Blast furnace anhydrous stemming with nearly spherical Al2O3-Si composite micro powder as plasticizer and preparation method of blast furnace anhydrous stemming

Abstract

The invention discloses a blast furnace anhydrous stemming taking nearly spherical Al2O3-Si composite micro powder as a plasticizer and a preparation method of the blast furnace anhydrous stemming. The blast furnace anhydrous stemming is prepared from 10%-20% of first-class aggregate, 5%-16% of second-class aggregate, 5%-16% of third-class aggregate, 4%-12% of fourth-class aggregate, 15%-40% of powder, 4%-20% of 3000-mesh nearly-spherical Al2O3-Si composite micro powder serving as an additive and 9%-16% of a liquid carbonaceous binding agent. The preparation method comprises the following steps: firstly, mixing and stirring the additive and various aggregates, then adding the carbonaceous binder and the powder, continuously stirring, and extruding and packaging the obtained pug after the obtained pug is qualified through Marshall value detection to obtain the blast furnace anhydrous stemming. The blast furnace anhydrous stemming prepared by using the method is relatively low in production cost, excellent in performance, safe and environment-friendly; and the prepared blast furnace anhydrous stemming does not collapse or scatter at different temperature sections and is good in plasticity, the iron notch depth meets the using requirement of a blast furnace, and the iron notch repairing capacity is high. Compared with the traditional anhydrous stemming, the anhydrous stemming provided by the invention has the advantage that the ton iron consumption is reduced by 8-18%.

Description

I. Technical Field:

[0001] The present invention belongs to the technical field of refractories, and particularly relates to a blast furnace anhydrous taphole clay using nearly spherical Al2O3-Si composite fine powder as a plasticizer and a preparation method thereof. II. Background Art:

[0002] Blast furnace anhydrous taphole clay is a functional refractory material used to plug the tapping hole of an ironmaking blast furnace and regularly open the taphole to smoothly discharge slag and iron. Appropriate plasticity of the taphole clay can ensure dense filling of the taphole and maintain the stability of the taphole depth. Traditional blast furnace anhydrous taphole clay uses soft clay as the plasticizer of the taphole clay. Soft clay has the advantages of improving tapping and ramming of the taphole, accelerating sintering, being easily obtainable, and having low cost. With the increase of the smelting intensity of the blast furnace, the requirements for the erosion resistance of the taphole clay by slag and iron are getting higher and higher. Soft clay has disadvantages such as a high content of low-melting substances, which will reduce the refractoriness, the free water that is not easily removed will reduce the high-temperature strength of the taphole clay, and a large amount of low-melting substances are easily formed with the high-temperature blast furnace slag, which will seriously reduce the slag and iron erosion resistance of the blast furnace anhydrous taphole clay.

[0003] In recent years, measures such as selecting high-quality ball clay, reducing the addition ratio of clay, and adding various fine powders have been taken to reduce the influence of clay on the performance of blast furnace anhydrous taphole clay, but the negative impact of clay on the taphole clay has not been eliminated.

[0004] In production applications, the water content of high-quality ball clay is relatively high. Adding it to the anhydrous taphole clay will increase the addition amount of the binder. After being subjected to high temperature, a large number of pores are formed after the water volatilizes, reducing the density and bonding strength of the blast furnace anhydrous taphole clay. Due to the relatively large surface energy, low structural energy, and the adjacent endothermic valleys of adsorbed water and structural water of ball clay, the heating temperature range for dehydration treatment without changing the plasticity of ball clay is relatively narrow and the drying efficiency is low, increasing the cost of ball clay. At the same time, clay contains low-melting impurities such as CaO, MgO, Fe2O3, K2O, and Na2O, which reduce the refractoriness of the anhydrous taphole clay, are easily formed into low-melting substances with the blast furnace slag, and reduce the slag and iron erosion resistance. III. Summary of the Invention:

[0005] The technical problem to be solved by the present invention is: Based on the existing situation of the preparation method of blast furnace anhydrous taphole clay in the prior art and the adverse effects of the existing plasticizers on the performance of blast furnace anhydrous taphole clay such as refractoriness, bonding strength, and slag erosion resistance, the present invention provides a blast furnace anhydrous taphole clay using nearly spherical Al2O3-Si composite fine powder as a plasticizer and a preparation method thereof. Using the present invention to prepare blast furnace anhydrous taphole clay, it has lower production costs, excellent performance, safety and environmental protection; therefore, the present invention has good market prospects and lower consumption of anhydrous taphole clay per ton of iron.

[0006] To solve the above problems, the technical solution adopted by the present invention is:

[0007] The present invention provides a blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer. In terms of mass percentage, the blast furnace anhydrous taphole clay is composed of 10-20% of a first type of aggregate, 5-16% of a second type of aggregate, 5-16% of a third type of aggregate, 4-12% of a fourth type of aggregate, 15-40% of powder, 4-20% of an additive, and 9-16% of a liquid binder;

[0008] The first type of aggregate is at least one of aluminum-chromium slag with a particle size of 0.074-3 mm, recycled SiC-bonded mullite material with a particle size of 0.074-3 mm, quartz sand with a particle size of 0.074-3 mm, and pyrophyllite with a particle size of 0.074-3 mm;

[0009] The second type of aggregate is at least one of recycled Si3N4-bonded SiC material with a particle size of 0.074-3 mm and recycled Al2O3-SiC-C material with a particle size of 0.074-3 mm;

[0010] The third type of aggregate is at least one of dry coke quenching screenings with a particle size of 0.074-2 mm and carbon additive screenings with a particle size of 0.074-1.5 mm;

[0011] The fourth type of aggregate is at least one of kyanite tailing sand with a particle size of 0.074-3 mm and zircon waste with a particle size of 0.074-0.5 mm;

[0012] The powder is at least one of recycled Si3N4-bonded SiC material with a mesh size of 200, recycled SiC-bonded mullite material with a mesh size of 325, aluminum-chromium slag with a mesh size of 325, and ferrosilicon nitride with a mesh size of 200;

[0013] The additive is 3000-mesh near-spherical Al2O3-Si composite fine powder; the liquid binder is a liquid carbonaceous binder.

[0014] For the blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer as described above, the chemical component contents in the aluminum-chromium slag are Al2O3 + Cr2O3 > 97.5%, K2O + Na2O < 0.5%, Fe2O3 < 0.5% (the aluminum-chromium slag is a hazardous waste solid slag generated during the smelting of chromite to produce chromium oxide and is a recycled material after being harmlessly treated at 1300 ± 100 °C), and its particle size is 1-3 mm, 0.074 mm-1 mm, and 325 mesh.

[0015] For the blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer as described above, the chemical component contents in the recycled SiC-bonded mullite material are Al2O3 > 65.0%, SiC > 10%, CaO < 0.5%, K2O + Na2O < 0.5%, and its particle size is 1-3 mm, 0.074 mm-1 mm, and 325 mesh;

[0016] The processing method of the recycled SiC-bonded mullite material is as follows:

[0017] a. For refractory materials remaining after use in the iron and steel industry or cement industry, manually cut off the deteriorated layer, and then use a pair-roll crusher to crush them into particulate materials with a particle size of 0.074 - 5 mm. The obtained particulate materials are magnetically separated by a magnetic separator to remove metal impurities;

[0018] b. For the particulate materials after removing metal impurities, use the tail gas of a kiln at 150 - 300 °C to fully stir and preheat the materials and water. The concentration of CO2 in the kiln tail gas is 25.0 ± 5.0%; then place them in a reaction kettle for treatment. The treatment temperature is 120 - 200 °C, the pressure is 0.2 - 0.8 MPa, and the time is 2 - 6 h. Finally, dry and process them to obtain recycled SiC-bonded mullite materials with particle sizes of 1 - 3 mm, 0.074 mm - 1 mm, and 325 mesh.

[0019] For the blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer as described above, the content of each chemical component in the quartz sand is SiO2 > 98.5%, Fe2O3 < 1.0%, and its particle size is 1 - 3 mm and 0.074 - 1 mm;

[0020] The content of each chemical component in the pyrophyllite is Al2O3 > 15.0%, SiO2 > 80.0%, Fe2O3 < 0.5%, K2O + Na2O < 0.5%, and its particle size is 1 - 3 mm and 0.074 mm - 1 mm.

[0021] For the blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer as described above, the content of each chemical component in the recycled Si3N4-bonded SiC material is SiC > 70.0%, Si3N4 > 20.0%, K2O + Na2O < 0.5%; its particle size is 1 - 3 mm, 0.074 mm - 1 mm, and 200 mesh;

[0022] The processing method of the recycled Si3N4-bonded SiC material is as follows:

[0023] a. For the residual refractory materials generated in the iron and steel industry or aluminum electrolysis industry, select and remove the deteriorated materials, use a vibrating screen to screen out impurities, and then use a pair-roll crusher to crush them into particulate materials with a particle size of 0.074 - 5 mm. The obtained particulate materials with a particle size of 0.074 - 5 mm are magnetically separated by a magnetic separator to remove metal impurities;

[0024] b. Then, use the kiln exhaust gas at 150 - 300°C to fully stir and preheat the granular material with a particle size of 0.074 - 5 mm and water obtained after removing metal impurities. The concentration of CO2 in the kiln exhaust gas is 20 - 25%. The preheated material is placed in a reaction kettle for treatment at a temperature of 120 - 200°C, a pressure of 0.2 - 0.8 MPa, and a time of 2 - 6 h. Then, dry the obtained material and process it into regenerated Si3N4 - bonded SiC material with particle sizes of 1 - 3 mm, 0.074 mm - 1 mm, and 200 mesh.

[0025] According to the above - mentioned blast - furnace anhydrous taphole clay with near - spherical Al2O3 - Si composite micro - powder as a plasticizer, the content of each chemical component in the regenerated Al2O3 - SiC - C material is Al2O3 + SiC > 80.0%, CaO < 1.0%, Fe2O3 < 1.0%, and its particle size is 1 - 3 mm and 0.074 mm - 1 mm.

[0026] The processing method of the regenerated Al2O3 - SiC - C material is as follows:

[0027] a. For the castable removed after use in the tapping yard of blast - furnace ironmaking, or the refractory brick removed after use in the torpedo ladle, or the slide plate taken off - line after use in the steel ladle, manually select and remove the deteriorated materials, use a vibrating screen to screen out impurities, and use a pair - roll crusher to crush them into granular materials with a particle size of 0.074 - 5 mm. The obtained granular materials are removed of metal impurities by a magnetic separator.

[0028] b. Use a vibrating air - separation machine (utilizing the difference in bulk density) to distinguish the slag and the regenerated material from the granular materials removed of metal impurities. After processing, regenerated Al2O3 - SiC - C material with particle sizes of 1 - 3 mm and 0.074 mm - 1 mm is obtained.

[0029] According to the above - mentioned blast - furnace anhydrous taphole clay with near - spherical Al2O3 - Si composite micro - powder as a plasticizer, the content of each chemical component in the dry - quenched coke screenings is fixed carbon > 85.0%, ash < 12.5%, volatile matter < 1.0%, and its particle size is 0.074 - 2 mm.

[0030] The dry - quenched coke screenings are the coke produced by the dry - quenching process in the coking industry, which are the screenings that cannot be used in the iron and steel industry and cannot generate high - value products.

[0031] The content of each chemical component in the recarburizer screenings is fixed carbon > 90.0%, ash < 7.5%, volatile matter < 1.5%, and its particle size is 0.074 - 1.5 mm.

[0032] The recarburizer screenings are the screenings that are sold at a loss because the graphitized recarburizer does not meet the usage requirements of metallurgical customers.

[0033] The content of each chemical component in the cyanite tailings sand is Al2O3 > 10.0%, SiO2 > 80.0%, Fe2O3 < 1.0%, K2O + Na2O < 0.5%, and its particle size is 0.074 - 3 mm; the cyanite tailings sand is a low-grade cyanite ore discarded during the cyanite mining process without screening value;

[0034] The content of each chemical component in the zircon waste is Al2O3 > 50.0%, SiO2 > 45.0%, Fe2O3 < 1.0%, K2O + Na2O < 0.5%, and its particle size is 0.074 - 0.5 mm; the zircon waste is the material discarded during the flotation of zircon sand from the zircon ore, and is used as the raw material for the blast furnace anhydrous taphole clay after screening;

[0035] The content of each chemical component in the ferrosilicon nitride is Si3N4 ≥ 75%, N ≥ 30%, Fe 11 - 17%, K2O + CaO < 0.5%, and its particle size is 200 mesh.

[0036] According to the above blast furnace anhydrous taphole clay with near-spherical Al2O3-Si composite micro-powder as the plasticizer, the 3000-mesh near-spherical Al2O3-Si composite micro-powder is mixed by Al2O3 micro-powder and Si micro-powder in a weight ratio of 1:9 - 9:1; the performance of the liquid carbonaceous binder is a viscosity of 300 Pa·S at 50°C, a moisture content < 1%, and a residual carbon value detected at 800°C × 7 min greater than 30 wt% (the carbonaceous binder is obtained by the high-temperature and high-pressure reaction of the decrystallized anthracene oil and phenolic resin produced by coal coking).

[0037] According to the above blast furnace anhydrous taphole clay with near-spherical Al2O3-Si composite micro-powder as the plasticizer, the Al2O3 micro-powder in the 3000-mesh Al2O3-Si composite micro-powder is selected from the alumina micro-powder that cannot be recycled for ceramic diaphragms in the process of recycling alumina powder from waste lithium battery ceramic diaphragms, and the typical values of its particle size distribution are d (10) = 0.59 μm, d (50) = 1.24 μm, d (90) = 4.36 μm, and the BET is 2.0 m 2 / g; the Si micro-powder in the 3000-mesh Al2O3-Si composite micro-powder is selected from the elemental silicon micro-powder generated during the squaring of silicon rods or the slicing of silicon ingots, and the typical values of its particle size distribution are d (10) = 0.51 μm, d (50) = 1.14 μm, d (90) = 5.67 μm, and the BET is 6.1 m 2 / g.

[0038] In the additive, the Al2O3 fine powder and Si fine powder in the 3000-mesh Al2O3-Si composite fine powder have a relatively small difference in the sphere diameter of the two kinds of fine powders, and have the effect of generating plasticity with equal sphere diameters, which can fully meet the plasticity of the blast furnace anhydrous taphole clay, and the refractoriness and the slag and iron erosion resistance are significantly improved.

[0039] In addition, a preparation method of a blast furnace anhydrous taphole clay using a near-spherical Al2O3-Si composite fine powder as a plasticizer is provided. The preparation method includes the following steps:

[0040] 1) Mix the Al2O3 fine powder and Si fine powder according to a weight ratio of 1:9 to 9:1 to obtain a 3000-mesh near-spherical Al2O3-Si composite fine powder after mixing;

[0041] 2) Weigh various raw materials according to the proportion of the blast furnace anhydrous taphole clay;

[0042] 3) Place the weighed additive near-spherical Al2O3-Si composite fine powder in a spherical mixer for premixing, and the premixing time is 120-180 min (there is no obvious color difference and good flow state in the premixed composite powder);

[0043] 4) Put the weighed various aggregates and the premixed additive ingredients into batching truck A, and put the weighed powder materials into batching truck B; then place the raw materials in batching truck A in a mixing and kneading mixer for stirring (the stirring time is 10-20 min), then add 95% of the total amount of the liquid carbonaceous binder and continue stirring. After stirring for 10-15 min, add the raw materials in batching truck B, and then add the remaining 5% of the liquid carbonaceous binder and continue kneading for 10-20 min, and take a sample to detect the Marsh value;

[0044] 5) After passing the Marsh value test, obtain qualified mud, and control the temperature of the qualified mud to be 45-55 °C; pass the obtained qualified mud through a belt into an extruder, extrude the taphole clay with a qualified shape through the extruder, and then perform packaging to obtain a product, namely, a blast furnace anhydrous taphole clay using a near-spherical Al2O3-Si composite fine powder as a plasticizer.

[0045] The positive and beneficial effects of the present invention:

[0046] 1. During the preparation of the blast furnace anhydrous taphole clay in the present invention, the additives are fully premixed in advance. By selecting appropriate mixing equipment, optimizing the mixing time, adding materials in batches and optimizing the combined particle size, and strictly controlling the temperature of the mud during stirring (45 - 55 °C; when the mud temperature is low, heat preservation and heating measures are considered, and when the temperature is high, heat dissipation and cooling measures are taken); and near-spherical Al2O3-Si composite fine powder is used as the only plastic additive in the batching. Therefore, the blast furnace anhydrous taphole clay prepared by the technical solution of the present invention does not collapse or disperse at different temperature ranges, has good plasticity, the taphole depth meets the requirements of blast furnace use, and has strong ability to repair the taphole. The consumption of the taphole clay per ton of iron of the present invention is reduced by 8 - 18% compared with the traditional taphole clay.

[0047] 2. The near-spherical Al2O3-Si composite fine powder adopted in the present invention completely replaces the clay-based plasticizer in the traditional blast furnace anhydrous taphole clay. Due to the large specific surface area of the composite fine powder, part of the carbonaceous binder is accumulated at normal temperature. Before plugging, the anhydrous taphole clay in the mud gun fills the nozzle without deformation, avoiding the damage of the nozzle due to contact with slag and iron during plugging and affecting the plugging quality; during the plugging process, affected by the temperature, the carbonaceous binder is released in time between the particles to play a lubricating role, ensuring smooth mud injection. At the same time, a large amount of nano-scale elemental silicon is contained in the fine powder. The taphole clay in the taphole channel is easy to in-situ generate silicon carbide with carbon elements under the high-temperature reducing atmosphere, improving the bonding strength and density of the anhydrous taphole clay, enhancing the slag and iron erosion resistance ability, prolonging the tapping time, and reducing the consumption per ton of iron. The ratio of the two kinds of Al2O3 fine powder and Si fine powder in the composite fine powder can be adjusted according to the front-of-furnace equipment and the smelting intensity of the blast furnace.

[0048] 3. The blast furnace anhydrous taphole clay prepared by the technical solution of the present invention does not collapse or disperse at different temperature ranges, has good plasticity, the taphole depth meets the requirements of blast furnace use, and has strong ability to repair the taphole. Proven by the use of multiple blast furnaces, the qualified rate of the taphole depth of the blast furnace anhydrous taphole clay of the present invention reaches 90.5 - 97.2%, which is increased by 2.0 - 6.0% compared with the traditional blast furnace anhydrous taphole clay; the average number of taphole leakage and interruption furnaces per month is 4 - 12 furnaces, which is 6 - 10 furnaces less than the traditional blast furnace anhydrous taphole clay; the opening strength is moderate, and the opening time-consuming is 4 - 8 minutes, while the opening time-consuming of the traditional blast furnace anhydrous taphole clay is 1 - 15 minutes, and the narrowing of the opening time-consuming range is convenient for the high-yield and smooth operation of the blast furnace; the tapping time is increased by 10 - 15% compared with the traditional blast furnace anhydrous taphole clay, and the consumption of the taphole clay per ton of iron is reduced by 8 - 18%. Therefore, the present invention has significant economic advantages and high cost performance. IV. Specific Embodiments:

[0049] The following further elaborates the present invention in combination with embodiments, but does not limit the protection scope of the technical solution of the present invention.

[0050] In the following examples, the contents of various chemical components in the used aluminum-chromium slag are: Al2O3 + Cr2O3 > 97.5%, K2O + Na2O < 0.5%, Fe2O3 < 0.5% (the aluminum-chromium slag is a hazardous waste solid slag generated during the smelting of chromite to produce chromium oxide, and is a recycled material after being treated harmlessly at 1300 ± 100 °C), and its particle sizes are 1 - 3 mm, 0.074 mm - 1 mm, and 325 mesh.

[0051] The contents of various chemical components in the used recycled SiC-bonded mullite material are: Al2O3 > 65.0%, SiC > 10%, CaO < 0.5%, K2O + Na2O < 0.5%, and its particle sizes are 1 - 3 mm, 0.074 mm - 1 mm, and 325 mesh;

[0052] The processing method of the recycled SiC-bonded mullite material is as follows:

[0053] a. For the refractory materials remaining after use in the iron and steel industry or cement industry, remove the deteriorated layer by manual cutting, and then crush them into particulate materials with a particle size of 0.074 - 5 mm using a pair-roll crusher. The obtained particulate materials are magnetically separated by a magnetic separator to remove metal impurities;

[0054] b. For the particulate materials from which metal impurities have been removed, use the kiln tail gas at 150 - 300 °C to fully stir and preheat the materials and water. The concentration of CO2 in the kiln tail gas is 25.0 ± 5.0%; then place them in a reaction kettle for treatment, with a treatment temperature of 120 - 200 °C, a pressure of 0.2 - 0.8 MPa, and a time of 2 - 6 h. Finally, dry and process them to obtain a recycled SiC-bonded mullite material with particle sizes of 1 - 3 mm, 0.074 mm - 1 mm, and 325 mesh.

[0055] The contents of various chemical components in the used quartz sand are: SiO2 > 98.5%, Fe2O3 < 1.0%, and its particle sizes are 1 - 3 mm and 0.074 - 1 mm; the contents of various chemical components in the pyrophyllite are: Al2O3 > 15.0%, SiO2 > 80.0%, Fe2O3 < 0.5%, K2O + Na2O < 0.5%, and its particle sizes are 1 - 3 mm, 0.074 mm - 1 mm.

[0056] The contents of various chemical components in the used recycled Si3N4-bonded SiC material are: SiC > 70.0%, Si3N4 > 20.0%, K2O + Na2O < 0.5%; its particle sizes are 1 - 3 mm, 0.074 mm - 1 mm, and 200 mesh;

[0057] The processing method of the recycled Si3N4-bonded SiC material is as follows:

[0058] a. The residual refractory materials generated from the iron and steel industry or the aluminum electrolysis industry are selected to remove deteriorated materials, screened by a vibrating screen to remove impurities, and then crushed into granular materials with a particle size of 0.074 - 5 mm by a pair-roll crusher. The obtained granular materials with a particle size of 0.074 - 5 mm are magnetically separated by a magnetic separator to remove metal impurities;

[0059] b. Then, the granular materials with a particle size of 0.074 - 5 mm obtained after removing metal impurities and water are fully stirred and preheated with the kiln tail gas at 150 - 300 °C. The concentration of CO2 in the kiln tail gas is 20 - 25%; the preheated materials are placed in a reaction kettle for treatment at a temperature of 120 - 200 °C, a pressure of 0.2 - 0.8 MPa, and a time of 2 - 6 h; then the obtained materials are dried and processed into regenerated Si3N4-bonded SiC materials with particle sizes of 1 - 3 mm, 0.074 mm - 1 mm, and 200 mesh.

[0060] In the regenerated Al2O3 - SiC - C materials used, the content of each chemical component is Al2O3 + SiC > 80.0%, CaO < 1.0%, Fe2O3 < 1.0%, and its particle size is 1 - 3 mm and 0.074 mm - 1 mm;

[0061] The processing method of the regenerated Al2O3 - SiC - C materials is as follows:

[0062] a. The castable removed after use in the tapping yard of blast furnace ironmaking, the refractory bricks removed after use in the torpedo ladle, or the slide plates taken off the ladle are manually selected to remove deteriorated materials, screened by a vibrating screen to remove impurities, and crushed into granular materials with a particle size of 0.074 - 5 mm by a pair-roll crusher. The obtained granular materials are magnetically separated by a magnetic separator to remove metal impurities;

[0063] b. The granular materials after removing metal impurities are separated into slag and regenerated materials by a vibrating air separator (using the difference in bulk density). After treatment and processing, regenerated Al2O3 - SiC - C materials with particle sizes of 1 - 3 mm and 0.074 mm - 1 mm are obtained.

[0064] In the dry coke quenching screen undersize used, the content of each chemical component is fixed carbon > 85.0%, ash < 12.5%, volatile matter < 1.0%, and its particle size is 0.074 - 2 mm; the dry coke quenching screen undersize is the coke produced by the dry quenching process in the coking industry, and the screen undersize that cannot be used in the iron and steel industry and cannot generate high value;

[0065] In the carburizer screen undersize used, the content of each chemical component is fixed carbon > 90.0%, ash < 7.5%, volatile matter < 1.5%, and its particle size is 0.074 - 1.5 mm; the carburizer screen undersize is the screen undersize sold at a loss because the graphitized carburizer does not meet the requirements of metallurgical customers;

[0066] The content of each chemical component in the cyanite tailings sand is Al2O3 > 10.0%, SiO2 > 80.0%, Fe2O3 < 1.0%, K2O + Na2O < 0.5%, and its particle size is 0.074 - 3 mm; the cyanite tailings sand is a low-grade cyanite ore discarded during the cyanite mining process without screening value.

[0067] The content of each chemical component in the zircon waste is Al2O3 > 50.0%, SiO2 > 45.0%, Fe2O3 < 1.0%, K2O + Na2O < 0.5%, and its particle size is 0.074 - 0.5 mm; the zircon waste is the material discarded during the flotation of zircon sand from the zircon ore, and is used as the raw material for the blast furnace anhydrous gunite after screening.

[0068] The content of each chemical component in the ferrosilicon nitride is Si3N4 ≥ 75%, N ≥ 30%, Fe 11 - 17%, K2O + CaO < 0.5%, and its particle size is 200 mesh.

[0069] The 3000-mesh near-spherical Al2O3-Si composite micropowder is formed by mixing Al2O3 micropowder and Si micropowder in a weight ratio of 1:9 - 9:1; the properties of the carbonaceous binder are a viscosity of 300 Pa·S at 50°C, a moisture content < 1%, and a residual carbon value detected at 800°C × 7 min greater than 30 wt% (the carbonaceous binder is obtained by the high-temperature and high-pressure reaction of the decrystallized anthracene oil and phenolic resin produced by coal coking).

[0070] The Al2O3 micropowder in the 3000-mesh Al2O3-Si composite micropowder is selected from the alumina micropowder that cannot be recycled for the ceramic separator in the process of recycling alumina powder from waste lithium battery ceramic separators, and the typical values of its particle size distribution are d (10) = 0.59 μm, d (50) = 1.24 μm, d (90) = 4.36 μm, and the BET is 2.0 m 2 / g; the Si micropowder in the 3000-mesh Al2O3-Si composite micropowder is selected from the elemental silicon micropowder generated during the squaring of silicon rods or the slicing of silicon ingots, and the typical values of its particle size distribution are d (10) = 0.51 μm, d (50) = 1.14 μm, d (90) = 5.67 μm, and the BET is 6.1 m 2 / g.

[0071] In the additive 3000-mesh Al2O3-Si composite micropowder, the Al2O3 micropowder and the Si micropowder have a small difference in sphere diameter, and have the effect of generating plasticity with equal sphere diameter, which can fully meet the plasticity of the blast furnace anhydrous gunite, and significantly improve the refractoriness and slag and iron erosion resistance.

[0072] Example 1:

[0073] The blast furnace anhydrous taphole clay of the present invention uses nearly spherical Al2O3-Si composite fine powder as a plasticizer. In terms of mass percentage, it is composed of 12% quartz sand with a particle size of 0.074 - 3 mm, 15% dry quenched coke screenings with a particle size of 0.074 - 2 mm, 5% recycled Al2O3-SiC-C material with a particle size of 0.074 - 3 mm, 10% cyanite tailing sand with a particle size of 0.074 - 3 mm, 33% recycled SiC-bonded mullite material with a mesh size of 325, 10% nearly spherical Al2O3-Si composite fine powder with a mesh size of 3000, and 15% liquid carbonaceous binder.

[0074] The preparation method of the blast furnace anhydrous taphole clay of Example 1 of the present invention using nearly spherical Al2O3-Si composite fine powder as a plasticizer is as follows in detail:

[0075] 1) Mix Al2O3 fine powder and Si fine powder in a weight ratio of 9:1. After mixing, nearly spherical Al2O3-Si composite fine powder with a mesh size of 3000 is obtained;

[0076] 2) Weigh various raw materials according to the proportion of the blast furnace anhydrous taphole clay described in Example 1;

[0077] 3) Place the weighed additive, nearly spherical Al2O3-Si composite fine powder, in a spherical mixer for premixing for 130 min. After premixing, the composite powder has no obvious color difference and good flow state;

[0078] 4) Put the weighed various aggregates and the premixed additive ingredients into batching truck A, and put the weighed powder materials into batching truck B; then place the raw materials in batching truck A into a mixing and stirring machine for stirring (the stirring time is 15 min), then add 95% of the total amount of the liquid carbonaceous binder and continue stirring. After stirring for 10 min, add the raw materials in batching truck B, and then add the remaining 5% of the liquid carbonaceous binder and continue stirring for 20 min, and take samples to detect the Marsh value;

[0079] 5) After passing the Marsh value test, the qualified mud material is discharged from the mixer, and the temperature of the qualified mud material is controlled at 45 - 55 °C; then it enters the extruder through a belt, and the taphole clay of qualified shape is extruded by the extruder and enters the packaging process to obtain the product, the blast furnace anhydrous taphole clay using nearly spherical Al2O3-Si composite fine powder as a plasticizer.

[0080] The blast furnace anhydrous taphole clay product prepared in this example and the traditional anhydrous taphole clay are made at 80 °C with an outer diameter Inner diameter The crucible with a depth of 38 mm, after being smoked and solidified at 300 °C for 24 h, was respectively filled with 100 g of blast furnace slag and blast furnace iron blocks, and then subjected to carbon burial treatment at 1500 °C for 3 h. After cooling to room temperature and taking out, observations were made. The crucible made of the product of the present invention had no obvious cracks, while the upper end face of the crucible made of traditional anhydrous taphole clay had tiny cracks. After cutting along the axial center line, the iron block in the crucible made of the product of the present invention fell off from the anhydrous taphole clay, while the crucible made of the traditional product penetrated about 3 mm along the internal cracks. This shows that the product prepared in this example has strong resistance to molten iron penetration and a low probability of leakage or breakage of the iron notch during use. For the comparison of the crucibles filled with blast furnace slag, no obvious erosion was found in the crucible made of the product of the present invention, the thickness of the metamorphic layer around the slag hole was 2 - 3 mm, and the thickness of the metamorphic layer at the bottom of the slag hole was 3 - 4 mm; while for the crucible made of traditional anhydrous taphole clay, the thickness of the metamorphic layer around the slag hole was 3 - 5 mm, and the thickness of the metamorphic layer at the bottom of the slag hole was 7 - 9 mm. It can be seen that although a large amount of SiO2 was introduced in the raw materials in this example, mainly in the form of coarse particles, and the content of SiO2 in the fine powder and micro powder was strictly controlled, both the slag erosion resistance and the iron penetration resistance were greatly improved.

[0081] The product prepared in this example is mainly used in the single-tuyere ironmaking blast furnace. This type of blast furnace has the characteristics of weak opening and plugging equipment capabilities, low daily iron output, low requirements for iron tapping time, and short sintering time of the taphole clay. In a certain 580 m 3 The usage data on a blast furnace are as follows: the qualification rate of the iron notch depth is greater than 90%, there is no phenomenon of wet iron notch when opening after an iron tapping interval of 30 min, the opening strength is moderate, and the iron tapping time is increased by 8.2% compared with the traditional anhydrous taphole clay.

[0082] Example 2:

[0083] The anhydrous taphole clay for blast furnace of the present invention using nearly spherical Al2O3 - Si composite micro - powder as a plasticizer, expressed in mass percentage, is composed of 12% of pyrophyllite with a particle size of 0.074 - 3 mm, 12% of dry - quenched coke screenings with a particle size of 0.074 - 2 mm, 10% of recycled Al2O3 - SiC - C material with a particle size of 0.074 - 3 mm, 8% of zircon waste material with a particle size of 0.074 - 0.5 mm, 15% of recycled Si3N4 - bonded SiC material with a mesh size of 200, 10% of aluminochromite slag with a mesh size of 325, 10% of ferrosilicon nitride with a mesh size of 200, 10% of nearly spherical Al2O3 - Si composite micro - powder with a mesh size of 3000, and 13% of liquid carbonaceous binder.

[0084] The preparation method of the anhydrous taphole clay for blast furnace of the present invention in Example 2 using nearly spherical Al2O3 - Si composite micro - powder as a plasticizer is basically the same as that in Example 1, except that:

[0085] In step 1): The Al2O3 micro - powder and Si micro - powder were mixed in a weight ratio of 7:3, and after mixing, nearly spherical Al2O3 - Si composite micro - powder with a mesh size of 3000 was obtained.

[0086] The product prepared in this embodiment is mainly used for blast furnaces with double tapholes. Compared with blast furnaces with single tapholes, the taphole opening and closing equipment is stronger, the opening diameter is larger, and the requirements for tapping time and taphole depth are significantly improved. It is required that the anhydrous gunite maintain the taphole depth and the resistance to slag and iron erosion and penetration be improved.

[0087] Using the product prepared in this embodiment, tests were carried out respectively in a 1280 m 3 blast furnace and a 1780 m 3 blast furnace. The usage effect data are shown in Table 1.

[0088] Table 1 Usage effect data of the product obtained in Example 2 in a 1280 m 3 blast furnace and a 1780 m 3 blast furnace

[0089]

[0090] Example 3:

[0091] The anhydrous gunite for blast furnace of the present invention with near-spherical Al2O3-Si composite powder as the plasticizer is composed of, by mass percentage: 3% of pyrophyllite with a particle size of 0.074 - 3 mm, 14% of alumina-chromite slag with a particle size of 0.074 - 3 mm, 8% of screened material of recarburizer with a particle size of 0.074 - 1.5 mm, 15% of recycled Si3N4-bonded SiC material with a particle size of 0.074 - 3 mm,

[0092] 5% of waste zirconium silicate with a particle size of 0.074 - 0.5 mm, 10% of recycled Si3N4-bonded SiC material with a mesh size of 200, 5% of alumina-chromite slag with a mesh size of 325, 15% of ferrosilicon nitride with a mesh size of 200, 15% of near-spherical Al2O3-Si composite powder with a mesh size of 3000, and 10% of liquid carbonaceous binder.

[0093] The preparation method of the anhydrous gunite for blast furnace of the present invention in Example 3 with near-spherical Al2O3-Si composite powder as the plasticizer is basically the same as that of Example 1, except that:

[0094] In step 1): Al2O3 powder and Si powder are mixed in a weight ratio of 2:8, and after mixing, near-spherical Al2O3-Si composite powder with a mesh size of 3000 is obtained.

[0095] The product prepared in this embodiment is applicable to large blast furnaces with a daily iron output of more than 7500 tons. The data statistics of using the product of this embodiment in a 3200 m 3 blast furnace for 50 furnaces are as follows: the average taphole depth is 3.53 m, and the diameter of the tapping drill bit The opening time is 6.6 minutes, the average tapping time is 176 minutes, the average tapping volume per furnace is 868 tons, the average mud punching volume per furnace is 312 kg, and the consumption of gunite per ton of iron is 0.32 kg. The consumption of gunite per ton of iron of the blast furnace traditional anhydrous gunite of the product of the present invention is 0.43 kg.

Claims

1. A blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer, characterized in that: In terms of mass percentage, the blast furnace waterless clay gunite is composed of 10-20% of a first type of aggregate, 5-16% of a second type of aggregate, 5-16% of a third type of aggregate, 4-12% of a fourth type of aggregate, 15-40% of powder, 4-20% of additive, and 9-16% of liquid binder; The first type of aggregate is at least one of aluminum-chromium slag with a particle size of 0.074-3 mm, recycled SiC-bonded mullite material with a particle size of 0.074-3 mm, quartz sand with a particle size of 0.074-3 mm, and pyrophyllite with a particle size of 0.074-3 mm; The second type of aggregate is at least one of recycled Si3N4-bonded SiC material with a particle size of 0.074-3 mm and recycled Al2O3-SiC-C material with a particle size of 0.074-3 mm; The third type of aggregate is at least one of the screened materials of dry quenched coke with a particle size of 0.074-2 mm and the screened materials of recarburizer with a particle size of 0.074-1.5 mm; The fourth type of aggregate is at least one of cyanite tailing sand with a particle size of 0.074-3 mm and zircon waste material with a particle size of 0.074-0.5 mm; The powder is at least one of recycled Si3N4-bonded SiC material with a mesh size of 200, recycled SiC-bonded mullite material with a mesh size of 325, aluminum-chromium slag with a mesh size of 325, and ferrosilicon nitride with a mesh size of 200; The additive is a near-spherical Al2O3-Si composite micro-powder with a mesh size of 3000; the liquid binder is a liquid carbonaceous binder.

2. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: In the aluminum-chromium slag, the content of each chemical component is Al2O3 + Cr2O3 > 97.5%, K2O + Na2O < 0.5%, Fe2O3 < 0.5%, and its particle size is 1-3 mm, 0.074 mm-1 mm, and 325 mesh; 3. The blast furnace anhydrous taphole clay using nearly spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: In the recycled SiC-bonded mullite material, the content of each chemical component is Al2O3 > 65.0%, SiC > 10%, CaO < 0.5%, K2O + Na2O < 0.5%, and its particle size is 1-3 mm, 0.074 mm-1 mm, and 325 mesh; The processing method of the recycled SiC-bonded mullite material is as follows: a. For the refractory materials remaining after use in the iron and steel industry or cement industry, the deteriorated layer is removed by manual cutting, and then the materials are crushed into particulate materials with a particle size of 0.074-5 mm by a pair-roll crusher. The obtained particulate materials are magnetically separated by a magnetic separator to remove metal impurities; b. For the particulate materials from which metal impurities have been removed, the materials and water are fully stirred and preheated with the tail gas of a furnace at 150-300 °C, and the concentration of CO2 in the tail gas of the furnace is 25.0 ± 5.0%; then they are placed in a reaction kettle for treatment, the treatment temperature is 120-200 °C, the pressure is 0.2-0.8 MPa, and the time is 2-6 h. Finally, they are dried and processed to obtain the recycled SiC-bonded mullite material with a particle size of 1-3 mm, 0.074 mm-1 mm, and 325 mesh.

4. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: In the quartz sand, the content of each chemical component is SiO2 > 98.5%, Fe2O3 < 1.0%, and its particle size is 1-3 mm and 0.074-1 mm; The content of each chemical component in the pyrophyllite is Al2O3 > 15.0%, SiO2 > 80.0%, Fe2O3 < 0.5%, K2O + Na2O < 0.5%, and its particle size is 1 - 3 mm and 0.074 mm - 1 mm.

5. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: The content of each chemical component in the recycled Si3N4 - bonded SiC material is SiC > 70.0%, Si3N4 > 20.0%, K2O + Na2O < 0.5%; its particle size is 1 - 3 mm, 0.074 mm - 1 mm and 200 mesh; The processing method of the recycled Si3N4 - bonded SiC material is as follows: a. The residual refractory materials generated in the iron and steel industry or the aluminum electrolysis industry are selected to remove deteriorated materials, and impurities are removed by a vibrating screen, and then crushed into particulate materials with a particle size of 0.074 - 5 mm by a pair - roll crusher. The obtained particulate materials with a particle size of 0.074 - 5 mm are magnetically separated by a magnetic separator to remove metal impurities; b. Then, the particulate materials with a particle size of 0.074 - 5 mm obtained after removing metal impurities and water are fully stirred and pre - heated by the tail gas of a kiln at 150 - 300 °C. The concentration of CO2 in the tail gas of the kiln is 20 - 25%; the pre - heated materials are placed in a reaction kettle for treatment. The treatment temperature is 120 - 200 °C, the pressure is 0.2 - 0.8 MPa, and the time is 2 - 6 h; then the obtained materials are dried and processed into recycled Si3N4 - bonded SiC materials with a particle size of 1 - 3 mm, 0.074 mm - 1 mm and 200 mesh.

6. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: The content of each chemical component in the recycled Al2O3 - SiC - C material is Al2O3 + SiC > 80.0%, CaO < 1.0%, Fe2O3 < 1.0%, and its particle size is 1 - 3 mm and 0.074 mm - 1 mm; The processing method of the recycled Al2O3 - SiC - C material is as follows: a. The castable removed after use in the tapping yard of blast furnace ironmaking, the refractory bricks removed after use in the torpedo ladle, or the slide plates taken off the steel ladle are manually selected to remove deteriorated materials, impurities are sieved out by a vibrating screen, and crushed into particulate materials with a particle size of 0.074 - 5 mm by a pair - roll crusher. The obtained particulate materials are magnetically separated by a magnetic separator to remove metal impurities; b. The particulate materials after removing metal impurities are separated into slag and recycled materials by a vibrating air separator, and after processing, recycled Al2O3 - SiC - C materials with a particle size of 1 - 3 mm and 0.074 mm - 1 mm are obtained.

7. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: The chemical components of the dry - quenched coke screen - down material are fixed carbon > 85.0%, ash < 12.5%, volatile matter < 1.0%, and its particle size is 0.074 - 2 mm; The dry - quenched coke screen - down material is the coke produced by the dry - quenching process in the coking industry, which cannot be used in the iron and steel industry and cannot produce high - value screen - down materials; The content of each chemical component in the recarburizer screen - down material is fixed carbon > 90.0%, ash < 7.5%, volatile matter < 1.5%, and its particle size is 0.074 - 1.5 mm; The recarburizer screen - down material is the screen - down material sold at a loss because the graphitized recarburizer does not meet the requirements of metallurgical customers. The content of each chemical component in the cyanite tailing sand is Al2O3 > 10.0%, SiO2 > 80.0%, Fe2O3 < 1.0%, K2O + Na2O < 0.5%, and its particle size is 0.074 - 3 mm; the cyanite tailing sand is a low-grade cyanite ore discarded during the cyanite mining process without screening value. The content of each chemical component in the zircon waste is Al2O3 > 50.0%, SiO2 > 45.0%, Fe2O3 < 1.0%, K2O + Na2O < 0.5%, and its particle size is 0.074 - 0.5 mm; the zircon waste is the material discarded during the flotation of zircon sand from the zircon ore, and is used as the raw material for the blast furnace anhydrous taphole clay after screening. The content of each chemical component in the ferrosilicon nitride is Si3N4 ≥ 75%, N ≥ 30%, Fe 11 - 17%, K2O + CaO < 0.5%, and its particle size is 200 mesh.

8. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 1, characterized in that: The 3000-mesh near-spherical Al2O3-Si composite micro-powder is mixed by Al2O3 micro-powder and Si micro-powder according to the weight ratio of 1:9 - 9:1; the properties of the liquid carbonaceous binder are viscosity of 300 Pa·S at 50°C, moisture content < 1%, and the residual carbon value detected at 800°C × 7 min is greater than 30 wt%.

9. The blast furnace anhydrous taphole clay using near-spherical Al2O3-Si composite fine powder as a plasticizer according to claim 8, characterized in that: The Al2O3 micropowder in the 3000-mesh Al2O3-Si composite micropowder is selected from the alumina micropowder that cannot be recycled for ceramic diaphragms in the process of recycling alumina powder from waste lithium battery ceramic diaphragms, and the typical value of its particle size distribution is d (10) = 0.59 μm, d (50) = 1.24 μm, d (90) = 4.36 μm, and the BET is 2.0 m 2 / g; the Si micropowder in the 3000-mesh Al2O3-Si composite micropowder is selected from the elemental silicon micropowder generated during the process of slicing silicon rods or ingots, and the typical value of its particle size distribution is d (10) = 0.51 μm, d (50) = 1.14 μm, d (90) = 5.67 μm, and the BET is 6.1 m 2 / g.

10. A preparation method of a blast furnace anhydrous taphole clay using nearly spherical Al2O3-Si composite fine powder as a plasticizer, characterized in that, The preparation method includes the following steps: 1) Mix Al2O3 micro-powder and Si micro-powder according to the weight ratio of 1:9 - 9:1, and obtain 3000-mesh near-spherical Al2O3-Si composite micro-powder after mixing. 2) Weigh various raw materials according to the mixing ratio of the blast furnace anhydrous taphole clay. 3) Place the weighed additive, the near-spherical Al2O3-Si composite micro-powder, into a spherical mixer for premixing, and the premixing time is 120 - 180 min. 4) Put the weighed various aggregates and the premixed additive ingredients into batching truck A, and the weighed powder materials into batching truck B; then place the raw materials in batching truck A into a mixing and stirring machine for stirring (the stirring time is 10 - 20 min), then add 95% of the total amount of the liquid carbonaceous binder and continue stirring. After stirring for 10 - 15 min, add the raw materials in batching truck B, and then add the remaining 5% of the liquid carbonaceous binder and continue mixing for 10 - 20 min, and take samples to detect the Marsh value. 5) After passing the Marsh value test, obtain qualified mud, and control the temperature of the qualified mud to be 45 - 55°C; convey the obtained qualified mud into an extruder through a belt, extrude the taphole clay with a qualified shape through the extruder, and then carry out packaging to obtain the product, the blast furnace anhydrous taphole clay with the near-spherical Al2O3-Si composite micro-powder as the plasticizer.

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