Method for preparing high-performance steel ladle brick by using waste ASC refractory material

Abstract

The invention discloses a method for preparing a high-performance steel ladle brick by using a waste ASC refractory material, and relates to the technical field of refractory materials. The method comprises the following steps: washing, cleaning and drying a waste ASC material, crushing, screening, carrying out magnetic separation to remove iron, mixing with high bauxite, magnesia, silicon carbide, silicon powder, alumina powder, a whisker reinforcing agent and phosphorus-doped silicon carbide composite powder, carrying out ultrasonic dispersion, adding a composite binder, uniformly stirring in a nitrogen atmosphere, carrying out sealed aging, putting into a mold, compacting, and carrying out vacuum drying to obtain a finished product. Finally, demolding and removing flashes and burrs to obtain a blank; and the blank is fed into a furnace to be sintered, and the high-performance steel ladle brick is obtained after cooling. The mechanical strength, refractoriness, thermal shock resistance and slag corrosion resistance of the steel ladle brick are effectively improved by introducing the whisker reinforcing agent, the phosphorus-doped silicon carbide composite powder and other components. Therefore, the method has a wider application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refractory materials, and particularly relates to a method for preparing high-performance ladle lining bricks by using waste ASC refractory materials. BACKGROUND

[0002] In the steelmaking process, the ladle is a key container for carrying molten steel, and the performance of its lining bricks is directly related to the quality of the molten steel, production efficiency, and production cost. The ladle lining bricks need to withstand the scouring and erosion of high-temperature molten steel and frequent temperature changes, and therefore are required to have high refractoriness, good thermal shock resistance, slag erosion resistance, and mechanical strength. However, the ladle lining bricks on the market still have certain deficiencies in performance. The slag erosion resistance of some lining bricks is poor, and in the molten steel smelting process, the lining bricks are easily eroded by slag, which shortens the service life of the lining bricks, increases the maintenance cost of the ladle, and may affect the quality of the molten steel. At the same time, the production process of some lining bricks is complex, and the cost of raw materials is high, which makes the overall cost of the ladle lining bricks high, limiting the application of the ladle lining bricks.

[0003] At present, in the preparation technology of the ladle lining bricks, there are few methods that can effectively utilize waste Al2O3-SiC-C system refractory materials (referred to as ASC refractory materials). Most of the preparation processes still rely on virgin refractory raw materials. Because the composition and structure of the waste ASC refractory materials are relatively complex, and are eroded and damaged to different degrees in the use process, it is difficult to meet the same performance requirements as the virgin materials when the waste ASC refractory materials are reused. When the waste ASC refractory materials are added to the preparation process of the ladle lining bricks, there may be compatibility problems between the materials, which may cause the strength, thermal shock resistance, and other performances of the lining bricks to decrease. Therefore, a method for effectively utilizing waste ASC refractory materials to prepare ladle lining bricks with excellent mechanical strength, refractoriness, thermal shock resistance, and slag erosion resistance needs to be developed. SUMMARY

[0004] The present application aims to provide a method for preparing high-performance ladle lining bricks by using waste ASC refractory materials, and solve the following technical problems: The existing method for preparing ladle lining bricks by using waste ASC refractory materials still has the problem of poor mechanical strength, refractoriness, thermal shock resistance, and slag erosion resistance of the prepared ladle lining bricks.

[0005] The purpose of the present application can be achieved by the following technical solutions: A method for preparing high-performance ladle lining bricks by using waste ASC refractory materials, comprising the following steps: S1: performing scouring, cleaning, drying, crushing, screening, and magnetic separation to remove iron from the waste ASC materials to obtain waste ASC refractory particles; S2: mix and ultrasonic disperse waste ASC refractory particles, bauxite, magnesia, silicon carbide, silicon powder, alumina powder, whisker reinforcing agent, phosphorus-doped silicon carbide composite powder, then add composite binder and stir for 20-30 min under nitrogen atmosphere, then seal and age for 4-6 h to obtain mixed raw materials; S3: put the mixed raw materials into a mold and compact, then demold and remove burrs to obtain a blank; S4: put the blank into a furnace for sintering treatment, and obtain high-performance ladle lining brick after cooling; The whisker reinforcing agent is a mullite-based composite whisker prepared by first reacting an aluminum-silicon alloy powder at 90-110°C to obtain an alkali solution, then adjusting the pH to 9-10, and then compounding with diatomite at 100°C, and then reacting at 180°C. The phosphorus-doped silicon carbide composite powder is prepared by first mixing silicon carbide powder, composite aluminum dihydrogen phosphate solution, magnesium oxide nano powder, and polyethylene glycol at 300°C under nitrogen atmosphere, then uniformly ball-milling after adding ammonium dihydrogen phosphate, and then high-temperature treatment at 1200-1300°C. The composite binder is prepared from deionized water, composite sol, phenolic resin, polyvinyl alcohol, and anhydrous ethanol.

[0006] Preferably, the mass ratio of the waste ASC refractory particles, bauxite, magnesia, silicon carbide, silicon powder, alumina powder, whisker reinforcing agent, phosphorus-doped silicon carbide composite powder, and composite binder in S2 is 50-70:30-50:5-10:1-3:0.5-1:0.5-1:2-3:3-5:10-20.

[0007] Preferably, the sintering treatment in S4 is: first, under nitrogen atmosphere, heat to 120°C at a rate of 5-8°C / min and keep for 2-3 h, then heat to 180-220°C at a rate of 2-4°C / min and keep for 3-4 h, then heat to 800°C at a rate of 4-5°C / min and keep for 2-2.5 h, and then heat to 1400-1450°C at a rate of 5°C / min and keep for 2-3 h.

[0008] Preferably, the preparation method of the whisker reinforcing agent is as follows: Disperse the aluminum-silicon alloy powder in sodium hydroxide aqueous solution and stir at 90-110°C for 50-60 min, then adjust the pH to 9-10 at 25-35°C, then add diatomite and stir at 100°C for 30-40 min, then react at 180°C for 6-8 h, centrifuge, wash, and dry to obtain the whisker reinforcing agent.

[0009] Preferably, the amount ratio of the aluminum-silicon alloy powder, sodium hydroxide aqueous solution, and diatomite is 10-12 g:200-250 mL:0.5 g. The mass fraction of silicon in the aluminum-silicon alloy powder is 12%; The concentration of the sodium hydroxide aqueous solution is 2-4 mol / L.

[0010] Preferably, the preparation method of the composite sol is as follows: Add aluminum isopropyl alcohol to tetraethyl orthosilicate and stir for 15-20 min under a nitrogen atmosphere, then add 75℃ nitric acid aqueous solution dropwise under a nitrogen atmosphere and stir for 2-3 h at 73-77℃, adjust the pH to 5.5-6.5 after cooling and stir for 10-15 min, then add ammonium metatungstate powder while stirring and ultrasonic dispersion, and finally rotary evaporate at 40℃ under a vacuum degree of -0.095 MPa to 26-30 g to obtain the composite sol.

[0011] Preferably, the mass ratio of the tetraethyl orthosilicate, aluminum isopropyl alcohol, nitric acid aqueous solution, and ammonium metatungstate powder is 5.88:4.12:15-16:0.082; The mass fraction of the nitric acid aqueous solution is 3%.

[0012] Preferably, the preparation method of the phosphorus-doped silicon carbide composite powder is as follows: A1: Add aluminum dihydrogen phosphate to deionized water and stir for 30-50 min at 40-50℃ to obtain an aluminum dihydrogen phosphate solution; A2: Add the aluminum dihydrogen phosphate solution to silicon carbide micro powder at 40℃ while stirring, stir for 20-30 min, then add magnesium oxide nano powder and polyethylene glycol while stirring and stir for 15-20 min, then heat to 300℃ at a rate of 10℃ / min under a nitrogen atmosphere and maintain for 30-40 min, then add ammonium dihydrogen phosphate and ball mill for 30-50 min under a nitrogen atmosphere, then heat to 1200-1300℃ at a rate of 10℃ / min and maintain for 2-3 h, and sieve through an 800 mesh sieve to obtain the phosphorus-doped silicon carbide composite powder.

[0013] Preferably, the mass ratio of the deionized water and aluminum dihydrogen phosphate in A1 is 85-90:15; The mass ratio of the silicon carbide micro powder, aluminum dihydrogen phosphate solution, magnesium oxide nano powder, polyethylene glycol, and ammonium dihydrogen phosphate in A2 is 100:25:10:0.1-0.3:0.5-2.

[0014] Preferably, the preparation method of the composite binder is as follows: Add the composite sol to deionized water and stir for 10-15 min, then add phenolic resin, polyvinyl alcohol, and anhydrous ethanol and stir for 20-30 min to obtain the composite binder; The mass ratio of the deionized water, composite sol, phenolic resin, polyvinyl alcohol, and anhydrous ethanol is 5-8:4-6:3-8:0.5-1:1-2.

[0015] The beneficial effects of the present application are as follows: The application provides a method for preparing high-performance ladle lining bricks from waste ASC refractory materials, which effectively improves the mechanical strength, fire resistance, thermal shock resistance and slag erosion resistance of the ladle lining bricks prepared from waste ASC refractory materials.

[0016] (1) The whisker synergist can fill the matrix voids after uniform dispersion, reduce the porosity, form a dense particle-whisker skeleton, and bear part of the load when stress is transmitted, hinder the compression deformation of the micropores in the matrix, and avoid the structure collapse caused by local stress concentration. When the crack propagates, the whisker synergist will span across both ends of the crack, and the crack will continue to expand by overcoming the interfacial bonding force between the whisker and the matrix or by breaking the whisker, which consumes a large amount of energy; the crack will deflect when it meets the whisker, rather than penetrating straight through, further reducing the crack propagation efficiency and improving the bending strength. The whisker synergist itself has high fire resistance and does not soften or decompose at high temperature, and can be used as a high-temperature skeleton to support the matrix structure; a small amount of silicate glass phase in the matrix softens easily at high temperature, and the whisker can hinder its migration and aggregation, avoid the overall softening caused by local melting, and improve the fire resistance. After the whisker synergist fills the voids, the porosity of the matrix is reduced, the channel for slag infiltration is reduced, and internal erosion is inhibited; the whisker synergist can react with the slag to form a low-viscosity glass phase, which uniformly covers the surface of the matrix and forms a dense isolation layer, thereby hindering the further reaction of the slag and the matrix; the whisker synergist can improve the surface hardness of the matrix and reduce the scouring and abrasion of the lining brick surface by slag flow. The thermal expansion coefficient of the mullite whisker synergist is relatively small compared with the matrix, which reduces the interfacial thermal stress during thermal cycling and reduces the probability of microcrack initiation; the whisker can pin the microcracks generated during thermal cycling to prevent their expansion into macrocracks; at the same time, the slight diffusion of the whisker and the matrix interface at high temperature can heal part of the microcracks, further improving the thermal shock resistance.

[0017] (2) The composite sol can uniformly fill the gaps of waste ASC particles, high alumina bauxite and other aggregates, reduce the porosity of the blank, and form a dense structure; during high-temperature sintering, the silicon-aluminum components in the sol react with the surface of the aggregate to form a continuous silicate ceramic bonding layer, replacing the traditional loose physical bonding and improving the load transfer efficiency between particles; the tungstate in the sol can be converted into tungsten oxide nanoparticles at high temperature, which are uniformly dispersed in the matrix, hindering crystal slip and further improving the compression load bearing capacity; the ceramic bonding layer formed by the composite sol has a certain toughness, which can effectively hinder the initiation and propagation of cracks when the blank is subjected to bending force, avoiding fracture caused by stress concentration; the silicon-aluminum-tungsten composite phase forms a bridging structure at the particle interface, tightly connecting the dispersed aggregate particles and improving the overall flexural toughness and reducing the risk of brittle fracture; the fluidity of the composite sol can fill the micro-cracks and defects in the mixed raw materials, reduce the influence of stress weak points during the flexural process, make the strength more stable, and further improve the flexural strength; after the composite sol fills the pores, the channels for slag to penetrate into the matrix are reduced, the internal erosion probability is reduced, and only slight surface erosion occurs; at high temperature, the tungstate in the sol can react with low-melting-point components such as FeO and MnO in the slag to generate high-melting-point tungstate, forming a dense protective layer on the surface of the blank and hindering the further reaction of the slag and the matrix; the silicon-aluminum-tungsten composite phase has strong chemical inertness and is not easy to chemically react with the ladle slag, reducing the risk of matrix erosion and dissolution. The ceramic bonding layer formed by the composite sol has a low thermal expansion coefficient and a high matching degree with the matrix, which can reduce the interfacial thermal stress caused by the difference in thermal expansion during the thermal cycle; the amorphous silicate in the composite phase occurs viscous flow at high temperature, which can heal the small cracks caused by thermal shock and avoid the strength decrease caused by crack accumulation; the silicon-aluminum-tungsten composite phase has rigidity and a certain toughness, can absorb part of the energy during the thermal cycle, reduce the risk of brittle fracture, and further improve the overall thermal shock stability.

[0018] (3) The silicon carbide in the phosphorus-doped silicon carbide composite powder is a high-hardness and high-modulus phase, and the silicon carbide micropowder in the composite powder is uniformly dispersed in the matrix to form a skeleton support, effectively bearing external pressure and reducing plastic deformation of the matrix; during preparation of the composite powder, the phosphate generated by decomposition of aluminum dihydrogen phosphate and ammonium dihydrogen phosphate forms a low-viscosity glass phase during sintering, filling the intergranular gaps, reducing the porosity of the blank, and improving the structural compactness; phosphorus doping forms a hydroxyl layer on the surface of the silicon carbide, and the hydroxyl layer reacts with aluminum oxide and magnesium oxide in the matrix to generate stable bonding phases such as magnesium phosphate and aluminum phosphate, reducing intergranular interface cracks and improving load transfer efficiency; the silicon carbide particles have high hardness and strong wear resistance, and when microcracks occur in the matrix, the silicon carbide particles can block the crack propagation path, or make the crack deflect and branch, and consume the fracture energy; the nanometer magnesium oxide in the composite powder refines the matrix grains and reduces grain boundary defects; the carbon network formed by the residual carbon of polyethylene glycol at high temperature cooperates with the silicon carbide particles to improve the toughness of the matrix; the silicon carbide particles and the matrix form a soft-hard alternating microstructure, which can disperse stress concentration when subjected to bending load, and avoid brittle fracture caused by local overload. The silicon carbide has excellent chemical inertness to the ladle slag, and after uniform distribution of the composite powder, a silicon carbide protective layer can be formed on the surface of the matrix to block the chemical reaction between the slag and the matrix; the phosphate glass phase flows viscously at high temperature, and can heal the small pores and cracks in the matrix, reducing the penetration path of the slag; the densified structure further reduces the depth of slag penetration; the dense silicon dioxide-phosphorus pentoxide composite film formed on the surface of the silicon carbide by phosphorus doping can neutralize low-melting-point components such as FeO and MnO in the slag, and inhibit the chain reaction of slag corrosion-permeation-spalling. The thermal expansion coefficient of the silicon carbide is slightly lower than the average thermal expansion coefficient of the matrix, and during thermal cycling, the low-expansion property of the silicon carbide can buffer the thermal expansion and contraction stress of the matrix, reducing crack initiation; phosphorus doping improves the interfacial bonding state of the silicon carbide and the matrix, reducing thermal stress concentration caused by the difference in interfacial thermal expansion coefficient; the fine crystal phase generated by the reaction of nanometer magnesium oxide and phosphate further improves the thermal stability of the interface; during high-temperature thermal shock cycling, the phosphate glass phase can flow viscously again to heal the small cracks generated during thermal cycling; the rigid support of the silicon carbide particles can prevent the cracks from further expanding into macroscopic cracks.

[0019] Of course, it is not necessary for any product embodying the present application to achieve all of the above advantages. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. The embodiments described below are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0021] Example 1: A method for preparing high-performance ladle lining bricks using waste ASC refractory materials is as follows: S1: 10 g of aluminum-silicon alloy powder with a silicon mass fraction of 12% was dispersed in 200 mL of a 2 mol / L sodium hydroxide aqueous solution and heated to 90°C for stirring for 50 min, then the pH was adjusted to 9 with 10% ammonia water at 25°C, then 0.5 g of diatomite was added and stirred at 100°C for 30 min, then reacted in a high-pressure reaction kettle at 180°C for 6 h, centrifuged and washed with deionized water for 3 times, and then vacuum dried at 80°C for 6 h to obtain a whisker reinforcing agent; S2: 4.12 g of aluminum isopropoxide was added to 5.88 g of tetraethyl orthosilicate and stirred for 15 min under a nitrogen atmosphere, then 15 g of 3% nitric acid solution at 75°C was added dropwise under a nitrogen atmosphere and stirred at 73°C for 2 h, then cooled and adjusted to pH 5.5 with 10% ammonia water and stirred for 10 min, then 0.082 g of ammonium metatungstate powder was added while stirring and ultrasonic dispersed for 10 min, and finally rotary evaporated to 26 g at 40°C and a vacuum degree of -0.095 MPa to obtain a composite sol; S3: 15 g of aluminum dihydrogen phosphate was added to 85 g of deionized water and stirred at 40°C for 30 min to obtain an aluminum dihydrogen phosphate solution; S4: 25 g of the aluminum dihydrogen phosphate solution was added dropwise to 100 g of silicon carbide powder with an average particle size of 20 μm at 40°C at a rate of 5 mL / min while stirring, stirred for 20 min, then 10 g of magnesium oxide nano-powder, 0.1 g of polyethylene glycol were added while stirring, and stirred for 15 min, then heated to 300°C at a rate of 10°C / min under a nitrogen atmosphere and held for 30 min, then 0.5 g of ammonium dihydrogen phosphate was added and ball-milled under a nitrogen atmosphere for 30 min, and finally heated to 1200°C at a rate of 10°C / min and held for 2 h, and then sieved through an 800 mesh sieve to obtain phosphorus-doped silicon carbide composite powder; S5: 4 g of the composite sol was added to 5 g of deionized water and stirred for 10 min, then 3 g of phenolic resin, 0.5 g of polyvinyl alcohol, and 1 g of anhydrous ethanol were added and stirred for 20 min to obtain a composite binder; S6: The waste ASC material was subjected to high-pressure water flow scouring at 1.5 MPa, ultrasonic cleaning for 30 min, then dried at 105°C for 4 h, then crushed, sieved, and then subjected to magnetic separation to remove iron at a magnetic field strength of 1000 Gs to obtain waste ASC refractory particles with a particle size of 0.1-5 mm; S7: 50 g of waste ASC refractory particles, 30 g of high alumina bauxite, 5 g of magnesia, 1 g of silicon carbide, 0.5 g of silicon powder, 0.5 g of alumina powder, 2 g of whisker reinforcing agent, 3 g of phosphorus-doped silicon carbide composite powder were mixed and ultrasonically dispersed for 20 min, then 10 g of composite binder was added and stirred for 20 min under a nitrogen atmosphere, and then sealed and aged for 4 h to obtain a mixed raw material; S8: The mixed raw material was placed in a mold, then pressed at 220 MPa for 50 s, then demolded and deburred to obtain a blank; S9: The blank was sent into a furnace, first heated to 120°C at 5°C / min and kept for 2 h under a nitrogen atmosphere, then heated to 180°C at 2°C / min and sintered for 3 h, then heated to 800°C at 4°C / min and kept for 2 h, then heated to 1400°C at 5°C / min and kept for 2 h, and then cooled in the furnace to obtain a high-performance ladle lining brick.

[0022] Example 2: A method for preparing a high-performance ladle lining brick using waste ASC refractory material is as follows: S1: 11 g of aluminum-silicon alloy powder with a silicon mass fraction of 12% was dispersed in 225 mL of a 3 mol / L sodium hydroxide aqueous solution and heated to 100°C and stirred for 55 min, then the pH was adjusted to 9.5 with 10% ammonia water at 30°C, then 0.5 g of diatomite was added and stirred at 100°C for 35 min, then reacted in a high-pressure reaction kettle at 180°C for 7 h, centrifuged and washed with deionized water 4 times, and then vacuum dried at 80°C for 7 h to obtain a whisker reinforcing agent; S2: 4.12 g of aluminum isopropoxide was added to 5.88 g of tetraethyl orthosilicate and stirred under a nitrogen atmosphere for 18 min, then 15.5 g of 3% mass fraction 75°C nitric acid solution was added dropwise under a nitrogen atmosphere and stirred at 75°C for 2.5 h, then cooled and adjusted to pH 6 with 10% ammonia water and stirred for 13 min, then 0.082 g of ammonium metatungstate powder was added while stirring and ultrasonically dispersed for 15 min, and finally rotary evaporated to 28 g at 40°C and a vacuum degree of -0.095 MPa to obtain a composite sol; S3: 15 g of aluminum dihydrogen phosphate was added to 87 g of deionized water and stirred at 45°C for 40 min to obtain an aluminum dihydrogen phosphate solution; S4: While stirring, 25 g of aluminum dihydrogen phosphate solution was added dropwise into 100 g of silicon carbide micropowder with an average particle size of 20 μm at 40 °C at a rate of 5 mL / min, and after stirring for 25 min, 10 g of magnesium oxide nanometer powder, 0.2 g of polyethylene glycol were added while stirring and stirred for 18 min, then heated to 300 °C at a rate of 10 °C / min under a nitrogen atmosphere and kept for 35 min, then 1.2 g of ammonium dihydrogen phosphate was added and ball milled for 40 min under a nitrogen atmosphere, and finally heated to 1250 °C at a rate of 10 °C / min and kept for 2.5 h, and then sieved through an 800 mesh sieve to obtain phosphorus-doped silicon carbide composite powder; S5: 5 g of composite sol was added to 6.5 g of deionized water and stirred for 13 min, then 5.5 g of phenolic resin, 0.8 g of polyvinyl alcohol, and 1.5 g of anhydrous ethanol were added and stirred for 25 min to obtain a composite binder; S6: The waste ASC material was subjected to high-pressure water flow scouring at 1.8 MPa, ultrasonic cleaning for 40 min, then dried at 110 °C for 5 h, then crushed, sieved, and then subjected to magnetic separation to remove iron at a magnetic field strength of 1300 Gs to obtain waste ASC refractory particles with a particle size of 0.1-5 mm; S7: 60 g of waste ASC refractory particles, 40 g of high alumina bauxite, 8 g of magnesia, 2 g of silicon carbide, 0.8 g of silicon powder, 0.8 g of alumina powder, 2.5 g of whisker reinforcing agent, and 4 g of phosphorus-doped silicon carbide composite powder were mixed and ultrasonically dispersed for 25 min, then 15 g of composite binder was added and stirred under a nitrogen atmosphere for 25 min, then sealed and aged for 5 h to obtain a mixed raw material; S8: The mixed raw material was placed in a mold, then pressed at 260 MPa for 70 s, then demolded and the flash and burrs were removed to obtain a blank; S9: The blank was sent into a furnace, first heated to 120 °C at a rate of 6 °C / min and kept for 2.5 h under a nitrogen atmosphere, then heated to 200 °C at a rate of 3 °C / min and kept for sintering for 3.5 h, then heated to 800 °C at a rate of 4.5 °C / min and kept for 2.2 h, then heated to 1430 °C at a rate of 5 °C / min and kept for 2.5 h, and then cooled in the furnace to obtain a high-performance ladle lining brick.

[0023] Example 3: A method for preparing a high-performance ladle lining brick using waste ASC refractory material is as follows: S1: 12 g of aluminum-silicon alloy powder with a silicon mass fraction of 12% was dispersed in 250 mL of a 4 mol / L sodium hydroxide aqueous solution and heated to 110 °C and stirred for 60 min, then the pH was adjusted to 10 with 10% ammonia water at 35 °C, then 0.5 g of diatomite was added and stirred at 100 °C for 40 min, then reacted in a high-pressure reaction kettle at 180 °C for 8 h, centrifuged and washed with deionized water for 5 times, then vacuum dried at 80 °C for 8 h to obtain a whisker reinforcing agent; S2: 4.12 g aluminum isopropoxide was added into 5.88 g tetraethyl orthosilicate and stirred for 20 min under nitrogen atmosphere, then 16 g 3% by mass 75 ℃ nitric acid solution was added dropwise under nitrogen atmosphere and stirred for 3 h at 77 ℃, after cooling, the pH was adjusted to 6.5 with 10% by mass ammonia water and stirred for 15 min, then 0.082 g ammonium metatungstate powder was added while stirring and ultrasonic dispersed for 20 min, finally, rotary evaporation was performed at 40 ℃ and a vacuum degree of -0.095 MPa to 30 g, to obtain a composite sol; S3: 15 g aluminum dihydrogen phosphate was added into 90 g deionized water and stirred for 50 min at 50 ℃, to obtain an aluminum dihydrogen phosphate solution; S4: 25 g aluminum dihydrogen phosphate solution was added dropwise into 100 g silicon carbide micropowder with an average particle size of 20 μm at 5 mL / min while stirring at 40 ℃, after stirring for 30 min, 10 g magnesium oxide nano-powder, 0.3 g polyethylene glycol were added while stirring, and stirred for 20 min, then heated to 300 ℃ at a rate of 10 ℃ / min under nitrogen atmosphere and kept for 40 min, then 2 g ammonium dihydrogen phosphate was added and ball-milled for 50 min under nitrogen atmosphere, finally, heated to 1300 ℃ at a rate of 10 ℃ / min and kept for 3 h, and sieved through an 800-mesh screen, to obtain phosphorus-doped silicon carbide composite powder; S5: 6 g composite sol was added into 8 g deionized water and stirred for 15 min, then 8 g phenolic resin, 1 g polyvinyl alcohol, 2 g anhydrous ethanol were added and stirred for 30 min, to obtain a composite binder; S6: the waste ASC material was subjected to high-pressure water flow scouring at 2.0 MPa, ultrasonic cleaning for 50 min, then dried at 115 ℃ for 6 h, then broken, sieved, and subjected to magnetic separation for iron removal at a magnetic field strength of 1500 Gs, to obtain waste ASC refractory particles with a particle size of 0.1-5 mm; S7: 70 g waste ASC refractory particles, 50 g bauxite, 10 g magnesia, 3 g silicon carbide, 1 g silicon powder, 1 g alumina powder, 3 g whisker reinforcing agent, and 5 g phosphorus-doped silicon carbide composite powder were mixed and ultrasonic dispersed for 30 min, then 20 g composite binder was added and stirred for 30 min under nitrogen atmosphere, and then sealed and aged for 6 h, to obtain a mixed raw material; S8: the mixed raw material was placed into a mold, then pressed at 300 MPa for 90 s, then demolded and the flash and burrs were removed, to obtain a green body; S9: the green body was put into a furnace, first heated to 120 ℃ at a rate of 8 ℃ / min and kept for 3 h under nitrogen atmosphere, then heated to 220 ℃ at a rate of 4 ℃ / min and kept for sintering for 4 h, then heated to 800 ℃ at a rate of 5 ℃ / min and kept for 2.5 h, then heated to 1450 ℃ at a rate of 5 ℃ / min and kept for 3 h, and then cooled in the furnace, to obtain a high-performance ladle lining brick.

[0024] Comparative Example 1: The comparative example is compared with example 1 only without adding "whisker reinforcing agent" in the preparation process of S7, and the rest of the steps and parameters are the same. The comparative example will not be repeated, and finally the high-performance ladle lining brick is obtained.

[0025] Comparative Example 2: The comparative example is compared with example 1 only without adding "composite sol" in the preparation process of S7, and the rest of the steps and parameters are the same. The comparative example will not be repeated, and finally the high-performance ladle lining brick is obtained.

[0026] Comparative Example 3: The comparative example is compared with example 1 only without adding "phosphorus-doped silicon carbide composite powder" in the preparation process of S5, and the rest of the steps and parameters are the same. The comparative example will not be repeated, and finally the high-performance ladle lining brick is obtained.

[0027] Performance test: Determination of compressive strength: According to GB / T 5072-2008 standard, the strength (MPa) of the 40mm×40mm×40mm sample when it is destroyed is determined at a pressure rate of 0.5MPa / s. The compressive strength (MPa) of the high-performance ladle lining brick prepared by example 1- example 3 and comparative example 1- comparative example 3 of the application is determined by the above method, and the test results are shown in table 1; Determination of flexural strength: According to GB / T 3001-2017 standard, the strength (MPa) of the 125mm×40mm×40mm sample when it is destroyed is determined at a pressure rate of 0.5MPa / s and a span of 100mm. The flexural strength (MPa) of the high-performance ladle lining brick prepared by example 1- example 3 and comparative example 1- comparative example 3 of the application is determined by the above method, and the test results are shown in table 1; Determination of refractoriness: According to GB / T 7322-2017 standard, the refractoriness (℃) of the high-performance ladle lining brick prepared by example 1- example 3 and comparative example 1- comparative example 3 of the application is determined at a heating rate of 2.5℃ / min, and the test results are shown in table 1; Determination of corrosion resistance: According to GB / T 8931-2007 standard, the static crucible method is used to determine the corrosion area percentage (%) of the crucible-shaped sample after being kept at 1600℃ for 6h. The corrosion resistance (%) of the high-performance ladle lining brick prepared by example 1- example 3 and comparative example 1- comparative example 3 of the application is determined by the above method, and the test results are shown in table 1; Determination of thermal shock resistance: According to GB / T 3087-2016 standard, the compressive strength retention rate (%) after 150 cycles was determined, with 1100℃ for 30min and then room temperature air cooling for 30min as one cycle. The thermal shock resistance (%) of the high-performance ladle lining bricks prepared by the above method was determined, and the test results of examples 1-3 and comparative examples 1-3 are shown in table 1 Table 1: Performance test results of examples 1-3 and comparative examples 1-3 Item Compressive strength / MPa Flexural strength / MPa Fire resistance / °C Erosion resistance / % Thermal shock resistance / % Example 1 110.7 23.2 1841 6.1 90.2 Example 2 111.2 23.6 1847 5.7 90.5 Example 3 110.9 23.5 1844 5.9 90.2 Comparative Example 1 84.7 14.8 1829 10.6 71.1 Comparative Example 2 85.2 16.3 1836 11.0 78.7 Comparative Example 3 88.9 19.0 1835 11.5 76.8 Data analysis: As can be seen from table 1, the low-temperature-resistant food packaging composite bag prepared by the examples of the present application has excellent compressive strength, folding strength, fire resistance, corrosion resistance and thermal shock resistance.

[0028] The above describes one embodiment of the present application in detail, but the content described is only the preferred embodiment of the present application, and cannot be considered as limiting the scope of the present application. Any equivalent changes and improvements made within the scope of the present application should still belong to the patent scope of the present application.

Claims

1. A method for preparing high-performance steel ladle lining bricks using waste ASC refractory materials, characterized in that, Includes the following steps: S1: The waste ASC material is washed, dried, crushed, screened, and magnetically separated to remove iron, resulting in waste ASC refractory granules. S2: Mix waste ASC refractory granules, high-alumina bauxite, magnesia, silicon carbide, silicon powder, alumina powder, whisker reinforcement, and phosphorus-doped silicon carbide composite powder and ultrasonically disperse them. Then add composite binder and stir for 20-30 minutes under nitrogen atmosphere. Then seal and age for 4-6 hours to obtain mixed raw materials. S3: Place the mixed raw materials into the mold and compact them, then demold and remove the flash and burrs to obtain the blank; S4: The billet is sent into the furnace for sintering and then cooled to obtain high-performance ladle lining bricks. The whisker reinforcement is a mullite-based composite whisker prepared by using aluminum-silicon alloy powder as the aluminum-silicon source, undergoing alkaline hydrolysis at 90-110℃, adjusting the pH to 9-10, first combining it with diatomaceous earth at 100℃, and then reacting it at 180℃. The phosphorus-doped silicon carbide composite powder is prepared by first heating silicon carbide micro powder, composite aluminum dihydrogen phosphate solution, magnesium oxide nanopowder and polyethylene glycol at 300℃ in a nitrogen atmosphere, then adding ammonium dihydrogen phosphate and ball milling evenly, and then treating at a high temperature of 1200-1300℃. The composite adhesive is prepared from deionized water, composite sol, phenolic resin, polyvinyl alcohol, and anhydrous ethanol.

2. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 1, characterized in that, The mass ratio of the waste ASC refractory granules, high-alumina bauxite, magnesia, silicon carbide, silicon powder, alumina powder, whisker reinforcement, phosphorus-doped silicon carbide composite powder, and composite binder in S2 is 50-70:30-50:5-10:1-3:0.5-1:0.5-1:2-3:3-5:10-20.

3. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 1, characterized in that, The sintering process described in S4 is as follows: under a nitrogen atmosphere, first heat the temperature to 120℃ at 5-8℃ / min and hold for 2-3 hours, then heat the temperature to 180-220℃ at 2-4℃ / min and hold for sintering for 3-4 hours, then heat the temperature to 800℃ at 4-5℃ / min and hold for 2-2.5 hours, and finally heat the temperature to 1400-1450℃ at 5℃ / min and hold for 2-3 hours.

4. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 1, characterized in that, The preparation method of the whisker reinforcing agent is as follows: Aluminum-silicon alloy powder is dispersed in an aqueous sodium hydroxide solution and stirred at 90-110℃ for 50-60 min. Then, the pH is adjusted to 9-10 at 25-35℃. Diatomaceous earth is then added and stirred at 100℃ for 30-40 min. The mixture is then reacted at 180℃ for 6-8 h. After centrifugation, washing, and drying, whisker reinforcing agent is obtained.

5. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 4, characterized in that, The ratio of aluminum-silicon alloy powder, sodium hydroxide aqueous solution, and diatomaceous earth is 10-12g: 200-250mL: 0.5g; The mass fraction of silicon in the aluminum-silicon alloy powder is 12%. The concentration of the sodium hydroxide aqueous solution is 2-4 mol / L.

6. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 1, characterized in that, The preparation method of the composite sol is as follows: Aluminum isopropoxide was added to tetraethyl orthosilicate and stirred for 15-20 min under a nitrogen atmosphere. Then, nitric acid aqueous solution at 75°C was added dropwise under a nitrogen atmosphere and stirred at 73-77°C for 2-3 h. After cooling, the pH was adjusted to 5.5-6.5 and stirred for 10-15 min. Then, ammonium metatungstate powder was added and ultrasonically dispersed. Finally, rotary evaporation was performed to obtain the composite sol.

7. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 6, characterized in that, The mass ratio of tetraethyl orthosilicate, aluminum isopropoxide, aqueous nitric acid solution, and ammonium metatungstate powder is 5.88:4.12:15-16:0.

082. The mass fraction of the nitric acid aqueous solution is 3%.

8. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 1, characterized in that, The preparation method of the phosphorus-doped silicon carbide composite powder is as follows: A1: Add aluminum dihydrogen phosphate to deionized water and stir at 40-50℃ to obtain an aluminum dihydrogen phosphate solution; A2: Add aluminum dihydrogen phosphate solution dropwise to silicon carbide micro powder at 40℃, stir for 20-30 min, then add magnesium oxide nanoparticles and polyethylene glycol and stir for 15-20 min. Then, heat to 300℃ under a nitrogen atmosphere and hold for 30-40 min. Next, add ammonium dihydrogen phosphate and ball mill under a nitrogen atmosphere for 30-50 min. Finally, heat to 1200-1300℃ and hold for 2-3 h. After sieving, obtain phosphorus-doped silicon carbide composite powder.

9. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 8, characterized in that, The mass ratio of deionized water to aluminum dihydrogen phosphate in A1 is 85-90:15; The mass ratio of silicon carbide micro powder, aluminum dihydrogen phosphate solution, magnesium oxide nanopowder, polyethylene glycol, and ammonium dihydrogen phosphate in A2 is 100:25:10:0.1-0.3:0.5-2.

10. The method for preparing high-performance steel ladle lining bricks using waste ASC refractory material according to claim 1, characterized in that, The composite adhesive is prepared as follows: Add the composite sol to deionized water and stir for 10-15 minutes. Then add phenolic resin, polyvinyl alcohol, and anhydrous ethanol and stir for 20-30 minutes to obtain the composite adhesive. The mass ratio of the deionized water, composite sol, phenolic resin, polyvinyl alcohol, and anhydrous ethanol is 5-8:4-6:3-8:0.5-1:1-2.