A low-carbon magnesium-carbon brick with good corrosion resistance and preparation method thereof

Abstract

The invention relates to the technical field of refractory materials, and in particular to a low-carbon magnesia carbon brick with good corrosion resistance and a preparation method thereof. The low-carbon magnesia carbon brick comprises the following components in parts by weight: 36 to 45 parts of fused magnesia sand with a particle size of 1 to 3 mm; 45 to 55 parts of fused magnesia sand with a particle size of 0.088 to 1 mm; 20 to 30 parts of fused magnesia sand with a particle size of ≤0.088 mm; 10 to 15 parts of amorphous graphite; 5 to 10 parts of a binder; 2 to 4 parts of aluminum powder; 2 to 3 parts of silicon carbide with a particle size of ≤0.088 mm; and 0.5 to 2 parts of boron carbide with a particle size of ≤0.088 mm. The preparation method is as follows: add fused magnesia with a particle size of 1 to 3 mm and fused magnesia with a particle size of 0.088 to 1 mm to a mixer and stir; then add fused magnesia with a particle size of ≤0.088 mm and amorphous graphite to the mixer and stir; then add a binder to the mixer and stir; finally, add aluminum powder, boron carbide and silicon carbide to the mixer; add the mixed materials to the prepared mold, press into shape, and send to a drying kiln for drying. By adding amorphous graphite to prepare low-carbon magnesia carbon bricks, the porosity and volume density of low-carbon magnesia carbon bricks can be improved and the erosion rate can be slowed down.

Description

Technical Field

[0001] The invention relates to the technical field of refractory materials, and in particular to a low-carbon magnesium-carbon brick with good corrosion resistance and a preparation method thereof. Background Art

[0002] Magnesia carbon brick is a carbon composite refractory material that combines the excellent properties of graphite and magnesia sand. It has excellent corrosion resistance and thermal shock resistance and is widely used as a furnace lining material in refining ladles.

[0003] Although magnesium carbon bricks have many advantages, they also have some obvious shortcomings. For example, at high temperatures, the carbon in magnesium carbon bricks easily reacts with oxygen, resulting in a decrease in material performance and affecting service life; the high carbon content of magnesium carbon bricks causes carbon increase problems when smelting quality steel or ultra-low carbon steel; and, graphite is a valuable non-renewable resource, and the high carbon content in magnesium carbon bricks will aggravate the consumption of carbon resources.

[0004] However, simply reducing the carbon content in magnesia carbon bricks will affect its key properties such as thermal shock resistance and slag erosion resistance. Summary of the invention

[0005] In order to overcome the defects of the prior art, the technical problem solved by the present invention is to provide a low-carbon magnesium carbon brick with good corrosion resistance and a preparation method thereof. The present invention prepares the low-carbon magnesium carbon brick by adding amorphous graphite, which can improve the porosity and volume density of the low-carbon magnesium carbon brick and can slow down the corrosion rate.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A low-carbon magnesium-carbon brick with good corrosion resistance comprises the following components in parts by weight:

[0008]

[0009] The MgO content in the fused magnesia is ≥95%.

[0010] The carbon content of the amorphous graphite is ≥97%, and the particle size of the amorphous graphite is ≤325 meshes.

[0011] The aluminum content in the aluminum powder is ≥98%, and the particle size of the aluminum powder is ≤325 meshes.

[0012] The binder is a thermosetting phenolic resin.

[0013] A method for preparing a low-carbon magnesium-carbon brick with good corrosion resistance, the specific steps are as follows:

[0014] 1) The components are prepared according to the above ratios, and fused magnesia with a particle size of 1 to 3 mm and fused magnesia with a particle size of 0.088 to 1 mm are added to a mixer and stirred for 3 to 5 mm; then fused magnesia with a particle size of ≤ 0.088 mm and amorphous graphite are added to the mixer and stirred for 3 to 5 minutes;

[0015] 2) Add the binder to the mixer and stir for 2 to 3 minutes; finally, add the aluminum powder, boron carbide and silicon carbide to the mixer and stir for 4 to 6 minutes;

[0016] 3) Add the mixed materials into the prepared mold, press them into shape, and then send them into a drying kiln at 150-200°C and dry them for 10-15 hours to obtain the finished product.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The present invention prepares low-carbon magnesium carbon bricks by adding amorphous graphite, which can improve the porosity and volume density of the low-carbon magnesium carbon bricks, slow down the erosion rate, and increase the service life;

[0019] 2) The present invention uses boron carbide and silicon carbide in combination, wherein the magnesium borate complex generated after the boron carbide reacts is liquid at high temperatures and can fill pores to form a protective layer; and although silicon carbide has relatively low oxidation resistance, it can synergize with other components to effectively prevent graphite from being oxidized, thereby improving the corrosion resistance and slag resistance of the brick.

[0020] 3) The present invention adds aluminum powder, and the oxidation product of the aluminum powder will further combine with magnesium oxide to form magnesium-aluminum spinel, forming a dense layer, thereby improving the corrosion resistance of the low-carbon magnesium-carbon brick. DETAILED DESCRIPTION

[0021] The specific implementation mode of the present invention is further described below:

[0022] Example 1

[0023] The present invention provides a low-carbon magnesium carbon brick with good corrosion resistance, comprising the following components in parts by weight:

[0024]

[0025]

[0026] The MgO content in the fused magnesia is ≥95%.

[0027] The carbon content of the amorphous graphite is ≥97%, and the particle size of the amorphous graphite is ≤325 meshes.

[0028] The aluminum content in the aluminum powder is ≥98%, and the particle size of the aluminum powder is ≤325 meshes.

[0029] The binder is a thermosetting phenolic resin.

[0030] A method for preparing a low-carbon magnesium-carbon brick with good corrosion resistance, the specific steps are as follows:

[0031] 1) According to the above-mentioned proportions, fused magnesia with a particle size of 1 to 3 mm and fused magnesia with a particle size of 0.088 to 1 mm are added to a mixer and stirred for 5 mm; then fused magnesia with a particle size of ≤ 0.088 mm and amorphous graphite are added to the mixer and stirred for 5 minutes;

[0032] 2) Add the binder to the mixer and stir for 2-3 minutes; finally, add the aluminum powder, boron carbide and silicon carbide to the mixer and stir for 6 minutes;

[0033] 3) Add the mixed materials into the prepared mold, press them into shape, and then send them into a drying kiln at 150-200°C and dry them for 14 hours to obtain the finished product.

[0034] Example 2

[0035] A low-carbon magnesium-carbon brick with good corrosion resistance comprises the following components in parts by weight:

[0036]

[0037] The MgO content in the fused magnesia is ≥95%.

[0038] The carbon content of the amorphous graphite is ≥97%, and the particle size of the amorphous graphite is ≤325 meshes.

[0039] The aluminum content in the aluminum powder is ≥98%, and the particle size of the aluminum powder is ≤325 meshes.

[0040] The binder is a thermosetting phenolic resin.

[0041] A method for preparing a low-carbon magnesium-carbon brick with good corrosion resistance, the specific steps are as follows:

[0042] 1) According to the above-mentioned proportions, fused magnesia with a particle size of 1 to 3 mm and fused magnesia with a particle size of 0.088 to 1 mm are added to a mixer and stirred for 3 to 5 mm; then fused magnesia with a particle size of ≤ 0.088 mm and amorphous graphite are added to the mixer and stirred for 3 minutes;

[0043] 2) Add the binder to the mixer and stir for 2 minutes; finally, add the aluminum powder, boron carbide and silicon carbide to the mixer and stir for 4 minutes;

[0044] 3) Add the mixed materials into the prepared mold, press them into shape, and then send them into a drying kiln at 150-200°C and dry them for 10 hours to obtain the finished product.

[0045] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A low-carbon magnesium carbon brick with good corrosion resistance, characterized in that: Contains the following components in parts by weight:

2. A low-carbon magnesium-carbon brick with good corrosion resistance according to claim 1, characterized in that: The MgO content in the fused magnesia is ≥95%.

3. The low-carbon magnesium-carbon brick with good corrosion resistance according to claim 1, characterized in that: The carbon content of the amorphous graphite is ≥97%, and the particle size of the amorphous graphite is ≤325 meshes.

4. The low-carbon magnesium-carbon brick with good corrosion resistance according to claim 1, characterized in that: The aluminum content in the aluminum powder is ≥98%, and the particle size of the aluminum powder is ≤325 meshes.

5. The low-carbon magnesia-carbon brick with good corrosion resistance according to claim 1, characterized in that: The binder is a thermosetting phenolic resin.

6. A method for preparing a low-carbon magnesium-carbon brick with good corrosion resistance as claimed in claim 1, characterized in that: The specific steps are as follows: 1) The components are prepared according to the above ratios, and fused magnesia with a particle size of 1 to 3 mm and fused magnesia with a particle size of 0.088 to 1 mm are added to a mixer and stirred for 3 to 5 mm; then fused magnesia with a particle size of ≤ 0.088 mm and amorphous graphite are added to the mixer and stirred for 3 to 5 minutes; 2) Add the binder to the mixer and stir for 2 to 3 minutes; finally, add the aluminum powder, boron carbide and silicon carbide to the mixer and stir for 4 to 6 minutes; 3) Add the mixed materials into the prepared mold, press them into shape, and then send them into a drying kiln at 150-200°C and dry them for 10-15 hours to obtain the finished product.

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