High-temperature high-strength ceramic wear-resistant castable and preparation method and construction method thereof

Abstract

The application belongs to the technical field of refractory materials, and discloses a high-temperature and high-strength ceramic wear-resistant castable and a preparation method and construction method thereof.The high-temperature and high-strength ceramic wear-resistant castable comprises the following raw materials in percentage by mass: 14-22% of mullite with a particle size of 8-5 mm, 16-24% of mullite with a particle size of 5-3 mm, 13-18% of brown corundum with a particle size of 3-1 mm, 12-19% of brown corundum with a particle size of 1-0.074 mm, 16-25% of brown corundum with a particle size of less than 0.074 mm, 3-7% of active alumina powder, 4-7% of submicron SiO2 powder, 0.3-0.6% of pure calcium aluminate cement, 1-1.5% of rare earth modified titanium-aluminum alloy fibers, 0.05-0.15% of a water reducing agent, 0.03-0.1% of an anti-explosion fiber and 3.5-4.5% of water.The submicron SiO2 powder is used as a binder to give the castable a certain normal-temperature strength, and the active alumina powder is combined to provide high-temperature strength; the brown corundum and sintered mullite are used as aggregates, and the rare earth modified titanium-aluminum steel fiber is combined to give the castable high-temperature and high-strength wear-resistant performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of refractory materials, and particularly relates to a high-temperature high-strength ceramic wear-resistant castable and a preparation method and construction method thereof. BACKGROUND

[0002] In the high-temperature industry, mechanical impact, wear and tear, and thermal stress damage are common forms of damage to the lining materials in industrial furnaces, and huge economic losses are caused by maintenance due to wear and tear every year. Industrial furnaces such as hot blast stove three-way junction, slag flushing channel, granulation tower, cyclone dust collector, flue, sintering air tank, coke oven bracket column, etc. The traditional lining material of this kind adopts various high-chromium and high-manganese alloy lining plates. The wear-resistant material using alloy lining plate has good wear resistance, impact resistance, easy processing and other advantages, but its acid and alkali corrosion resistance, volume stability, high temperature resistance and other properties have a large gap with non-metallic materials.

[0003] The wear-resistant material uses inorganic non-metallic material instead of metal material, which has obvious advantages. The service cycle of the whole cast wear-resistant castable is 3-5 times that of the alloy wear-resistant lining plate, although the cost per meter of the two materials is equivalent, but the wear-resistant castable has a longer service cycle and less material usage, and the comprehensive cost can be reduced by 50-70%. And in the later stage of service, only the cast or daubing of the bottom of the wear-resistant lining is needed for quick repair and maintenance, the material usage is small, and the cost is very low, while the wear-resistant alloy lining plate needs to be replaced as a whole, the construction period and cost will be higher; the whole wear-resistant castable is casted on the wear-resistant parts of the industrial furnace, which has short construction period, low construction difficulty, long service cycle, low maintenance cost, can save a lot of resources, reduce cost and increase efficiency, and is energy-saving and environment-friendly.

[0004] The traditional high-strength wear-resistant castable adopts pure calcium aluminate cement combination. Due to the existence of CaO in the cement, Al2O3 and SiO2 in the aggregate are easy to form low-melting substances such as calcium melilite at high temperature, which seriously affects the high-temperature performance of the material, and greatly reduces the overall wear resistance of the material at high temperature. At the same time, the pure calcium aluminate cement combined wear-resistant castable also has the risk of long baking time and easy cracking. Therefore, it is necessary to develop a new type of high-temperature high-strength wear-resistant castable without cement combination. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a high-temperature high-strength ceramic wear-resistant castable and a preparation method and construction method thereof to solve the problems existing in the prior art. Submicron SiO2 powder is used as a binder to give the castable certain room temperature strength, and active alumina powder is used to provide high-temperature strength. Brown corundum and sintered mullite are used as aggregate, and rare earth modified titanium-aluminum steel fiber is used to give the castable high-temperature high-strength wear-resistant performance.

[0006] To solve the technical problems proposed in the present application, the present application provides a high-temperature high-strength ceramic wear-resistant castable, comprising the following raw materials in mass percentage: mullite with particle size of 8-5mm 14-22%, mullite with particle size of 5-3mm 16-24%, brown corundum with particle size of 3-1mm 13-18%, brown corundum with particle size of 1-0.074mm 12-19%, brown corundum with particle size of ≤0.074mm 16-25%, active alumina powder 3-7%, submicron SiO2 powder 4-7%, pure calcium aluminate cement 0.3-0.6%, and additionally 1-1.5% of the total mass of the above-mentioned raw materials of rare earth modified titanium-aluminum alloy fiber, 0.05-0.15% of water reducing agent, 0.03-0.1% of explosion-proof fiber and 3.5-4.5% of water.

[0007] In the above scheme, the mullite is mullite M60, the Al2O3 content is 59.5-61.5wt%, the SiO2 content is 31.3-33.7wt%, the Fe2O3 content is 0.5-1.5wt%, and the water absorption is ≤0.5%.

[0008] In the above scheme, the brown corundum has the Al2O3 content of 94.5-95.5wt%, the SiO2 content of 0.5-0.8wt%, the Fe2O3 content of 0.01-0.03wt%, the CaO content of 0.2-0.3wt%, the C content of 0.05-0.12wt%, the S content of 0.05-0.08wt%, and the bulk density ≥3.85g / cm 3 .

[0009] In the above scheme, the active alumina powder has the Al2O3 content >99.5wt%, the median particle size D 50 is 1.5-1.8μm.

[0010] In the above scheme, the submicron SiO2 powder is obtained by mixing silicon tetrachloride and oxygen with the molar ratio of 1:(6-7), then combusting at 2400-2450℃ for 2-3h, and cooling and solidifying.

[0011] In the above scheme, the submicron SiO2 powder is spherical amorphous silicon powder, the particle size has a unimodal distribution, D 10 is 0.11-0.15μm, D 50 is 0.31-0.37μm, D 90 is 0.79-0.84μm, and D 99 is 0.86-0.92μm.

[0012] In the above scheme, the SiO2 content of the sub-micron SiO2 powder is 99.93-99.95 wt%, the Fe2O3 content is 0.001-0.002 wt%, the Al2O3 content is 0.001-0.003 wt%, the Na2O content is 0.01-0.02 wt%, the K2O content is 0.01-0.02 wt%, the SO3 content is 0.01-0.03 wt%, and the pH value is 6.8-7.4.

[0013] In the above scheme, the pure calcium aluminate cement is CA70 calcium aluminate cement, the Al2O3 content is 68.5-71.0 wt%, the SiO2 content is 0.6-0.9 wt%, the Fe2O3 content is 0.3-0.5 wt%, and the CaO content is 29.0-30.5 wt%.

[0014] In the above scheme, the rare earth modified titanium-aluminum alloy fiber has a length of 40-50 mm and a diameter of 0.8-1.0 mm, and a softening temperature of 1600-1650℃.

[0015] In the above scheme, the preparation method of the rare earth modified titanium-aluminum alloy fiber comprises the following steps:

[0016] 1) dissolving a lanthanum source, a cerium source, and a ytterbium source in a solvent to obtain a mixed rare earth solution;

[0017] 2) placing titanium-aluminum alloy fibers into the mixed rare earth solution for vacuum immersion, and drying after taking out, to obtain titanium-aluminum alloy fibers after first treatment;

[0018] 3) mixing lanthanum chloride, cerium sulfate, and ytterbium chloride uniformly to obtain a mixed rare earth coating material;

[0019] 4) smearing the mixed rare earth coating material on the surface of the titanium-aluminum alloy fibers after first treatment, and then drying and heating and solidifying to obtain the rare earth modified titanium-aluminum alloy fiber.

[0020] Further, the lanthanum source is one of lanthanum chloride and lanthanum nitrate.

[0021] Further, the cerium source is one of cerium chloride and cerium sulfate.

[0022] Further, the ytterbium source is one of ytterbium nitrate and ytterbium sulfate.

[0023] Further, the solvent is one of NaCl solution, Na2SO4 solution, and NaNO3 solution, and the mass concentration is 30-40%.

[0024] Further, in the mixed rare earth solution, the molar ratio of the lanthanum source, the cerium source, and the ytterbium source is (2-2.5):(2-3):1.

[0025] Further, the total mass concentration of the lanthanum source, cerium source and ytterbium source in the mixed rare earth solution is 10-15%.

[0026] Further, the content of Al in the titanium-aluminum alloy fiber is 46.5-49.0 wt%, the content of Ti is 47.5-50.0 wt%, the content of Cr is 1.5-2.0 wt%, and the content of Mn is 0.3-0.8 wt%.

[0027] Further, in step 2), the mass ratio of the titanium-aluminum alloy fiber to the mixed rare earth solution during the impregnation is 1:(2-3).

[0028] Further, the vacuum degree of the vacuum impregnation is 0.06-0.09 MPa, and the impregnation time is 69-75 h.

[0029] Further, in step 2), the drying temperature is 105-110°C, and the drying time is 20-24 h.

[0030] Further, the mass ratio of lanthanum chloride, cerium sulfate and ytterbium chloride in the mixed rare earth coating material is (2.5-3):(1.5-2):1.

[0031] Further, in step 4), the mass ratio of the titanium-aluminum alloy fiber after the first treatment to the mixed rare earth coating material during the smearing is (9-10):1.

[0032] Further, in step 4), the drying temperature is 105-110°C, and the drying time is 20-24 h.

[0033] Further, the curing temperature of the heating and curing is 350-400°C, the holding time is 3-3.5 h, and the heating rate is 2-3°C / min.

[0034] In the above scheme, the water reducing agent is a powder-like polyethylene glycol polymer superplasticizer FS20.

[0035] In the above scheme, the anti-explosion fiber is a polypropylene fiber, the length of which is 3-3.5 mm, the diameter of which is 20-30 μm, and the softening temperature of which is 60-70°C.

[0036] In the above scheme, the high-temperature and high-strength ceramic wear-resistant castable has a 110°C x 24 h flexural strength ≥12.0 MPa, a 110°C x 24 h compressive strength ≥100.0 MPa, a 1100°C x 3 h flexural strength ≥20.0 MPa, a 1100°C x 3 h compressive strength ≥150.0 MPa, a 1550°C x 3 h flexural strength ≥35.0 MPa, a 1550°C x 3 h compressive strength ≥200.0 MPa, a 1400°C x 1 h high-temperature flexural strength ≥15.0 MPa, and a 1500°C x 3 h wear value ≤2 cm.3 After 1550 DEG C x 3h firing, the linear change rate is less than or equal to ±0.3%.

[0037] The application further provides a preparation method of the high-temperature high-strength ceramic wear-resistant castable.

[0038] The mullite of each particle size, the brown corundum of each particle size, the active alumina powder, the submicron SiO2 powder and the pure calcium aluminate cement are pre-stirred and mixed, then the rare earth modified titanium-aluminum alloy fiber, the water reducing agent and the explosion-proof fiber are added and stirred and mixed, and finally the water is added and stirred and mixed to obtain the high-temperature high-strength ceramic wear-resistant castable.

[0039] In the above scheme, the stirring rate of the stirring is greater than or equal to 20 r / min.

[0040] The application further provides a construction method of the high-temperature high-strength ceramic wear-resistant castable.

[0041] The high-temperature high-strength ceramic wear-resistant material is subjected to vibration forming and integral cast construction, is demolded after natural hardening of the material, and is subjected to baking and then heating to a working temperature for service after wet curing.

[0042] In the above scheme, the time for the natural hardening is 20-24 h.

[0043] In the above scheme, the time for the wet curing is 72-84 h.

[0044] In the above scheme, the baking is divided into three stages: first, heating to 140-160 DEG C for 32-40 h, then heating to 335-375 DEG C for 20-26 h, and finally heating to 620-680 DEG C for 20-26 h, and the heating rate is 10-12 DEG C / h.

[0045] In the above scheme, after the baking is completed, the temperature is increased to the working temperature at a rate of 30-35 DEG C / h.

[0046] The technical concept of the application is as follows:

[0047] 1) Traditional wear-resistant material uses cement as binder, and has high strength at room temperature, but CaO in cement and Al2O3, SiO2 in material form low-melting substance at high temperature, which significantly reduces the high-temperature performance; if SiO2 powder is introduced as binder, there are many impurities, low purity, uneven particle size, and agglomeration phenomenon, relatively poor dispersibility, difficult to control material solidification time, and low material demolding strength. The submicron SiO2 powder is prepared by burning silicon tetrachloride and oxygen at a specific temperature, and the obtained submicron SiO2 powder has high purity and unique particle size distribution, and the pH value is 6.8-7.4, which is neutral, neither acidic silicon powder which has a retarding effect on castable, nor alkaline silicon powder which has an accelerating effect on castable, and is easy to control the hardening time of castable and demolding treatment. Subsequently, CA70 cement is used as an accelerator and dispersed on the surface and voids of the synthesized submicron SiO2 powder, and the CA70 cement hydrate is used as a nucleation point to promote the nucleation and crystal growth of the Si-O-Si bond formed by the hydration of the submicron SiO2 powder, forming a network structure; under this synergistic excitation, the Si-O-Si bond of the submicron SiO2 powder continuously forms a network three-dimensional chain structure, which can be directly used as a castable binder, so that the material has strength at room temperature, and the demolding and bending strength is ≥3MPa; under high temperature, the sintering activity and amorphous structure of SiO2 in the submicron SiO2 powder and Al2O3 in the active alumina powder form an interlaced distributed mullite reinforcing phase through in-situ sintering reaction, further improving the thermal shock stability and high-temperature bending strength of the material.

[0048] 2) Traditional wear-resistant castable generally enhances the wear resistance of the material by adding steel fibers, but ordinary steel fibers are easily fused at 1300℃, and the size and cross-sectional shape of the steel fibers are not easy to control, which is not conducive to the fluidity of the castable. The rare earth modified titanium-aluminum steel fiber of the present application can significantly improve the heat resistance and maintain good metal toughness at 1500℃, enhance the toughness, mechanical impact resistance and mechanical strength of the castable, improve the thermal shock resistance of the castable, prevent the microcracks generated in the castable from expanding or extending under the action of thermal stress and mechanical stress to cause fracture or spalling, and the alloy fiber is easy to bridge and wrap the castable, without affecting the fluidity of the castable. The lanthanum source, cerium source and ytterbium source are first infiltrated into the titanium-aluminum steel fiber by vacuum impregnation, and the crystal grains are refined. The atomic radius of the rare earth element is larger than that of titanium and aluminum, and the property is relatively active. The surface defects of the titanium-aluminum alloy phase are easily filled by vacuum pressure difference impregnation, the interfacial tension of the new and old two phases is reduced, the growth rate of the crystal nucleus is improved, and a surface active film is formed between the crystal grains and the alloy, refining the titanium-aluminum alloy structure. A protective layer is formed on the surface of the alloy by smearing a mixed solution of lanthanum sulfate, cerium nitrate and ytterbium chloride on the surface. Through the internal structure catalytic toughening and surface wrapping strengthening modification treatment, the high-temperature performance of the titanium-aluminum steel fiber is improved by synergistic effect.

[0049] 3) In the component design of high-temperature high-strength ceramic wear-resistant castable, the application takes brown corundum and sintered mullite as aggregate, the brown corundum has high strength and rough surface, the sintered mullite has high purity, good grain development and smooth surface, and good thermal shock stability, and the two play a network skeleton role in the material. The mullite is used to inhibit the thermal expansion damage of brown corundum due to high thermal expansion coefficient and high elastic modulus, and the brown corundum is used to enhance the impact resistance of mullite. The alumina powder and sub-micron silicon powder added at the same time have high reactivity, which is beneficial to the generation of mullite without introducing other impurities at high temperature, and improves the purity and structure network tightness of the whole material system. Through the grading design of mullite and brown corundum and the close packing of different particle size active powders, the strength and wear resistance of the castable are greatly improved.

[0050] Compared with the prior art, the application has the following beneficial effects:

[0051] The application synthesizes a sub-micron SiO2 powder with high purity and unique particle size distribution as a binder, which has almost no agglomeration between particles and neutral pH value, and does not have the effects of accelerating or retarding hardening of the castable, solving the problems of low normal temperature strength and difficult demolding of the sub-micron silicon powder as a binder. In order to realize the high-temperature high-strength wear-resistant performance of the sub-micron SiO2 powder combined with the castable, brown corundum and mullite are selected as aggregate, the high strength, wear resistance of brown corundum raw material and the thermal shock stability of mullite are fully utilized, and the reasonable ratio of brown corundum and mullite is used to achieve high-temperature wear-resistant performance. At the same time, the in-situ sintering reaction of sub-micron SiO2 powder and active alumina powder generates interlaced distributed mullite phase, so that the whole material system is a corundum-mullite composite material. In addition, the rare earth modified titanium-aluminum steel fiber further enhances the toughness, mechanical impact resistance and mechanical strength of the castable, and improves the high-temperature wear resistance and thermal shock resistance of the castable. DETAILED DESCRIPTION

[0052] In order to better understand the application, the following examples further illustrate the content of the application, but the content of the application is not limited to the following examples.

[0053] In the following examples, the mullite used is mullite M60, the Al2O3 content is 59.5-61.5wt%, the SiO2 content is 31.3-33.7wt%, the Fe2O3 content is 0.5-1.5wt%, and the water absorption is ≤0.5%;

[0054] The Al2O3 content of the brown corundum used is 94.5-95.5wt%, the SiO2 content is 0.5-0.8wt%, the Fe2O3 content is 0.01-0.03wt%, the CaO content is 0.2-0.3wt%, the C content is 0.05-0.12wt%, the S content is 0.05-0.08wt%, and the bulk density is ≥3.85g / cm3 3 ;

[0055] The Al2O3 content of the active alumina powder used is >99.5wt%, the median particle size D 50 is 1.5-1.8μm;

[0056] The pure calcium aluminate cement used is CA70 calcium aluminate cement, the Al2O3 content is 68.5-71.0wt%, the SiO2 content is 0.6-0.9wt%, the Fe2O3 content is 0.3-0.5wt%, and the CaO content is 29.0-30.5wt%;

[0057] The water reducing agent used is a powdered polyethylene glycol polymer high-efficiency water reducing agent FS20;

[0058] The explosion-proof fiber used is a polypropylene fiber, the length is 3-3.5mm, the diameter is 20-30μm, and the softening temperature is 60-70℃;

[0059] The titanium-aluminum alloy fiber used has an Al content of 48.3wt%, a Ti content of 49.3wt%, a Cr content of 1.8wt%, and a Mn content of 0.6wt%.

[0060] Example 1

[0061] A high-temperature high-strength ceramic wear-resistant castable comprises the following raw materials by mass percentage: 18% of mullite with a particle size of 8-5mm, 20% of mullite with a particle size of 5-3mm, 15% of brown corundum with a particle size of 3-1mm, 15% of brown corundum with a particle size of 1-0.074mm, 21.5% of brown corundum with a particle size of ≤0.074mm, 5% of active alumina powder, 5% of sub-micron SiO2 powder, 0.5% of pure calcium aluminate cement, plus 1.5% of the total mass of the above raw materials of rare earth modified titanium-aluminum alloy fiber, 0.1% of water reducing agent, 0.05% of explosion-proof fiber, and 4.2% of water.

[0062] In this embodiment, the sub-micron SiO2 powder is obtained by mixing silicon tetrachloride and oxygen at a molar ratio of 1:6.3, combusting at 2420°C for 2.6h, and then cooling and solidifying; the SiO2 content is 99.938wt%, the Fe2O3 content is 0.0014wt%, the Al2O3 content is 0.0015wt%, the Na2O content is 0.014wt%, the K2O content is 0.011wt%, the SO3 content is 0.021wt%, and the pH value is 6.9; it is spherical amorphous silicon micro-powder, the particle size is unimodal distribution, D 10 is 0.13μm, D 50 is 0.34μm, D 90 is 0.81μm, and D 99 is 0.89μm.

[0063] In this embodiment, the preparation method of the rare earth modified titanium-aluminum alloy fiber comprises the following steps:

[0064] 1) Dissolve lanthanum chloride, cerium chloride and ytterbium nitrate in a solvent at a molar ratio of 2.2:2.5:1, the solvent is a mixed solution of NaCl and NaNO3 with a mass concentration of 32% (the mass ratio of NaCl to NaNO3 is 1:1), to obtain a mixed rare earth solution; the total mass concentration of lanthanum chloride, cerium chloride and ytterbium nitrate in the mixed rare earth solution is 12%;

[0065] 2) Put the titanium-aluminum alloy fiber into the mixed rare earth solution for vacuum immersion, the mass ratio of the titanium-aluminum alloy fiber to the mixed rare earth solution is 1:2.2 during immersion, the vacuum degree is 0.068MPa, the immersion time is 73h, and after the immersion is completed, the titanium-aluminum alloy fiber is taken out and dried at 108°C for 22h to obtain the titanium-aluminum alloy fiber after the first treatment;

[0066] 3) Mix lanthanum chloride, cerium sulfate and ytterbium chloride uniformly at a mass ratio of 2.6:1.7:1 to obtain a mixed rare earth coating material;

[0067] 4) Smear the mixed rare earth coating material on the surface of the titanium-aluminum alloy fiber after the first treatment, the mass ratio of the titanium-aluminum alloy fiber after the first treatment to the mixed rare earth coating material is 9.6:1 during smearing, and after smearing, first dry at 108°C for 21h, then heat to 359°C at a rate of 2.5°C / min and keep for 3.2h to solidify, to obtain the rare earth modified titanium-aluminum alloy fiber; the length of the rare earth modified titanium-aluminum alloy fiber is 40-50mm, the diameter is 0.8-1.0mm, and the softening temperature is 1600-1650°C.

[0068] Example 2

[0069] The high-temperature high-strength ceramic wear-resistant castable comprises the following raw materials in mass percentage: 20% of mullite with particle size of 8-5mm, 17% of mullite with particle size of 5-3mm, 16% of brown corundum with particle size of 3-1mm, 15% of brown corundum with particle size of 1-0.074mm, 19.4% of brown corundum with particle size of less than 0.074mm, 6% of active alumina powder, 6% of submicron SiO2 powder, 0.6% of pure calcium aluminate cement, 1.3% of rare earth modified titanium-aluminum alloy fiber, 0.12% of water reducing agent, 0.06% of anti-explosion fiber and 3.9% of water.

[0070] In the embodiment, the submicron SiO2 powder is obtained by mixing silicon tetrachloride and oxygen at a molar ratio of 1:6.6, burning at 2445 DEG C for 2.4h, and then cooling and solidifying; the SiO2 content is 99.941wt%, the Fe2O3 content is 0.0013wt%, the Al2O3 content is 0.0014wt%, the Na2O content is 0.013wt%, the K2O content is 0.012wt%, the SO3 content is 0.022wt%, and the pH value is 7.2; the submicron SiO2 powder is spherical amorphous silicon powder, the particle size is unimodal distribution, D 10 is 0.14um, D 50 is 0.36um, D 90 is 0.82um, D 99 is 0.91um.

[0071] In the embodiment, the preparation method of the rare earth modified titanium-aluminum alloy fiber comprises the following steps:

[0072] 1) dissolving lanthanum nitrate, cerium sulfate and ytterbium sulfate in a solvent at a molar ratio of 2.4:2.3:1, the solvent is a mixed solution of NaNO3 and Na2SO4 with mass concentration of 37% (mass ratio of NaNO3 to Na2SO4 is 1:1), to obtain a mixed rare earth solution; the total mass concentration of lanthanum nitrate, cerium sulfate and ytterbium sulfate in the mixed rare earth solution is 14%;

[0073] 2) putting titanium-aluminum alloy fiber into the mixed rare earth solution for vacuum immersion, the mass ratio of titanium-aluminum alloy fiber to mixed rare earth solution is 1:2.8 during the immersion, the vacuum degree is 0.087MPa, the immersion time is 71h, and after the immersion, the titanium-aluminum alloy fiber is taken out and dried at 107 DEG C for 23h to obtain the titanium-aluminum alloy fiber after the first treatment;

[0074] 3) mixing lanthanum chloride, cerium sulfate and ytterbium chloride uniformly at a mass ratio of 2.7:1.8:1 to obtain a mixed rare earth coating material;

[0075] 4) After the first treatment, the titanium-aluminum alloy fiber surface is coated with a mixed rare earth coating material, and the mass ratio of the titanium-aluminum alloy fiber after the first treatment to the mixed rare earth coating material is 9.8:1 during the coating. After coating, it is first dried at 107°C for 22h, then heated to 380°C at a rate of 2.6°C / min and held for 3.3h for solidification, to obtain a rare earth modified titanium-aluminum alloy fiber; the length of the rare earth modified titanium-aluminum alloy fiber is 40-50mm, the diameter is 0.8-1.0mm, and the softening temperature is 1600-1650°C.

[0076] Example 3

[0077] A high-temperature high-strength ceramic wear-resistant castable includes the following raw materials by mass percentage: 15% of mullite with a particle size of 8-5mm, 18% of mullite with a particle size of 5-3mm, 18% of brown corundum with a particle size of 3-1mm, 18% of brown corundum with a particle size of 1-0.074mm, 16.6% of brown corundum with a particle size of ≤0.074mm, 7% of active alumina powder, 7% of sub-micron SiO2 powder, 0.4% of pure calcium aluminate cement, plus 1.1% of the total mass of the above raw materials of rare earth modified titanium-aluminum alloy fiber, 0.13% of water reducing agent, 0.07% of anti-explosion fiber, and 4.1% of water.

[0078] In this embodiment, the sub-micron SiO2 powder is obtained by mixing silicon tetrachloride and oxygen at a molar ratio of 1:6.4, then burning at 2428°C for 2.5h, and then cooling and solidifying; the SiO2 content is 99.943wt%, the Fe2O3 content is 0.0012wt%, the Al2O3 content is 0.0022wt%, the Na2O content is 0.015wt%, the K2O content is 0.013wt%, the SO3 content is 0.025wt%, and the pH value is 7.0; it is spherical amorphous silicon powder, the particle size is unimodal distribution, D 10 is 0.12μm, D 50 is 0.33μm, D 90 is 0.80μm, D 99 is 0.88μm.

[0079] In this embodiment, the preparation method of the rare earth modified titanium-aluminum alloy fiber includes the following steps:

[0080] 1) Dissolve lanthanum chloride, cerium sulfate and ytterbium sulfate in a solvent at a molar ratio of 2.1:2.6:1, and the solvent is a mixed solution of NaCl and Na2SO4 with a mass concentration of 35%(NaCl and Na2SO4 mass ratio 1:1), to obtain a mixed rare earth solution; the total mass concentration of lanthanum chloride, cerium chloride and ytterbium nitrate in the mixed rare earth solution is 13%;

[0081] 2) vacuum dipping the titanium-aluminum alloy fiber into the mixed rare earth solution, the mass ratio of the titanium-aluminum alloy fiber to the mixed rare earth solution being 1:2.6, the vacuum degree being 0.079 MPa, the dipping time being 72 h, and after the dipping, the titanium-aluminum alloy fiber is taken out and dried at 109 ℃ for 21 h to obtain the titanium-aluminum alloy fiber after the first treatment;

[0082] 3) mixing lanthanum chloride, cerium sulfate and ytterbium chloride uniformly according to the mass ratio of 2.9:1.6:1 to obtain the mixed rare earth coating material;

[0083] 4) smearing the mixed rare earth coating material on the surface of the titanium-aluminum alloy fiber after the first treatment, the mass ratio of the titanium-aluminum alloy fiber after the first treatment to the mixed rare earth coating material being 9.3:1, and after the smearing, the titanium-aluminum alloy fiber is first dried at 106 ℃ for 23 h, then heated to 362 ℃ at a rate of 2.4 ℃ / min and kept for 3.4 h to solidify, to obtain the rare earth modified titanium-aluminum alloy fiber; the length of the rare earth modified titanium-aluminum alloy fiber is 40-50 mm, the diameter is 0.8-1.0 mm, and the softening temperature is 1600-1650 ℃.

[0084] The high-temperature high-strength ceramic wear-resistant castable in the above examples is prepared and constructed according to the following steps:

[0085] 1) the mullite of each particle size, the brown corundum of each particle size, the active alumina powder, the sub-micron SiO2 powder and the pure calcium aluminate cement are pre-mixed and stirred, then the rare earth modified titanium-aluminum alloy fiber, the water reducing agent and the anti-explosion fiber are added and stirred, and finally the water is added and stirred to obtain the high-temperature high-strength ceramic wear-resistant castable;

[0086] 2) the high-temperature high-strength ceramic wear-resistant material is vibrated and formed and constructed by casting, the material is demolded after natural hardening for 20-24 h, and then is baked after wet curing for 72-84 h, the baking system is as follows: first heated to 150 ℃ and kept for 36 h, then heated to 350 ℃ and kept for 24 h, and finally heated to 650 ℃ and kept for 24 h, the heating rate is 10 ℃ / h, and after the baking, the material is heated to the working temperature at a rate of 30 ℃ / h for service.

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 1 is only that:

[0089] 1) the sub-micron SiO2 powder is replaced by a commercially available high-purity silicon powder, the SiO2 content of which is 99.1 wt%, the Fe2O3 content is 0.0018 wt%, the Al2O3 content is 0.0012 wt%, the Na2O content is 0.012 wt%, the K2O content is 0.032 wt%, the SO3 content is 0.039 wt%, and the pH value is 3.9; the particle size thereof is unimodal distribution, D 10 0.16 μm, D50 D50 is 0.39 μm, D90 is 0.91 μm, and D99 is 0.99 μm. 90 D50 is 0.39 μm, D90 is 0.91 μm, and D99 is 0.99 μm. 99 D50 is 0.39 μm, D90 is 0.91 μm, and D99 is 0.99 μm.

[0090] 2) The rare earth modified titanium-aluminum alloy fiber is replaced by a commercially available steel fiber, with a length of 40-50 mm, a diameter of 0.8-1.0 mm, and a softening temperature of 1280-1320 °C.

[0091] The properties of the castable of each example and the comparative example were tested, and the test results are shown in the following table.

[0092] Table 1: Test results of properties

[0093]

[0094]

[0095] The high-strength ceramic wear-resistant castable produced by the embodiment has high strength and high construction efficiency, and has good thermal shock stability, good wear resistance, no falling off, long service life, and the service life can be more than 10 years.

[0096] The above examples are merely examples for clearly illustrating, but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and here, all the embodiments do not need to be exhausted, and thus the obvious changes or variations still fall within the protection scope of the present application.

Claims

1. A high temperature high strength ceramic wear resistant castable characterized in that, The raw materials include the following mass percentages: mullite with a particle size of 8-5mm 14-22%, mullite with a particle size of 5-3mm 16-24%, brown corundum with a particle size of 3-1mm 13-18%, brown corundum with a particle size of 1-0.074mm 12-19%, brown corundum with a particle size of ≤0.074mm 16-25%, active alumina powder 3-7%, submicron SiO2 powder 4-7%, pure calcium aluminate cement 0.3-0.6%, and additionally 1-1.5% of the total mass of the above raw materials of rare earth modified titanium-aluminum alloy fiber, 0.05-0.15% of water reducing agent, 0.03-0.1% of anti-explosion fiber, and 3.5-4.5% of water; The SiO2 content of the sub-micron SiO2 powder is 99.93-99.95 wt%, the Fe2O3 content is 0.001-0.002 wt%, the Al2O3 content is 0.001-0.003 wt%, the Na2O content is 0.01-0.02 wt%, the K2O content is 0.01-0.02 wt%, the SO3 content is 0.01-0.03 wt%, and the pH value is 6.8-7.4; the sub-micron SiO2 powder is spherical amorphous silica powder, the particle size thereof is unimodal distribution, D 10 0.11-0.15 μm, D 50 0.31-0.37 μm, D 90 0.79-0.84 μm, and D 99 0.86-0.92 μm.

2. The high temperature high strength ceramic refractory castable of claim 1, wherein, The submicron SiO2 powder is obtained by mixing silicon tetrachloride and oxygen at a molar ratio of 1:(6-7), then combusting at 2400-2450℃ for 2-3h, and then cooling and solidifying.

3. The high temperature high strength ceramic refractory castable of claim 1, wherein, The length of the rare earth modified titanium-aluminum alloy fiber is 40-50mm, the diameter is 0.8-1.0mm, and the softening temperature is 1600-1650℃.

4. The high temperature high strength ceramic refractory castable of claim 1, wherein, The preparation method of the rare earth modified titanium-aluminum alloy fiber includes the following steps: 1) Dissolving a lanthanum source, a cerium source, and a ytterbium source in a solvent to obtain a mixed rare earth solution; 2) Placing titanium-aluminum alloy fiber into the mixed rare earth solution for vacuum immersion, and then drying to obtain titanium-aluminum alloy fiber after first treatment; 3) Mixing lanthanum chloride, cerium sulfate, and ytterbium chloride uniformly to obtain a mixed rare earth coating material; 4) Smearing the mixed rare earth coating material on the surface of the titanium-aluminum alloy fiber after first treatment, and then drying, heating, and solidifying to obtain rare earth modified titanium-aluminum alloy fiber.

5. A high temperature high strength ceramic refractory castable according to claim 4, characterized in that, The Al content in the titanium-aluminum alloy fiber is 46.5-49.0wt%, the Ti content is 47.5-50.0wt%, the Cr content is 1.5-2.0wt%, and the Mn content is 0.3-0.8wt%; in the mixed rare earth solution, the molar ratio of the lanthanum source, the cerium source, and the ytterbium source is (2-2.5):(2-3):1, and the total mass concentration of the lanthanum source, the cerium source, and the ytterbium source is 10-15%; the vacuum degree of vacuum immersion is 0.06-0.09MPa, and the immersion time is 69-75h.

6. The high temperature high strength ceramic refractory castable of claim 4, wherein, In the mixed rare earth coating material, the mass ratio of lanthanum chloride, cerium sulfate, and ytterbium chloride is (2.5-3):(1.5-2):1; the mass ratio of the titanium-aluminum alloy fiber after first treatment to the mixed rare earth coating material is (9-10):1; the solidification temperature of heating and solidification is 350-400℃, the holding time is 3-3.5h, and the heating rate is 2-3℃ / min.

7. The high temperature high strength ceramic refractory castable of claim 1, wherein, The mullite is mullite M60; the brown corundum has an Al2O3 content of 94.5-95.5 wt%, a SiO2 content of 0.5-0.8 wt%, an Fe2O3 content of 0.01-0.03 wt%, a CaO content of 0.2-0.3 wt%, a C content of 0.05-0.12 wt%, and a S content of 0.05-0.08 wt%, and a bulk density ≥ 3.85 g / cm 3 ; the active alumina powder has an Al2O3 content > 99.5 wt% and a median particle size D 50 of 1.5-1.8 μm; the pure calcium aluminate cement is CA70 calcium aluminate cement; and the explosion-proof fiber is a polypropylene fiber having a length of 3-3.5 mm, a diameter of 20-30 μm, and a softening temperature of 60-70℃.

8. A process for the preparation of high temperature high strength ceramic wear resistant castable according to any one of claims 1 to 7, characterized in that, The method includes the following steps: Mixing mullite with different particle sizes, brown corundum with different particle sizes, active alumina powder, submicron SiO2 powder, and pure calcium aluminate cement in advance, then adding rare earth modified titanium-aluminum alloy fiber, water reducing agent, and anti-explosion fiber, and finally adding water to obtain high-temperature and high-strength ceramic wear-resistant castable.

9. A method for applying the high temperature high strength ceramic wear resistant castable according to any one of claims 1 to 7, characterized in that, The method includes the following steps: The high-temperature and high-strength ceramic wear-resistant material is subjected to vibration molding and integral casting construction, is demolded after natural hardening for 20-24 hours, is subjected to wet curing for 72-84 hours, is baked according to the baking system of first heating to 140-160 DEG C and keeping for 32-40 hours, then heating to 335-375 DEG C and keeping for 20-26 hours, finally heating to 620-680 DEG C and keeping for 20-26 hours, the heating rate is 10-12 DEG C / h, and after baking, the temperature is increased to the working temperature at a rate of 30-35 DEG C / h for service.

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