阅读说明：本技术 一种中频炉用高性能涂抹料中频炉用高性能涂抹料 (High-performance coating material for intermediate frequency furnace ) 是由 王佳宁 赵现华 张义先 侯中阳 曹贺 金钊 王皓 于 2021-10-09 设计创作，主要内容包括：本发明涉及一种中频炉用高性能涂抹料中频炉用高性能涂抹料,所述涂抹料的组分及重量百分比为：50％～60％的电熔白刚玉颗粒,20％～35％的白刚玉细粉,0～10％的氧化铝微粉,0～10％的粘土,0～8％的硅微粉,0～3％的氧化铬微粉,0～1％的增塑剂,1～5％的复合添加剂,外加10％的磷酸二氢铝液体结合剂；所述复合添加剂由柠檬酸和草酸组成。本发明通过添加由柠檬酸与草酸组成的复合添加剂,有效调节涂抹料的pH值,既可提高涂抹料的保质期,又能够增强涂抹料的高温强度,从而提高了中频炉炉衬的使用寿命。(The invention relates to a high-performance coating for an intermediate frequency furnace, which comprises the following components in percentage by weight: 50-60% of fused white corundum particles, 20-35% of white corundum fine powder, 0-10% of alumina micro powder, 0-10% of clay, 0-8% of silica micro powder, 0-3% of chromium oxide micro powder, 0-1% of plasticizer, 1-5% of composite additive and 10% of aluminum dihydrogen phosphate liquid binder; the compound additive consists of citric acid and oxalic acid. According to the invention, the composite additive consisting of citric acid and oxalic acid is added, so that the pH value of the coating material is effectively adjusted, the quality guarantee period of the coating material is prolonged, the high-temperature strength of the coating material is enhanced, and the service life of the furnace lining of the intermediate frequency furnace is prolonged.)

1. The high-performance coating material for the intermediate frequency furnace is characterized by comprising the following components in percentage by weight: 50-60% of fused white corundum particles, 20-35% of white corundum fine powder, 0-10% of alumina micro powder, 0-10% of clay, 0-8% of silica micro powder, 0-3% of chromium oxide micro powder, 0-1% of plasticizer, 1-5% of composite additive and 10% of aluminum dihydrogen phosphate liquid binder; the compound additive consists of citric acid and oxalic acid.

2. The high-performance coating for the intermediate frequency furnace according to claim 1, wherein the electro-fused white corundum particles are formed by mixing 3 kinds of particles with the particle sizes of 5-3 mm, 3-1 mm and 1-0 mm according to any proportion; the granularity of the white corundum fine powder is 325 meshes; electric meltingThe physical and chemical performance indexes of the white corundum particles and the white corundum fine powder are as follows: al (Al)₂O₃≥60％、TiO₂≥2.5％、Fe₂O₃≤1.5％、R₂O≤0.3％。

3. The high-performance coating for the intermediate frequency furnace is characterized in that the alumina micro powder is alpha-alumina micro powder, and the particle size is 1-3 μm; the physicochemical property index of the alpha-alumina micro powder is Al₂O₃≥99.0％、Fe₂O₃≤0.04％、R₂O≤0.3％、SiO₂≤0.1％。

4. The high-performance coating for the intermediate frequency furnace as claimed in claim 1, wherein the physical and chemical performance indexes of the silicon micropowder are as follows: SiO 2₂≥92％，Fe₂O₃≤0.1％。

5. The high-performance coating for the intermediate frequency furnace as claimed in claim 1, wherein the physical and chemical performance indexes of the aluminum dihydrogen phosphate liquid binder are as follows: p₂O₅≥33％，Al₂O₃≥8.5％,Fe₂O₃Less than or equal to 0.01, pH value of 1.5-2.5 and specific gravity of 1.467-1.47.

6. The high-performance coating for the intermediate frequency furnace as claimed in claim 1, wherein the plasticizer is methylcellulose.

7. The high-performance coating for the intermediate frequency furnace is characterized in that the clay is Guangxi white mud with the granularity of 200 meshes.

8. The high-performance coating for the intermediate frequency furnace as claimed in claim 1, wherein the compound additive comprises the following components in percentage by weight: 1-99% of citric acid and 1-99% of oxalic acid.

Technical Field

The invention relates to the technical field of unshaped refractory materials, in particular to a high-performance coating material for an intermediate frequency furnace.

Background

The intermediate frequency furnace is a power supply device for converting power frequency 50Hz alternating current into intermediate frequency (300-2000 Hz). Firstly, rectifying three-phase power frequency alternating current to form direct current, then converting the direct current into adjustable intermediate frequency current to be supplied to an induction coil, generating a strong magnetic field in the electrified coil, and heating a furnace burden body by utilizing an electromagnetic induction principle; according to the principle of electromagnetic effect, high-density magnetic lines generated in the induction coil can penetrate through non-metallic substances, cut metal materials contained in the induction coil, generate large eddy currents in the metal materials and instantly generate induction heating on the metal in a non-contact mode, so that metal furnace burden is melted.

The intermediate frequency furnace has the characteristics of high heating speed, high production efficiency, less oxidation and decarburization, material and cost saving, uniform heating, high temperature control precision and the like; in addition, compared with other smelting furnaces, the medium frequency furnace has the greatest advantage of being capable of recovering precious metals in metal furnace charges, effectively avoiding element burning loss in the smelting process of steel or alloy materials, and being an ideal resource recycling mode.

The inner side of a furnace lining material of the medium-frequency induction furnace is filled with high-temperature molten metal, the periphery of the furnace lining material is provided with a water-cooling induction coil, and the temperature of the furnace wall is sharply reduced after the molten metal is discharged from the furnace each time; the furnace lining material not only needs to bear shock of shock cooling and shock heating, but also needs to bear the scouring of molten metal which moves continuously due to electromagnetic stirring in the smelting process and the erosion of furnace slag; therefore, strict requirements are imposed on the selection and use of the lining material.

Disclosure of Invention

The invention provides a high-performance coating material for an intermediate frequency furnace, which is characterized in that a composite additive consisting of citric acid and oxalic acid is added to effectively adjust the pH value of the coating material, so that the quality guarantee period of the coating material can be prolonged, the high-temperature strength of the coating material can be enhanced, and the service life of a furnace lining of the intermediate frequency furnace is prolonged.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-performance coating material for an intermediate frequency furnace comprises the following components in percentage by weight: 50-60% of fused white corundum particles, 20-35% of white corundum fine powder, 0-10% of alumina micro powder, 0-10% of clay, 0-8% of silica micro powder, 0-3% of chromium oxide micro powder, 0-1% of plasticizer, 1-5% of composite additive and 10% of aluminum dihydrogen phosphate liquid binder; the compound additive consists of citric acid and oxalic acid.

The electric melting white corundum particles are formed by mixing 3 kinds of particles with the particle sizes of 5-3 mm, 3-1 mm and 1-0 mm according to any proportion; the granularity of the white corundum fine powder is 325 meshes; the physical and chemical performance indexes of the fused white corundum particles and the white corundum fine powder are as follows: al (Al)₂O₃≥60％、TiO₂≥2.5％、Fe₂O₃≤1.5％、R₂O≤0.3％。

The alumina micro powder is alpha-alumina micro powder with the granularity of 1-3 mu m; the physicochemical property index of the alpha-alumina micro powder is Al₂O₃≥99.0％、Fe₂O₃≤0.04％、R₂O≤0.3％、SiO₂≤0.1％。

The physical and chemical performance indexes of the silicon micro powder are as follows: SiO 2₂≥92％，Fe₂O₃≤0.1％。

The physical and chemical performance indexes of the aluminum dihydrogen phosphate liquid binding agent are as follows: p₂O₅≥33％，Al₂O₃≥8.5％,Fe₂O₃Less than or equal to 0.01, pH value of 1.5-2.5 and specific gravity of 1.467-1.47.

The plasticizer is methyl cellulose.

The clay is Guangxi white clay with the granularity of 200 meshes.

The compound additive comprises the following components in percentage by weight: 1-99% of citric acid and 1-99% of oxalic acid.

Compared with the prior art, the invention has the beneficial effects that:

the composite additive consisting of citric acid and oxalic acid is adopted, the citric acid and the oxalic acid have different acidity, and the pH value of the coating can be effectively adjusted after the citric acid and the oxalic acid are compounded, so that the quality guarantee period of the coating is prolonged, the high-temperature strength of the coating is enhanced, and the service life of a furnace lining of the intermediate frequency furnace is prolonged.

Detailed Description

The invention relates to a high-performance coating material for an intermediate frequency furnace, which comprises the following components in percentage by weight: 50-60% of fused white corundum particles, 20-35% of white corundum fine powder, 0-10% of alumina micro powder, 0-10% of clay, 0-8% of silica micro powder, 0-3% of chromium oxide micro powder, 0-1% of plasticizer, 1-5% of composite additive and 10% of aluminum dihydrogen phosphate liquid binder; the compound additive consists of citric acid and oxalic acid.

The electric melting white corundum particles are formed by mixing 3 kinds of particles with the particle sizes of 5-3 mm, 3-1 mm and 1-0 mm according to any proportion; the granularity of the white corundum fine powder is 325 meshes; the physical and chemical performance indexes of the fused white corundum particles and the white corundum fine powder are as follows: al (Al)₂O₃≥60％、TiO₂≥2.5％、Fe₂O₃≤1.5％、R₂O≤0.3％。

The alumina micro powder is alpha-alumina micro powder with the granularity of 1-3 mu m; the physicochemical property index of the alpha-alumina micro powder is Al₂O₃≥99.0％、Fe₂O₃≤0.04％、R₂O≤0.3％、SiO₂≤0.1％。

The physical and chemical performance indexes of the silicon micro powder are as follows: SiO 2₂≥92％，Fe₂O₃≤0.1％。

The physical and chemical performance indexes of the aluminum dihydrogen phosphate liquid binding agent are as follows: p₂O₅≥33％，Al₂O₃≥8.5％,Fe₂O₃Less than or equal to 0.01, pH value of 1.5-2.5 and specific gravity of 1.467-1.47.

The plasticizer is methyl cellulose.

The clay is Guangxi white clay with the granularity of 200 meshes.

The compound additive comprises the following components in percentage by weight: 1-99% of citric acid and 1-99% of oxalic acid.

The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples.

[ example 1 ]

In the embodiment, the high-performance coating for the intermediate frequency furnace comprises the following components in percentage by weight: 55% of white corundum particles, wherein the granularity is 10% of 5-3 mm, 20% of 3-1 mm and 25% of 1-0 mm; 28.5 percent of white corundum fine powder with the granularity of 200 meshes, 8 percent of alumina micro powder, 5 percent of silicon micro powder, 1 percent of chromium oxide micro powder, 0.5 percent of methyl cellulose and 2 percent of composite additive (wherein 1 percent of citric acid and 1 percent of oxalic acid).

The mixture prepared according to the proportion is stirred for 2 minutes, 8 percent of aluminum dihydrogen phosphate is added and then stirred for 3 minutes, the mixture is molded into a sample block with the size of 40mm multiplied by 160mm by vibration casting, the sample block is maintained for 24 hours, baked for 24 hours at the temperature of 110 ℃, baked for 3 hours at the temperature of 1450 ℃ in a high-temperature furnace, and the temperature is preserved for 0.5 hour at the temperature of 1400 ℃.

And sealing the rest pug, storing in shade, and observing the shelf life.

The product performance test results are shown in table 1.

TABLE 1

Bulk density after baking at 110 ℃ for 24h	2.71g/cm3
		Cold bending strength at 110 deg.c for 24 hr after baking	4.4Mpa
Cold state compression strength after baking at 110 deg.C for 24h	19Mpa
		Cold fracture strength at 1450 deg.C for 3 hr after firing	14.1Mpa
Cold state compression strength at 1450 deg.C for 3h	40.2Mpa
		Permanent line change rate after 1450 ℃ x 3h firing	-0.1％
High-temperature rupture strength of 1400 ℃ for 0.5h	0.3Mpa
		Shelf life/day	60

[ example 2 ]

In the embodiment, the high-performance coating for the intermediate frequency furnace comprises the following components in percentage by weight: 55% of white corundum particles, wherein the granularity is 12% of 5-3 mm, 20% of 3-1 mm and 23% of 1-0 mm; 28.5 percent of white corundum fine powder with the granularity of 200 meshes, 8 percent of alumina micro powder, 5 percent of silicon micro powder, 1 percent of chromium oxide micro powder, 0.5 percent of methyl cellulose and 2 percent of composite additive (wherein, 1.5 percent of citric acid and 0.5 percent of oxalic acid).

The mixture prepared according to the proportion is stirred for 2 minutes, 8 percent of aluminum dihydrogen phosphate is added and then stirred for 3 minutes, the mixture is molded into a sample block with the size of 40mm multiplied by 160mm by vibration casting, the sample block is maintained for 24 hours, baked for 24 hours at the temperature of 110 ℃, baked for 3 hours at the temperature of 1450 ℃ in a high-temperature furnace, and the temperature is preserved for 0.5 hour at the temperature of 1400 ℃.

And sealing the rest pug, storing in shade, and observing the shelf life.

The results of the product property measurements are shown in Table 2.

TABLE 2

Bulk density after baking at 110 ℃ for 24h	2.77g/cm3
		Cold bending strength at 110 deg.c for 24 hr	3.5Mpa
Cold state compression strength at 110 deg.c for 24 hr	22Mpa
		Cold fracture strength at 1450 deg.C for 3 hr after burning	16Mpa
Cold state compression strength at 1450 deg.C for 3h after burning	50.9Mpa
		Permanent line change rate after 1450 deg.C x 3h burning	-0.3％
High-temperature rupture strength of 1400 ℃ for 0.5h	0.5Mpa
		Shelf life/day	60

[ example 3 ]

In the embodiment, the high-performance coating for the intermediate frequency furnace comprises the following components in percentage by weight: 55% of white corundum particles, wherein the granularity is 10% of 5-3 mm, 25% of 3-1 mm and 20% of 1-0 mm; 28.5 percent of white corundum fine powder with the granularity of 200 meshes, 8 percent of alumina micro powder, 5 percent of silicon micro powder, 1 percent of chromium oxide micro powder, 0.5 percent of methyl cellulose and 2 percent of composite additive (wherein, 0.5 percent of citric acid and 1.5 percent of oxalic acid).

The mixture prepared according to the proportion is stirred for 2 minutes, 8 percent of aluminum dihydrogen phosphate is added and then stirred for 3 minutes, the mixture is molded into a sample block with the size of 40mm multiplied by 160mm by vibration casting, the sample block is maintained for 24 hours, baked for 24 hours at the temperature of 110 ℃, baked for 3 hours at the temperature of 1450 ℃ in a high-temperature furnace, and the temperature is maintained for 0.5 hour at the temperature of 1400 ℃.

And sealing the rest pug, storing in shade, and observing the shelf life.

The product performance test results are shown in Table 3.

TABLE 3

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.