Fireproof aluminum-magnesium spinel brick material and preparation method thereof

Abstract

The invention relates to the technical field of spinel bricks, in particular to a refractory aluminum-magnesium spinel brick material and a preparation method thereof.The refractory aluminum-magnesium spinel brick material is prepared from, by weight, 35-40 parts of fused magnesite, 20-30 parts of aluminum-magnesium spinel, 10-15 parts of mullite-doped modified external auxiliaries, 7-11 parts of stabilizing materials, 6-10 parts of high-aluminum micro powder and 3-6 parts of external binding agents. According to the aluminum-magnesium spinel brick material disclosed by the invention, the fused magnesia and the aluminum-magnesium spinel are matched with the high-aluminum micro powder, the binding agent is additionally added, and meanwhile, the added mullite-doped modified external additive and the stabilizing material are mutually blended and synergized, so that the strength, the wear resistance and the heat insulation of the obtained aluminum-magnesium spinel brick material are harmoniously improved; and the product has obvious fire-resistant and alkali-resistant erosion stability effects.

Description

Technical Field

[0001] The present invention relates to the technical field of spinel bricks, and particularly to a refractory alumina-magnesia spinel brick material and a preparation method thereof. Background Art

[0002] The cement rotary kiln is an important device in cement production. The lining material in the high-temperature zone of the cement rotary kiln is a key factor to ensure the stable operation of the kiln body in a high-temperature environment. The magnesia-ferrite-alumina spinel material is currently considered the best material to replace magnesia-chrome bricks for the burning zone of the cement rotary kiln.

[0003] The existing spinel brick materials have poor compressive strength performance. At the same time, the wear resistance, heat insulation and heat preservation properties of the products are poor. It is difficult to achieve coordinated improvement of strength, wear resistance, heat insulation and heat preservation for the products. In addition, the fire resistance and alkali erosion stability of the products are poor, which limits the use efficiency of the products. Based on this, the present invention makes further improvements. Summary of the Invention

[0004] Aiming at the defects of the existing technology, the purpose of the present invention is to provide a refractory alumina-magnesia spinel brick material and a preparation method thereof to solve the problems raised in the above background art.

[0005] The present invention adopts the following technical solutions to solve the technical problems: The present invention provides a refractory alumina-magnesia spinel brick material, including the following raw materials in parts by weight: 35-40 parts of fused magnesia, 20-30 parts of alumina-magnesia spinel, 10-15 parts of external additive modified by doped mullite, 7-11 parts of stabilizer, 6-10 parts of high-alumina micro-powder, 3-6 parts of external binder; the preparation method of the external additive modified by doped mullite is as follows: S01, preparation of the modifier for doped mullite; S02, prepare a sodium dodecylbenzenesulfonate solution with a mass fraction of 5-8% and a sodium silicate solution with a mass fraction of 6-9%; Add 3-5 parts by weight of barium zirconate and 2-3 parts by weight of strontium titanate to 5-8 parts by weight of the sodium dodecylbenzenesulfonate solution and stir evenly to obtain an auxiliary adjusting solution; S03, add 2-3 parts by weight of basalt fiber and 1-3 parts by weight of boron nitride to 4-7 parts by weight of the sodium silicate solution and blend evenly to obtain an external additive; Stir the external additive and the auxiliary adjusting solution evenly according to a weight ratio of 3:5 to obtain an external auxiliary functional solution; S04, blend and ball-mill the modifier for doped mullite and the external auxiliary functional solution according to a weight ratio of 5:(2-3), with a ball-milling speed of 1000-1500 r / min and ball-milling for 1-2 h. After the ball-milling is completed, filter and dry to obtain the external additive modified by doped mullite; the preparation method of the stabilizer is as follows: S101: 2-4 parts by weight of titanium oxide, 3-5 parts by weight of wollastonite, and 2-3 parts by weight of volcanic ash are mixed and sintered for 1-2 hours at a sintering temperature of 300-350° C., to obtain a sintered body; 5-8 parts by weight of dopamine hydrochloride solution and 4-7 parts by weight of the sintered body are uniformly blended to obtain a modified solution; S102: preheating the expanded vermiculite at 60-65° C. for 1-2 hours, ultrasonically treating the preheated expanded vermiculite and the modified liquid in a weight ratio of 3:5. After the ultrasonic treatment is completed, washing, filtering, and drying are performed to obtain a stabilized material.

[0006] Preferably, the particle size of the fused magnesia is 0.2-0.5 mm; The mass fraction of aluminum oxide in the aluminum-magnesium spinel is 75-80%, the total mass fraction of aluminum oxide and magnesium oxide is ≥98%, and the particle size of the aluminum-magnesium spinel is 0.05-0.07 mm; The particle size of high-alumina micropowder is 0.4-0.6µm; the added binder is paper pulp.

[0007] The mullite-modified external additive is prepared by mixing and ball-milling the mullite-modified modifier with an external functional liquid. The mullite-modified modifier is mixed and stirred with a mullite sintering agent and a doping liquid. The mullite in the mullite sintering agent is sintered and improved with boron oxide and lanthanum oxide. With mullite as the matrix, the high temperature resistance of the system is enhanced. The coordination of boron oxide and lanthanum oxide fills the system structure, further enhancing the performance coordination and performance stability of the system.

[0008] Preferably, the basalt fiber has a diameter of 10-15 μm and a length of 0.5-0.8 mm.

[0009] Preferably, the specific preparation method of the modifier mixed with mullite is: S01a: adding 3-5 parts by weight of titanium carbide, 4-6 parts by weight of double-walled carbon nanotubes and 1-2 parts by weight of silane coupling agent KH550 to 5-8 parts by weight of 4-6% cerium nitrate solution and blending them evenly to obtain a doping solution; S01b: Mullite, boron oxide and lanthanum oxide are uniformly mixed in a weight ratio of (5-8): (3-4): 2, and then sintered to obtain a mullite sintered mixture. The mullite sintered preparation and the added liquid were mixed and stirred thoroughly in a weight ratio of 3:5, and then filtered and dried to obtain a mullite-added modifier.

[0010] Preferably, the double-walled carbon nanotubes have a diameter of 3-5 nm, a length of 1-2 μm, and a specific surface area of 380-400 μm. 2 / g; the sintering temperature of the sintering treatment is 750-800℃, and the sintering time is 1-2h.

[0011] The double-walled carbon nanotubes in the doping solution are combined with cerium nitrate solution, titanium carbide, and silane coupling agent KH550. Through the coordination and optimization of the raw materials, carbon nanotubes are used as the matrix raw materials to enhance the interfacial effect of the system. The coordination of cerium nitrate solution and titanium carbide can further enhance the synergistic effect between the doping solution and the mullite firing agent. As a result, the modifier for doping mullite not only enhances the interfacial property of the system and improves the interfacial connectivity between the raw materials, but also optimizes the performance coordination and stability of the system. The external auxiliary functional liquid is prepared by combining an admixture with an auxiliary adjusting liquid. The admixture uses sodium silicate solution in combination with basalt fiber and boron nitride raw materials. At the same time, the barium zirconate, strontium titanate, and sodium dodecylbenzenesulfonate solution in the auxiliary adjusting liquid are further coordinated. Through the needle-like structure of barium zirconate and strontium titanate and the flaky structure of boron nitride, the system structure is further strengthened. At the same time, the external auxiliary functional liquid can better coordinate with the modifier for doping mullite. As a result, the external auxiliary agent modified with doping mullite further optimizes the performance coordination and stability of the system in the system.

[0012] Preferably, the mass fraction of the dopamine hydrochloride solution is 4-7%; the ultrasonic power of the ultrasonic treatment is 350-400W, and the ultrasonic treatment is carried out for 1h.

[0013] The stabilizing material is prepared by preheating expanded vermiculite and then subjecting it to ultrasonic treatment with a modified liquid. The modified liquid is prepared by uniformly blending a dopamine hydrochloride solution and a sintered body. The sintered body is further coordinated by titanium oxide, wollastonite, and volcanic ash, and then subjected to sintering improvement treatment. Through the further supplementation of titanium oxide, wollastonite, and volcanic ash into the system, the stabilizing material thus prepared is further coordinated with the external auxiliary agent modified with doping mullite. As a result, the performance of the product is further coordinated and improved, and the stability of the product is further optimized.

[0014] The present invention also provides a method for preparing a refractory alumina-magnesia spinel brick material, comprising the following steps: Weigh the raw materials according to parts by weight, form the raw materials, with a forming pressure of 100-150 MPa and a forming time of 1-2 h, and then carry out sintering treatment. After the sintering is completed, a refractory alumina-magnesia spinel brick material is obtained.

[0015] Preferably, the sintering temperature for the sintering treatment is 1500-1530 °C, and the sintering time is 5-8 h.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The aluminum-magnesium spinel brick material of the present invention uses fused magnesia, aluminum-magnesium spinel, combined with high-alumina micro-powder, an external binder, and at the same time, an externally added auxiliary agent modified by doped mullite and a stabilizer are mutually blended and synergistically effective, so that the strength, wear resistance, and heat preservation and insulation of the obtained aluminum-magnesium spinel brick material are coordinately improved, and the fire resistance and alkali erosion resistance stability effects of the product are remarkable. Detailed implementation manners

[0017] The following combines specific embodiments to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0018] A refractory aluminum-magnesium spinel brick material in this embodiment includes the following raw materials in parts by weight: 35-40 parts of fused magnesia, 20-30 parts of aluminum-magnesium spinel, 10-15 parts of externally added auxiliary agent modified by doped mullite, 7-11 parts of stabilizer, 6-10 parts of high-alumina micro-powder, and 3-6 parts of externally added binder.

[0019] The particle size of the fused magnesia in this embodiment is 0.2-0.5 mm; The mass fraction of alumina in the aluminum-magnesium spinel is 75-80%, the total mass fraction of alumina and magnesia ≥98%, and the particle size of the aluminum-magnesium spinel is 0.05-0.07 mm; The particle size of the high-alumina micro-powder is 0.4-0.6 µm; the externally added binder is pulp.

[0020] The preparation method of the externally added auxiliary agent modified by doped mullite in this embodiment is as follows: S01, preparation of the modifier for doped mullite; S02, preparation of a sodium dodecylbenzenesulfonate solution with a mass fraction of 5-8% and a sodium silicate solution with a mass fraction of 6-9%; 3-5 parts by weight of barium zirconate and 2-3 parts by weight of strontium titanate are added to 5-8 parts by weight of the sodium dodecylbenzenesulfonate solution and stirred evenly to obtain an auxiliary adjustment liquid; S03, adding 2-3 parts by weight of basalt fiber and 1-3 parts by weight of boron nitride to 4-7 parts by weight of the sodium silicate solution and blending evenly to obtain an external additive; The external additive and the auxiliary adjustment liquid are stirred evenly according to a weight ratio of 3:5 to obtain an external auxiliary functional liquid; S04, the modifier for doped mullite and the external auxiliary functional liquid are blended and ball-milled according to a weight ratio of 5:(2-3), the ball-milling speed is 1000-1500 r / min, and the ball-milling is carried out for 1-2 h. After the ball-milling is completed, suction filtration and drying are carried out to obtain the externally added auxiliary agent modified by doped mullite.

[0021] The basalt fiber of this embodiment has a diameter of 10-15 μm and a length of 0.5-0.8 mm.

[0022] The specific preparation method of the modifier mixed with mullite in this embodiment is: S01a: adding 3-5 parts by weight of titanium carbide, 4-6 parts by weight of double-walled carbon nanotubes and 1-2 parts by weight of silane coupling agent KH550 to 5-8 parts by weight of 4-6% cerium nitrate solution and blending them evenly to obtain a doping solution; S01b: Mullite, boron oxide and lanthanum oxide are uniformly mixed in a weight ratio of (5-8): (3-4): 2, and then sintered to obtain a mullite sintered mixture. The mullite sintered preparation and the added liquid were mixed and stirred thoroughly in a weight ratio of 3:5, and then filtered and dried to obtain a mullite-added modifier.

[0023] The double-walled carbon nanotubes of this embodiment have a diameter of 3-5 nm, a length of 1-2 μm, and a specific surface area of 380-400 m 2 / g; the sintering temperature of the sintering treatment is 750-800℃, and the sintering time is 1-2h.

[0024] The preparation method of the stabilizing material of this embodiment is: S101: 2-4 parts by weight of titanium oxide, 3-5 parts by weight of wollastonite, and 2-3 parts by weight of volcanic ash are mixed and sintered for 1-2 hours at a sintering temperature of 300-350° C., to obtain a sintered body; 5-8 parts by weight of dopamine hydrochloride solution and 4-7 parts by weight of the sintered body are uniformly blended to obtain a modified solution; S102: preheating the expanded vermiculite at 60-65° C. for 1-2 hours, ultrasonically treating the preheated expanded vermiculite and the modified liquid in a weight ratio of 3:5. After the ultrasonic treatment is completed, washing, filtering, and drying are performed to obtain a stabilized material.

[0025] The mass fraction of the dopamine hydrochloride solution in this embodiment is 4-7%; the ultrasonic power of the ultrasonic treatment is 350-400W, and the ultrasonic treatment is performed for 1 hour.

[0026] A method for preparing a refractory alumina-magnesia spinel brick material according to this embodiment includes the following steps: The raw materials are weighed according to parts by weight, and the raw materials are molded at a molding pressure of 100-150 MPa for 1-2 hours, and then sintered. After the sintering is completed, a refractory alumina-magnesia spinel brick material is obtained.

[0027] The sintering temperature of the sintering process in this embodiment is 1500-1530° C., and the sintering time is 5-8 hours.

[0028] Example 1.

[0029] A refractory alumina-magnesia spinel brick material of this embodiment includes the following raw materials in parts by weight: 35 parts of fused magnesia, 20 parts of aluminum-magnesium spinel, 10 parts of external additive modified by mullite, 7 parts of stabilizer, 6 parts of high-aluminum micropowder, and 3 parts of external binder.

[0030] The particle size of the fused magnesia in this embodiment is 0.2 mm; The mass fraction of aluminum oxide in the aluminum-magnesium spinel is 75%, the total mass fraction of aluminum oxide and magnesium oxide is ≥98%, and the particle size of the aluminum-magnesium spinel is 0.05 mm; The particle size of high alumina powder is 0.4µm; the added binder is paper pulp.

[0031] The preparation method of the mullite-modified external additive of this embodiment is as follows: S01, preparation of a modifier mixed with mullite; S02, prepare 5% by mass of sodium dodecylbenzenesulfonate solution and 6% by mass of sodium silicate solution; 3 parts by weight of barium zirconate and 2 parts by weight of strontium titanate were added to 5 parts by weight of sodium dodecylbenzenesulfonate solution and stirred to obtain a co-adjusting solution; S03, adding 2 parts by weight of basalt fiber and 1 part by weight of boron nitride to 4 parts by weight of sodium silicate solution and blending them evenly to obtain an admixture; The admixture and the auxiliary liquid are mixed evenly in a weight ratio of 3:5 to obtain an external auxiliary functional liquid; S04, the modifier mixed with mullite and the external functional liquid are mixed and ball-milled in a weight ratio of 5:2, the ball milling speed is 1000 r / min, the ball milling is carried out for 1 hour, and after the ball milling is completed, the mixture is filtered and dried to obtain the external additive modified with mullite.

[0032] The basalt fiber of this embodiment has a diameter of 10 μm and a length of 0.5 mm.

[0033] The specific preparation method of the modifier mixed with mullite in this embodiment is: S01a: 3 parts by weight of titanium carbide, 4 parts of double-walled carbon nanotubes and 1 part by weight of silane coupling agent KH550 are added to 5 parts by weight of a 4% by mass cerium nitrate solution and mixed uniformly to obtain a doping solution; S01b: Mullite, boron oxide and lanthanum oxide are uniformly mixed in a weight ratio of 5:3:2, and then sintered to obtain a mullite sintered mixture. The mullite sintered preparation and the added liquid were mixed and stirred thoroughly in a weight ratio of 3:5, and then filtered and dried to obtain a mullite-added modifier.

[0034] The double-walled carbon nanotubes in this embodiment have a diameter of 3 nm, a length of 1 μm, and a specific surface area of 380 m 2 / g; The sintering temperature for the sintering treatment is 750 °C, and sintering is carried out for 1 h.

[0035] The preparation method of the composite material in this embodiment is as follows: S101: Blend 2 parts by weight of titanium oxide, 3 parts by weight of wollastonite, and 2 parts by weight of volcanic ash and sinter for 1 h. The sintering temperature is 300 °C. After sintering is completed, a sintered body is obtained; Blend 5 parts by weight of hydrochloric acid dopamine solution and 4 parts by weight of the sintered body evenly to obtain a modified liquid; S102: Preheat expanded vermiculite at 60 °C for 1 h. Ultrasonically treat the preheated expanded vermiculite and the modified liquid according to a weight ratio of 3:5. After ultrasonic treatment, wash with water, filter by suction, and dry to obtain the composite material.

[0036] The mass fraction of the hydrochloric acid dopamine solution in this embodiment is 4%; the ultrasonic power for ultrasonic treatment is 350 W, and ultrasonic treatment is carried out for 1 h.

[0037] The preparation method of a refractory alumina-magnesia spinel brick material in this embodiment includes the following steps: Weigh the raw materials according to parts by weight, form the raw materials. The forming pressure is 100 MPa, and forming is carried out for 1 h. Then, carry out sintering treatment. After sintering is completed, a refractory alumina-magnesia spinel brick material is obtained.

[0038] The sintering temperature for the sintering treatment in this embodiment is 1500 °C, and sintering is carried out for 5 h.

[0039] Example 2. A refractory alumina-magnesia spinel brick material in this embodiment includes the following raw materials by weight: 40 parts of fused magnesia, 30 parts of alumina-magnesia spinel, 15 parts of external additive modified by doped mullite, 11 parts of composite material, 10 parts of high-alumina micro-powder, and 6 parts of external binder.

[0040] The particle size of the fused magnesia in this embodiment is 0.5 mm; The mass fraction of alumina in the alumina-magnesia spinel is 80%, the total mass fraction of alumina and magnesia ≥ 98%, and the particle size of the alumina-magnesia spinel is 0.07 mm; The particle size of the high-alumina micro-powder is 0.6 µm; the external binder is pulp.

[0041] The preparation method of the external additive modified by doped mullite in this embodiment is as follows: S01, preparation of the modifier for doped mullite; S02, prepare a sodium dodecylbenzenesulfonate solution with a mass fraction of 8% and a sodium silicate solution with a mass fraction of 9%; Add 5 parts by weight of barium zirconate and 3 parts by weight of strontium titanate to 8 parts by weight of the sodium dodecylbenzenesulfonate solution and stir evenly to obtain an auxiliary adjustment liquid; S03, adding 3 parts by weight of basalt fiber and 3 parts by weight of boron nitride to 7 parts by weight of sodium silicate solution and blending them evenly to obtain an admixture; The admixture and the auxiliary liquid are mixed evenly in a weight ratio of 3:5 to obtain an external auxiliary functional liquid; S04, the modifier mixed with mullite and the external functional liquid are mixed in a weight ratio of 5:3 and ball-milled at a ball milling speed of 1500 r / min for 2 h. After the ball milling is completed, the mixture is filtered and dried to obtain the external additive modified with mullite.

[0042] The basalt fiber of this embodiment has a diameter of 15 μm and a length of 0.8 mm.

[0043] The specific preparation method of the modifier mixed with mullite in this embodiment is: S01a: adding 5 parts by weight of titanium carbide, 6 parts of double-walled carbon nanotubes and 2 parts by weight of silane coupling agent KH550 to 8 parts by weight of 6% cerium nitrate solution and blending them evenly to obtain a doping solution; S01b: Mullite, boron oxide and lanthanum oxide are uniformly mixed in a weight ratio of 8:4:2, and then sintered to obtain a mullite sintered mixture. The mullite sintered preparation and the added liquid were mixed and stirred thoroughly in a weight ratio of 3:5, and then filtered and dried to obtain a mullite-added modifier.

[0044] The double-walled carbon nanotubes in this embodiment have a diameter of 5 nm, a length of 2 μm, and a specific surface area of 400 m 2 / g; the sintering temperature of the sintering treatment is 800℃ and the sintering time is 2h.

[0045] The preparation method of the stabilizing material of this embodiment is: S101: 4 parts by weight of titanium oxide, 5 parts by weight of wollastonite, and 3 parts by weight of volcanic ash are mixed and sintered for 2 hours at a sintering temperature of 350° C., to obtain a sintered body; 8 parts by weight of dopamine hydrochloride solution and 7 parts by weight of the sintered body are uniformly blended to obtain a modified solution; S102: preheating the expanded vermiculite at 65° C. for 2 h, ultrasonically treating the preheated expanded vermiculite and the modified liquid in a weight ratio of 3:5. After the ultrasonic treatment is completed, washing, filtering, and drying are performed to obtain a stabilized material.

[0046] The mass fraction of the dopamine hydrochloride solution in this embodiment is 7%; the ultrasonic treatment power is 400 W, and the ultrasonic treatment is performed for 1 hour.

[0047] A method for preparing a refractory alumina-magnesia spinel brick material according to this embodiment includes the following steps: Weigh the raw materials by weight parts, form the raw materials, with a forming pressure of 150 MPa and a forming time of 2 h, and then perform sintering treatment. After the sintering is completed, a refractory alumina-magnesia spinel brick material is obtained.

[0048] In this example, the sintering temperature for the sintering treatment is 1530 °C and the sintering time is 8 h.

[0049] Example 3. A refractory alumina-magnesia spinel brick material in this example includes the following raw materials by weight parts: 37.5 parts of fused magnesia, 25 parts of alumina-magnesia spinel, 12.5 parts of external additive modified by doped mullite, 9 parts of stabilizer, 8 parts of high-alumina micro-powder, and 4.5 parts of external binder.

[0050] The particle size of the fused magnesia in this example is 0.35 mm; The mass fraction of alumina in the alumina-magnesia spinel is 78.5%, the total mass fraction of alumina and magnesia is ≥98%, and the particle size of the alumina-magnesia spinel is 0.06 mm; The particle size of the high-alumina micro-powder is 0.5 µm; the external binder is pulp.

[0051] The preparation method of the external additive modified by doped mullite in this example is as follows: S01, preparation of the modifier for doped mullite; S02, prepare a sodium dodecylbenzenesulfonate solution with a mass fraction of 6.5% and a sodium silicate solution with a mass fraction of 7.5%; Add 4 parts by weight of barium zirconate and 2.5 parts by weight of strontium titanate to 6.5 parts by weight of the sodium dodecylbenzenesulfonate solution and stir evenly to obtain an auxiliary adjusting solution; S03, add 2.5 parts by weight of basalt fiber and 2 parts by weight of boron nitride to 5.5 parts by weight of the sodium silicate solution and blend evenly to obtain an external additive; Stir the external additive and the auxiliary adjusting solution evenly according to a weight ratio of 3:5 to obtain an external auxiliary functional solution; S04, blend and ball-mill the modifier for doped mullite and the external auxiliary functional solution according to a weight ratio of 5:2.5, with a ball-milling speed of 1250 r / min and a ball-milling time of 1.5 h. After the ball-milling is completed, perform suction filtration and drying to obtain the external additive modified by doped mullite.

[0052] The diameter of the basalt fiber in this example is 12.5 µm and the length is 0.65 mm.

[0053] The specific preparation method of the modifier for doped mullite in this example is as follows: S01a: Add 4 parts by weight of titanium carbide, 5 parts of double-walled carbon nanotubes, and 1.5 parts by weight of silane coupling agent KH550 to 6.5 parts by weight of a 5% cerium nitrate solution and blend evenly to obtain an additive solution; S01b: Blend mullite, boron oxide, and lanthanum oxide evenly according to a weight ratio of 6.5:3.5:2, and then perform sintering treatment. After the sintering is completed, a mullite sintering agent is obtained. Blend the mullite sintering agent and the doping liquid evenly according to a weight ratio of 3:5, stir well, then perform suction filtration and drying to obtain a modifier doped with mullite.

[0054] In this example, the diameter of the double-walled carbon nanotubes is 4 nm, the length is 1.5 μm, and the specific surface area is 390 m 2 / g; the sintering temperature for the sintering treatment is 775 °C, and the sintering is carried out for 1.5 h.

[0055] The preparation method of the binder in this example is as follows: S101: Blend 3 parts by weight of titanium oxide, 4 parts by weight of wollastonite, and 2.5 parts by weight of volcanic ash, and sinter for 2 h at a sintering temperature of 325 °C. After the sintering is completed, a sintered body is obtained. Blend 6.5 parts by weight of hydrochloric acid dopamine solution and 5.5 parts by weight of the sintered body evenly to obtain a modified liquid. S102: Preheat expanded vermiculite at 62.5 °C for 2 h, and ultrasonically treat the preheated expanded vermiculite and the modified liquid according to a weight ratio of 3:5. After the ultrasonic treatment, wash with water, perform suction filtration, and dry to obtain a binder.

[0056] In this example, the mass fraction of the hydrochloric acid dopamine solution is 5.5%; the ultrasonic power for the ultrasonic treatment is 375 W, and the ultrasonic treatment is carried out for 1 h.

[0057] A preparation method of a refractory alumina-magnesia spinel brick material in this example includes the following steps: Weigh the raw materials according to parts by weight, mold the raw materials, with a molding pressure of 125 MPa and a molding time of 1.25 h, and then perform sintering treatment. After the sintering is completed, a refractory alumina-magnesia spinel brick material is obtained.

[0058] In this example, the sintering temperature for the sintering treatment is 1515 °C, and the sintering is carried out for 6.5 h.

[0059] Comparative Example 1. The difference from Example 3 is that the external additive modified with doped mullite is not added.

[0060] Comparative Example 2. The difference from Example 3 is that the modifier doped with mullite is not added in the preparation of the external additive modified with doped mullite.

[0061] Comparative Example 3. The difference from Example 3 is that the external additive functional liquid is not added in the preparation of the external additive modified with doped mullite.

[0062] Comparative Example 4. The difference from Example 3 is that the external additive is not added in the preparation of the external additive functional liquid.

[0063] Comparative Example 5. The difference from Example 3 is that basalt fiber and boron nitride are not added to the admixture.

[0064] Comparative Example 6. The difference from Example 3 is that no auxiliary adjustment liquid is added in the preparation of the external auxiliary functional liquid.

[0065] Comparative Example 7. The difference from Example 3 is that barium zirconate and strontium titanate are not added to the auxiliary adjustment liquid.

[0066] Comparative Example 8. The difference from Example 3 is that no stabilizer is added.

[0067] Comparative Example 9. The difference from Example 3 is that no preheated expanded vermiculite is added to the stabilizing material.

[0068] Comparative Example 10. The difference from Example 3 is that no modifying liquid is added to the stabilizing material.

[0069] Comparative Example 11. The difference from Example 3 is that no sintered body is added to the modifying liquid.

[0070] Comparative Example 12. The difference from Example 3 is that no titanium oxide or wollastonite is added to the sintered body.

[0071] The products of Examples 1-3 and Comparative Examples 1-12 were subjected to conventional performance tests, and fire resistance and alkali corrosion resistance stability were tested (the products were placed under 5% sodium chloride salt spray conditions for 24 hours, and then treated under 120°C fire conditions for 12 hours, the above being one cycle, and the cycle was repeated 10 times);

[0072] From comparative examples 1-12 and example 3, it can be seen that under normal conditions, the compressive strength, thermal insulation and wear resistance of the product of example 3 can be improved in a coordinated manner, with a compressive strength as high as 112 MPa, a thermal conductivity as low as 0.02 W / mk, and a wear resistance as low as 1.8 g / cm 3 , and the product has excellent performance stability under fire resistance and alkali corrosion resistance conditions; The performance of the product showed a significant deterioration trend when no mullite-modified external additives or any of the stabilizers were added to the product. The performance of the product was most significant when the synergistic effect of the two was achieved. The performance of the products tended to deteriorate when no modifier for mullite was added to the preparation of the mullite-modified external additive, no external functional liquid was added to the preparation of the mullite-modified external additive, and no admixture was added to the preparation of the external functional liquid. In addition, when basalt fiber and boron nitride are not added to the admixture, no auxiliary adjustment liquid is added in the preparation of the external auxiliary functional liquid, and barium zirconate and strontium titanate are not added to the auxiliary adjustment liquid, the performance of the product also shows a trend of deterioration to varying degrees. The external auxiliary functional liquid prepared by combining the auxiliary adjustment liquid obtained by the specific process of the present invention and the external auxiliary functional liquid with the admixture, and the mullite-modified external auxiliary prepared by combining the mullite-adjusted modifier, have the most significant performance effects. The effects of other methods are not as obvious as those of the present invention.

[0073] No preheated expanded vermiculite was added to the stabilizing material, no modifying liquid was added to the stabilizing material, no sintered body was added to the modifying liquid, and no titanium oxide and wollastonite were added to the sintered body. The performance of the product also showed a trend of deterioration. The performance effect of the product was most significant when the modifying liquid obtained by combining the specific sintered body of the present invention and the stabilizing material made by combining the modifying liquid with preheated expanded vermiculite were used.

[0074] In addition, the product of the present invention is not treated with a modifier containing mullite, and the performance of the product has an obvious trend of deterioration. In this regard, the present invention further explores and processes it.

[0075] The specific preparation method of the modifier mixed with mullite is as follows: S01a: 4 parts by weight of titanium carbide, 5 parts by weight of double-walled carbon nanotubes, and 1.5 parts by weight of silane coupling agent KH550 were added to 6.5 parts by weight of a 6% cerium nitrate solution and mixed uniformly to obtain a doping solution; S01b: Mullite, boron oxide and lanthanum oxide are uniformly mixed in a weight ratio of 6.5:3.5:2, and then sintered to obtain a mullite sintered mixture. The mullite sintered preparation and the added liquid were mixed and stirred thoroughly in a weight ratio of 3:5, and then filtered and dried to obtain a mullite-added modifier.

[0076] Experimental Example 1. The same as Example 3, except that no doping liquid is added in the preparation of the modifier doped with mullite.

[0077] Experimental Example 2. The same as Example 3, except that titanium carbide and double-walled carbon nanotubes are not added to the doping liquid.

[0078] Experimental Example 3. The same as Example 3, except that the cerium nitrate solution and the silane coupling agent KH550 were not added to the doping solution.

[0079] Experimental Example 4. The same as Example 3, the only difference is that the mullite sintering agent is not added.

[0080] Experimental Example 5. Same as Example 3, except that boron oxide and lanthanum oxide are not added to the mullite burning conditioner.

[0081] The product performance tests of Experimental Examples 1-5 are as follows:

[0082] It can be seen from Experimental Examples 1-5 that in the preparation of the modifier doped with mullite, the mullite burning conditioner is not added, and the product performance deteriorates most significantly among the preparation factors of the modifier doped with mullite. At the same time, when the doping liquid is not added in the preparation of the modifier doped with mullite, the product performance also shows an obvious deterioration trend. In addition, when titanium carbide and double-walled carbon nanotubes are not added to the doping liquid, cerium nitrate solution and silane coupling agent KH550 are not added to the doping liquid, and boron oxide and lanthanum oxide are not added to the mullite burning conditioner, the product performance shows different degrees of deterioration trends. The modifier doped with mullite prepared by combining the doping liquid obtained by the specific method of the present invention with the mullite burning conditioner has the most significant product performance effect, and the effects of using other methods to replace it are not as obvious as that of the present invention.

[0083] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0084] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A refractory alumina-magnesia spinel brick material, characterized in that, It includes the following raw materials in parts by weight: 35-40 parts of fused magnesia, 20-30 parts of aluminum-magnesium spinel, 10-15 parts of external additive modified by mullite, 7-11 parts of stabilizer, 6-10 parts of high-aluminum micropowder, and 3-6 parts of external binder; The preparation method of the mullite-modified external additive is as follows: S01, preparation of a modifier mixed with mullite; S02, prepare 5-8% by mass of sodium dodecylbenzenesulfonate solution and 6-9% by mass of sodium silicate solution; Add 3-5 parts by weight of barium zirconate and 2-3 parts by weight of strontium titanate to 5-8 parts by weight of sodium dodecylbenzenesulfonate solution and stir evenly to obtain a co-adjusting solution; S03, adding 2-3 parts by weight of basalt fiber and 1-3 parts by weight of boron nitride to 4-7 parts by weight of sodium silicate solution and blending them evenly to obtain an admixture; The admixture and the auxiliary liquid are mixed evenly in a weight ratio of 3:5 to obtain an external auxiliary functional liquid; S04, mixing the modifier and the external functional liquid mixed with mullite in a weight ratio of 5:(2-3) and ball milling at a ball milling speed of 1000-1500 r / min for 1-2 hours. After the ball milling is completed, the mixture is filtered and dried to obtain the external additive modified with mullite; The preparation method of the stabilized material is as follows: S101: 2-4 parts by weight of titanium oxide, 3-5 parts by weight of wollastonite, and 2-3 parts by weight of volcanic ash are mixed and sintered for 1-2 hours at a sintering temperature of 300-350° C., to obtain a sintered body; 5-8 parts by weight of dopamine hydrochloride solution and 4-7 parts by weight of the sintered body are uniformly blended to obtain a modified solution; S102: preheating the expanded vermiculite at 60-65° C. for 1-2 hours, ultrasonically treating the preheated expanded vermiculite and the modified liquid in a weight ratio of 3:

5. After the ultrasonic treatment is completed, washing, filtering, and drying are performed to obtain a stabilized material.

2. The refractory alumina-magnesia spinel brick material according to claim 1, wherein, The particle size of the fused magnesia is 0.2-0.5 mm; The mass fraction of aluminum oxide in the aluminum-magnesium spinel is 75-80%, the total mass fraction of aluminum oxide and magnesium oxide is ≥98%, and the particle size of the aluminum-magnesium spinel is 0.05-0.07 mm; The particle size of high-alumina micropowder is 0.4-0.6µm; the added binder is paper pulp.

3. A refractory alumina-magnesia spinel brick material according to claim 1, characterized in that, The basalt fiber has a diameter of 10-15 μm and a length of 0.5-0.8 mm.

4. A refractory alumina-magnesia spinel brick material according to claim 1, characterized in that, The specific preparation method of the modifier mixed with mullite is as follows: S01a: adding 3-5 parts by weight of titanium carbide, 4-6 parts by weight of double-walled carbon nanotubes and 1-2 parts by weight of silane coupling agent KH550 to 5-8 parts by weight of 4-6% cerium nitrate solution and blending them evenly to obtain a doping solution; S01b: Mullite, boron oxide and lanthanum oxide are uniformly mixed in a weight ratio of (5-8): (3-4): 2, and then sintered to obtain a mullite sintered mixture. The mullite sintered preparation and the added liquid were mixed and stirred thoroughly in a weight ratio of 3:5, and then filtered and dried to obtain a modifier mixed with mullite.

5. A refractory alumina-magnesia spinel brick material according to claim 4, characterized in that, The diameter of the double-walled carbon nanotubes is 3 - 5 nm, the length is 1 - 2 μm, and the specific surface area is 380 - 400 m 2 / g; the sintering temperature for the sintering treatment is 750 - 800 °C, and the sintering is carried out for 1 - 2 h.

6. A refractory alumina-magnesia spinel brick material according to claim 1, characterized in that, The mass fraction of the dopamine hydrochloride solution is 4-7%; the ultrasonic power of the ultrasonic treatment is 350-400W, and the ultrasonic treatment is performed for 1 hour.

7. The preparation method of the refractory alumina-magnesia spinel brick material according to any one of claims 1-6, characterized in that, The following steps are involved: Weigh the raw materials by weight parts, form the raw materials, with the forming pressure of 100 - 150 MPa and form for 1 - 2 h, then conduct sintering treatment. After the sintering is completed, refractory alumina-magnesia spinel brick materials are obtained.

8. The preparation method of the refractory alumina-magnesia spinel brick material according to claim 7, characterized in that, The sintering temperature for the sintering treatment is 1500 - 1530 °C and sinter for 5 - 8 h.

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