阅读说明：本技术 一种含钽型高炉陶瓷杯用耐火材料及其制备方法 (Refractory material for tantalum-containing blast furnace ceramic cup and preparation method thereof ) 是由 朱媛媛 杨建� 陈智慧 于 2021-09-24 设计创作，主要内容包括：本发明属于耐火材料领域,具体涉及一种含钽型高炉陶瓷杯用耐火材料及其制备方法。耐火材料按重量百分含量其组成为：棕刚玉65-80％,碳化硅5-25％,片状氧化铝粉2-10％,结合黏土1-5％,五氧化二钽1-4％；另外加入总原料重量2-4％的结合剂。本发明耐火材料,引入超细氧化钽粉体,该材料在高温、高压和强还原的条件下形成的立方相TaCy均匀分散在制品基质中,且TaCy强的共价键属性和极低的自扩散系数使陶瓷杯制品具有更加优异的耐压强度、荷重软化温度和高温抗热震性能。另外,加入片状氧化铝改善陶瓷杯的断裂韧性。利用碳化钽和片状氧化铝的协同作用,有望明显提高炉体的使用寿命。(The invention belongs to the field of refractory materials, and particularly relates to a refractory material for a tantalum-containing blast furnace ceramic cup and a preparation method thereof. The refractory material comprises the following components in percentage by weight: 65-80% of brown corundum, 5-25% of silicon carbide, 2-10% of flake alumina powder, 1-5% of combined clay and 1-4% of tantalum pentoxide; in addition, a binding agent accounting for 2 to 4 percent of the total weight of the raw materials is added. According to the refractory material, the superfine tantalum oxide powder is introduced, the cubic TaCy formed by the material under the conditions of high temperature, high pressure and strong reduction is uniformly dispersed in the product matrix, and the strong covalent bond property and the extremely low self-diffusion coefficient of the TaCy enable the ceramic cup product to have more excellent compression strength, refractoriness under load and high-temperature thermal shock resistance. In addition, the addition of the flake alumina improves the fracture toughness of the ceramic cup. By utilizing the synergistic effect of the tantalum carbide and the flaky alumina, the service life of the furnace body is expected to be obviously prolonged.)

1. The refractory material for the tantalum-containing blast furnace ceramic cup is characterized by comprising the following components in percentage by weight: 65-80% of brown corundum, 5-25% of silicon carbide, 2-10% of flake alumina powder, 1-5% of combined clay and 1-4% of tantalum pentoxide; and adding a binding agent accounting for 2-4% of the total weight of the raw materials.

2. The refractory according to claim 1, wherein the tantalum pentoxide has a particle size of 0.5 μm to 5 μm.

3. The refractory according to claim 1, wherein the tabular alumina powder has an alumina content of 99% or more; the alumina has a particle size of 0.5-5 μm, a thickness of 0.2-0.5 μm, and a ratio of diameter to thickness of 2.5-20.

4. The refractory according to claim 1, wherein the binder is composed of sulfonate and lignin, and the mass ratio of sulfonate to lignin is 1: 1.

5. The method for preparing the refractory material for the blast furnace ceramic cup according to claim 1, comprising the following steps:

(1) mixing materials: weighing the raw materials according to the proportion, uniformly grinding the brown corundum and the silicon carbide, adding a binding agent, and mixing and grinding for 5-8 minutes; adding the flaky alumina, the tantalum pentoxide and the combined clay, and mixing and grinding for 10-20 minutes to prepare a uniformly mixed wet material;

(2) and forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200-300 MPa;

(3) and (3) drying: placing the green bricks obtained in the step (2) in a drying kiln for drying, heating to 110-150 ℃ at the heating rate of 3-5 ℃/min, and preserving heat for 15-25 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln.

6. The method for producing a refractory for a blast furnace ceramic cup according to claim 5, wherein the firing system in the step (4) is: the initial temperature is 300 ℃, the temperature is maintained for 30-60min, the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, the temperature is raised to 1450-1600 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 12-18h, and the material is taken out of the kiln after being naturally cooled to below 60 ℃.

Technical Field

The invention belongs to the field of refractory materials, and particularly relates to a refractory material for a tantalum-containing blast furnace ceramic cup and a preparation method thereof.

Background

The ceramic cup is a ceramic refractory masonry with a certain thickness, high refractoriness under load, low heat conduction, wear resistance and erosion resistance built on the inner side of a carbonaceous furnace lining of a furnace bottom and a furnace hearth. During the production of the blast furnace, because of the heat insulation and preservation effects of the ceramic furnace lining, the iron slag directly contacts the ceramic furnace lining, thereby not only reducing the heat loss through the furnace lining, but also protecting the carbon bricks and enabling the carbon bricks to avoid the brittle fracture zone of 800 ℃ to 1100 ℃. The heat insulation and heat preservation effects of the ceramic cup can reduce the heat loss of the furnace hearth, improve the temperature of the iron slag, facilitate the recovery of the furnace condition after the blast furnace is stopped, and prolong the service life of the furnace hearth. In order to further increase the service life of blast furnaces, researchers have made constant improvements to the materials of "ceramic cups". For example, the mechanical property, the thermal shock resistance and the molten iron melting loss resistance of the corundum brick are enhanced by using the beta-Sialon combined corundum brick as the refractory material of the blast furnace hearth ceramic cup. In addition, the maintenance techniques for ceramic cups are also constantly being updated. For example, titanium oxide is partially converted into a solid solution of carbides or nitrides of Ti in a high-temperature reducing atmosphere in a furnace by introducing a titanium-containing mineral, and these high-melting-point substances are mixed with molten iron and graphitic carbon precipitated in the molten iron, and are deposited on the working surface or in brick joints of the eroded part of the hearth, thereby playing a role in protecting the hearth.

However, the existing refractory materials still have the problems of insufficient strength and poor refractory performance.

Disclosure of Invention

The invention aims to provide a novel blast furnace ceramic cup refractory material and a preparation method thereof, and aims to solve the problems in the background art. By utilizing the technical scheme of the invention, the ceramic cup obtains higher strength and toughness, and the service life of the furnace body is prolonged.

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

the invention provides a novel ceramic cup refractory material, which comprises, by weight, 65-80% of brown corundum, 5-25% of silicon carbide, 2-10% of flake alumina powder, 1-5% of clay (Guangxi white mud) and 1-4% of tantalum pentoxide; and adding a binding agent accounting for 2-4% of the total weight of the raw materials.

According to the ceramic cup refractory material, the particle size of the brown corundum is less than 5 mm;

the granularity of the silicon carbide is less than 5mm, wherein the content of the silicon carbide is not less than 90%

According to the ceramic cup refractory described above, the particle size of the tantalum pentoxide is 0.5 μm to 5 μm, and preferably the particle size of the tantalum pentoxide is 0.5 μm to 2 μm.

According to the ceramic cup refractory material, the content of alumina in the flaky alumina powder is not less than 99%; the diameter of the flake alumina is 0.5-5 μm, the thickness is 0.2-0.5 μm, and the ratio of diameter to thickness is 2.5-20; preferably, the aspect ratio is 8 to 12.

According to the ceramic cup refractory material, the combined clay is Guangxi white clay, wherein the content of alumina is not less than 30%; preferably, the bound clay content is 1-2%.

According to the ceramic cup refractory material, the bonding agent is composed of sulfonate and lignin, and the mass ratio of the sulfonate to the lignin is 1: 1.

The invention also provides a preparation method of the refractory material for the tantalum-containing blast furnace ceramic cup, which comprises the following steps:

(1) mixing materials: weighing the raw materials according to the raw material composition proportion of the refractory material for the tantalum-containing blast furnace ceramic cup, uniformly grinding brown corundum and silicon carbide, adding a binding agent, and mixing and grinding for 5-8 minutes; adding flake aluminum oxide, tantalum pentoxide and combined clay (Guangxi white mud), and mixing and grinding for 10-20 minutes to obtain uniformly mixed wet material.

(2) And forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200-300 MPa;

(3) and (3) drying: drying the green brick obtained in the step (2) in a drying kiln, heating to 110-150 ℃ at the heating rate of 3-5 ℃/min, and preserving heat for 15-25 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln, wherein the sintering system is as follows: the initial temperature is 300 ℃, the temperature is maintained for 30-60min, the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, the temperature is raised to 1450-1600 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 12-18h, and the material is taken out of the kiln after being naturally cooled to below 60 ℃.

The invention has the beneficial effects that:

1. on the basis of the traditional ceramic cup, the tantalum-containing ceramic cup product of the invention is introduced with superfine tantalum oxide powder, the cubic phase TaCy (y is 0.8-1.0) formed by superfine tantalum pentoxide under the conditions of high temperature, high pressure and strong reduction is uniformly dispersed in the substrate of the product, and the ceramic cup product has more excellent compression strength, refractoriness under load and high-temperature thermal shock resistance due to the strong covalent bond property and extremely low self-diffusion coefficient of the TaCy.

2. According to the invention, the flaky alumina serving as a second phase toughening agent is added into the ceramic cup, and when the blast furnace runs at high temperature, the anisotropic tensile stress of crack tip stress and thermal expansion interact. The microcrack generated in the crack tip region can deflect the crack along the interface between the matrix and the flaky crystal grains, the energy for promoting the crack to expand is consumed, the toughening effect is generated through the bridging action, the fracture toughness of the ceramic cup is improved, and the service life of the furnace body is prolonged.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

Example 1:

the novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 75% of brown corundum, 12% of silicon carbide, 5% of flake alumina powder, 4% of combined clay and 4% of tantalum pentoxide; adding 3% of the binder based on the total weight. The particle size of the tantalum pentoxide is 2.0-4.0 μm. The particle size of the flaky alumina is 1.0-2.0 μm, and the ratio of the particle size to the thickness of the flaky alumina is 5.0; the bonding agent consists of sulfonate and lignin, and the mass ratio of the sulfonate to the lignin is 1: 1.

The preparation steps are as follows:

(1) mixing materials: after the brown corundum and the silicon carbide are ground uniformly, adding a binding agent, and mixing and grinding for 6 minutes; then adding the flaky alumina, the tantalum pentoxide and the combined clay, and mixing and grinding for 15 minutes to prepare a uniformly mixed wet material.

(2) And forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200 ℃;

(3) and (3) drying: placing the green bricks obtained in the step (2) into a drying kiln for drying, heating to 120 ℃ at the heating rate of 5 ℃/min, and preserving heat for 20 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln, wherein the sintering system is as follows: the initial temperature is 300 ℃, the temperature is kept for 45min, then the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, then the temperature is raised to 1550 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 15h, and the sintered product is naturally cooled to below 60 ℃ and taken out.

Example 2:

the novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 70% of brown corundum, 15% of silicon carbide, 8% of flake alumina powder, 4% of combined clay and 3% of tantalum pentoxide; adding 3% of the binder based on the total weight. The particle size of the tantalum pentoxide is 2.0-4.0 μm. The particle size of the flaky alumina is 2.0-3.0 mu m, and the ratio of the particle size to the thickness of the flaky alumina is 5.0; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation steps are as follows:

(1) mixing materials: after the brown corundum and the silicon carbide are ground uniformly, adding a binding agent, and mixing and grinding for 6 minutes; then adding the flaky alumina, the tantalum pentoxide and the combined clay, and mixing and grinding for 15 minutes to prepare a uniformly mixed wet material.

(2) And forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200 ℃;

(3) and (3) drying: placing the green bricks obtained in the step (2) into a drying kiln for drying, heating to 120 ℃ at the heating rate of 5 ℃/min, and preserving heat for 20 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln, wherein the sintering system is as follows: the initial temperature is 300 ℃, the temperature is kept for 45min, then the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, then the temperature is raised to 1550 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 15h, and the sintered product is naturally cooled to below 60 ℃ and taken out.

Example 3:

the novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 65% of brown corundum, 20% of silicon carbide, 10% of flake alumina powder, 4% of combined clay and 1% of tantalum pentoxide; adding 3% of the binder based on the total weight. The particle size of the tantalum pentoxide is 1.0-2.0 μm. The particle size of the flaky alumina is 3.0-5.0 mu m, and the diameter-thickness ratio is 15; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation steps are as follows:

(1) mixing materials: after the brown corundum and the silicon carbide are ground uniformly, adding a binding agent, and mixing and grinding for 6 minutes; then adding the flaky alumina, the tantalum pentoxide and the combined clay, and mixing and grinding for 15 minutes to prepare a uniformly mixed wet material.

(2) And forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200 ℃;

(3) and (3) drying: placing the green bricks obtained in the step (2) into a drying kiln for drying, heating to 120 ℃ at the heating rate of 5 ℃/min, and preserving heat for 20 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln, wherein the sintering system is as follows: the initial temperature is 300 ℃, the temperature is kept for 45min, then the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, then the temperature is raised to 1550 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 15h, and the sintered product is naturally cooled to below 60 ℃ and taken out.

Example 4:

the novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 70% of brown corundum, 15% of silicon carbide, 8% of flake alumina powder, 4% of combined clay and 3% of tantalum pentoxide; in addition, 3 percent of the binder is added based on the weight of the total raw materials. The particle size of the tantalum pentoxide is 1.0-2.0 μm. The particle size of the flaky alumina is 2.0-3.0 mu m, and the diameter-thickness ratio is 10; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation steps are as follows:

(1) mixing materials: after the brown corundum and the silicon carbide are ground uniformly, adding a binding agent, and mixing and grinding for 6 minutes; then adding the flaky alumina, the tantalum pentoxide and the combined clay, and mixing and grinding for 15 minutes to prepare a uniformly mixed wet material.

(2) And forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200 ℃;

(3) and (3) drying: placing the green bricks obtained in the step (2) into a drying kiln for drying, heating to 120 ℃ at the heating rate of 5 ℃/min, and preserving heat for 20 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln, wherein the sintering system is as follows: the initial temperature is 300 ℃, the temperature is kept for 45min, then the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, then the temperature is raised to 1550 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 15h, and the sintered product is naturally cooled to below 60 ℃ and taken out.

Example 5:

the novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 70% of brown corundum, 15% of silicon carbide, 8% of flake alumina powder, 4% of combined clay and 3% of tantalum pentoxide; in addition, 3 percent of the binder is added based on the weight of the total raw materials. The particle size of the tantalum pentoxide is 1.0-2.0 μm. The particle size of the flaky alumina is 2.0-3.0 mu m, and the diameter-thickness ratio is 10; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation steps are as follows:

(1) mixing materials: after the brown corundum and the silicon carbide are ground uniformly, adding a binding agent, and mixing and grinding for 6 minutes; then adding the flaky alumina, the tantalum pentoxide and the combined clay, and mixing and grinding for 15 minutes to prepare a uniformly mixed wet material.

(2) And forming: pressing the formed wet material obtained in the step (1) into a green brick under the pressure of 200 ℃;

(3) and (3) drying: placing the green bricks obtained in the step (2) into a drying kiln for drying, heating to 120 ℃ at the heating rate of 5 ℃/min, and preserving heat for 20 h;

(4) and firing: and (4) sintering the dried green bricks obtained in the step (3) by adopting a high-temperature tunnel kiln, wherein the sintering system is as follows: the initial temperature is 300 ℃, the temperature is kept for 45min, the temperature is raised to 1000 ℃ at the heating rate of 10 ℃/min, the temperature is kept for 60min, the temperature is raised to 1450 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 15h, and the sintered product is naturally cooled to below 60 ℃ and taken out.

Comparative example 1

The novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 73% of brown corundum, 15% of silicon carbide, 8% of flake alumina powder and 4% of bound clay; in addition, 3 percent of the binder is added based on the weight of the total raw materials. The particle size of the flaky alumina is 2.0-3.0 mu m, and the diameter-thickness ratio is 10; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation procedure was the same as in inventive example 4.

Comparative example 2

The novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 75% of brown corundum, 18% of silicon carbide, 4% of combined clay and 3% of tantalum pentoxide; in addition, 3 percent of the binder is added based on the weight of the total raw materials. The particle size of the tantalum pentoxide is 1.0-2.0 μm. The particle size of the flaky alumina is 2.0-3.0 mu m, and the diameter-thickness ratio is 10; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation procedure was the same as in inventive example 4.

Comparative example 3

The novel ceramic cup refractory material disclosed by the invention comprises the following raw materials in percentage by weight: 70% of brown corundum, 15% of silicon carbide, 8% of flake alumina powder, 4% of combined clay and 3% of tantalum pentoxide; in addition, 3 percent of the binder is added based on the weight of the total raw materials. The granularity of the tantalum pentoxide is 100nm-400 nm. The particle size of the flaky alumina is 2.0-3.0 mu m, and the diameter-thickness ratio is 10; the binding agent consists of sulfonate and lignin, and the ratio of the sulfonate to the lignin is 1: 1.

The preparation procedure was the same as in inventive example 4.

The technical indexes of the performance of the ceramic cups obtained in the examples 1 to 5 and the comparative examples 1 to 3 of the present invention are shown in Table 1.

TABLE 1 technical indices of performance of ceramic cups of the products obtained in inventive examples 1-5 and comparative examples