CN101007730A - Alumina-spinel flame-proof material for refining aluminium furnace and its production method - Google Patents

Abstract

The invention relates to a corundum-spinel refractory material for refining aluminum furnaces in the technical field of refractory materials and a production method thereof. The components and weight percentages of the material are as follows: 55-60% of white corundum, 10-30% of magnesium-aluminum spinel, 5-10% of electric fused magnesia, and 10%-20% of α-alumina micropowder. According to the weight percentage of the mixture, first add the white corundum with a particle size of 3-1mm and 1-0.5mm and the magnesium-aluminum spinel with a particle size of 1-0.5mm in the raw material and stir, and at the same time add 2% by weight of the prepared material Calcium lignosulfonate solution as an additive, after mixing, add 180-mesh white corundum, 0.5-0mm and 180-mesh magnesia-alumina spinel, fused magnesia and α-alumina micropowder, and then add 3% by weight of the prepared materials Calcium lignosulfonate solution, continue to mix, then press molding, dry, heat preservation. The invention is not easy to be reduced by the aluminum melt, reduces inclusions in the aluminum melt, and improves the purity of aluminum.

Description

Corundum-spinel refractory material for refining aluminum furnace and production method thereof

technical field

The invention relates to a production method in the technical field of refractory materials, in particular to a corundum-spinel refractory material for refining aluminum furnaces and a production method thereof.

Background technique

Aluminum is the second largest metal material after steel, and is widely used in aerospace, transportation, electronics, light industry and building materials and other fields. At present, the quality of my country's aluminum products is not high, and the current high-performance aluminum materials mainly rely on imports. Among them, the purity level of aluminum melt is not high, the metallurgical quality of materials is poor, and the purification effect is unstable, which is one of the important reasons why the performance of aluminum materials in my country is difficult to improve. The quality gap between domestic products and foreign products is mainly due to the high content of impurity elements, gases and non-metallic inclusions in the products.

The inclusions in the aluminum melt mainly come from the contact reaction between the aluminum melt and N ₂ , O ₂ , H ₂ O, CO and other gases in the furnace gas, as well as refractories and fluxes. The contact reaction between refractory materials and aluminum melt and flux is one of the main sources of inclusions in aluminum melt. The existence of inclusions in aluminum melt will affect the quality of aluminum or aluminum alloy products. Most of the refractory materials for refining aluminum melt are high-alumina-based shaped products and unshaped refractories. These high-alumina refractories are mainly used in melting furnaces for aluminum melts, static furnaces (holding furnaces), Flume and other parts.

After searching the literature of the prior art, it was found that "Research on the Corrosion Resistance of Special High Alumina Bricks for Aluminum Smelting Furnaces" published by Zhao Shiming et al. In this paper, high-alumina bricks are proposed for aluminum smelting and the corrosion resistance of high-alumina bricks is studied. The disadvantage is that high alumina bricks contain silicon dioxide, which can be reduced by metal aluminum during use and affect the chemical composition of metal aluminum liquid.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the prior art, to provide a corundum-spinel refractory material for refining aluminum furnace and its production method, so that it is not easy to be reduced by the aluminum melt, thereby reducing the inclusions in the aluminum melt , Improve the purity of aluminum.

The present invention is achieved through the following technical scheme. The corundum-spinel refractory material for refining aluminum furnace has the following components and weight percentages: 55% to 60% of white corundum, 10% to 10% of magnesium aluminum spinel 30%, fused magnesia 5-10%, α-alumina micropowder 10%-20%.

The white corundum has three particle sizes: 3-1 mm, 1-0.5 mm and 180 mesh.

The magnesium aluminum spinel has a particle size of 1-0.5 mm, 0.5-0 mm and 180 mesh.

The particle size of the fused magnesia is 180 mesh.

The composition and weight percentage of the white corundum: Al ₂ O ₃ ≥ 98.5, SiO ₂ ≤ 0.25, Fe ₂ O ₃ ≤ 0.3, K ₂ O+Na ₂ O ≤ 0.3.

The magnesium-aluminum spinel includes components and weight percentages: Al ₂ O ₃ ≥ 60, MgO ≥ 27.

The fused magnesia includes components and weight percentages: MgO≥98, CaO≤1.2, SiO ₂ ≤0.6.

The α-alumina micropowder includes components and weight percentages: Al ₂ O ₃ ≥ 98.5, SiO 2 ≤ 0.2, Fe ₂ O ₃ ≤ 0.08, K ₂ O+Na ₂ O ≤ 0.55.

The present invention also provides a production method for the above-mentioned corundum-spinel refractory material for refining aluminum furnaces, specifically: using white corundum, magnesia-aluminum spinel, fused magnesia, and α-alumina micropowder as raw materials, according to the above-mentioned raw materials When mixing, first add white corundum with a particle size of 3-1mm and 1-0.5mm and magnesium-aluminum spinel with a particle size of 1-0.5mm in the raw material and stir, and at the same time add 2 % by weight of calcium lignosulfonate solution as an additive, after mixing for 2 to 3 minutes, add 180-mesh white corundum, 0.5-0mm and 180-mesh magnesia-alumina spinel, fused magnesia and α-alumina micropowder, and then add The calcium lignosulfonate solution of 3% by weight of the prepared material is continuously mixed, then pressed into shape, dried, and kept warm to obtain the corundum-spinel refractory material for refining aluminum furnaces.

The calcium lignosulfonate solution has a density of 1.15-1.20 g/cm ³ .

The described continuation of mixing takes 8 to 10 minutes.

The press molding refers to: use 150Mpa pressure to press to grow a 125mm wide 25mm and 25mm high spline.

The drying refers to drying at 110° C. to 120° C. for 24 hours.

The heat preservation refers to: heat preservation at 1650° C. for 3 hours.

In the present invention, magnesia-alumina spinel is added in advance, and during the sintering process, a part of magnesia-alumina spinel is generated by the reaction of fused magnesia and alumina micropowder to form a corundum-spinel refractory material. Magnesium-aluminum spinel has the characteristics of high melting point, high strength at room temperature and high temperature, low thermal expansion coefficient, good thermal conductivity, and strong chemical corrosion resistance. It is a high-quality refractory raw material. Experiments show that the normal temperature flexural strength of the obtained samples is greater than 26.5Mpa, the normal temperature compressive strength is greater than 70Mpa, the porosity is less than 20%, the bulk density is greater than 2.95g/cm ³ , and the linear expansion rate is less than 1.2%.

Detailed ways

The embodiments of the present invention are described in detail below: the present embodiment is implemented under the premise of the technical solution of the present invention, and detailed implementation and specific operation process are provided, but the protection scope of the present invention is not limited to the following implementation example.

Example 1:

Component weight percent of corundum-spinel refractory material for refining aluminum furnace: white corundum: 3-1mm 45%, 1-0.5mm 5%, 180 mesh 5%, magnesium-aluminum spinel: 1-0.5mm 5%, 0.5 ~0mm 10%; α-alumina powder 20%; fused magnesia 180 mesh 10%.

First mix the materials. When mixing the materials, first add calcium lignosulfonate solution additives with a particle size of 0.5 mm or more, accounting for 2% by weight of the prepared materials. After mixing evenly, add raw materials with a particle size of 0.5 mm or less. The weight percentage of the prepared material is 3% calcium lignosulfonate solution additive, continue to mix for about 8 to 10 minutes, after mixing well, use 150Mpa pressure to press into a 125mm×25mm×25mm sample strip, after drying at 120°C for 24 hours, Fire at 1650°C for three hours.

The normal temperature physical properties of the obtained sample: the normal temperature flexural strength is 29.50MPa, the normal temperature compressive strength is 102.93MPa, the porosity is 20.17%, the bulk density is 2.95g/cm ³ , and the linear change rate is 1.07%.

Example 2:

Component weight percent of corundum-spinel refractory material for refining aluminum furnace: weighed white corundum: 3-1mm 45%, 1-0.5mm 10%, 180 mesh 5%; magnesium-aluminum spinel: 1-0.5mm 5% , 0.5 ~ 0mm5%; α-alumina powder 20%; fused magnesia 180 mesh 10%.

First mix the materials. When mixing the materials, first add calcium lignosulfonate solution additives with a particle size of 0.5 mm or more, accounting for 2% by weight of the prepared materials. After mixing evenly, add raw materials with a particle size of 0.5 mm or less. The weight percentage of the prepared material is 3% calcium lignosulfonate solution additive, and the mixing is continued for about 8 to 10 minutes. After mixing well, use 150Mpa pressure to press it into a sample strip of 125mm×25mm×25mm, dry it at 120°C for 24 hours, then heat it at 1650°C for three hours and burn it.

The normal temperature physical properties of the obtained sample: the normal temperature flexural strength is 21.55MPa, the normal temperature compressive strength is 63.77MPa, the porosity is 19.53%, the bulk density is 2.93g/cm ³ , and the linear change rate is 0.98%.

Example 3:

Component weight percentage of corundum-spinel refractory material for refining aluminum furnace: weighed white corundum: 3-1mm 45%, 1-0.5mm 5%, 180 mesh 5%; magnesium-aluminum spinel: 1-0.5mm 5% , 0.5 ~ 0mm10%, 180 mesh 5%; α-alumina powder 16.5%; fused magnesia 180 mesh 8.5%.

First mix the materials. When mixing the materials, first add calcium lignosulfonate solution additives with a particle size of 0.5 mm or more, accounting for 2% by weight of the prepared materials. After mixing evenly, add raw materials with a particle size of 0.5 mm or less. The weight percentage of the prepared materials is 3% calcium lignosulfonate solution, and the mixing is continued for about 8 to 10 minutes. After mixing well, use 150Mpa pressure to press it into a sample strip of 125mm×25mm×25mm, dry it at 120°C for 24 hours, then heat it at 1650°C for three hours and burn it.

The normal temperature physical properties of the obtained sample: the normal temperature flexural strength is 27.27MPa, the normal temperature compressive strength is 91.30MPa, the porosity is 19.42%, the bulk density is 2.99g/cm ³ , and the linear change rate is 1.11%.

Example 4:

Component weight percentage of corundum-spinel refractory material for refining aluminum furnace: weighed white corundum: 3-1mm 45%, 1-0.5mm 5%, 180 mesh 5%; magnesium-aluminum spinel: 1-0.5mm 5% , 0.5 ~ 0mm10%, 180 mesh 15%; α-alumina powder 10%; fused magnesia 180 mesh 5%.

First mix the materials. When mixing the materials, first add calcium lignosulfonate solution additives with a particle size of 0.5 mm or more, accounting for 2% by weight of the prepared materials. After mixing evenly, add raw materials with a particle size of 0.5 mm or less. The weight percentage of the prepared material is 3% calcium lignosulfonate solution additive, and the mixing is continued for about 8 to 10 minutes. After mixing well, use 150Mpa pressure to press it into a sample strip of 125mm×25mm×25mm, dry it at 120°C for 24 hours, then heat it at 1650°C for three hours and burn it.

The normal temperature physical properties of the obtained sample: the normal temperature flexural strength is 28.11MPa, the normal temperature compressive strength is 79.70MPa, the porosity is 19.31%, the bulk density is 3.05g/cm ³ , and the linear change rate is 0.88%.

Claims (10)

1, a kind of alumina-spinel flame-proof material for refining aluminium furnace is characterized in that, its component and weight percent thereof are as follows: white fused alumina 55～60%, magnesium-aluminium spinel 10%～30%, electrosmelted magnesite clinker 5～10%, Alpha-alumina micro mist 10%～20%.

2, alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that, described white fused alumina, its grain graininess have three kinds: 3～1mm, 1～0.5mm and 180 orders;

Described white fused alumina, component that it comprises and weight percent: Al ₂O ₃〉=98.5, SiO ₂≤ 0.25, Fe ₂O ₃≤ 0.3, K ₂O+Na ₂O≤0.3.

3, alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that, described magnesium-aluminium spinel, its grain graininess are 1～0.5mm, 0.5～0mm and 180 orders;

Described magnesium-aluminium spinel, component that it comprises and weight percent: Al ₂O ₃〉=60, MgO 〉=27.

4, alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that, described electrosmelted magnesite clinker, its grain graininess are 180 orders;

Described electrosmelted magnesite clinker, component that it comprises and weight percent: MgO 〉=98, CaO≤1.2, SiO ₂≤ 0.6.

5, alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that,

Described Alpha-alumina micro mist, component that it comprises and weight percent: Al ₂O ₃〉=98.5, SiO ₂≤ 0.2, Fe ₂O ₃≤ 0.08, K ₂O+Na ₂O≤0.55.

6, a kind of preparation method who gets alumina-spinel flame-proof material for refining aluminium furnace according to claim 1, it is characterized in that, with white fused alumina, magnesium-aluminium spinel, electrosmelted magnesite clinker, the Alpha-alumina micro mist is a raw material, weight percent batch mixing according to raw material, adding earlier grain graininess in the raw material during batch mixing and be the white fused alumina of 3～1mm and 1～0.5mm and magnesium-aluminium spinel that grain graininess is 1～0.5mm stirs, add simultaneously and account for the lignin sulfonic acid calcium solution of proportioned material 2% weight percent as additive, mix the back and add 180 purpose white fused aluminas, 0.5～0mm and 180 purpose magnesium-aluminium spinels, electrosmelted magnesite clinker and Alpha-alumina micro mist, add the lignin sulfonic acid calcium solution that accounts for proportioned material 3% weight percent again, continue to mix, compression moulding then, oven dry, insulation obtains described alumina-spinel flame-proof material for refining aluminium furnace.

7, refined aluminum stove according to claim 1 is characterized in that with the preparation method of corundum～spinel refractory materials described wooden calcium sulfonate solution density is 1.15～1.20g/cm ³

8, the preparation method of alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that, described compression moulding is meant: with the batten of 150Mpa pressure compacting wide 25mm of growth 125mm and high 25mm.

9, the preparation method of alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that, described oven dry is meant: 110 ℃～120 ℃ oven dry 24 hours.

10, the preparation method of alumina-spinel flame-proof material for refining aluminium furnace according to claim 1 is characterized in that, described insulation is meant: be incubated 3 hours down at 1650 ℃.