CN101851106B - Antioxidation aluminium unburned carbon brick and preparation method thereof - Google Patents

Abstract

The invention relates to an antioxidation aluminium unburned carbon brick and a preparation method thereof. The invention adopts the technical scheme that the antioxidation aluminium unburned carbon brick is made of the following raw materials by weight percent: 15-50% of 3-1mm brown fused alumina, 10-20% of 1-0mm brown fused alumina, 0-10% of brown fused alumina of 325 meshes, 0-15% of brown fused alumina of 100 meshes, 0-15% of 3-1mm fused magnesia, 0-10% of 1-0mm fused magnesia, 0-25% of bauxite, 1-5% of aluminium powder, 5-15% of graphite, 0-5% of silicon carbide powder, 3-8% of ferro silicon nitride, 0-1% of asphalt and 2-4% of phenolic resin. The preparation method comprises the working procedures of premixing, mixing and milling, pressing to form a green body, and drying. The invention promotes the sintering of carbonic refractory bricks by introducing the ferro silicon nitride, thus improving the effects of antioxidation and corrosion resistance.

Description

Antioxidation aluminium unburned carbon brick and preparation method thereof

Technical field

The present invention relates in the ferrous metallurgy to relate to particularly a kind of aluminium unburned carbon brick that improves antioxidant property with not burning the carbon brick field.

Background technology

Along with ironmaking, the development of Steel industry and the raising of production efficiency, the performance requriements of refractory materials is also improved constantly.Particularly the performance requriements that does not burn the carbon brick refractory product to used in hot metal pretreatment, converter, the ladle is more and more higher.In a series of smelting processes such as hot metal pretreatment, converter, ladle, because reaction is violent, the working conditions of not burning carbon brick is very harsh, easily cause the carbon brick oxidation and decarbonization, cause the washing away of its anti-molten iron, molten steel, slag, erosion performance to descend, greatly reduce the work-ing life of material, shortened life cycle, increase the usage quantity of carbon brick, cause smelting cost to increase.

Carbon containing refractory has good slag resistance and anti-thermal shock stability, thereby becomes one of important refractory material system.This mainly be because, carbon is the fabulous material of chemical property, life-time service is softening under the high temperature, almost acid and alkali, alkali, salt and organic erosion.In addition, carbon has difficult wettability to slag.

But, under comparatively high temps, carbon but very easily with oxidizing gas (such as O ₂) chemical reaction occurs, so that the loss of the premium properties of carbon containing refractory is totally.Therefore, in order to prevent the oxidation of carbon containing refractory, need carbon containing refractory is carried out anti-oxidation processing.

Summary of the invention

In order to overcome the above problems, it is good to the invention provides a kind of antioxidant property, the antioxidation aluminium unburned carbon brick that increases the service life.

To achieve these goals, the technical solution used in the present invention is: a kind of antioxidation aluminium unburned carbon brick is characterized in that being made by following raw materials by weight:

Palm fibre corundum 3mm～1mm 15～50%

Palm fibre corundum 1mm～0mm 10～20%

Palm fibre corundum 325 orders 0～10%

Palm fibre corundum 100 orders 0～15%

Electrosmelted magnesite clinker 3mm～1mm 0～15%

Electrosmelted magnesite clinker 1mm～0mm 0～10%

Alumina 3mm～1mm 0～25%

Aluminium powder 1～5%

Graphite 5～15%

Carborundum powder 0～5%

Ferro-silicon nitride 3～8%

Pitch 0～1%

Resol 2～4%.

Preferably, Fe content is 12%～17% in the ferro-silicon nitride.

The preparation method of above-mentioned antioxidation aluminium unburned carbon brick is as follows:

1) by above-mentioned proportioning, take by weighing brown corundum, electrosmelted magnesite clinker, ferro-silicon nitride and resol, pre-mixed grind is 8～10 minutes in sand mill, and then adds remaining raw material, mixed grind 12～15 minutes;

2) material that mixes is added in the mould, pressurize at 500 tons～800 tons friction presses, make base substrate;

3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 180 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.

Owing to introduced ferro-silicon nitride, thereby improved the antioxidant property of aluminium unburned carbon brick among the present invention, its mechanism is: ferro-silicon nitride is silicon nitride and iron phase material (α-Fe or Fe ₃Si) mixture is so under the high temperature oxidation atmosphere, in the carbon containing refractory brick of interpolation ferro-silicon nitride there be the composition of easy oxidation: SiC, C, Si ₃N ₄, Fe ₃Si and α-Fe.From the dynamic process of material oxidation, at oxygen by Decarburized layer during to internal divergence, ferro-silicon nitride (Fe-Si ₃N ₄) in after the silicon nitride oxidation, remaining iron phase material then plays the effect of filtration fraction oxygen, generates ferric oxide; And the generation of ferric oxide is so that the melting point depression of zone of oxidation, the mobile enhancing, thus forming fine and close uniformly zone of oxidation, the shutoff pore has stoped the diffusion of oxygen to inside, has reached the purpose that prevents inner oxidation of coal.Because the effect of ferric oxide, behind the interpolation ferro-silicon nitride, the sealing of product surface zone of oxidation early that is to say, can form earlier the zone of oxidation that is covered in material surface and the further oxidation that stops carbon.

The invention has the beneficial effects as follows: the present invention is by adding ferro-silicon nitride (Fe-Si ₃N ₄) in aluminium unburned carbon brick, thus play further anti-oxidation effect.Through putting into practice: the folding strength after burn (1) is significantly improved; (2) result of oxidation test does not add the little 1.8～2.6mm of practical decarburized depth of ferro-silicon nitride relatively; (3) use Static crucible method, drill out the cinder hole of Φ 50mm * 50mm at the article center position, and in cinder hole, be respectively charged into 40 gram scum and slags.Find after 6 hours 1600 ℃ of insulations, corrode the little 0.5mm～0.9mm of depth of erosion thickness that test result does not add ferro-silicon nitride relatively.Thereby explanation is by after introducing ferro-silicon nitride, and carbon containing refractory brick has been played short sintering, improved the effectiveness of anti-oxidant and erosion-resisting characteristics.

Embodiment

Embodiment 1 antioxidation aluminium silicon-carbon brick (anti-oxidant Al ₂O ₃-SiC-C brick)

(1) proportioning raw materials sees Table 1

(2) preparation method is as follows:

1) press the proportioning of table 1, take by weighing brown corundum, ferro-silicon nitride and resol, pre-mixed grind is 8～10 minutes in sand mill, and then adds remaining raw material, mixed grind 12～15 minutes;

2) material that mixes is added in the mould, pressurize at 500 tons～800 tons friction presses, make base substrate;

3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 180 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.Dry kiln length is not less than 24 meters, 40～70 minutes/car in go-cart interval.

Finished product test the results are shown in Table 1.

The detection method of antioxidant property: press the proportioning of table 1, just do not add ferro-silicon nitride, the amount of ferro-silicon nitride substitutes with carborundum powder, makes simultaneously the Al of nonnitrogenous SiClx iron ₂O ₃-SiC-C brick.1000 ℃ are incubated 4 hours, the thickness of test Decarburized layer.

The detection method of erosion-resisting characteristics: press the proportioning of table 1, just do not add ferro-silicon nitride, the amount of ferro-silicon nitride substitutes with carborundum powder, makes simultaneously the Al of nonnitrogenous SiClx iron ₂O ₃-SiC-C brick.Use Static crucible method, drill out the cinder hole of Φ 50mm * 50mm at the article center position, and in cinder hole, be respectively charged into 40 gram scum and slags.1600 ℃ of insulations 6 hours.The depth of erosion of test product.

Embodiment 2 antioxidation aluminium silicon-carbon brick (anti-oxidant Al ₂O ₃-SiC-C brick)

(1) proportioning raw materials sees Table 1

(2) preparation method is as follows:

1) press the proportioning of table 1, take by weighing brown corundum, ferro-silicon nitride and resol, pre-mixed grind is 8～10 minutes in sand mill, and then adds remaining raw material, mixed grind 12～15 minutes;

2) material that mixes is added in the mould, pressurize at 500 tons～800 tons friction presses, make base substrate;

3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 180 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.Dry kiln length is not less than 24 meters, 40～70 minutes/car in go-cart interval.

Finished product test the results are shown in Table 1.

Embodiment 3 antioxidation aluminium magnesia carbon brick (anti-oxidant Al ₂O ₃-MgO-C brick)

(1) proportioning raw materials sees Table 2

(2) preparation method is as follows:

1) press the proportioning of table 2, take by weighing brown corundum, electrosmelted magnesite clinker, ferro-silicon nitride and resol, pre-mixed grind is 8～10 minutes in sand mill, and then adds remaining raw material, mixed grind 12～15 minutes;

2) material that mixes is added in the mould, pressurize at 500 tons～800 tons friction presses, make base substrate;

3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 180 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.Dry kiln length is not less than 24 meters, 40～70 minutes/car in go-cart interval.

Finished product test the results are shown in Table 2.

The detection method of antioxidant property: press the proportioning of table 2, just do not add ferro-silicon nitride, the amount of ferro-silicon nitride substitutes with alumina, makes simultaneously the Al of nonnitrogenous SiClx iron ₂O ₃-SiC-C brick.1000 ℃ are incubated 4 hours, the thickness of test Decarburized layer.

The detection method of erosion-resisting characteristics: press the proportioning of table 2, just do not add ferro-silicon nitride, the amount of ferro-silicon nitride substitutes with alumina, makes simultaneously the Al of nonnitrogenous SiClx iron ₂O ₃-SiC-C brick.Use Static crucible method, drill out the cinder hole of Φ 50mm * 50mm at the article center position, and in cinder hole, be respectively charged into 40 gram scum and slags.1600 ℃ of insulations 6 hours.The depth of erosion of test product.

Embodiment 4 antioxidation aluminium magnesia carbon brick (anti-oxidant Al ₂O ₃-MgO-C brick)

(1) proportioning raw materials sees Table 2

(2) preparation method is as follows:

1) press the proportioning of table 2, take by weighing brown corundum, electrosmelted magnesite clinker, ferro-silicon nitride and resol, pre-mixed grind is 8～10 minutes in sand mill, and then adds remaining raw material, mixed grind 12～15 minutes;

2) material that mixes is added in the mould, pressurize at 500 tons～800 tons friction presses, make base substrate;

3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 180 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.Dry kiln length is not less than 24 meters, 40～70 minutes/car in go-cart interval.

Finished product test the results are shown in Table 2.

The anti-oxidant Al of table 1 ₂O ₃-SiC-C brick

The anti-oxidant Al of table 2 ₂O ₃-MgO-C brick

Claims (4)

1. antioxidation aluminium unburned carbon brick is characterized in that being made by following raw materials by weight:

2. antioxidation aluminium unburned carbon brick is characterized in that being made by following raw materials by weight:

3. according to claim 1 or 2 described antioxidation aluminium unburned carbon bricks, it is characterized in that Fe content is 12%～17% in the described ferro-silicon nitride.

4. the preparation method of claim 1 or 2 described antioxidation aluminium unburned carbon bricks is characterized in that step is as follows:

1) by claim 1 or 2 described proportionings, take by weighing brown corundum, electrosmelted magnesite clinker, ferro-silicon nitride and resol, pre-mixed grind is 8～10 minutes in sand mill, and then adds remaining raw material, mixed grind 12～15 minutes;

2) material that mixes is added in the mould, pressurize at 500 tons～800 tons friction presses, make base substrate;

3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 180 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.