Unshaped refractory material with high thermal shock resistance and preparation method thereof

Abstract

The invention belongs to the technical field of refractory materials, and particularly relates to a high-thermal-shock-resistance unshaped refractory material and a preparation method thereof. The high-thermal-shock-resistance unshaped refractory material provided by the invention comprises corundum, magnesium aluminate spinel, a binding agent, nano micro powder, quartz glass powder, polymeric aluminum phosphate and sodium tripolyphosphate. The high-alumina cement, the alumina sol and the silica powder jointly form a binding agent, so that the overall expansion rate of the material is reduced, and the interface bonding strength and the cracking resistance in the thermal shock resistance process are improved; the alumina sol with low acid content and high solid content is prepared by adopting a hydrothermal method, so that the thermal expansion difference is reduced, thermal shock is buffered, and the thermal shock resistance of the unshaped refractory material is further improved; the nano carbon black, the nano cerium oxide and the nano aluminum oxide jointly form the nano micro powder, and the thermal shock resistance of the unshaped refractory material is remarkably improved through a synergistic mechanism of thermal conductivity regulation, grain refinement and interface strengthening.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of refractory materials, and particularly relates to a high-thermal-shock-resistance amorphous refractory material and a preparation method thereof. BACKGROUND

[0002] As an important branch in the field of refractory materials, amorphous refractory materials have been applied to the high-temperature industrial fields such as steel, metallurgy, building materials, chemical industry and energy due to their remarkable advantages such as no need for pre-firing, convenient construction, strong adaptability, high resource utilization rate and controllable cost, and have become the core protective material for the lining of high-temperature kilns and thermal equipment. The performance of the amorphous refractory material directly determines the service life, operation stability and production safety of the thermal equipment, and plays an irreplaceable role in protecting the continuous and efficient production of high-temperature industries, reducing energy consumption and operation and maintenance costs.

[0003] In the actual production process of high-temperature industries, thermal equipment often faces extremely harsh temperature conditions, frequent temperature rising and falling operations and local temperature fluctuations, which will make the lining refractory material continuously bear periodic thermal stress. The repeated accumulation and release of this thermal stress can easily cause micro-cracks in the material. With the expansion and penetration of the cracks, the material will eventually appear peeling, cracking and even overall failure, which is called "thermal shock damage". Therefore, the thermal shock resistance has become a key indicator for measuring the core performance of amorphous refractory materials. Research and development of amorphous refractory materials with excellent thermal shock resistance is one of the core research directions in the field of refractory materials.

[0004] At present, the conventional means for improving the thermal shock resistance of amorphous refractory materials in the industry mainly include optimizing the particle size distribution to improve the material density and pore structure, and introducing mineral components with low expansion coefficient to reduce thermal stress. However, optimizing the particle size distribution can easily sacrifice the room temperature strength and high-temperature compressive strength of the material, leading to structural deformation of the material when it bears high-temperature load. The introduction of mineral components with low expansion coefficient significantly increases the material preparation cost, which is not conducive to large-scale application.

[0005] The Chinese patent application file with the publication number CN106316433A discloses an amorphous refractory material, which comprises forsterite 40%-60%, yttrium oxide powder 20%-30%, zirconium oxide powder 10%-20%, binder 5%-9%, and plasticizer 1%-5%. The particle size grade and the corresponding mass ratio of forsterite, with the mass of forsterite being 100%, are as follows: 8-5mm 20%-30%, 5-3mm 50%-65%, 3-1mm 10%-15%, and less than 1mm ≤5%. However, the proportion of coarse particles in the formula is high, and the proportion of fine powder and micro powder is low. The coarse particle grading will lead to difficulty in forming a dense accumulation structure during construction and vibration, and a large number of penetrating pores are easily left, which not only reduces the normal temperature mechanical strength and high temperature compressive strength of the material, but also may exacerbate thermal stress concentration due to uneven pore distribution, affecting the stability of thermal shock resistance. In addition, after high proportion of forsterite is compounded with yttrium oxide and zirconium oxide components, the difference in the thermal expansion coefficient between the components is large, and interface microcracks are easily generated due to thermal expansion mismatch during high temperature service, affecting the service life. SUMMARY

[0006] In order to solve the technical problems of poor thermal shock resistance in the prior art, the purpose of the present application is to provide a high thermal shock resistance amorphous refractory material and a preparation method thereof.

[0007] In order to achieve the above purpose, the technical scheme of the present application is as follows: A high thermal shock resistance amorphous refractory material comprises the following components in parts by weight: corundum 70-80 parts, magnesium aluminate spinel 50-60 parts, binder 20-35 parts, nano micro powder 12-20 parts, quartz glass powder 10-15 parts, polyaluminum phosphate 3-8 parts, and sodium tripolyphosphate 1-3 parts. The binder is composed of high alumina cement, aluminum sol and silicon powder in a mass ratio of (10-15):(7-11):(3-6).

[0008] By the technical scheme, the high-alumina cement, the aluminum sol and the silica micropowder are used to form the binder, the high-alumina cement is used as inorganic cementing material, and after hydration, calcium aluminate, calcium dialuminate and other hydration products are generated to form a three-dimensional network structure, and the material has normal temperature and medium-low temperature strength, and at high temperature, the hydration products are dehydrated to convert into corundum phase to form a firm ceramic bond with the refractory aggregate to improve the stability of the matrix structure, the corundum phase of the high-alumina cement has a low thermal expansion coefficient to reduce the overall expansion rate of the material; the aluminum sol has high activity, and at normal temperature, a dense alumina gel film can be formed by water evaporation to fill the small pores between the hydration products of the high-alumina cement, and at high temperature, the aluminum sol is converted into gamma-Al2O3 to further react with alumina in the high-alumina cement to form a continuous ceramic bonding interface, meanwhile, the gel film can improve the interface wettability of the binder and the refractory aggregate, reduce the interface pores and cracks, and reduce the concentration of thermal stress on the interface; the silica micropowder has high specific surface area and reactivity, and at high temperature, the silica micropowder can react with calcium oxide and alumina in the high-alumina cement to generate low-melting-point anorthite or magnesium aluminate spinel phase to fill the micrometer-level pores in the matrix, the thermal expansion coefficient of the anorthite and magnesium aluminate spinel phase is low to further reduce the overall thermal expansion difference of the material and reduce thermal stress, and the particles of the silica micropowder can also improve the matrix density through the filling effect, and the needle-like crystal structure of the magnesium aluminate spinel phase can form an "interlaced support" in the matrix to improve the fracture toughness of the material and enhance the cracking resistance in the thermal shock process.

[0009] In addition, the quartz glass powder forms a low-viscosity glass phase at high temperature to fill the micropores, improve the density, and relieve thermal stress; the polyaluminum phosphate decomposes at high temperature to release phosphorus pentoxide and react with alumina and other oxides in the amorphous refractory material to generate aluminum phosphate salt ceramic phase to fill the pores between the aggregate and form a continuous ceramic bonding interface to improve the high-temperature compressive strength of the material, and the decomposition process forms uniform micropores in the amorphous refractory material to buffer thermal stress through elastic deformation of the micropores and inhibit crack propagation; the sodium tripolyphosphate can optimize particle dispersity and improve the matrix density.

[0010] Further, the binder is composed of the high-alumina cement, the aluminum sol and the silica micropowder in a mass ratio of (12-14):(8-10):(5-6).

[0011] Further, the preparation method of the aluminum sol is as follows: aluminum isopropoxide is added into a reaction kettle, deionized water is added dropwise under stirring, the temperature in the reaction kettle is controlled to be less than 50 DEG C during the dropping process, after the dropping is completed, the stirring is continued for 30-50 min, the temperature is raised to 85-90 DEG C, and the temperature is kept for 2-3 h, isopropyl alcohol is recovered by distillation, and after cooling, concentrated nitric acid is added and stirred uniformly, the temperature is raised to 220-230 DEG C, and the temperature is kept for 20-22 h, and then the aluminum sol is obtained after cooling and filtration.

[0012] By the technical scheme, the low-acid high-solid-content aluminum sol is prepared by the hydrothermal method, the low-acid content can avoid the erosion problem of refractory aggregate caused by the high-acid content of the aluminum sol, the isopropyl alcohol aluminum is selected to recover isopropyl alcohol by distillation, the content of impurities in the aluminum sol is reduced, meanwhile, the addition of water can be reduced, the porosity of the refractory material is reduced, the hydrothermal reaction for 20-22 hours can improve the crystallinity of the colloidal particles, and the crystal grain size is uniformly distributed. In the use process of the unshaped refractory material, the aluminum sol can be quickly converted into γ-Al2O3, and after the nanoscale colloidal particles are converted into aluminum oxide, the nanoscale colloidal particles can fill the small pores in the refractory material matrix, and at the same time, a slight solid-phase reaction occurs with the surface of the aggregate to form a dense bonding layer, the material density is improved, the thermal expansion difference is reduced, the thermal shock is buffered, and then the thermal shock resistance of the unshaped refractory material is improved.

[0013] Further, the deionized water in the preparation method of the aluminum sol is deionized water boiled and cooled to 40-45 DEG C; the dropping speed of the deionized water is 10-15 mL / min.

[0014] By the technical scheme, the deionized water is boiled and cooled before use, which can effectively remove the dissolved oxygen in the deionized water and reduce the oxidation and agglomeration of the colloidal particles, and the dropping speed of the deionized water can be controlled to avoid the local rapid hydrolysis and precipitation caused by the too fast addition of the deionized water.

[0015] Further, the mass ratio of the isopropyl alcohol aluminum to the deionized water in the preparation method of the aluminum sol is 1:(1.5-1.7); the mass ratio of the isopropyl alcohol aluminum to the concentrated nitric acid is (50-60):1; and the mass percentage of the concentrated nitric acid is 65%-70%.

[0016] Further, the nanometer micro-powder is composed of nanometer carbon black, nanometer cerium oxide and nanometer aluminum oxide according to the mass ratio of (5-9):(7-12):(15-20).

[0017] By the technical scheme, the nanometer carbon black, nanometer cerium oxide and nanometer aluminum oxide are used to form the nanometer micro-powder, and through the synergistic mechanism of thermal conduction regulation, grain refinement and interface strengthening, the thermal shock resistance of the unshaped refractory material is significantly improved. The nanometer carbon black can construct a three-dimensional thermal conduction network in the unshaped refractory material to accelerate the dispersion of thermal stress, the nanometer cerium oxide can inhibit the abnormal growth of the crystal grain through the grain boundary pinning effect, and the nanometer aluminum oxide can be used as an active sintering aid to form a dense solid solution with the matrix to improve the interface bonding strength and reduce the interface peeling caused by the thermal shock cycle.

[0018] Further, the nanometer micro-powder is composed of nanometer carbon black, nanometer cerium oxide and nanometer aluminum oxide according to the mass ratio of (7-9):(9-11):(17-19).

[0019] Further, the corundum has a particle size of 5-8 mm, 3-5 mm, 1-3 mm or 0.074-1 mm, the mass percentage of the corundum with a particle size of 5-8 mm is 40%-55%, the mass percentage of the corundum with a particle size of 3-5 mm is 25%-40%, the mass percentage of the corundum with a particle size of 1-3 mm is 10%-20%, and the mass percentage of the corundum with a particle size of 0.074-1 mm is 2%-5%.

[0020] Further, the magnesium-aluminum spinel has a particle size of 5-8 mm, 3-5 mm or 1-3 mm, the mass percentage of the magnesium-aluminum spinel with a particle size of 5-8 mm is 45%-60%, the mass percentage of the magnesium-aluminum spinel with a particle size of 3-5 mm is 20%-30%, and the mass percentage of the magnesium-aluminum spinel with a particle size of 1-3 mm is 15%-20%.

[0021] By the technical solution, the continuous grading is adopted to realize the close packing of the aggregate, reduce the apparent porosity of the unshaped refractory material, optimize the pore size and the shape distribution of the pores, and adjust the gradient buffer of the thermal expansion difference of the unshaped refractory material through the particle grading, so that the thermal shock resistance of the unshaped refractory material is improved.

[0022] The application further provides a preparation method of the high-thermal-shock-resistance unshaped refractory material, specifically including the following steps: sieving the corundum and the magnesium-aluminum spinel according to the particle size, removing impurities and over-standard particles, drying, putting into a stirrer, stirring for 3-5 min, then adding quartz glass powder, stirring for 2-3 min, continuously adding the stirred binder, stirring for 5-6 min, then adding nano micro-powder, polyaluminum phosphate and sodium tripolyphosphate, stirring for 20-30 min, then drying at 200-250 DEG C for 12-14 h, calcining at 1600-1800 DEG C for 2-3 h, cooling to 1000-1200 DEG C for 3-4 h, cooling to 600-700 DEG C for 2-3 h, cooling to 200-300 DEG C for 1-1.5 h, naturally cooling, packaging, and obtaining the high-thermal-shock-resistance unshaped refractory material.

[0023] By the technical solution, the corundum and the magnesium-aluminum spinel aggregate are sieved according to the particle size, stress concentration caused by large-particle aggregate or abnormal generation of high-temperature liquid phase caused by impurities is avoided, the quartz glass powder is added after the corundum and the magnesium-aluminum spinel are mixed in the mixing process, the quartz glass powder can be uniformly coated on the surface of the aggregate, and uneven distribution of mullite generated by the reaction between the quartz glass powder and aluminum oxide at high temperature is avoided, and the gradient heating and segmented heat preservation process can optimize the microstructure and the thermal shock resistance.

[0024] Compared with the prior art, the high-thermal-shock-resistance unshaped refractory material and the preparation method thereof have the following technical advantages: (1) The high alumina cement, aluminum sol and silicon micropowder are used to jointly form the binder, so that the overall expansion rate of the material is reduced, the interface bonding strength is improved, and the cracking resistance in the thermal shock process is improved; (2) The low-acid high-solid-content aluminum sol is prepared by the hydrothermal method, the thermal expansion difference is reduced, the thermal shock is buffered, and the thermal shock resistance of the unshaped refractory material is improved; (3) The nanometer carbon black, nanometer cerium oxide and nanometer aluminum oxide are used to jointly form the nanometer micropowder, and through the synergistic mechanism of heat conduction regulation, grain refinement and interface strengthening, the thermal shock resistance of the unshaped refractory material is significantly improved. DETAILED DESCRIPTION

[0025] The following will be further described in combination with specific embodiments, but the present application is not limited to the following embodiments. Those skilled in the art can make various modifications according to the basic idea of the present application, as long as the modifications do not deviate from the basic idea of the present application, and are within the scope of the present application.

[0026] The raw materials described in the specific embodiment are commercially available unless otherwise specified.

[0027] Example 1 A high thermal shock resistance unshaped refractory material comprises the following components in parts by weight: corundum 70g, magnesium aluminate spinel 60g, binder 35g, nanometer micropowder 20g, quartz glass powder 15g, polyaluminum phosphate 8g, sodium tripolyphosphate 3g; The binder is composed of high alumina cement, aluminum sol and silicon micropowder in a mass ratio of 10:7:3; the nanometer micropowder is composed of nanometer carbon black, nanometer cerium oxide and nanometer aluminum oxide in a mass ratio of 5:7:15.

[0028] The preparation method of the aluminum sol is as follows: 500g of aluminum isopropoxide is added to a reaction kettle, 750g of deionized water boiled and cooled to 40℃ is added dropwise at a speed of 10mL / min under stirring at a speed of 300rpm, the temperature in the reaction kettle is controlled to be <50℃ during the dropwise adding process, after the dropwise adding is completed, stirring is continued for 30min, the temperature is raised to 85℃ at a temperature rising rate of 5℃ / min, a condensing device is started at the same time, the temperature is kept for 2h, isopropyl alcohol is recovered by distillation, cooling is performed, 10g of concentrated nitric acid with a mass percentage of 65% is added, stirring is uniformly performed, the temperature is raised to 220℃ at a temperature rising rate of 10℃ / min, the temperature is kept for 20h, cooling is performed, and the aluminum sol is obtained by filtering through a 500 mesh filter screen.

[0029] The particle size of the corundum is 5mm, 3mm, 1mm and 0.074mm, the mass percentage of the corundum with a particle size of 5mm is 40%, the mass percentage of the corundum with a particle size of 3mm is 40%, the mass percentage of the corundum with a particle size of 1mm is 15%, and the mass percentage of the corundum with a particle size of 0.074mm is 5%.

[0030] The particle size of the magnesium aluminate spinel is 5 mm, 3 mm and 1 mm, the mass percentage of the magnesium aluminate spinel with a particle size of 5 mm is 60%, the mass percentage of the magnesium aluminate spinel with a particle size of 3 mm is 20%, and the mass percentage of the magnesium aluminate spinel with a particle size of 1 mm is 20%.

[0031] The preparation method of the high thermal shock resistance amorphous refractory material is as follows: corundum and magnesium aluminate spinel are sieved according to particle size, impurities and excessive particles are removed, dried, put into a blender, stirred for 3 min, then quartz glass powder is added, stirred for 2 min, the prepared binder is continuously added, stirred for 5 min, then nano powder, polyaluminum phosphate and sodium tripolyphosphate are added, stirred for 20 min, then dried at 200 DEG C for 12 h, calcined at 1600 DEG C for 2 h, cooled to 1000 DEG C and kept for 3 h, cooled to 600 DEG C and kept for 2 h, cooled to 200 DEG C and kept for 1 h, naturally cooled, packaged, and the high thermal shock resistance amorphous refractory material is obtained.

[0032] Example 2 A high thermal shock resistance amorphous refractory material comprises the following components in weight percentage: 80 g of corundum, 50 g of magnesium aluminate spinel, 20 g of binder, 12 g of nano powder, 10 g of quartz glass powder, 3 g of polyaluminum phosphate and 1 g of sodium tripolyphosphate; The binder is composed of high-alumina cement, aluminum sol and silicon powder in a mass ratio of 15:11:6; the nano powder is composed of nano carbon black, nano cerium oxide and nano aluminum oxide in a mass ratio of 9:12:20.

[0033] The preparation method of the aluminum sol is as follows: 600 g of aluminum isopropoxide is added into a reaction kettle, 1020 g of deionized water boiled and cooled to 45 DEG C is added dropwise at a speed of 15 mL / min under the condition of stirring at a speed of 400 rpm, the temperature in the reaction kettle is controlled to be less than 50 DEG C during the dropwise adding process, after the dropwise adding process, the stirring is continued for 50 min, the temperature is raised to 90 DEG C at a temperature rising rate of 5 DEG C / min, at the same time, a condensing device is started, the temperature is kept for 3 h, isopropyl alcohol is recovered by distillation, cooled, 10 g of concentrated nitric acid with a mass percentage of 70% is added, stirred uniformly, the temperature is raised to 230 DEG C at a temperature rising rate of 10 DEG C / min, kept for 22 h, cooled, filtered through a 500 mesh filter screen, and the aluminum sol is obtained.

[0034] The particle size of the corundum is 8 mm, 5 mm, 3 mm and 1 mm, the mass percentage of the corundum with a particle size of 8 mm is 55%, the mass percentage of the corundum with a particle size of 5 mm is 25%, the mass percentage of the corundum with a particle size of 3 mm is 18%, and the mass percentage of the corundum with a particle size of 1 mm is 2%.

[0035] The particle size of the magnesium aluminate spinel is 8 mm, 5 mm and 3 mm, the mass percentage of the magnesium aluminate spinel with a particle size of 8 mm is 50%, the mass percentage of the magnesium aluminate spinel with a particle size of 5 mm is 30%, and the mass percentage of the magnesium aluminate spinel with a particle size of 3 mm is 20%.

[0036] The preparation method of the high thermal shock resistance amorphous refractory material is as follows: corundum and magnesium aluminate spinel are sieved according to particle size, impurities and excessive particles are removed, dried, put into a blender, stirred for 5 min, then quartz glass powder is added, stirred for 3 min, continue to add the stirred binder, stir for 6 min, then add nano powder, polyaluminum phosphate and sodium tripolyphosphate, stir for 30 min, then dry at 250 DEG C for 14 h, calcine at 1800 DEG C for 3 h, cool to 1200 DEG C and keep for 4 h, cool to 700 DEG C and keep for 3 h, cool to 300 DEG C and keep for 1.5 h, naturally cool, package, and obtain the high thermal shock resistance amorphous refractory material.

[0037] Example 3 A high thermal shock resistance amorphous refractory material comprises the following components in parts by weight: corundum 75 g, magnesium aluminate spinel 55 g, binder 28 g, nano powder 18 g, quartz glass powder 13 g, polyaluminum phosphate 5 g, and sodium tripolyphosphate 2 g; The binder is composed of high-alumina cement, aluminum sol and silicon powder in a mass ratio of 13:9:5; the nano powder is composed of nano carbon black, nano cerium oxide and nano aluminum oxide in a mass ratio of 8:11:18.

[0038] The preparation method of the aluminum sol is as follows: 550 g of aluminum isopropoxide is added into a reaction kettle, 880 g of deionized water boiled and cooled to 43 DEG C is added dropwise at a speed of 13 mL / min under stirring at a speed of 350 rpm, the temperature in the reaction kettle is controlled to be less than 50 DEG C during the dropwise adding process, after the dropwise adding process, stirring is continued for 40 min, the temperature is raised to 88 DEG C at a speed of 5 DEG C / min, a condensing device is opened at the same time, the temperature is kept for 2.5 h, isopropyl alcohol is recovered by distillation, cooled, 10 g of concentrated nitric acid with a mass percentage of 68% is added, stirred uniformly, the temperature is raised to 225 DEG C at a speed of 10 DEG C / min, kept for 21 h, cooled, filtered through a 500 mesh filter screen, and the aluminum sol is obtained.

[0039] The particle size of the corundum is 7 mm, 4 mm, 2 mm and 0.091 mm, the mass percentage of the corundum with a particle size of 7 mm is 50%, the mass percentage of the corundum with a particle size of 4 mm is 30%, the mass percentage of the corundum with a particle size of 2 mm is 15%, and the mass percentage of the corundum with a particle size of 0.091 mm is 5%.

[0040] The particle size of the magnesium aluminate spinel is 6 mm, 4 mm and 2 mm, the mass percentage of the magnesium aluminate spinel with a particle size of 6 mm is 57%, the mass percentage of the magnesium aluminate spinel with a particle size of 4 mm is 25%, and the mass percentage of the magnesium aluminate spinel with a particle size of 2 mm is 18%.

[0041] The preparation method of the high thermal shock resistance amorphous refractory material is as follows: corundum and magnesium aluminate spinel are sieved according to particle size, impurities and excessive particles are removed, dried, put into a blender, stirred for 4 min, then quartz glass powder is added, stirred for 2 min, the prepared binder is continuously added, stirred for 5 min, then nano powder, polyaluminum phosphate and sodium tripolyphosphate are added, stirred for 25 min, then dried at 225 DEG C for 13 h, calcined at 1700 DEG C for 2.5 h, cooled to 1100 DEG C, kept for 3.5 h, cooled to 650 DEG C, kept for 2.5 h, cooled to 250 DEG C, kept for 1.2 h, naturally cooled, packaged, and the high thermal shock resistance amorphous refractory material is obtained.

[0042] Example 4 The high thermal shock resistance amorphous refractory material and the preparation method thereof in the example are similar to those in example 3, and the difference between the example and example 3 is that: in the example, the binder is composed of high-alumina cement, aluminum sol and silicon powder in a mass ratio of 14:8:5, and the nano powder is composed of nano carbon black, nano cerium oxide and nano aluminum oxide in a mass ratio of 8:10:19.

[0043] Comparative Example 1 The amorphous refractory material and the preparation method thereof in the comparative example are similar to those in example 4, and the difference between the comparative example and example 4 is that: in the comparative example, an equal amount of high-alumina cement is used instead of aluminum sol in the binder.

[0044] Comparative Example 2 The amorphous refractory material and the preparation method thereof in the comparative example are similar to those in example 4, and the difference between the comparative example and example 4 is that: in the comparative example, an equal amount of high-alumina cement is used instead of silicon powder in the binder.

[0045] Comparative Example 3 The amorphous refractory material and the preparation method thereof in the comparative example are similar to those in example 4, and the difference between the comparative example and example 4 is that: in the preparation method of the aluminum sol in the comparative example, an equal amount of tap water is used instead of boiled and cooled deionized water.

[0046] Comparative Example 4 The amorphous refractory material and the preparation method thereof in the comparative example are similar to those in example 4, and the difference between the comparative example and example 4 is that: in the nano powder in the comparative example, an equal amount of nano aluminum oxide is used instead of nano cerium oxide.

[0047] Comparative Example 5 The inaminate refractory material and the preparation method thereof in the present comparative example are similar to those in Example 4, and the difference between the present comparative example and Example 4 is that the present comparative example uses equal amount of nano-aluminum oxide instead of nano-carbon black in the nano-micropowder.

[0048] Comparative Example 6 The inaminate refractory material and the preparation method thereof in the present comparative example are similar to those in Example 4, and the difference between the present comparative example and Example 4 is that the present comparative example uses equal amount of quartz glass powder instead of polymeric aluminum phosphate.

[0049] Test Example Thermal shock resistance, slag resistance and corrosion resistance test: the refractory materials prepared in Example 1-Example 4, Comparative Example 1-Comparative Example 6 are added into water and latex and stirred, and then are applied on the test column in a conventional manner, and after drying, the test column is tested, the test column is made of graphite carbon fiber cloth material, and can withstand a maximum temperature of 2500°C. The thermal shock resistance is represented by the number of cycles between water cooling and 1400°C that can be withstood. The corrosion resistance is represented by the corrosion size after the erosion test of the steelmaking slag at 1400°C, and the larger the test result is, the lower the corrosion resistance is. The slag resistance is represented by the penetration size of the steelmaking slag after the erosion test, and the larger the test result value is, the weaker the slag resistance is.

[0050] Mechanical property test: the refractory materials prepared in Example 1-Example 4, Comparative Example 1-Comparative Example 6 are tested for cold modulus of rupture according to GB / T3001-2017; and the refractory materials prepared in Example 1-Example 4, Comparative Example 1-Comparative Example 6 are tested for high temperature modulus of rupture according to GB / T3002-2017.

[0051] The test results are shown in Table 1.

[0052] Table 1 Performance test results

[0053] According to the test results of Example 1-Example 4 and Comparative Example 1, the aluminum sol formed aluminum oxide gel film can be filled in the micro-pores, improve the bonding performance with the aggregate interface, form a ceramic bonding interface, and thus improve the thermal shock resistance and mechanical properties.

[0054] According to the test results of Example 1-Example 4 and Comparative Example 2, the silicon micropowder can improve the fracture toughness of the material, enhance the cracking resistance, and thus improve the thermal shock resistance and mechanical properties of the material.

[0055] According to the test results of examples 1-4 and comparative example 3, the aluminum sol prepared by using the deionized water after boiling and cooling can avoid the agglomeration of colloidal particles, and maximize the effect of the aluminum sol, while the impurities and oxygen contained in the deionized water not only introduce a large amount of impurities into the refractory material, but also make the colloidal particles oxidize and agglomerate, affecting the use effect.

[0056] According to the test results of examples 1-4 and comparative examples 4-5, among the nano-powders, the nano cerium oxide and nano carbon black can play the role of grain boundary pinning and heat conduction, and can improve the thermal shock resistance and mechanical properties of the refractory material by inhibiting crack propagation and avoiding stress concentration.

[0057] According to the test results of examples 1-4 and comparative example 6, the polymeric aluminum phosphate can react with aluminum oxide in the refractory material at high temperature to generate aluminum phosphate salt ceramic filled between the aggregates, thereby improving the interfacial bonding strength and further improving the thermal shock resistance and mechanical properties.

[0058] The above examples are only examples of the present application, and not limit the present application. Those skilled in the art cannot modify the above examples without departing from the spirit and scope of the present application. All equivalent modifications or changes made by those skilled in the art without departing from the technical idea of the present application still fall within the protection scope of the present application.

Claims

1. A high thermal shock resistant monolithic refractory material, characterized in that, Comprise the following components by weight parts: corundum 70-80 parts, magnesium aluminate spinel 50-60 parts, binder 20-35 parts, nano powder 12-20 parts, quartz glass powder 10-15 parts, polyaluminum phosphate 3-8 parts, sodium tripolyphosphate 1-3 parts; The binder is composed of high-alumina cement, aluminum sol and silicon powder in a mass ratio of (10-15):(7-11):(3-6).

2. The high thermal shock resistant monolithic refractory material of claim 1, wherein, The binder is composed of high-alumina cement, aluminum sol and silicon powder in a mass ratio of (12-14):(8-10):(5-6).

3. The high thermal shock resistant monolithic refractory material of claim 1, wherein, The preparation method of the aluminum sol is as follows: aluminum isopropyl alcohol is added to a reaction kettle, and deionized water is added dropwise under stirring, the temperature in the reaction kettle is controlled to be less than 50℃ during the dropping process, after the dropping is completed, the stirring is continued for 30-50min, the temperature is raised to 85-90℃, and the temperature is kept for 2-3h, the isopropyl alcohol is recovered by distillation, and then the concentrated nitric acid is added and stirred uniformly, the temperature is raised to 220-230℃, the temperature is kept for 20-22h, and then the aluminum sol is obtained after cooling and filtration.

4. The high thermal shock resistant monolithic refractory material of claim 3, wherein, In the preparation method of the aluminum sol, the deionized water is boiled and then cooled to 40-45℃; and the dropping speed of the deionized water is 10-15mL / min.

5. The high thermal shock resistant monolithic refractory material of claim 3, wherein, In the preparation method of the aluminum sol, the mass ratio of the aluminum isopropyl alcohol to the deionized water is 1:(1.5-1.7), the mass ratio of the aluminum isopropyl alcohol to the concentrated nitric acid is (50-60):1, and the mass percentage of the concentrated nitric acid is 65%-70%.

6. The high thermal shock resistant monolithic refractory material of claim 1, wherein, The nano powder is composed of nano carbon black, nano cerium oxide and nano aluminum oxide in a mass ratio of (5-9):(7-12):(15-20).

7. The high thermal shock resistant monolithic refractory material of claim 6, wherein, The nano powder is composed of nano carbon black, nano cerium oxide and nano aluminum oxide in a mass ratio of (7-9):(9-11):(17-19).

8. The high thermal shock resistant monolithic refractory material of claim 1, wherein, The particle size of the corundum is 5-8mm, 3-5mm, 1-3mm and 0.074-1mm, the mass percentage of the corundum with a particle size of 5-8mm is 40%-55%, the mass percentage of the corundum with a particle size of 3-5mm is 25%-40%, the mass percentage of the corundum with a particle size of 1-3mm is 10%-20%, and the mass percentage of the corundum with a particle size of 0.074-1mm is 2%-5%.

9. The high thermal shock resistant monolithic refractory material of claim 1, wherein, The particle size of the magnesium aluminate spinel is 5-8mm, 3-5mm and 1-3mm, the mass percentage of the magnesium aluminate spinel with a particle size of 5-8mm is 45%-60%, the mass percentage of the magnesium aluminate spinel with a particle size of 3-5mm is 20%-30%, and the mass percentage of the magnesium aluminate spinel with a particle size of 1-3mm is 15%-20%.

10. Process for the production of high thermal shock resistant monolithic refractory material according to any one of claims 1 to 9, characterized in that, Specifically: corundum and magnesium aluminate spinel according to particle size are sieved respectively, impurities and excessive particles are removed, dried, put into a blender, stirred for 3-5 min, then quartz glass powder is added, stirred for 2-3 min, continue to add the binder stirred, stir for 5-6 min, then add nano powder, polyaluminum phosphate and sodium tripolyphosphate, stir for 20-30 min, then dry at 200-250℃ for 12-14 h, calcine at 1600-1800℃ for 2-3 h, cool to 1000-1200℃ and keep for 3-4 h, cool to 600-700℃ and keep for 2-3 h, cool to 200-300℃ and keep for 1-1.5 h, naturally cool, package, to obtain high thermal shock resistance amorphous refractory material.

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