阅读说明：本技术 一种碳纳米纤维改性的含碳耐火浇注料及其制备方法 (Carbon nanofiber modified carbon-containing refractory castable and preparation method thereof ) 是由 周强 杨威 钱文杰 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种碳纳米纤维改性的含碳耐火浇注料及其制备方法,碳纳米纤维改性的含碳耐火浇注料按照重量份数计算,包括：100份骨料、10～30份胶结料、8～15份掺和料和0.2～0.8份促凝剂；其中,骨料是使用耐火材料和耐火材料包覆液混合后经过烧结得到；耐火材料包覆液为硝酸铈铵改性后的酚醛树脂溶液。本发明基于市场上的耐火浇注料与炉渣具有强润湿性,抗渣侵蚀性能较差的缺陷对耐火浇注材料进行了一系列的改进。将耐火浇注材料的骨料成分中常规使用的金属氧化物使用改性后的酚醛树脂溶液进行包覆处理,然被进行烧结,最终得到碳纳米纤维改性的含碳耐火浇注料。(The invention discloses a carbon nanofiber modified carbon-containing refractory castable and a preparation method thereof, wherein the carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 10-30 parts of cementing material, 8-15 parts of admixture and 0.2-0.8 part of coagulant; wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering; the refractory material coating liquid is a phenol formaldehyde resin solution modified by ammonium cerium nitrate. The invention carries out a series of improvements on the refractory castable material based on the defects that the refractory castable material in the market has strong wettability with furnace slag and has poor slag erosion resistance. And coating the metal oxide which is conventionally used in the aggregate component of the refractory castable material by using the modified phenolic resin solution, and sintering to finally obtain the carbon-containing refractory castable material modified by the carbon nanofiber.)

1. A carbon nanofiber modified carbon-containing refractory castable is characterized by comprising the following components in parts by weight: 100 parts of aggregate, 10-30 parts of cementing material, 8-15 parts of admixture and 0.2-0.8 part of coagulant; wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering; the refractory material coating liquid is a phenol formaldehyde resin solution modified by ammonium cerium nitrate.

2. The carbon nanofiber modified carbon-containing refractory castable material according to claim 1, wherein the cementing material comprises, in parts by weight: 100 parts of alumina cement and 12-20 parts of sodium silicate.

3. The carbon nanofiber modified carbon-containing refractory castable according to claim 1, wherein the particle size of the admixture is less than or equal to 0.088mm, and the admixture comprises 100 parts by weight of aluminum oxide, 12-18 parts by weight of silicon dioxide and 5-10 parts by weight of chromium diboride.

4. The carbon nanofiber modified carbon-containing refractory castable according to claim 1, wherein the coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate in a mass ratio of 1: 0.2-0.5.

5. The carbon nanofiber modified carbon-containing refractory castable according to claim 1, wherein the refractory material has a particle size of 0.16-5 mm, and comprises, in parts by weight: 100 parts of aluminum oxide, 10-15 parts of silicon dioxide and 2-8 parts of chromium diboride.

6. The carbon nanofiber modified carbon-containing refractory castable according to claim 1, wherein the preparation method of the aggregate is as follows:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, dropwise adding a cerium ammonium nitrate solution at room temperature while stirring, and continuously stirring at room temperature for 8-10 hours after completely dropwise adding to obtain a mixed reaction liquid A; the preparation method comprises the following steps of preparing a cerium ammonium nitrate solution from cerium ammonium nitrate and N, N-dimethylformamide according to a mass ratio of 1: 3-5, wherein the mass ratio of phenolic resin to N, N-dimethylformamide is 1: 5-8, and the mass ratio of the cerium ammonium nitrate solution to phenolic resin is 1: 10-12;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 2-5 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 1-3;

s3, placing the mixed reactant B in a drying box, heating to 100-120 ℃, drying for 10-12 h, heating to 180-200 ℃, curing for 12-15 h, placing in a high-temperature reaction furnace, heating to 1150-1350 ℃ under the protection of nitrogen, preserving heat for 2-5 h, and cooling to room temperature along with the furnace to obtain the aggregate.

7. The carbon nanofiber modified carbon-containing refractory castable according to claim 6, wherein in S3, the temperature rise rate of the high-temperature reaction furnace is 3-6 ℃/min.

8. The carbon nanofiber modified carbon-containing refractory castable according to claim 6, wherein in S3, the temperature of the high-temperature reaction furnace is 1250 ℃.

9. The preparation method of the carbon nanofiber modified carbon-containing refractory castable material as claimed in claim 1, characterized by comprising the following steps:

step 1, weighing the aggregate and the admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, and obtaining the carbon nanofiber modified carbon-containing refractory castable after uniform mixing and grinding.

10. The method for preparing the carbon nanofiber modified carbon-containing refractory castable according to claim 9, wherein in the step 3, the addition amount of water is 1-3% of the mass of the second mixture.

Technical Field

The invention relates to the field of refractory castable, in particular to a carbon nanofiber modified carbon-containing refractory castable and a preparation method thereof.

Background

The refractory material is a key structural material of a high-temperature smelting and high-temperature kiln and other thermal equipment, can bear corresponding physical and chemical changes and mechanical action, is an indispensable basic material of a high-temperature technology, and is widely applied to the fields of steel, ceramics, building materials, electronics, petrifaction and the like. Wherein the refractory material consumption in the steel industry is the largest. The traditional refractory material takes alumina, chromium oxide or carbon as a main component, and the traditional refractory material has to ensure enough structural stability when being used in a high-temperature environment. The traditional oxide refractory material has strong wettability with slag, and the slag erosion resistance is poor, so that the service life of a furnace lining is greatly reduced.

Disclosure of Invention

The invention provides a carbon nanofiber modified carbon-containing refractory castable and a preparation method thereof, aiming at the problems that the traditional oxide refractory material has strong wettability with slag, the slag corrosion resistance is poor, and the service life of a furnace lining is greatly reduced.

The purpose of the invention is realized by adopting the following technical scheme:

in a first aspect, the invention provides a carbon nanofiber modified carbon-containing refractory castable, which comprises the following components in parts by weight: 100 parts of aggregate, 10-30 parts of cementing material, 8-15 parts of admixture and 0.2-0.8 part of coagulant; wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering; the refractory material coating liquid is a phenol formaldehyde resin solution modified by ammonium cerium nitrate.

Preferably, the carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 20 parts of cementing material, 12 parts of admixture and 0.6 part of coagulant.

Preferably, the cementing agent comprises the following components in parts by weight: 100 parts of alumina cement and 12-20 parts of sodium silicate.

Preferably, the particle size of the blend is less than or equal to 0.088mm, and the blend comprises the following components in parts by weight: 100 parts of aluminum oxide, 12-18 parts of silicon dioxide and 5-10 parts of yttrium carbide.

Preferably, the blend comprises the following components in parts by weight: 100 parts of aluminum oxide, 15 parts of silicon dioxide and 8 parts of yttrium carbide.

Preferably, the coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate according to the mass ratio of 1: 0.2-0.5.

Preferably, the particle size of the refractory material is 0.16-5 mm, and the refractory material comprises the following components in parts by weight: 100 parts of aluminum oxide, 10-15 parts of silicon dioxide and 2-8 parts of chromium diboride.

Preferably, the refractory material comprises the following components in parts by weight: 100 parts of aluminum oxide, 12 parts of silicon dioxide and 5 parts of chromium diboride.

Preferably, the preparation method of the aggregate comprises the following steps:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, dropwise adding a cerium ammonium nitrate solution at room temperature while stirring, and continuously stirring at room temperature for 8-10 hours after completely dropwise adding to obtain a mixed reaction liquid A; the preparation method comprises the following steps of preparing a cerium ammonium nitrate solution from cerium ammonium nitrate and N, N-dimethylformamide according to a mass ratio of 1: 3-5, wherein the mass ratio of phenolic resin to N, N-dimethylformamide is 1: 5-8, and the mass ratio of the cerium ammonium nitrate solution to phenolic resin is 1: 10-12;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 2-5 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 1-3;

s3, placing the mixed reactant B in a drying box, heating to 100-120 ℃, drying for 10-12 h, heating to 180-200 ℃, curing for 12-15 h, placing in a high-temperature reaction furnace, heating to 1150-1350 ℃ under the protection of nitrogen, preserving heat for 2-5 h, and cooling to room temperature along with the furnace to obtain the aggregate.

Preferably, in the S3, the temperature rising rate of the high-temperature reaction furnace is 3-6 ℃/min.

Preferably, in S3, the temperature of the high temperature reaction furnace is 1250 ℃.

In a second aspect, the invention provides a preparation method of a carbon-containing refractory castable modified by carbon nanofibers, which comprises the following steps:

step 1, weighing the aggregate and the admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, and obtaining the carbon nanofiber modified carbon-containing refractory castable after uniform mixing and grinding.

Preferably, in the step 3, the adding amount of the water is 1-3% of the mass of the second mixed material.

The invention has the beneficial effects that:

the invention carries out a series of improvements on the refractory castable material based on the defects that the refractory castable material in the market has strong wettability with furnace slag and has poor slag erosion resistance. And coating the metal oxide which is conventionally used in the aggregate component of the refractory castable material by using the modified phenolic resin solution, and sintering to finally obtain the carbon-containing refractory castable material modified by the carbon nanofiber.

The phenolic resin has high carbon residue rate, and under the condition that the temperature is about 1000 ℃, the phenolic resin can generate high carbon residue, which is beneficial to maintaining the structural stability of the phenolic resin. The invention utilizes the characteristic of the phenolic resin, adopts the phenolic resin as the basic material for preparing the carbon fiber, fuses the phenolic resin with the refractory material and then sinters the carbon fiber to form the carbon nanofiber on the surface of the refractory material, thereby enhancing the resistance of the refractory material to the slag.

Compared with the conventional metal oxide, the component of the refractory material used by the invention is added with chromium diboride, and the corrosion resistance and the thermal shock resistance of the refractory material are enhanced after the material is added. The rare earth element containing cerium is added in the modification process of the phenolic resin, cerium bi-carbide can be formed in the sintering process, and the carbon nano-fiber containing cerium bi-carbide is formed after being fused with carbon nano-fiber formed by other carbon sources and is coated on the surface of the refractory material, so that the improvement of the refractory material is completed.

In addition, the invention also adds the rare earth carbide yttrium carbide into the admixture, wherein the yttrium carbide has higher melting point and density, and is added as an additive with small grain size to further improve the mechanical property of the refractory material.

Detailed Description

For the purpose of more clearly illustrating the present invention and more clearly understanding the technical features, objects and advantages of the present invention, the technical solutions of the present invention will now be described in detail below, but are not to be construed as limiting the implementable scope of the present invention.

The invention carries out a series of improvements on the refractory castable material based on the defects that the refractory castable material in the market has strong wettability with furnace slag and has poor slag erosion resistance. The improvement lies in that:

firstly, the components of the refractory material of the traditional refractory castable are replaced, alumina is used as a main material, chromium diboride is added, and the chromium diboride is not applied to the refractory material in the current market, because the melting point and the hardness of the chromium diboride are not as good as those of alumina in terms of the base number of the material, but after the chromium diboride is added, the corrosion resistance and the thermal shock resistance of the refractory castable are enhanced.

Secondly, the surface of the refractory material is coated with a layer of modified phenolic resin, the modified phenolic resin is obtained by reacting ammonium ceric nitrate with phenolic resin, the ammonium ceric nitrate has strong oxidizing property and can oxidize phenolic hydroxyl in the phenolic resin to form quinone, the quinone has strong chelating property and can form chelate with metal ions, so that rare earth element cerium can be combined to form chelate to obtain cerium-containing mixed organic matter, and compared with the resin, the organic metal-containing chelate has better compatibility and grafting property on inorganic metal materials, so that the coating is more uniform.

The modified phenolic resin is sintered at high temperature after being mixed with other refractory materials, cerium and part of organic compounds can generate cerium dicarbonide in the co-sintering process, the rest carbon sources form carbon nanofibers in the sintering process, and the combination of the cerium dicarbonide and the carbon nanofibers is formed on the surface of the refractory materials to finally obtain the required aggregate. The aggregate is found after being used, so that the problems that the traditional metal oxide refractory material has strong wettability and poor slag corrosion resistance with slag at present can be solved, the brittleness problem of carbon fibers is also improved, the refractory material is more durable, and the service life of a furnace lining is prolonged.

The invention is further described below with reference to the following examples.

Example 1

A carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 20 parts of cementing material, 11 parts of admixture and 0.5 part of coagulant.

Wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering. The particle size of the refractory material is 0.16-5 mm, and the refractory material comprises the following components in parts by weight: 100 parts of aluminum oxide, 12 parts of silicon dioxide and 5 parts of chromium diboride.

The preparation method of the aggregate comprises the following steps:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, dropwise adding a cerium ammonium nitrate solution at room temperature while stirring, and continuously stirring at room temperature for 9 hours after completely dropwise adding to obtain a mixed reaction liquid A; the preparation method comprises the following steps of preparing a cerium ammonium nitrate solution from cerium ammonium nitrate and N, N-dimethylformamide according to a mass ratio of 1:4, wherein the mass ratio of phenolic resin to N, N-dimethylformamide is 1:7, and the mass ratio of the cerium ammonium nitrate solution to the phenolic resin is 1: 11;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 3 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 2;

s3, placing the mixed reactant B in a drying oven, heating to 110 ℃, drying for 11h, heating to 190 ℃, curing for 13h, then placing in a high-temperature reaction furnace, heating to 1250 ℃ under the protection of nitrogen, wherein the temperature rise rate of the high-temperature reaction furnace is 5 ℃/min, keeping the temperature for 4h, and cooling to room temperature along with the furnace to obtain the aggregate.

The cementing material comprises the following components in parts by weight: 100 parts of alumina cement and 18 parts of sodium silicate.

The particle size of the admixture is less than or equal to 0.088mm, and the admixture comprises the following components in parts by weight: 100 parts of aluminum oxide, 15 parts of silicon dioxide and 7 parts of yttrium carbide.

The coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate according to the mass ratio of 1: 0.3.

The preparation method of the carbon-containing refractory castable modified by the carbon nanofibers comprises the following steps:

step 1, weighing aggregate and admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, wherein the adding amount of the water is 2% of the mass of the second mixed material, and uniformly mixing and grinding to obtain the carbon nanofiber modified carbon-containing refractory castable.

Example 2

A carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 10 parts of cementing material, 8 parts of admixture and 0.2 part of coagulant;

wherein, the aggregate is obtained by mixing and sintering a refractory material and a refractory material coating liquid, the particle size of the refractory material is 0.16-5 mm, and the aggregate comprises: 100 parts of aluminum oxide, 10 parts of silicon dioxide and 2 parts of chromium diboride.

The preparation method of the aggregate comprises the following steps:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, dropwise adding a cerium ammonium nitrate solution at room temperature while stirring, and continuously stirring at room temperature for 8 hours after completely dropwise adding to obtain a mixed reaction liquid A; the preparation method comprises the following steps of preparing a cerium ammonium nitrate solution from cerium ammonium nitrate and N, N-dimethylformamide according to a mass ratio of 1:3, wherein the mass ratio of phenolic resin to N, N-dimethylformamide is 1:5, and the mass ratio of the cerium ammonium nitrate solution to the phenolic resin is 1: 10;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 2 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 1;

s3, placing the mixed reactant B in a drying box, heating to 100 ℃, drying for 10h, heating to 180 ℃, curing for 12h, then placing in a high-temperature reaction furnace, heating to 1150 ℃ under the protection of nitrogen, wherein the temperature rise rate of the high-temperature reaction furnace is 3 ℃/min, carrying out heat preservation for 2h, and cooling to room temperature along with the furnace to obtain the aggregate.

The cementing material comprises the following components in parts by weight: 100 parts of alumina cement and 12 parts of sodium silicate.

The particle size of the admixture is less than or equal to 0.088mm, and the admixture comprises the following components in parts by weight: 100 parts of aluminum oxide, 12 parts of silicon dioxide and 5 parts of yttrium carbide.

The coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate according to the mass ratio of 1: 0.2.

The preparation method of the carbon-containing refractory castable modified by the carbon nanofibers comprises the following steps:

step 1, weighing aggregate and admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, wherein the adding amount of the water is 1% of the mass of the second mixed material, and uniformly mixing and grinding to obtain the carbon nanofiber modified carbon-containing refractory castable.

Example 3

A carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 30 parts of cementing material, 15 parts of admixture and 0.8 part of coagulant;

wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering. The particle size of the refractory material is 0.16-5 mm, and the refractory material comprises the following components in parts by weight: 100 parts of aluminum oxide, 15 parts of silicon dioxide and 8 parts of chromium diboride.

The cementing material comprises the following components in parts by weight: 100 parts of alumina cement and 20 parts of sodium silicate.

The particle size of the admixture is less than or equal to 0.088mm, and the admixture comprises the following components in parts by weight: 100 parts of aluminum oxide, 18 parts of silicon dioxide and 10 parts of yttrium carbide.

The coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate according to the mass ratio of 1: 0.5.

The preparation method of the aggregate comprises the following steps:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, dropwise adding a cerium ammonium nitrate solution at room temperature while stirring, and continuously stirring at room temperature for 10 hours after completely dropwise adding to obtain a mixed reaction liquid A; the preparation method comprises the following steps of preparing a cerium ammonium nitrate solution from cerium ammonium nitrate and N, N-dimethylformamide according to a mass ratio of 1:5, wherein the mass ratio of phenolic resin to N, N-dimethylformamide is 1:8, and the mass ratio of the cerium ammonium nitrate solution to the phenolic resin is 1: 12;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 5 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 3;

s3, placing the mixed reactant B in a drying box, heating to 120 ℃, drying for 12h, heating to 200 ℃, curing for 15h, then placing in a high-temperature reaction furnace, heating to 1350 ℃ under the protection of nitrogen, wherein the temperature rise rate of the high-temperature reaction furnace is 6 ℃/min, keeping the temperature for 5h, and then cooling to room temperature along with the furnace to obtain the aggregate.

The preparation method of the carbon-containing refractory castable modified by the carbon nanofibers comprises the following steps:

step 1, weighing aggregate and admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, wherein the adding amount of the water is 3% of the mass of the second mixed material, and uniformly mixing and grinding to obtain the carbon nanofiber modified carbon-containing refractory castable.

Comparative example 1

A carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 20 parts of cementing material, 11 parts of admixture and 0.5 part of coagulant.

Wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering. The particle size of the refractory material is 0.16-5 mm, and the refractory material comprises the following components in parts by weight: 100 parts of aluminum oxide, 12 parts of silicon dioxide and 5 parts of chromium diboride.

The preparation method of the aggregate comprises the following steps:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, and uniformly stirring at room temperature to obtain a mixed reaction solution A; wherein the mass ratio of the phenolic resin to the N, N-dimethylformamide is 1: 7;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 3 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 2;

s3, placing the mixed reactant B in a drying oven, heating to 110 ℃, drying for 11h, heating to 190 ℃, curing for 13h, then placing in a high-temperature reaction furnace, heating to 1250 ℃ under the protection of nitrogen, wherein the temperature rise rate of the high-temperature reaction furnace is 5 ℃/min, keeping the temperature for 4h, and cooling to room temperature along with the furnace to obtain the aggregate.

The cementing material comprises the following components in parts by weight: 100 parts of alumina cement and 18 parts of sodium silicate.

The particle size of the admixture is less than or equal to 0.088mm, and the admixture comprises the following components in parts by weight: 100 parts of aluminum oxide, 15 parts of silicon dioxide and 7 parts of yttrium carbide.

The coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate according to the mass ratio of 1: 0.3.

The preparation method of the carbon-containing refractory castable modified by the carbon nanofibers comprises the following steps:

step 1, weighing aggregate and admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, wherein the adding amount of the water is 2% of the mass of the second mixed material, and uniformly mixing and grinding to obtain the carbon nanofiber modified carbon-containing refractory castable.

Comparative example 2

A carbon nanofiber modified carbon-containing refractory castable comprises the following components in parts by weight: 100 parts of aggregate, 20 parts of cementing material, 11 parts of admixture and 0.5 part of coagulant.

Wherein, the aggregate is obtained by mixing a refractory material and a refractory material coating liquid and then sintering. The particle size of the refractory material is 0.16-5 mm, and the refractory material comprises the following components in parts by weight: 100 parts of alumina and 17 parts of silica.

The preparation method of the aggregate comprises the following steps:

s1, weighing phenolic resin, dissolving the phenolic resin in N, N-dimethylformamide, and uniformly stirring at room temperature to obtain a mixed reaction solution A; wherein the mass ratio of the phenolic resin to the N, N-dimethylformamide is 1: 7;

s2, weighing a refractory material, adding the refractory material into the mixed reaction liquid A, stirring at the speed of 300-500 rpm for 3 hours at room temperature, removing the solvent under reduced pressure, and degassing to obtain a mixed reactant B; wherein the mass ratio of the refractory material to the mixed reaction liquid A is 1: 2;

s3, placing the mixed reactant B in a drying oven, heating to 110 ℃, drying for 11h, heating to 190 ℃, curing for 13h, then placing in a high-temperature reaction furnace, heating to 1250 ℃ under the protection of nitrogen, wherein the temperature rise rate of the high-temperature reaction furnace is 5 ℃/min, keeping the temperature for 4h, and cooling to room temperature along with the furnace to obtain the aggregate.

The cementing material comprises the following components in parts by weight: 100 parts of alumina cement and 18 parts of sodium silicate.

The particle size of the admixture is less than or equal to 0.088mm, and the admixture comprises the following components in parts by weight: 100 parts of alumina and 22 parts of silica.

The coagulant is obtained by mixing calcium aluminate and calcium fluoroaluminate according to the mass ratio of 1: 0.3.

The preparation method of the carbon-containing refractory castable modified by the carbon nanofibers comprises the following steps:

step 1, weighing aggregate and admixture according to the amount, adding the aggregate and the admixture into a mixing mill, and uniformly mixing and milling to obtain a first mixture;

step 2, adding the cementing material weighed according to the amount into the first mixed material, and uniformly mixing and grinding to obtain a second mixed material;

and 3, adding the coagulant weighed according to the amount into the second mixed material, adding water while mixing and grinding, wherein the adding amount of the water is 2% of the mass of the second mixed material, and uniformly mixing and grinding to obtain the carbon nanofiber modified carbon-containing refractory castable.

In order to more clearly illustrate the invention, the carbon nanofiber modified carbon-containing refractory castable prepared in the embodiments 1 to 3 of the invention and the comparative example is tested.

The detection method comprises the following steps:

apparent porosity: testing according to the standard of GB/T2997-2000.

Normal temperature compressive strength: testing according to the standard of GB/T5072.2-2004.

High-temperature flexural strength: detecting according to GB/T3002-2004 at 1000 deg.C for 2 h.

Thermal shock resistance: expressed as flexural strength retention. The detection is carried out by adopting an oil quenching method, wherein the delta is about 1100 ℃, and the oil quenching is carried out for 5 times, and the method comprises the following steps: the carbon-containing refractory castable materials of examples 1 to 3 and comparative examples 1 to 2 were tested for the breaking strength of X0, then buried in carbon atmosphere, treated for 0.5h, taken out and rapidly soaked in oil for 5min, then dried, after the above steps are fully performed for 5 times, the breaking strength X1 is measured again, and then calculated according to the formula: the breaking strength retention (%) ═ X1/X0 × 100%.

And (3) measuring the slag corrosion resistance: the test was carried out according to the GB/T8931-2007 standard, and expressed as the corrosion index (%).

The results are shown in Table 1.

TABLE 1 comparison of the properties of different carbon-containing refractory casting materials

	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						Apparent porosity (%)	11	12	11	14	18
Normal temperature compressive strength (MPa)	66	64	67	63	64
						High temperature rupture strength (MPa)	18.2	17.3	17.8	7.1	6.6
Flexural modulus (GPa)	5.9	5.4	5.8	2.4	2.2
						Breaking strength retention (%)	78	75	79	65	53
Erosion index (%)	8	8	7	24	32

As can be seen from table 1 above, the carbon-containing refractory castable prepared in embodiments 1 to 3 of the present invention has a lower apparent porosity, a higher high-temperature flexural strength and a higher flexural modulus than the above-mentioned proportion, a better thermal shock resistance (flexural strength retention), and a lower erosion index, which also indicates a better slag corrosion resistance.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.