physical properties after firing, and erosion resistance were compared according to the type and addition amount of the basic compound during binder production.

[0097] 1) Bulk specific gravity Based on KSL 3114 (2010), the refractory material was put into white kerosene (impregnating liquid), and the bulk specific gravity after drying or firing was calculated using the following formula 1.

[0098] [Formula 1] ρ b (Bulk specific gravity) = m1 / (m3 - m2) × ρliq m1: Dry mass of refractory (g) m2: Apparent mass of impregnated refractory (g) m3: Mass of impregnated specimen (g) ρ liq : Density of impregnating solution

[0099] 2) Porosity Based on KSL 3114 (2010), the refractory was placed in white kerosene (impregnating solution), and the apparent porosity after drying or firing was calculated using the following Equation 2.

[0100] [Equation 2] π a (Porosity) = (m3 - m1) / (m3 - m2) × 100 m1: Dry mass of refractory (g) m2: Apparent mass of impregnated refractory (g) m3: Mass of impregnated specimen (g)

[0101] 3) Compressive strength For a refractory with dimensions of 60 mm × 60 mm × 60 mm, the compressive strength was measured using a hydraulic compression strength testing machine by the method described in KSL 3115.

[0102] 4) Erosion resistance Using a rotary erosion tester, the refractory was heated to 1,650 - 1,700 °C with a burner, and the erosion resistance was measured using a mixture containing steel and steelmaking slag as an erosive agent at a weight ratio of 1:1.

[0103] The erosion resistance is indicated by the relative erosion index with respect to a reference specimen. The erosion index represents the erosion amount of Example 53 as 100. At this time, the lower the erosion index, the better the erosion resistance.

[0104] 5) Analysis of harmful gases Using a thermal analysis and mass spectrometer (STA-MS), the mass of the gas released when the weight decreased during the thermal decomposition analysis of the refractory was measured, the components of the released decomposition gas were analyzed, and the results are shown in FIGS. 1 and 2. FIG. 1 shows the results of the component analysis of the decomposition gas released from the refractory of Example 52, and FIG. 2 shows the results of the component analysis of the decomposition gas released from the refractory of Comparative Example 1.

[0105] 6) Residual linear expansibility It is to measure the linear change rate of the refractory after firing. A 50 mm × 40 mm × 60 mm refractory was placed in a crucible filled with coke, fired at 1,500 °C for 5 hours, cooled to room temperature, and then the ratio of the changed length to the initial length was calculated to measure the residual linear change.

[0106]

Table 9

[0107] As shown in Table 9, compared with Comparative Example 1 using a phenolic resin, the examples had equivalent or superior molding specific gravity, physical properties after drying, and physical properties after firing. In particular, in the cases of Examples 52 and 55, they were superior in molding specific gravity and erosion resistance compared to the refractories using phenolic resin and molasses as binders.

[0108] As shown in FIGS. 1 and 2, while benzene (C6H6), toluene (C7H8), and phenol (C6H5OH) were released from the refractory of Comparative Example 1 (see FIG. 2), the refractory of Example 52 did not release any benzene (C6H6), toluene (C7H8), or phenol (C6H5OH), which are harmful substances (see FIG. 1), and was excellent in environmental friendliness.

[0109] Examples 58 to 63 and Comparative Examples 3 and 4. Production of magnesia-alumina-carbon (MAC) refractory bricks A liquid binder for refractories was produced using each component in the contents as described in Table 8. Then, refractory bricks, which are refractories, were produced using each component in the contents as described in Table 10.

[0110] Specifically, magnesia, alumina, aluminum, and flake graphite, which are refractory materials, were mixed , a liquid binder for refractory materials was added, kneaded at 25 to 35°C for 15 minutes, then formed into a size of 60 mm × 60 mm × 60 mm, dried at 200°C for 12 hours, and fired at 1000°C for 12 hours to produce a refractory material. The physical properties of the produced refractory material were measured by the same method as in Example 52, and the erosion index was expressed by setting the erosion amount of Example 63 to 100.

[0111] At this time, as the flake graphite, a product with a bulk specific gravity of 0.98 g / cm 3 , a specific surface area of 1 m 2 / g, and an average particle size of 350 μm was used, and for magnesia, a product with an average particle size of 4 mm was used. Also, as the phenol resin, 8027 (product number) of Kono Kasei was used, and as the molasses, molasses of Desan Co., Ltd. (total solid content of 80% or more) was used.

[0112]

Table 10

[0113] As shown in Table 10, compared with Comparative Example 3, Examples 58 to 63 had equivalent or superior molding specific gravity, physical properties after drying, and physical properties after firing. In particular, compared with Comparative Examples 3 and 4 using phenol resin or molasses, which are conventional binders, as the binder, the refractory material of Example 61 had a large molding specific gravity, large bulk specific gravity after drying and firing, low porosity, and high compressive strength, so it had excellent physical properties and excellent erosion resistance. Examples 64 to 69 and Comparative Examples 5 and 6. Production of alumina-silicon carbide-magnesia (AGM) refractory bricks

[0114] A liquid binder for refractory materials was produced using each component in the content as described in Table 8. Then, refractory bricks, which are refractory materials, were produced using each component in the content as described in Table 11.

[0115] ​Specifically, magnesia, alumina, aluminum, and flake graphite, which are refractory materials, were mixed, a binder for refractory materials was added, and after kneading at 25 to 35 °C for 15 minutes, it was formed into a size of 60 mm × 60 mm × 60 mm and dried at 200 °C for 12 hours, and then fired at 1000 °C for 12 hours to produce a refractory material. The physical properties of the produced refractory material were measured by the same method as in Example 52, and the erosion index was expressed with the erosion amount of Example 65 as 100.

[0116] At this time, as the flake graphite, a product with a bulk specific gravity of 0.98 g / cm 3 , a specific surface area of 1 m 2 / g, and an average particle size of 350 μm was used, and for magnesia, a product with an average particle size of 4 mm was used. Also, as the phenolic resin, Kono Kasei's 8027 (product number) was used, and as the molasses, Desan Co., Ltd.'s molasses (total solid content of 80% or more) was used.

[0117]

Table 11

[0118] As shown in Table 11, compared with Comparative Example 5, Examples 64 to 69 had equivalent or superior molding specific gravity, physical properties after drying, and physical properties after firing. In particular, compared with Comparative Examples 5 and 6 using phenolic resin or molasses as the binder, the refractory material of Example 67 had a large molding specific gravity, large bulk specific gravity after drying and firing, low porosity, and high compressive strength, so it had excellent physical properties and excellent erosion resistance.

[0119] Examples 70 to 74 and Comparative Examples 7 and 8. Production of refractory materials A liquid binder for refractory materials was produced using each component in the content as described in Table 8. Then, refractory bricks, which are refractory materials, were produced using each component in the content as described in Table 12.

[0120] Specifically, magnesia, aluminum, and flake graphite, which are refractory materials, were mixed, a hot property improver was added, and after adding a binder for refractory materials, it was kneaded at 25 to 35 °C for 15 minutes and then , it was formed into a size of 60 mm × 60 mm × 60 mm, dried at 200 °C for 12 hours, and fired at 1000 °C for 12 hours to produce a refractory material. The physical properties of the produced refractory material were measured by the same method as in Example 53, and the erosion index was expressed with the erosion amount of Comparative Example 1 as 100.

[0121] At this time, as the flaky graphite, a product with a bulk specific gravity of 0.98 g / cm 3 , a specific surface area of 1 m 2 / g, and an average particle size of 350 μm was used, and for magnesia, a product with an average particle size of 4 mm was used. Also, as the phenolic resin, Kono Kasei's 8027 (product number) was used, and as the molasses, Desan Co., Ltd.'s molasses (total solid content of 80% or more) was used.

[0122]

Table 12

[0123] As shown in Table 12, compared with Example 70 that does not contain a hot property improver, the refractory materials of Examples 71 to 74 to which hot property improvers such as pitch, carbon black, B4C, and Si3N4 were added were equivalent or superior in terms of molding specific gravity, physical properties after drying, and physical properties after firing. In particular, Examples 71 to 74 were superior in erosion resistance and spalling resistance to Comparative Example 7.

[0124] Also, Example 74 containing silicon nitride (Si3N4) had an erosion resistance improvement of 15% or more compared to Comparative Example 1, and the residual linear expansibility also improved.

Claims

1. i) Water, ii) NaOH, NaCl, Na 2 O, Na 2 CO 3 , NaHCO 3 , 2Na 2 one or more basic compounds selected from the group consisting of CO3.3H2O2, K2O, KOH, KCl, K2S, KNH2, MgO, Mg(OH)2, MgCO3, MgCl, MgO.CaO, MgCO3.CaCO3, CaO, CaCO3 and Ca(OH)2; and iii) an organic acid containing three or more carboxy groups; containing water and an organic acid in a weight ratio of 1.0:0.2 to 0.8; The organic acid and the basic compound are contained in a weight ratio of 5 to 100:1.0, A liquid binder for fire-resistant materials that does not contain phenolic resin.

2. A liquid binder for fire-resistant materials as described in claim 1, wherein the one or more basic compounds include one or more selected from the group consisting of NaOH, NaCl, Na2O, NaHCO3, 2Na2CO3.3H2O2, K2O, KOH, KCl, MgO, Mg(OH)2, MgCO3, MgCl, MgO.CaO, MgCO3.CaCO3, CaO, CaCO3 and Ca(OH)2.

3. A liquid binder for fire-resistant materials as described in claim 1, wherein the one or more basic compounds include one or more selected from the group consisting of NaOH, NaCl, Na2O, NaHCO3, 2Na2CO3.3H2O2, K2O, KOH, KCl, MgO, Mg(OH)2, MgCO3, MgCO3.CaCO3 and CaCO3.

4. 2. The liquid binder for fireproof material according to claim 1, wherein the organic acid having three or more carboxy groups includes at least one selected from the group consisting of citric acid and ethylenediaminetetraacetic acid.

5. A liquid binder for fire-resistant materials as described in claim 1, comprising water and an organic acid in a weight ratio of 1.0:0.3 to 0.

8.

6. The liquid binder for refractory materials according to claim 1, comprising an organic acid and a basic compound in a weight ratio of 5 to 50:1.

0.

7. Further comprising one or more selected from the group consisting of a stabilizer and a viscosity enhancer, The stabilizer is one or more selected from the group consisting of tartaric acid, lactic acid, oxalic acid, boric acid, and phosphoric acid, The viscosity enhancer is one or more selected from the group consisting of corn starch, potato starch, carbomer, xanthan gum, methyl cellulose, methymethyl cellulose, and molasses. The liquid binder for refractory materials according to claim 1.

8. The stabilizer is tartaric acid. The liquid binder for refractory materials according to claim 7.

9. The viscosity enhancer is corn starch. The liquid binder for refractory materials according to claim 7.

10. The liquid binder for refractory materials according to claim 7, comprising 0.1 to 15% by weight of a stabilizer and 0.1 to 10% by weight of a viscosity enhancer based on the total weight of the liquid binder for refractory materials.

11. A refractory material comprising the liquid binder for refractory materials according to any one of claims 1 to 10; and a refractory material.

12. The refractory material according to claim 11, wherein the refractory material comprises one or more selected from the group consisting of magnesia-based, alumina-based, chrome-based, dolomite-based, and graphite-based refractory materials.

13. A refractory material according to claim 11, further comprising one or more hot property improvers selected from the group consisting of pitch, silicon nitride (Si₃N₄), boron carbide (B₄C), and carbon black.

14. The hot property improver is pitch. The refractory material according to claim 13.

15. The liquid binder for refractory materials according to any one of claims 1 to 10; and refractory materials; comprising refractory bricks.

16. The refractory brick according to claim 15, which is a magnesia-carbon refractory brick, a magnesia-alumina-carbon refractory brick, an alumina-silica refractory brick, a magnesia-chrome refractory brick, a magnesia-spinel refractory brick, an alumina-silicon carbide-carbon refractory brick, an alumina-carbon refractory brick, an alumina-silicon carbide-magnesia refractory brick or a magnesia refractory brick.

17. The refractory brick according to claim 15, which is a reduced-fired brick, a fired brick or an unfired brick.

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