Downhole brick produced by using solid waste alumina sagger and preparation method thereof

Abstract

The invention discloses a collector nozzle brick produced by using a solid waste alumina sagger, which comprises the following components in percentage by weight: 72-83% of solid waste corundum alumina sagger, 5-8% of Yixing east white mud, 2-5% of aluminum-silicon alloy powder, 2-3% of solid waste graphite sagger, 3-5% of lithium-based soil and 4-7% of flint clay powder, and the sum of the weight of all the components in the formula is 100%. And 4-5% of liquid thermosetting resin. The invention aims to provide the collector nozzle brick which is long in service life, capable of utilizing the waste saggar, resource-saving, small in diameter expansion and low in melting loss, and the preparation method of the collector nozzle brick.

Description

Technical Field

[0001] The invention relates to the field of refractory materials with inorganic materials as base materials, and more specifically to a downspout brick produced by using solid waste alumina sagger and a preparation method thereof. Background Art

[0004] Alumina has a wide range of downstream applications, mainly including electrolytic aluminum, ceramics, refractory materials, abrasives, flame retardants and other fields. The tight supply of upstream bauxite corresponds to the strong domestic downstream demand, especially the support role of electrolytic aluminum demand. Electrolytic aluminum is the main source of aluminum products in my country, and the production of electrolytic aluminum cannot be separated from alumina as raw material. The domestic electrolytic aluminum operating capacity remains high, and aluminum plants also have strong demand for corundum alumina.

[0006] Since most of the raw materials used in the refractory industry are mineral resources formed over a long geological period, even if the country reasonably regulates the resource utilization rate, there is still the possibility of resource depletion or grade reduction. At present, the downstream demand for corundum and alumina is still on the rise. If we want to ease the contradiction between supply and demand, we can only solve it by releasing the supply side, including opening up domestic mines, releasing new domestic alumina production capacity, and opening the import window. Summary of the invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide a downspout brick produced from solid waste alumina sagger and a preparation method thereof, which has a long service life, can utilize discarded saggers, save resources, has a small diameter expansion and low melting loss.

[0008] According to one aspect of the present invention, a drain brick produced using solid waste alumina sagger is provided, which comprises, by weight percentage, 72%-83% of solid waste corundum alumina sagger, 5%-8% of Yixing Fudong white mud, 2%-5% of aluminum silicon alloy powder, 2%-3% of solid waste graphite sagger, 3%-5% of lithium-based soil, 4%-7% of coke gem powder, the sum of the weights of all components in the above formula being 100%, and 4-5% of liquid thermosetting resin.

[0009] In some embodiments, the solid waste corundum alumina sagger particles account for 60%, and the solid waste corundum alumina sagger fine powder accounts for 12% to 23%.

[0010] In some embodiments, the particle diameter of the solid waste corundum alumina sagger is: 3-1, 1-0, 0.5-0 mm;

[0011] The fine powders of solid waste corundum alumina sagger are: 325 mesh and 200 mesh;

[0012] Yixing Fudong white mud: 200 mesh;

[0013] The aluminum-silicon alloy powder is: 180 mesh;

[0014] The waste graphite crucible is: 325 mesh;

[0015] The lithium-based clay is: 200 mesh;

[0016] The burned kaolin powder is: 180 mesh;

[0017] The thermosetting resin is liquid.

[0018] In some embodiments, the particle size distribution of the waste corundum alumina crucible by weight percentage is:

[0019] 3 - 1 mm: 18% - 25%

[0020] 1 - 0 mm: 20% - 28%

[0021] 0.5 - 0 mm: 12% - 7%

[0022] The sum of the weight percentages of the particle size distribution of the above-mentioned waste corundum alumina crucible is 60%.

[0023] In some embodiments, the waste corundum alumina crucible: the Al2O3 content ≥ 93%, the SiO2 content ≤ 6%, the CaO content ≤ 0.2%, the NaO content ≤ 0.3;

[0024] The Yixing Fudong white clay: the Al2O3 content ≥ 28%, the Fe2O3 content ≤ 2.2%, the SiO2 content ≥ 46%;

[0025] The aluminum-silicon alloy powder: the active aluminum Al ≥ 85%; the Si content ≥ 12%;

[0026] The waste graphite crucible: the C content ≥ 96%; the said lithium-based clay: the Al2O3 content ≥ 25%, the SiO2 content ≤ 70%;

[0027] The burned kaolin powder: the Al2O3 content ≥ 45%, the SiO2 content ≥ 49%, the Fe2O3 content ≤ 1.2%;

[0028] The thermosetting resin: the residual carbon content 48 ± 2%, the solid content 68 - 78%, the viscosity 16800 - 21000 mPa.

[0029] In some embodiments, the preparation method of the submerged nozzle brick produced with the waste alumina crucible includes the following steps:

[0030] S1, raw material selection;

[0031] S2, raw material processing;

[0032] S3, raw material inspection;

[0033] S4. Shaping;

[0034] S5. Drying;

[0035] S6. Firing;

[0036] S6. Brick body processing;

[0037] S7. Filling fire clay;

[0038] S8. Covering with iron shell;

[0039] S9. Final product inspection;

[0040] S10. Packaging and warehousing.

[0041] In some embodiments, the raw material processing includes the following steps:

[0042] S1. Raw material mixing, 72%-83% of waste corundum alumina crucible, 5%-8% of Yixing Fudong white mud, 2%-5% of aluminum-silicon alloy powder, 2%-3% of waste graphite crucible, 3%-5% of lithium-based soil, 4%-7% of fireclay powder. The sum of the weights of all components in the above formula is 100%, and 4-5% of liquid thermosetting resin;

[0043] S2. Stirring, using a stirring device to stir the above raw materials;

[0044] S3. Preheating, using a heating device to heat the above raw materials;

[0045] S4. Placing for standby.

[0046] In some embodiments, the drying includes: natural drying and heating drying;

[0047] Natural drying is: placing the formed brick blanks in a natural environment and drying for 36-48 hours;

[0048] Heating drying is: placing the brick blanks that have undergone natural drying into a drying kiln and slowly drying for 25-31 hours. The temperature of the drying kiln is preferably 175-185°C, keeping warm for 14-16 hours, and finally cooling down to room temperature at a uniform speed.

[0049] In some embodiments, the process of heating and drying during heating drying is: uniformly raising the temperature of the drying kiln to 60°C within 1 hour, and keeping warm at 60°C for 2 hours, then uniformly raising the temperature from 60°C to 180°C within 15 hours, and keeping warm at 180°C for 15 hours, and finally cooling down to room temperature at a uniform speed.

[0050] In some embodiments, in S6, during firing, the medium-high temperature tunnel kiln is uniformly heated to 900°C ± 30°C, keeping warm for 12-17 hours, and finally cooling down to room temperature at a uniform speed;

[0051] The temperature rising process is to evenly raise the temperature of the drying kiln to 100°C within 1 hour, hold the temperature at 100°C for 10 hours, then evenly raise the temperature from 100°C to 200°C within 15 hours, and hold the temperature at 200°C for 12 hours;

[0052] Low-temperature firing: Evenly raise the temperature to 900°C ± 30°C within 12 - 17 hours;

[0053] Final product inspection includes full inspection of the height, pore diameter, internal cracks in pores, brick shape symmetry, and each water outlet of the final product. 30% of the single weight should be randomly inspected per shift, and the porosity, bulk density, and physical and chemical indexes should be inspected for each batch.

[0054] A water outlet brick produced from solid waste alumina saggers and its preparation method according to the present invention have the beneficial effects of long service life, the ability to utilize waste saggers, resource conservation, small diameter expansion, and low melting loss compared with the prior art. The present invention recycles and continues to use the water outlet bricks re-prepared from waste corundum alumina saggers and waste graphite saggers, which is in line with the market's requirement for the reuse of waste materials in recent years. The production method of the present invention is unique, and the product performance is stable, which can meet the actual production needs of steel mills; through numerous studies on the uses and structures of waste materials and multiple actual trials, the quantity of waste materials and the consumption of refractory materials have been greatly reduced. From the perspective of reducing industrial solid waste inorganic non-metallic materials and the consumption of refractory materials for steelmaking, the production cost is reduced; at the same time, the highest service life is achieved with the least consumption of solid waste inorganic non-metallic materials (including maximizing the use of secondary resources, etc.), and the service life of the water outlet brick is increased by more than 50% compared with the original conventional one. Specific Embodiments

[0055] The present invention will be further described below in conjunction with specific embodiments.

[0056] The water outlet brick produced from solid waste alumina saggers, calculated by weight percentage, includes: 72% - 83% of waste corundum alumina saggers, 5% - 8% of Yixing Fudong white clay, 2% - 5% of aluminum-silicon alloy powder, 2% - 3% of waste graphite saggers, 3% - 5% of lithium-based clay, 4% - 7% of fireclay powder. The sum of the weights of all components in the above formula is 100%, and 4 - 5% of liquid thermosetting resin.

[0057] The proportion of waste corundum alumina sagger particles is 60%, and the proportion of waste corundum alumina sagger fine powder is 12% - 23%.

[0058] The particle size distribution of waste corundum alumina sagger particles is by weight percentage:

[0059] 3 - 1㎜ 18% - 25%

[0060] 1 - 0㎜ 20% - 28%

[0061] 0.5 to 0 mm, 12% to 7%

[0062] The sum of the weight percentage contents of the particle size distribution of the above-mentioned waste corundum alumina saggers is 60%.

[0063] Table 1: The physical and chemical indexes of the waste corundum alumina saggers are as follows,

[0064]

[0065] Scrapped waste corundum alumina saggers:

[0066] The corundum alumina saggers are mainly used for the high-temperature sintering of zirconia ceramics, alumina ceramics, and lithium batteries. They do not contain free silicon, kaolin, or reactive alumina, have a long service life, a small thermal expansion coefficient, a high load-bearing capacity at high temperatures, a high use temperature, and good thermal stability, etc.

[0067] With excellent properties such as high-temperature resistance, slag erosion resistance, and low expansion rate, this waste material can be used as the main raw material in shaped refractory products such as ladles and tundishes, and can also be used as the main raw material in working lining refractory materials such as ladle precast parts, castables, and castables for heating furnaces. It can also be used as an auxiliary material in shaped products and unshaped refractory materials to reduce cracks caused by thermal expansion stress and achieve the purpose of extending the service life.

[0068] Table 2: The physical and chemical indexes of the scrapped waste graphite saggers are as follows,

[0069]

[0070] Waste graphite saggers:

[0071] The graphite saggers have good thermal conductivity and high-temperature resistance. During high-temperature use, they have a small thermal expansion coefficient, certain anti-strain ability to sudden heat and sudden cold, strong corrosion resistance to acidic and alkaline solutions, and excellent chemical stability. They are mainly used for the sintering of lithium battery material lithium iron phosphate. It can improve its erosion resistance, reduce the porosity of the submerged nozzle refractory brick, and enhance its anti-permeation ability. At the same time, it can improve the good thermal shock resistance of the submerged nozzle refractory brick, improve the resistance to molten steel erosion and chemical corrosion, and extend the service life.

[0072] The particle diameters of the waste corundum alumina saggers are: 3 - 1, 1 - 0, 0.5 - 0 mm;

[0073] The fine powders of the waste corundum alumina saggers are respectively: 325 mesh, 200 mesh;

[0074] The Yixing Fudong white clay is: 200 mesh;

[0075] The aluminum-silicon alloy powder is: 180 mesh;

[0076] The solid waste graphite crucible is: 325 mesh;

[0077] The lithium-based soil is: 200 mesh;

[0078] The calcined flint clay powder is: 180 mesh;

[0079] The thermosetting resin is liquid.

[0080] The solid waste corundum alumina crucible: the Al2O3 content ≥ 93%, the SiO2 content ≤ 6%, the CaO content ≤ 0.2%, the NaO content ≤ 0.3;

[0081] The Yixing Fudong white clay: the Al2O3 content ≥ 28%, the Fe2O3 content ≤ 2.2%, the SiO2 content ≥ 46%;

[0082] The aluminum-silicon alloy powder: the active aluminum Al ≥ 85%; the Si content ≥ 12%;

[0083] The solid waste graphite crucible: the C content ≥ 96%; the said lithium-based soil: the Al2O3 content ≥ 25%, the SiO2 content ≤ 70%;

[0084] The calcined flint clay powder: the Al2O3 content ≥ 45%, the SiO2 content ≥ 49%, the Fe2O3 content ≤ 1.2%; Strong abrasion resistance: The calcined flint clay has very strong abrasion resistance and can maintain good luster for a long time. Good resistance to chemical erosion: The calcined flint clay has good resistance to both acids and alkalis and is not easily eroded by chemical reactions. Strong stability: The calcined flint clay has strong chemical stability and is not easily oxidized and corroded.

[0085] The nozzle brick prepared from this raw material has good load softening temperature, thermal shock stability and erosion resistance. Using the refractory nozzle brick produced from this raw material, the raw material price is low, the production cost is greatly reduced, and the comprehensive competitiveness in the contracting market is improved. At the same time, the thermal expansion coefficient of this raw material is small. Under the conditions of extremely cold and extremely hot molten steel in the ladle, the nozzle can be used continuously for multiple furnaces without cracking, improving the safety of steel casting and effectively protecting the equipment and personal safety.

[0086] The thermosetting resin: the residual carbon content is 48 ± 2%, the solid content is 68 - 78%, and the viscosity is 16800 - 21000 mpa.

[0087] Table 3: The percentage content of each component in the 3 formulations of the product test of the present invention

[0088]

[0089] Table 4: The comparison table of the physical and chemical test indexes of the products prepared according to the 3 formulations in Table 1

[0090]

[0091] According to the test results in Table 2, it can be seen that the above 3 formulas can be used normally, and Formula 1 has the best effect.

[0092] A method for preparing a submerged nozzle brick produced from solid waste alumina saggers includes the following steps:

[0093] S1. Raw material selection;

[0094] S2. Raw material processing;

[0095] S3. Raw material inspection;

[0096] S4. Molding;

[0097] S5. Drying;

[0098] S6. Firing;

[0099] S6. Brick body processing;

[0100] S7. Filling fire clay;

[0101] S8. Covering with an iron shell;

[0102] S9. Finished product inspection;

[0103] S10. Packaging and warehousing.

[0104] The raw material processing includes the following steps:

[0105] S1. Raw material mixing, 72%-83% of solid waste corundum alumina saggers, 5%-8% of Yixing Fudong white clay, 2%-5% of aluminum-silicon alloy powder, 2%-3% of solid waste graphite saggers, 3%-5% of lithium-based soil, 4%-7% of pyrophyllite powder, the sum of the weights of all components in the above formula is 100%, and 4-5% of liquid thermosetting resin;

[0106] S2. Stirring, using a stirring device to stir the above raw materials;

[0107] S3. Preheating, using a heating device to heat the above raw materials;

[0108] S4. Placing for standby.

[0109] The drying includes: natural drying and heating drying;

[0110] The natural drying is: placing the formed brick blanks in the natural environment and drying for 36-48 hours;

[0111] The heating drying is: placing the brick blanks that have undergone natural drying into a drying kiln and slowly drying for 25-31 hours. The temperature of the drying kiln is preferably 175-185°C, keeping warm for 14-16 hours, and finally cooling down to room temperature at a uniform speed.

[0112] During the heating and drying process, the temperature increase for drying is as follows: evenly raise the temperature of the drying kiln to 60°C within 1 hour, keep it at 60°C for 2 hours, then evenly increase the temperature from 60°C to 180°C within 15 hours, keep it at 180°C for 15 hours, and finally gradually decrease the temperature to room temperature at a uniform speed.

[0113] In S6, for firing, evenly raise the temperature of the medium-high temperature tunnel kiln to 900°C ± 30°C, keep it warm for 12 - 17 hours, and finally gradually decrease the temperature to room temperature at a uniform speed;

[0114] The temperature increase process is to evenly raise the temperature of the drying kiln to 100°C within 1 hour, keep it at 100°C for 10 hours, then evenly increase the temperature from 100°C to 200°C within 15 hours, and keep it at 200°C for 12 hours;

[0115] Low-temperature firing: evenly raise the temperature to 900°C ± 30°C within 12 - 17 hours;

[0116] Final product inspection includes full inspection of the height, pore diameter, internal cracks in pores, brick shape symmetry, and each water outlet of the final product. 30% of the single weight should be randomly inspected per shift, and the porosity, bulk density, and physical and chemical indicators should be inspected for each batch.

[0117] Preparation method of the water outlet brick produced with solid waste alumina crucible, production requirements:

[0118] (1) Weigh the ingredients strictly according to the ratio, mix the fine powder evenly. When preparing the mixed powder, add the additive between the materials. Check whether the chemical composition of the mixed powder stirred by the mixer is uniform.

[0119] (2) Control the temperature of the materials mixed by the wet mill or high-speed kneader to prevent the material temperature from being too high or too low, which may affect the mixing effect and formability. In winter, heat preservation measures should be taken. In summer, try to lower the room temperature as much as possible, preferably keep it around 25°C, and the humidity is about 50%.

[0120] (3) During molding, the pressure should be light first and then heavy, exhaust air in between to avoid cracks; the mud should be evenly distributed in the mold, and often check the parallelism of the bottom cover plate to prevent the water outlet from deforming and causing defective products;

[0121] (4) Strictly control the heating curve during the firing process. When cooling, it must be gradually decreased at a uniform and slow speed to prevent cracking.

[0122] In the specific process above, it is also necessary to pay attention to the following: solid waste corundum alumina sagger particle grading: 3~1mm, 1~0mm, 0.5~0mm, after crushing and screening, mix according to the formula in Table 3, add to the planetary mixer and mix for 3~6 minutes, then add thermosetting resin, mix evenly and then add the following fine powder: solid waste corundum alumina sagger, Yixing Fudong white mud, aluminum silicon alloy powder, solid waste graphite sagger, lithium-based soil, coke gem powder, mix for about 10 minutes, put down the grinding wheel The mud is pressurized to wrap the fine powder tightly on the particles. The molding is carried out with a hydraulic press of more than 1,000 tons. The materials are accurately weighed according to the shape and size of the bricks. The weighed materials are added to the mold and molded to the specified size. The overall dimensions, height, aperture, and cracks in the holes of each brick are measured. The brick shape is symmetrical. Each drain is fully inspected. 30% of the unit weight is sampled in each shift. The porosity and volume density of each batch are tested. Any unqualified phenomenon must be scrapped and the cause is found. The molded drain brick blanks generally need to be naturally dried for 1 day before entering the drying kiln. The brick blanks are slowly heated and dried in the drying kiln for 28 hours. The temperature of the drying kiln should not exceed 180±10℃. They are kept warm for 15 hours and finally cooled naturally to room temperature at a uniform speed. The specific heating process is to evenly raise the temperature of the drying kiln to 60℃ within 1 hour, and keep it at 60℃ for 2 hours, then evenly increase the temperature from 60℃ to 180℃ within 15 hours, and keep it at 180℃ for 15 hours, and finally drop to room temperature at a uniform rate; to prevent the generation and expansion of cracks in the drain bricks during use, the brick blanks should be assembled with iron shells and filled with fire clay in the middle, which can prevent the drain bricks from bursting during use due to extreme cold and heat, and prevent steel leakage accidents during the steel pouring process, resulting in abnormal pouring stop.

[0123] The above are only some embodiments of the present invention. It should be pointed out that for ordinary technicians in this field, other modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. The submerged nozzle brick produced from solid waste alumina saggers is characterized in that, By weight percentage, it includes: waste corundum alumina crucible 72%-83%, Yixing Fudong white clay 5%-8%, aluminum-silicon alloy powder 2%-5%, waste graphite crucible 2%-3%, lithium-based clay 3%-5%, pyrophyllite powder 4%-7%. The sum of the weights of all components in the above formula is 100%, and liquid thermosetting resin 4-5%.

2. The submerged nozzle brick produced from solid waste alumina saggers according to claim 1, wherein The proportion of the waste corundum alumina crucible particles is 60%, and the proportion of the waste corundum alumina crucible fine powder is 12%-23%.

3. The submerged nozzle brick produced from solid waste alumina saggers according to claim 2, characterized in that, The particle diameters of the waste corundum alumina crucible are: 3-1, 1-0, 0.5-0 mm; The fine powders of the waste corundum alumina crucible are respectively: 325 mesh, 200 mesh; The Yixing Fudong white clay is: 200 mesh; The aluminum-silicon alloy powder is: 180 mesh; The waste graphite crucible is: 325 mesh; The lithium-based clay is: 200 mesh; The pyrophyllite powder is: 180 mesh; The thermosetting resin is liquid.

4. The submerged nozzle brick produced from solid waste alumina saggers according to claim 3, wherein, The particle size distribution of the waste corundum alumina crucible by weight percentage is: 3～1㎜18％～25％ 1～0㎜20％～28％ 0.5～0㎜12％～7％ The sum of the weight percentage of the particle size distribution of the above waste corundum alumina crucible is 60%.

5. The submerged nozzle brick produced from solid waste alumina saggers according to claim 4, characterized in that, The waste corundum alumina crucible: Al2O3 content ≥ 93%, SiO2 content ≤ 6%, CaO content ≤ 0.2%, NaO content ≤ 0.3; The Yixing Fudong white clay: Al2O3 content ≥ 28%, Fe2O3 content ≤ 2.2%, SiO2 content ≥ 46%; The aluminum-silicon alloy powder: active aluminum Al ≥ 85%; Si content ≥ 12%; The waste graphite crucible: C content ≥ 96%; The lithium-based clay: Al2O3 content ≥ 25%, SiO2 content 70 ≤ %; The pyrophyllite powder: Al2O3 content ≥ 45%, SiO2 content ≥ 49%, Fe2O3 content ≤ 1.2%; The thermosetting resin: residual carbon content 48 ± 2%, solid content 68-78%, viscosity 16800-21000 mpa.

6. The preparation method of the submerged nozzle brick produced from solid waste alumina saggers according to claim 5, characterized in that, It includes the following steps: S1. Raw material selection; S2. Raw material processing; S3. Raw material inspection; S4. Molding; S5. Drying; S6. Firing; S6. Brick body processing; S7. Filling fire clay; S8. Covering with iron shell; S9. Finished product inspection; S10. Packaging and warehousing.

7. The preparation method of the submerged nozzle brick produced from solid waste alumina saggers according to claim 6, characterized in that, The raw material processing includes the following steps: S1. Raw material mixing, waste corundum alumina crucible 72%-83%, Yixing Fudong white clay 5%-8%, aluminum-silicon alloy powder 2%-5%, waste graphite crucible 2%-3%, lithium-based clay 3%-5%, pyrophyllite powder 4%-7%. The sum of the weights of all components in the above formula is 100%, and liquid thermosetting resin 4-5%; S2. Stirring, using a stirring device to stir the above raw materials; S3. Preheating, using a heating device to heat the above raw materials; S4. Placing for standby.

8. The preparation method of the submerged nozzle brick produced from solid waste alumina saggers according to claim 6, characterized in that, The drying includes: natural drying and heating drying; The natural drying is: placing the formed brick blank in a natural environment and drying for 36-48 hours; The heating and drying process is as follows: Place the brick blanks that have undergone natural drying into a drying kiln and slowly dry them for 25 - 31 hours. The temperature of the drying kiln is preferably 175 - 185°C, keep warm for 14 - 16 hours, and finally cool down to room temperature at a uniform speed.

9. The preparation method of the submerged nozzle brick produced with solid waste alumina saggers according to claim 8, characterized in that, In the heating and drying process, the temperature - rising and drying process is as follows: Uniformly raise the temperature of the drying kiln to 60°C within 1 hour, keep warm at 60°C for 2 hours, then uniformly raise the temperature from 60°C to 180°C within 15 hours, keep warm at 180°C for 15 hours, and finally cool down to room temperature at a uniform speed.

10. The preparation method of the submerged nozzle brick produced with solid waste alumina saggers according to claim 6, characterized in that, In S6, for firing, uniformly raise the temperature of the medium - high - temperature tunnel kiln to 900°C ± 30°C, keep warm for 12 - 17 hours, and finally cool down to room temperature at a uniform speed; The temperature - rising process is as follows: Uniformly raise the temperature of the drying kiln to 100°C within 1 hour, keep warm at 100°C for 10 hours, then uniformly raise the temperature from 100°C to 200°C within 15 hours, and keep warm at 200°C for 12 hours; The low - temperature firing: Uniformly raise the temperature to 900°C ± 30°C within 12 - 17 hours; The finished - product inspection includes full inspection of the height, pore diameter, internal cracks in pores, brick - shape symmetry, and each water outlet of the finished product. 30% of the single weight should be randomly inspected per shift, and for each batch, the porosity, bulk density, and physical and chemical indexes should be inspected.

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