CN114736007A - Low-heat-conductivity high-performance aluminum-magnesia-carbon molten pool brick and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of refractory materials, in particular to a low thermal conductivity and high performance aluminum-magnesium-carbon molten pool brick and a preparation method thereof. The components by weight include the following components: 60-80 parts of microporous corundum, 10 parts of fused magnesia ~20 parts, 1-10 parts of alumina micropowder, 0.5-2 parts of metal aluminum powder, 0.5-2 parts of metal silicon powder, 0.5-2 parts of high temperature asphalt powder, 5-10 parts of flake graphite and 2%-4% of binder In the present invention, the microporous corundum is introduced into the aluminum-magnesium-carbon molten pool brick, and the produced aluminum-magnesium-carbon molten pool brick not only has a low thermal conductivity, but also reduces molten steel Heat dissipation loss can achieve the purpose of energy saving and consumption reduction, and can also reduce the consumption of refractory per ton of steel, thereby producing huge economic benefits. At the same time, under high temperature conditions, graphite and microporous corundum react to produce silicon carbide whiskers, silicon carbide whiskers Strengthen the interface structure, thereby improving the high temperature mechanical properties of the material.

Description

A kind of low thermal conductivity high performance aluminum magnesium carbon molten pool brick and preparation method thereof

technical field

The invention relates to the technical field of refractory materials, in particular to a low thermal conductivity and high performance aluminum-magnesium-carbon molten pool brick and a preparation method thereof.

Background technique

Alumina-magnesia-carbon brick is a carbon-containing composite refractory material, which has the characteristics of high temperature resistance, slag resistance and spall resistance, and is widely used in ladle molten pool at home and abroad. The corundum used in traditional aluminum-magnesium-carbon molten pool bricks is dense corundum such as white corundum, brown corundum or tabular corundum. Such corundum raw materials have the characteristics of high bulk density and low apparent porosity. Pool bricks have the characteristics of high specific volume density and low apparent porosity, which are not conducive to the heat preservation of molten steel when applied to the metallurgical industry, and the heat loss is relatively fast.

To sum up, the present invention solves the existing problems by designing a low thermal conductivity and high performance aluminum-magnesium-carbon molten pool brick and a preparation method thereof.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the deficiencies of the existing technical problems, and the present invention provides a low thermal conductivity high-performance aluminum-magnesium-carbon molten pool brick and a preparation method thereof. Microporous corundum is introduced into the aluminum-magnesium-carbon molten pool brick, and the With the characteristics of low bulk density and high porosity of corundum, the aluminum-magnesium-carbon molten pool bricks produced not only have low thermal conductivity, reduce the heat loss of molten steel, achieve the purpose of energy saving and consumption reduction, but also reduce the consumption of refractory materials per ton of steel. , resulting in huge economic benefits. At the same time, under high temperature conditions, graphite and microporous corundum react to produce silicon carbide whiskers, and silicon carbide whiskers enhance the interface structure, thereby improving the high temperature mechanical properties of the material.

To achieve the above object, the present invention provides the following technical solutions:

An aluminum-magnesium-carbon molten pool brick with low thermal conductivity and high performance, comprising the following components by weight: 60-80 parts of microporous corundum, 10-20 parts of fused magnesia, 1-10 parts of alumina micropowder, metal aluminum 0.5-2 parts of powder, 0.5-2 parts of metal silicon powder, 0.5-2 parts of high temperature asphalt powder, 5-10 parts of flake graphite and 2%-4% of binder.

As a preferred solution of the present invention, the particle size distribution of the microporous corundum is 5-3mm, 3-1mm, 1-0.075mm, -200 mesh, and the mass percentage of the chemical composition of the microporous corundum is Al2O3≧99% , Bulk density≧2.9g/cm3, apparent porosity≧25%.

As a preferred solution of the present invention, the particle size of the fused magnesia fine powder is 3-1 mm, 1-0.075 mm, and the mass percentage of the chemical composition of the fused magnesia is MgO≧98%, CaO<1.0% , SiO2<1.0%, bulk density≧3.50g/cm3.

As a preferred solution of the present invention, the particle size of the alumina micropowder is 3 microns, and the mass percentage of the chemical composition of the alumina micropowder is Al2O3≧99%.

As a preferred solution of the present invention, the particle size of the metal aluminum powder is -325 mesh, and its purity is ≧99% by mass.

As a preferred solution of the present invention, the particle size of the metal silicon powder is -200 mesh, and its purity is ≧98% by mass.

As a preferred solution of the present invention, the particle size of the high-temperature asphalt powder is -200 mesh, and the solid content is ≧50%.

As a preferred solution of the present invention, the particle size of the graphite flakes is 100 mesh, and the mass percentage of the chemical composition of the graphite flakes is C≧95.0%, ash <0.7%, and moisture <0.5%.

As a preferred solution of the present invention, the particle size of the graphite flakes is 100 mesh, and the mass percentage of the chemical composition of the graphite flakes is C≧95.0%, ash <0.7%, and moisture <0.5%.

A preparation method of low thermal conductivity and high performance aluminum-magnesium-carbon molten pool brick, comprising the following steps:

S1, mixing: firstly add the microporous corundum particles and fused magnesia into the mixer for 3-5 minutes in a certain proportion, then slowly add the binder and mix for 3-5 minutes, and then add flake graphite to mix 7 to 10 minutes, and finally add microporous corundum fine powder, alumina fine powder, metal aluminum powder, metal silicon powder and high-temperature asphalt powder and mix for 35 to 40 minutes before discharging;

S2, forming: adding the mixed mud material into the mold according to a certain weight to press and form semi-finished bricks, and the pressure is 6300～10000KN;

S3, Baking: Put the pressed semi-finished brick into a drying kiln to bake and solidify, the baking temperature is 180-250℃, and the baking time is 12-24h.

Compared with the prior art, the beneficial effects of the present invention are:

1. In the present invention, by introducing microporous corundum into the aluminum-magnesium-carbon molten pool brick, utilizing the characteristics of low bulk density and high porosity of microporous corundum, the produced aluminum-magnesium-carbon molten pool brick not only has a lower thermal conductivity , reduce the heat dissipation loss of molten steel, achieve the purpose of energy saving and consumption reduction, and also reduce the consumption of refractory materials per ton of steel, thereby producing huge economic benefits. The silicon whiskers enhance the interfacial structure, thereby improving the high-temperature mechanical properties of the material.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative work, all belong to the protection scope of the present invention.

The present invention provides a technical scheme:

An aluminum-magnesium-carbon molten pool brick with low thermal conductivity and high performance, comprising the following components by weight: 60-80 parts of microporous corundum, 10-20 parts of fused magnesia, 1-10 parts of alumina micropowder, metal aluminum 0.5-2 parts of powder, 0.5-2 parts of metal silicon powder, 0.5-2 parts of high temperature asphalt powder, 5-10 parts of flake graphite and 2%-4% of binder.

As a further preferred solution of the present invention, the particle size distribution of the microporous corundum is 5-3mm, 3-1mm, 1-0.075mm, -200 mesh, and the mass percentage of the chemical composition of the microporous corundum is Al2O3 ≧99 %, bulk density≧2.9g/cm3, apparent porosity≧25%.

As a preferred solution of the present invention, the particle size of the fused magnesia fine powder is 3-1 mm, 1-0.075 mm, and the mass percentage of the chemical composition of the fused magnesia is MgO≧98%, CaO<1.0% , SiO2<1.0%, bulk density≧3.50g/cm3.

As a further preferred solution of the present invention, the particle size of the alumina fine powder is 3 microns, and the mass percentage of the chemical composition of the alumina fine powder is Al2O3≧99%.

As a further preferred solution of the present invention, the particle size of the metal aluminum powder is -325 mesh, and its purity is ≧99% by mass percentage.

As a further preferred solution of the present invention, the particle size of the metal silicon powder is -200 mesh, and its purity is ≧98% by mass percentage.

As a further preferred solution of the present invention, the particle size of the high-temperature asphalt powder is -200 mesh, and the solid content is ≧50%.

As a further preferred solution of the present invention, the particle size of the graphite flakes is 100 mesh, and the mass percentage of the chemical composition of the graphite flakes is C≧95.0%, ash <0.7%, and moisture <0.5%.

As a further preferred solution of the present invention, the particle size of the graphite flakes is 100 mesh, and the mass percentage of the chemical composition of the graphite flakes is C≧95.0%, ash <0.7%, and moisture <0.5%.

A preparation method of low thermal conductivity and high performance aluminum-magnesium-carbon molten pool brick, comprising the following steps:

S1, mixing: firstly add the microporous corundum particles and fused magnesia into the mixer for 3-5 minutes in a certain proportion, then slowly add the binder and mix for 3-5 minutes, and then add flake graphite to mix 7 to 10 minutes, and finally add microporous corundum fine powder, alumina fine powder, metal aluminum powder, metal silicon powder and high-temperature asphalt powder and mix for 35 to 40 minutes before discharging;

S2, forming: adding the mixed mud material into the mold according to a certain weight to press and form semi-finished bricks, and the pressure is 6300～10000KN;

S3, Baking: Put the pressed semi-finished brick into a drying kiln to bake and solidify, the baking temperature is 180-250℃, and the baking time is 12-24h.

Specific implementation cases:

Example 1

(1) Mixing: firstly add the microporous corundum particles and fused magnesia into the mixer for 5 minutes, then slowly add the binder and mix for 5 minutes, and then add flake graphite and mix for 10 minutes. Finally, add microporous corundum fine powder, alumina fine powder, metal aluminum powder, metal silicon powder and high temperature asphalt powder and mix for 40 minutes before discharging;

(2) molding: the mud material that the kneading is completed is added into the mold by a certain weight and is pressed and molded to make semi-finished bricks, and the pressure is 10000KN;

(3) Baking: Put the pressed semi-finished brick into the drying kiln to bake and solidify, the baking temperature is 200℃, and the baking time is 16h.

In this example, the components by weight include the following components: 70 parts of microporous corundum, 15 parts of fused magnesia, 3 parts of alumina micropowder, 1 part of metal aluminum powder, 1 part of metal silicon powder, and 1 part of high-temperature asphalt powder , 9 parts of flake graphite, 3% binder.

Example 2

(1) Mixing: firstly add the microporous corundum particles and fused magnesia into the mixer for 5 minutes, then slowly add the binder and mix for 5 minutes, and then add flake graphite and mix for 10 minutes. Finally, add microporous corundum fine powder, alumina fine powder, metal aluminum powder, metal silicon powder and high temperature asphalt powder and mix for 40 minutes before discharging;

(2) molding: the mud material that the kneading is completed is added into the mold by a certain weight and is pressed and molded to make semi-finished bricks, and the pressure is 10000KN;

(3) Baking: Put the pressed semi-finished brick into the drying kiln to bake and solidify, the baking temperature is 200℃, and the baking time is 16h.

In this example, the components by weight include the following components: 72 parts of microporous corundum, 13 parts of fused magnesia, 3 parts of alumina micropowder, 1 part of metal aluminum powder, 1 part of metal silicon powder, and 1 part of high temperature asphalt powder , 9 parts of flake graphite, 3% binder.

Example 3

(1) Mixing: firstly add the microporous corundum particles and fused magnesia into the mixer for 5 minutes, then slowly add the binder and mix for 5 minutes, and then add flake graphite and mix for 10 minutes. Finally, add microporous corundum fine powder, alumina fine powder, metal aluminum powder, metal silicon powder and high temperature asphalt powder and mix for 40 minutes before discharging;

(2) molding: the mud material that the kneading is completed is added into the mold by a certain weight and is pressed and molded to make semi-finished bricks, and the pressure is 10000KN;

(3) Baking: Put the pressed semi-finished brick into the drying kiln to bake and solidify, the baking temperature is 200℃, and the baking time is 16h.

In this example, the components by weight include the following components: 74 parts of microporous corundum, 11 parts of fused magnesia, 3 parts of alumina micropowder, 1 part of metal aluminum powder, 1 part of metal silicon powder, and 1 part of high temperature asphalt powder , 9 parts of flake graphite, 3% binder.

The detection data of Examples 1, 2, and 3 are shown in Table 1.

Table 1

As can be seen from the above table, compared with the indicators of the traditional aluminum-magnesium-carbon molten pool brick, the bulk density in this embodiment is reduced by 7%-8%, the thermal conductivity is reduced by about 26%, and the high-temperature flexural strength is increased by about 50% .

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (10)

1. The low-heat-conductivity high-performance aluminum-magnesia-carbon molten pool brick comprises the following components in parts by weight: 60-80 parts of microporous corundum, 10-20 parts of fused magnesia, 1-10 parts of alumina micropowder, 0.5-2 parts of metal aluminum powder, 0.5-2 parts of metal silicon powder, 0.5-2 parts of high-temperature asphalt powder, 5-10 parts of flake graphite and 2-4% of a binding agent.

2. The low-heat-conductivity high-performance aluminum-magnesium-carbon molten pool brick according to claim 1, wherein the microporous corundum particles have a particle size distribution of 5-3 mm, 3-1 mm, 1-0.075 mm and-200 meshes, the chemical composition of the microporous corundum accounts for 99% or more of Al2O3, a volume density of 2.9g/cm3 and an apparent porosity of 25% or more.

3. The low-heat-conductivity high-performance aluminum-magnesium-carbon molten pool brick according to claim 1, wherein the fused magnesite powder has a particle size of 3-1 mm and 1-0.075 mm, and the chemical composition of the fused magnesite is equal to or greater than 98% by mass of MgO, equal to or less than 1.0% by mass of CaO, equal to or less than 1.0% by mass of SiO2, and equal to or greater than 3.50g/cm3 by mass.

4. The low-heat-conductivity high-performance aluminum-magnesia-carbon molten pool brick as claimed in claim 1, wherein the particle size of the alumina micro powder is 3 microns, and the mass percentage of the chemical composition of the alumina micro powder is greater than or equal to 99% of Al2O 3.

5. The low-thermal-conductivity high-performance aluminum-magnesia carbon molten pool brick according to claim 1, wherein the metal aluminum powder has a particle size of-325 meshes and a purity of not less than 99% by mass.

6. The low-heat-conductivity high-performance aluminum-magnesia carbon molten pool brick according to claim 1, wherein the metal silicon powder has a particle size of-200 meshes and a purity of not less than 98% by mass.

7. The low-thermal-conductivity high-performance aluminum-magnesia carbon molten pool brick as claimed in claim 1, wherein the high-temperature asphalt powder has a particle size of-200 meshes and a solid content of not less than 50%.

8. The aluminum-magnesia carbon molten pool brick with low heat conductivity and high performance of claim 1, wherein the particle size of the crystalline flake graphite is 100 meshes, the chemical composition of the crystalline flake graphite accounts for not less than 95.0% by mass, the ash content is less than 0.7%, and the water content is less than 0.5%.

9. The aluminum-magnesia carbon molten pool brick with low heat conductivity and high performance of claim 1, wherein the particle size of the crystalline flake graphite is 100 meshes, the chemical composition of the crystalline flake graphite accounts for not less than 95.0% by mass, the ash content is less than 0.7%, and the water content is less than 0.5%.

10. The method for preparing the low thermal conductivity high performance almag molten bath brick according to claim 1, comprising the steps of:

s1, mixing: firstly, adding microporous corundum particles and fused magnesia into a mixer according to a certain proportion, dry-mixing for 3-5 minutes, then slowly adding a binding agent, mixing for 3-5 minutes, then adding crystalline flake graphite, mixing for 7-10 minutes, finally adding microporous corundum fine powder, alumina micro powder, metal aluminum powder, metal silicon powder and high-temperature asphalt powder, mixing for 35-40 minutes, and discharging;

s2, molding: adding the pug after mixing into a die according to a certain weight, and pressing and forming to prepare a semi-finished brick blank under the pressure of 6300-10000 KN;

s3, baking: and (3) placing the pressed semi-finished brick blank into a drying kiln for baking and curing, wherein the baking temperature is 180-250 ℃, and the baking time is 12-24 hours.