阅读说明：本技术 一种抗渣侵蚀的钢包熔池用镁碳砖及其制备方法 (Slag-corrosion-resistant magnesia carbon brick for ladle molten pool and preparation method thereof ) 是由 马四凯 李洪波 李维锋 魏振国 邹新国 李勇伟 孙佳琛 于 2019-12-05 设计创作，主要内容包括：本发明的一种抗渣侵蚀的钢包熔池用镁碳砖,其特征在于,包括如下质量分数的组分：电熔镁砂颗粒：50%～70%,电熔镁砂细粉：5%～20%,铝铬渣：5%～20%,金属铝粉：1%～5%,金属硅粉：1%～5%,鳞片石墨：10%～15%,结合剂：2%～4%。本发明的抗渣侵蚀的钢包熔池用镁碳砖具有显著提高的抗渣侵蚀性能；本方法减少了对电熔镁砂资源消耗,环保效应更明显,还可以降低生产成本。(The invention discloses a slag corrosion resistant magnesia carbon brick for a ladle molten pool, which is characterized by comprising the following components in percentage by mass: electrically fusing magnesite particles: 50% -70%, fused magnesia fine powder: 5-20%, aluminum chromium slag: 5% -20%, metal aluminum powder: 1% -5%, metal silicon powder: 1% -5%, crystalline flake graphite: 10% -15%, binder: 2 to 4 percent. The slag corrosion resistant magnesia carbon brick for the ladle molten pool has obviously improved slag corrosion resistance; the method reduces the consumption of fused magnesia resources, has more obvious environmental protection effect and can also reduce the production cost.)

1. The magnesia carbon brick for the slag corrosion resistant ladle molten pool is characterized by comprising the following components in percentage by mass: electrically fusing magnesite particles: 50% -70%, fused magnesia fine powder: 5-20%, aluminum chromium slag: 5% -20%, metal aluminum powder: 1% -5%, metal silicon powder: 1% -5%, crystalline flake graphite: 10% -15%, binder: 2 to 4 percent.

2. The slag erosion resistant magnesia carbon brick for the ladle molten pool according to claim 1, wherein the grain size distribution of the fused magnesia particles is 5-3 mm, 3-1 mm and 1-0.075 mm, and the mass ratio of the three grain size distributions is (2-6): (2-5): (2-4), the chemical compositions of the fused magnesia in percentage by mass are more than or equal to 96.3 percent of MgO, less than or equal to 1.4 percent of CaO, less than or equal to 1.4 percent of SiO2, and the volume density is more than or equal to 3.45g/cm³。

3. The slag erosion resistant magnesia carbon brick for the steel ladle melting pool according to claim 1, wherein the granularity of the fused magnesia fine powder is 120-400 meshes, and the fused magnesia comprises the following chemical components in percentage by mass of more than or equal to 97.2 percent of MgO, less than or equal to 1.0 percent of CaO, less than or equal to 1.0 percent of SiO2, and more than or equal to 3.50g/cm in volume density³。

4. The slag erosion resistant magnesia carbon brick for the ladle molten pool according to claim 1, characterized in that the grain size distribution of the aluminum-chromium slag particles is 5-3 mm, 3-1 mm and 1-0.075 mm, and the mass ratio of the three grain size distributions is (1-2): (1-2): (1-2), wherein the chemical composition of the aluminum chromium slag accounts for Al in percentage by mass₂O₃≥80%，Cr₂O₃Not less than 10 percent and volume density not less than 3.35g/cm³。

5. The slag corrosion resistant magnesia carbon brick for the ladle molten pool according to claim 1, wherein the granularity of the metal aluminum powder is 120-400 meshes, and the purity of the metal aluminum powder is more than or equal to 99% by mass of Al.

6. The slag erosion resistant magnesia carbon brick for a ladle molten pool according to claim 1, wherein the particle size of the metal silicon powder is 120-400 meshes, and the purity of the metal silicon powder is more than or equal to 97% by mass of Si.

7. The slag corrosion resistant magnesia carbon brick for the ladle molten pool according to claim 1, wherein the granularity of the crystalline flake graphite is 100-120 meshes, and the chemical compositions of the crystalline flake graphite in percentage by mass are more than or equal to 95.0 percent of C, less than or equal to 0.7 percent of ash and less than or equal to 0.5 percent of water.

8. The magnesia carbon brick for the slag corrosion resistant ladle furnace bath according to claim 1, wherein the bonding agent is thermosetting phenolic resin.

9. The preparation method of the magnesia carbon brick for the ladle molten pool according to any one of claims 1 to 8, characterized by comprising the following steps:

(1) mixing materials: dry-mixing the fused magnesia particles and the aluminum-chromium slag for 3-10 minutes, slowly adding a phenol solution of the binding agent, and continuously performing dry-mixing for 3-7 minutes; adding the crystalline flake graphite, and continuously performing dry mixing for 7-15 minutes; finally, adding the fused magnesia fine powder, the metal aluminum powder and the metal silicon powder, continuously mixing for 35-60 minutes, and discharging to obtain a pre-pressing material;

(2) molding: adding the prepressing material obtained in the step (1) into a die to be pressed and molded to prepare a semi-finished brick blank, wherein the pressure is 6300-10000 KN;

(3) baking: baking and curing the semi-finished brick blank obtained in the step (2), wherein the baking temperature is 180-250 ℃, and the baking time is 12-24 hours; cooling and discharging to obtain the magnesia carbon brick for the slag corrosion resistant ladle molten pool.

10. The preparation method according to claim 1, wherein the phenol solution of the binder has a solid content of 80% or more.

Technical Field

The invention belongs to the technical field of refractory materials, and particularly relates to a slag corrosion resistant magnesia carbon brick for a ladle molten pool and a preparation method thereof.

Background

The ladle bath brick is a carbon-containing composite refractory material, has high slag erosion resistance, high thermal shock resistance and high spalling resistance, and is not easy to be wetted by slag and molten steel, so the ladle bath brick is widely applied in the field of ferrous metallurgy, but along with the development of a steelmaking process, the cleanliness requirement of steel grades is more and more strict, and the more rigorous requirement is provided for the steelmaking process: the external refining types are more and more, the refining time is longer and longer, and the turnover time of the molten steel in the ladle container is prolonged, so that higher quality and service life requirements are provided for the ladle furnace hearth brick.

The aluminum-chromium slag is a solid waste generated in the process of smelting chromium by using a thermite reduction method, and harms the ecological environment and human health. The aluminum chromium slag has high content of aluminum oxide, chromium exists in a form of chromium oxide, aluminum oxide is a refractory oxide with excellent performance, and the chromium oxide has strong acid slag corrosion resistance. If the aluminum chromium slag is used as a refractory raw material and applied to the ladle molten pool brick, the pressure of environmental protection can be reduced, the current situation of high-quality refractory raw materials with high price can be relieved, and two purposes are achieved.

Disclosure of Invention

The invention provides a slag corrosion resistant magnesia carbon brick for a ladle molten pool and a preparation method thereof.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the magnesia carbon brick for the slag corrosion resistant ladle molten pool is characterized by comprising the following components in percentage by mass: electrically fusing magnesite particles: 50% -70%, fused magnesia fine powder: 5-20%, aluminum chromium slag: 5% -20%, metal aluminum powder: 1% -5%, metal silicon powder: 1% -5%, crystalline flake graphite: 10% -15%, binder: 2% -4%;

the particle size distribution of the fused magnesia particles is 5-3 mm, 3-1 mm and 1-0.075 mm, and the mass ratio of the three particle size distributions is (2-6): (2-5): (2-4), the chemical compositions of the fused magnesia in percentage by mass are more than or equal to 96.3 percent of MgO, less than or equal to 1.4 percent of CaO, less than or equal to 1.4 percent of SiO2, and the volume density is more than or equal to 3.45g/cm³；

The granularity of the fused magnesite fine powder is 120-400 meshes, and the fused magnesite comprises the following chemical components in percentage by mass of more than or equal to 97.2% of MgO, less than or equal to 1.0% of CaO, less than or equal to 1.0% of SiO2, and more than or equal to 3.50g/cm in volume density³；

The particle size distribution of the aluminum-chromium slag particles is 5-3 mm, 3-1 mm and 1-0.075 mm, and the mass ratio of the three particle size distributions is (1-2): (1-2): (1-2), wherein the chemical composition of the aluminum chromium slag accounts for Al in percentage by mass₂O₃≥80％，Cr₂O₃Not less than 10 percent and volume density not less than 3.35g/cm³；

The granularity of the metal aluminum powder is 120-400 meshes, and the purity of the metal aluminum powder is more than or equal to 99% by mass percent of Al;

the granularity of the metal silicon powder is 120-400 meshes, and the purity of the metal silicon powder is more than or equal to 97% by mass percent of Si;

the particle size of the crystalline flake graphite is 100-120 meshes, and the chemical components of the crystalline flake graphite in percentage by mass are more than or equal to 95.0% of C, less than or equal to 0.7% of ash and less than or equal to 0.5% of water;

the bonding agent is thermosetting phenolic resin.

The invention also provides a preparation method of the slag corrosion resistant magnesia carbon brick for the ladle molten pool, which is characterized by comprising the following steps:

(1) mixing materials: dry-mixing the fused magnesia particles and the aluminum-chromium slag for 3-10 minutes, slowly adding a phenol solution of the binding agent, and continuously performing dry-mixing for 3-7 minutes; adding the crystalline flake graphite, and continuously performing dry mixing for 7-15 minutes; finally, adding the fused magnesia fine powder, the metal aluminum powder and the metal silicon powder, continuously mixing for 35-60 minutes, and discharging to obtain a pre-pressing material;

(2) molding: adding the prepressing material obtained in the step (1) into a die to be pressed and molded to prepare a semi-finished brick blank, wherein the pressure is 6300-10000 KN;

(3) baking: baking and curing the semi-finished brick blank obtained in the step (2), wherein the baking temperature is 180-250 ℃, and the baking time is 12-24 hours; cooling and discharging to obtain the magnesia carbon brick for the slag corrosion resistant ladle molten pool.

Further, the solid content of the phenol solution of the binding agent is more than or equal to 80 percent.

The invention has the following beneficial effects:

adding a certain amount of aluminum-chromium slag into a steel ladle molten pool brick, and reacting aluminum oxide and chromium oxide in the aluminum-chromium slag with magnesium oxide in the molten pool brick in situ under a high-temperature condition to generate magnesium aluminate spinel and magnesium chromium spinel; because of the excellent slag penetration resistance and thermal shock stability of the magnesium aluminate spinel and the magnesium chromium spinel, compared with the performance of the prior ladle bath brick, the slag corrosion resistant magnesia carbon brick for the ladle bath has the advantages of obviously improved slag corrosion resistance, reduced consumption of fused magnesia resources, more obvious environmental protection effect and reduced production cost.

Detailed Description

It should be understood by those skilled in the art that the present embodiment is only for illustrating the present invention and is not to be used as a limitation of the present invention, and changes and modifications of the embodiment can be made within the scope of the claims of the present invention.

The starting materials used in this example are all commercially available.