A preparation method of nano high-performance iron ditch castable

Abstract

The present invention provides a method for preparing a nano high-performance iron ditch castable, belonging to the technical field of refractory materials, and the preparation method comprises the following steps: S1, by weight, the following raw materials are configured: 62-67 parts of brown corundum, 18-22 parts of silicon carbide, 4-7 parts of calcium-doped mesoporous zirconium oxide, 2-5 parts of vermiculite, 6-8 parts of alpha alumina micropowder, 2-3 parts of titanium dioxide, 1-3 parts of coke powder, 0.1-0.3 parts of aluminum powder, 1-3 parts of silicon powder, 1-2 parts of titanium powder, 1-3 parts of nano alumina, 2-3 parts of binder and 0.3-0.5 parts of water reducer; S2, the raw materials in S1 are put into a mixer, stirred for 10-15min, and mixed to obtain the nano high-performance iron ditch castable. The present invention reduces the apparent porosity of the castable under a high temperature use environment of 1450°C and improves its high temperature compressive strength.

Description

Technical Field

[0001] The invention belongs to the technical field of refractory materials, and in particular relates to a method for preparing a nano high-performance iron channel castable. Background Art

[0002] The iron ditch is the channel through which molten iron flows. The molten iron is immersed in the iron ditch for a long time. The molten iron and the iron ditch castable will have a long direct contact. In order to resist the erosion of molten iron and iron slag, the castable needs to introduce a carbon source. In the preparation process of the iron ditch castable, coke is used as a carbon source. Coke increases the carbon content of the castable, which helps to resist oxidation at high temperature and improve the corrosion resistance of the castable.

[0003] But at the same time, the addition of coke will increase the porosity of the castable, mainly because coke itself has a porous structure. Under high temperature conditions, these pores of coke will become channels for gas to escape; and coke will react with other components in the castable to produce gas (the reactivity of coke increases with increasing temperature), resulting in more pores inside the castable. The pores will occupy the space that should be filled by the solid particles of the castable, resulting in a decrease in the density of the castable, which in turn affects the strength of the castable (high temperature compressive strength). Summary of the invention

[0004] In order to solve the problems existing in the background technology, the present invention provides a method for preparing a nano high-performance iron channel castable, which reduces the apparent porosity of the castable in a high-temperature use environment and improves its high-temperature compressive strength.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0007] S1. Prepare the following raw materials by weight: 62-67 parts of brown corundum, 18-22 parts of silicon carbide, 4-7 parts of calcium-doped mesoporous zirconium oxide, 2-5 parts of vermiculite, 6-8 parts of α-alumina powder, 2-3 parts of titanium dioxide, 1-3 parts of coke powder, 0.1-0.3 parts of aluminum powder, 1-3 parts of silicon powder, 1-2 parts of titanium powder, 1-3 parts of nano-alumina, 2-3 parts of binder and 0.3-0.5 parts of water reducer;

[0008] S2. Put the raw materials in S1 into a mixer, stir for 10-15 minutes, and mix well to obtain the nano high-performance iron ditch castable.

[0009] Furthermore, the preparation method of the calcium-doped mesoporous zirconia is as follows:

[0010] A1, dissolving 1 mol of zirconium sulfate tetrahydrate and 0.3 mol of hexadecyltrimethylammonium bromide in 240 mL of an aqueous solution of ammonium sulfate having a volume concentration of 1.5 mmol / L to obtain a first mixed solution;

[0011] A2, aging the first mixed solution obtained in A1 at room temperature for 24 hours, hydrothermally treating it at 110° C. for 24 hours, washing it with deionized water, filtering it for multiple times, obtaining a first solid, and drying it to obtain a precursor powder;

[0012] A3. Take 5 g of the precursor powder obtained in A2, place it in a 0.25 mol / L phosphoric acid solution for post-treatment modification, and add 1 mol / L calcium nitrate solution dropwise, continue stirring for 3 hours, wash with deionized water, filter several times, obtain the second solid, dry, obtain the third solid, and calcine to obtain the calcium-doped mesoporous zirconium oxide.

[0013] Furthermore, in A2, the specific operation of drying is: placing the first solid in a drying oven and drying it at a temperature of 45-55° C. for 4-4.5 hours.

[0014] Furthermore, in A3, the specific operation of drying is: placing the second solid in a drying oven and drying at a temperature of 55-65° C. for 5-5.5 hours.

[0015] Furthermore, in A3, the specific operation of calcination is: placing the third solid in a calcination furnace and calcining at a temperature of 490-510° C. for 6-6.5 hours.

[0016] Furthermore, the particle size of the brown corundum is 80-100 mesh, and the particle size of the silicon carbide is 120-150 mesh.

[0017] Furthermore, the particle size of the calcium-doped mesoporous zirconia is less than 180 mesh, the particle size of the vermiculite is less than 195 mesh, the particle size of the α-alumina micropowder is less than 2500 mesh, the particle size of the coke powder is less than 180 mesh, the particle size of the aluminum powder is less than 200 mesh, the particle size of the silicon powder is less than 200 mesh, and the particle size of the titanium powder is less than 200 mesh.

[0018] Furthermore, the binder is pure calcium aluminate cement.

[0019] Furthermore, the water reducing agent is sodium hexametaphosphate.

[0020] This application has the following beneficial effects:

[0021] 1. The calcium-doped mesoporous zirconia and vermiculite of the present invention can produce a synergistic effect in a high-temperature use environment of 1450°C, synergistically reduce the apparent porosity of the castable at 1450°C, and synergistically improve the compressive strength of the castable at 1450°C; the apparent porosity test data of the final castable in a high-temperature use environment of 1450°C is as low as below 25.4%, and the compressive strength test data is as high as above 41.8MPa; to ensure that the castable of the present invention has excellent performance in a high-temperature use environment of 1450°C.

[0022] 2. In the present invention, calcium-doped mesoporous zirconia is added, which has a large specific surface area and pore volume, and is conducive to the adsorption and fixation of other components in the castable, thereby improving the compactness of the castable. In addition, the mesoporous structure of calcium-doped mesoporous zirconia can also quickly adsorb the gas generated by the castable at high temperature, thereby preventing these gases from forming pores in the castable, thereby reducing the apparent porosity of the castable.

[0023] When vermiculite is added and contacts with calcium-doped mesoporous zirconia, the calcium element of calcium-doped mesoporous zirconia and the silicate in vermiculite can react chemically under a high temperature environment of 1450°C to generate calcium silicate with a grid structure, which can not only enhance the interfacial bonding strength between the components of the castable, but also better fill the gaps in the castable, reduce the escape channel of gas (such as moisture, volatiles, etc.), thereby reducing the apparent porosity and improving the density. At the same time, calcium silicate itself has high strength and hardness, and can further enhance the overall mechanical properties of the castable (such as compressive strength). BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 , a comparative trend chart of apparent porosity test data of the castables prepared in Examples 1 to 4 of the present invention and Comparative Examples 1 to 4 at 1000° C. and 1450° C. respectively;

[0025] Figure 2 , a trend chart comparing the compressive strength test data of the castables prepared in Examples 1 to 4 of the present invention and Comparative Examples 1 to 4 at 1000°C and 1450°C respectively. DETAILED DESCRIPTION

[0026] The present application is further described in detail below with reference to the embodiments.

[0027] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0028] Example 1: (1) The preparation method of calcium-doped mesoporous zirconium oxide is as follows:

[0029] A1. Dissolve 1 mol of zirconium sulfate tetrahydrate and 0.3 mol of hexadecyltrimethylammonium bromide in 240 mL of an aqueous ammonium sulfate solution having a volume concentration of 1.5 mmol / L to obtain a first mixed solution.

[0030] In this step, zirconium sulfate tetrahydrate is the precursor for synthesizing mesoporous zirconium oxide, and hexadecyltrimethylammonium bromide is used as a template to help form a mesoporous structure. The use of an aqueous solution of ammonium sulfate with a volume concentration of 1.5 mmol / L as a solvent helps maintain the stability of the solution and does not have a negative impact on the subsequent hydrothermal reaction.

[0031] Among them, zirconium sulfate tetrahydrate (purity 99%) was purchased from Hubei Xinrunde Chemical Co., Ltd. Hexadecyltrimethylammonium bromide (purity 99%) was purchased from Shandong Lvying Chemical Technology Co., Ltd. Ammonium sulfate (purity 99%) was purchased from Sinopec Hunan Petrochemical Co., Ltd.

[0032] A2. The first mixed solution obtained in A1 was aged at room temperature for 24 hours, and then hydrothermally treated at 110°C for 24 hours. The first solid was washed with deionized water and filtered three times to obtain a first solid. The first solid was placed in a drying oven and dried at 50°C for 4.2 hours to obtain a precursor powder.

[0033] In this step, the aging process helps the interaction between the raw materials and prepares for the subsequent hydrothermal reaction. Hydrothermal treatment is the key to forming a mesoporous structure. The high temperature and high pressure environment helps accelerate the chemical reaction and form mesoporous materials.

[0034] A3. Take 5 g of the precursor powder obtained in A2, place it in 50 mL of 0.25 mol / L phosphoric acid solution for post-treatment modification, and add 1 mol / L calcium nitrate solution dropwise at the same time, add 20 mL in total, continue stirring for 3 hours, wash with deionized water, filter three times, and obtain the second solid. Place the second solid in a drying oven and dry it at 60°C for 5.2 hours to obtain a third solid. Place the third solid in a calcination furnace and calcine it at 500°C for 6.2 hours to obtain calcium-doped mesoporous zirconium oxide.

[0035] In this step, a 0.25 mol / L phosphoric acid solution helps to further adjust the pore structure and chemical properties of the material. Adding a 1 mol / L calcium nitrate solution dropwise and stirring for 3 hours can achieve calcium ion doping, which can replace some zirconium ions and thus change the performance of the material. The calcination process helps to remove the template and obtain a purer calcium-doped mesoporous zirconium oxide.

[0036] Among them, phosphoric acid was purchased from Jinan Chengmin Chemical Co., Ltd. Calcium nitrate was purchased from Jinan Qicai Chemical Co., Ltd.

[0037] (2) A method for preparing a nano high-performance iron ditch castable, comprising the following steps:

[0038] S1. Prepare the following raw materials by weight: 65 parts of brown corundum, 20 parts of silicon carbide, 6 parts of calcium-doped mesoporous zirconia, 3 parts of vermiculite, 7 parts of α-alumina micropowder, 2.5 parts of titanium dioxide, 2 parts of coke powder, 0.2 parts of aluminum powder, 2 parts of silica powder, 1.5 parts of titanium powder, 2 parts of nano alumina, 2.5 parts of pure calcium aluminate cement as a binder, and 0.4 parts of sodium hexametaphosphate as a water reducer.

[0039] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 13 minutes to mix them evenly, and then obtain nano high-performance iron ditch castable.

[0040] Among them, the particle size of brown corundum is 80-100 mesh, the particle size of silicon carbide is 120-150 mesh, the particle size of calcium-doped mesoporous zirconia is less than 180 mesh, the particle size of vermiculite is less than 195 mesh, the particle size of α-alumina micropowder is less than 2500 mesh, the particle size of coke powder is less than 180 mesh, the particle size of aluminum powder is less than 200 mesh, the particle size of silicon powder is less than 200 mesh, and the particle size of titanium powder is less than 200 mesh.

[0041] Brown corundum was purchased from Henan Youji Environmental Protection Technology Co., Ltd. Silicon carbide was purchased from Henan Dongli New Materials Co., Ltd. Vermiculite (200 mesh) was purchased from Hebei Zongrun Mineral Products Co., Ltd. Alpha alumina powder (3000 mesh) was purchased from Gongyi Hongle Mineral Products Co., Ltd. Coke powder (200 mesh) was purchased from Lingshou Tuyun Mineral Products Processing Plant. Aluminum powder is spherical aluminum powder (23-25μm) purchased from Hunan Jinhao New Materials Technology Co., Ltd. Silica powder is irregular silica powder (40μm) purchased from Bohuas Nano Technology (Ningbo) Co., Ltd. Titanium powder is high-purity titanium powder (300-400 mesh) purchased from Sichuan Xinshutai New Materials Co., Ltd. Pure calcium aluminate cement was purchased from Zhengzhou Kerui Refractory Materials Co., Ltd. Sodium hexametaphosphate was purchased from Hubei Xingfa Chemical Group Co., Ltd.

[0042] Embodiment 2: The difference between this embodiment and embodiment 1 is that: a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0043] S1. Prepare the following raw materials by weight: 62 parts of brown corundum, 18 parts of silicon carbide, 4 parts of calcium-doped mesoporous zirconia, 2 parts of vermiculite, 6 parts of α-alumina micropowder, 2 parts of titanium dioxide, 1 part of coke powder, 0.1 parts of aluminum powder, 1 part of silica powder, 1 part of titanium powder, 1 part of nano alumina, 2 parts of pure calcium aluminate cement as a binder, and 0.3 parts of sodium hexametaphosphate as a water reducer.

[0044] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 10 minutes to mix them evenly, so as to obtain nano high-performance iron ditch castable.

[0045] Embodiment 3: The difference between this embodiment and embodiment 1 is that: a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0046] S1. Prepare the following raw materials by weight: 67 parts of brown corundum, 22 parts of silicon carbide, 7 parts of calcium-doped mesoporous zirconium oxide, 5 parts of vermiculite, 8 parts of α-alumina micropowder, 3 parts of titanium dioxide, 3 parts of coke powder, 0.3 parts of aluminum powder, 3 parts of silica powder, 2 parts of titanium powder, 3 parts of nano alumina, 3 parts of pure calcium aluminate cement as a binder, and 0.5 parts of sodium hexametaphosphate as a water reducer.

[0047] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 15 minutes to mix them evenly, so as to obtain nano high-performance iron ditch castable.

[0048] Embodiment 4: The difference between this embodiment and embodiment 1 is that: a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0049] S1. Prepare the following raw materials by weight: 62 parts of brown corundum, 20 parts of silicon carbide, 5 parts of calcium-doped mesoporous zirconium oxide, 3 parts of vermiculite, 7 parts of α-alumina powder, 2 parts of titanium dioxide, 2 parts of coke powder, 0.1 parts of aluminum powder, 1 part of silica powder, 1 part of titanium powder, 1 part of nano alumina, 2.5 parts of pure calcium aluminate cement as a binder, and 0.4 parts of sodium hexametaphosphate as a water reducer.

[0050] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 12 minutes to mix them evenly, and then obtain nano high-performance iron ditch castable.

[0051] Comparative Example 1: The difference between this comparative example and Example 1 is that vermiculite and calcium-doped mesoporous zirconia are deleted.

[0052] Specifically, a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0053] S1. Prepare the following raw materials by weight: 65 parts of brown corundum, 20 parts of silicon carbide, 7 parts of alpha alumina powder, 2.5 parts of titanium dioxide, 2 parts of coke powder, 0.2 parts of aluminum powder, 2 parts of silicon powder, 1.5 parts of titanium powder, 2 parts of nano alumina, 2.5 parts of pure calcium aluminate cement as a binder, and 0.4 parts of sodium hexametaphosphate as a water reducer.

[0054] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 13 minutes to mix them evenly, and then obtain nano high-performance iron ditch castable.

[0055] Comparative Example 2: The difference between this comparative example and Example 1 is that the calcium-doped mesoporous zirconia is deleted.

[0056] Specifically, a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0057] S1. Prepare the following raw materials by weight: 65 parts of brown corundum, 20 parts of silicon carbide, 3 parts of vermiculite, 7 parts of α-alumina powder, 2.5 parts of titanium dioxide, 2 parts of coke powder, 0.2 parts of aluminum powder, 2 parts of silica powder, 1.5 parts of titanium powder, 2 parts of nano alumina, 2.5 parts of pure calcium aluminate cement as a binder, and 0.4 parts of sodium hexametaphosphate as a water reducer.

[0058] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 13 minutes to mix them evenly, and then obtain nano high-performance iron ditch castable.

[0059] Comparative Example 3: The difference between this comparative example and Example 1 is that vermiculite is deleted.

[0060] Specifically, a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0061] S1. Prepare the following raw materials by weight: 65 parts of brown corundum, 20 parts of silicon carbide, 6 parts of calcium-doped mesoporous zirconium oxide, 7 parts of α-alumina powder, 2.5 parts of titanium dioxide, 2 parts of coke powder, 0.2 parts of aluminum powder, 2 parts of silicon powder, 1.5 parts of titanium powder, 2 parts of nano alumina, 2.5 parts of pure calcium aluminate cement as a binder, and 0.4 parts of sodium hexametaphosphate as a water reducer.

[0062] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 13 minutes to mix them evenly, and then obtain nano high-performance iron ditch castable.

[0063] Comparative Example 4: The difference between this comparative example and Example 1 is that the calcium-doped mesoporous zirconia is replaced by zirconium oxide.

[0064] Specifically, a method for preparing a nano high-performance iron ditch castable comprises the following steps:

[0065] S1. Prepare the following raw materials by weight: 65 parts of brown corundum, 20 parts of silicon carbide, 6 parts of zirconium oxide, 3 parts of vermiculite, 7 parts of α-alumina powder, 2.5 parts of titanium dioxide, 2 parts of coke powder, 0.2 parts of aluminum powder, 2 parts of silicon powder, 1.5 parts of titanium powder, 2 parts of nano-alumina, 2.5 parts of pure calcium aluminate cement as a binder, and 0.4 parts of sodium hexametaphosphate as a water reducer. Among them, zirconium oxide (powder) is purchased from Zhengzhou Xinli Wear-Resistant Materials Co., Ltd.

[0066] S2. Put all the raw materials in S1 into a mixer, stir them at a stirring speed of 270r / min for 13 minutes to mix them evenly, and then obtain nano high-performance iron ditch castable.

[0067] Test example: Test object: Casting materials were prepared according to Example 1 to Example 4 and Comparative Example 1 to Comparative Example 4.

[0068] Test items and methods: After preparing the castables for each test object respectively, add water (the mass of water is 5% of the mass of the castable), continue stirring for 4 minutes to mix, and vibrate and cast into 40mm*40mm*160mm specimens, cure for 24 hours, bake at 110℃ for 24 hours, sinter in a high-temperature furnace at 1000℃ / 1450℃, hold for 3 hours, and heat at a rate of 10℃ / min. Test the following items: ① High temperature compressive strength - tested in accordance with GB / T 34218-2017; ② Apparent porosity - tested in accordance with GB / T 2997-2000.

[0069] Test results: See Table 1.

[0070] Table 1

[0071]

[0072] Result analysis: Analyze Example 1-Example 4 and combine the data in Table 1 and Figure 1-Figure 2 It can be seen that the porosity test data of the castable prepared by the present invention in a high temperature use environment of 1450°C is as low as below 25.4%, and the compressive strength test data is as high as above 41.8MPa, indicating that the castable prepared by the present invention has excellent performance in a high temperature use environment of 1450°C.

[0073] Analyze Example 1 and Comparative Examples 1-4 and combine the data in Table 1 and Figure 1-Figure 2 By comparing Comparative Example 1 with Comparative Example 2, it can be seen that compared with Comparative Example 1, vermiculite is added in Comparative Example 2. As a result, the apparent porosity test data of the castable prepared in Comparative Example 2 at 1000℃ and 1450℃ are 28.5% and 29.3%, respectively, which are greater than 26.8% and 27.5% of Comparative Example 1, respectively; the compressive strength test data of the castable prepared in Comparative Example 2 at 1000℃ and 1450℃ are 35.5MPa and 34.1MPa, respectively, which are less than 38.7MPa and 36.3MPa of Comparative Example 1, respectively. It shows that the addition of vermiculite alone will increase the apparent porosity of the castable prepared at 1000℃ and 1450℃, and reduce the compressive strength.

[0074] This is because vermiculite will expand at high temperatures (800-1000℃), and the volume will increase to fill the pores in the castable; the expansion of vermiculite can also offset the sintering shrinkage of the castable at high temperatures, and at the same time, fill the pores caused by the gas produced by the coke reaction. But at the same time, vermiculite will also produce gas during the expansion process, resulting in an increase in the apparent porosity. The two phases offset each other, and ultimately the addition of vermiculite alone will increase the porosity of the castable.

[0075] By comparing Comparative Example 1 and Comparative Example 3, it can be seen that compared with Comparative Example 1, calcium-doped mesoporous zirconia is added in Comparative Example 3, and the test data of apparent porosity of the castable prepared in Comparative Example 3 at 1000°C and 1450°C are 25.9% and 26.4%, respectively, which are less than 26.8% and 27.5% of Comparative Example 1, respectively; the test data of compressive strength of the castable prepared in Comparative Example 3 at 1000°C and 1450°C are 40.9MPa and 38.9MPa, respectively, which are greater than 38.7MPa and 36.3MPa of Comparative Example 1, respectively. It shows that the addition of calcium-doped mesoporous zirconia alone can reduce the apparent porosity of the castable prepared at 1000°C and 1450°C, and improve the compressive strength.

[0076] This is because the mesoporous structure of calcium-doped mesoporous zirconia gives it a large specific surface area and pore volume, which is conducive to the adsorption and fixation of other components in the castable, thereby improving the density of the castable. In addition, the mesoporous structure of calcium-doped mesoporous zirconia can also quickly adsorb the gas generated by the castable at high temperature, thereby preventing these gases from forming pores in the castable, thereby reducing the apparent porosity of the castable.

[0077] By comparing Comparative Example 3 with Example 1, it can be seen that compared with Comparative Example 3, under the premise that calcium-doped mesoporous zirconia already exists, vermiculite is added in Example 1. As a result, the test data of the apparent porosity of the castable prepared in Example 1 at 1000°C is 26.3%, which is greater than 25.9% of Comparative Example 3; the test data of the compressive strength of the castable prepared in Example 1 at 1000°C is 40.1MPa, which is less than 40.9MPa of Comparative Example 3. It shows that under the premise of the presence of calcium-doped mesoporous zirconia, the addition of vermiculite will still lead to an increase in the apparent porosity of the castable prepared at 1000°C and a decrease in the compressive strength.

[0078] However, the test data of the apparent porosity of the castable prepared in Example 1 at 1450°C is 25.1%, which is significantly lower than 26.4% of Comparative Example 3; the test data of the compressive strength of the castable prepared in Example 1 at 1450°C is 42.0MPa, which is significantly higher than 38.9MPa of Comparative Example 3. This shows that under the premise of the presence of calcium-doped mesoporous zirconia, the addition of vermiculite can produce a synergistic effect under the high temperature use environment of 1450°C, synergistically reduce the apparent porosity of the castable prepared at 1450°C, and synergistically improve the compressive strength of the castable prepared at 1450°C.

[0079] This is because when used at a high temperature of 1450℃, calcium-doped mesoporous zirconia comes into contact with vermiculite, and the calcium element of calcium-doped mesoporous zirconia reacts chemically with the silicate in vermiculite to generate calcium silicate with a grid structure. The formation of calcium silicate with a grid structure can not only enhance the interfacial bonding strength between the components of the castable, but also better fill the gaps in the castable, reduce the escape channels of gases (such as moisture, volatiles, etc.), thereby reducing the apparent porosity and improving the density. At the same time, calcium silicate itself has high strength and hardness, and can further enhance the overall mechanical properties of the castable (such as compressive strength).

[0080] By comparing Example 1 with Comparative Example 4, it can be seen that compared with Example 1, Comparative Example 4 replaces calcium-doped mesoporous zirconia with zirconium oxide, and the test data of apparent porosity and compressive strength of the castable prepared in Comparative Example 4 at 1000°C are similar to those of Example 1, without significant changes. This indicates that replacing calcium-doped mesoporous zirconia with zirconium oxide will not affect the apparent porosity and compressive strength of the castable prepared at 1000°C.

[0081] However, the test data of the apparent porosity of the castable prepared in Comparative Example 4 at 1450°C is significantly greater than that of Example 1, and the test data of the compressive strength of the castable prepared in Comparative Example 4 at 1450°C is significantly less than that of Example 1. This indicates that replacing calcium-doped mesoporous zirconia with zirconium oxide will increase the apparent porosity of the castable at 1450°C and reduce the compressive strength. This also proves that zirconium oxide itself and vermiculite cannot produce a synergistic effect at 1450°C.

[0082] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0083] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a nano high-performance iron ditch castable, characterized in that: The steps include: S1. Prepare the following raw materials by weight: 62-67 parts of brown corundum, 18-22 parts of silicon carbide, 4-7 parts of calcium-doped mesoporous zirconium oxide, 2-5 parts of vermiculite, 6-8 parts of α-alumina powder, 2-3 parts of titanium dioxide, 1-3 parts of coke powder, 0.1-0.3 parts of aluminum powder, 1-3 parts of silicon powder, 1-2 parts of titanium powder, 1-3 parts of nano-alumina, 2-3 parts of binder and 0.3-0.5 parts of water reducer; S2, putting the raw materials in S1 into a mixer, stirring for 10-15 minutes, and mixing well to obtain the nano high-performance iron ditch castable; The preparation method of the calcium-doped mesoporous zirconium oxide is as follows: A1, dissolving 1 mol of zirconium sulfate tetrahydrate and 0.3 mol of hexadecyltrimethylammonium bromide in 240 mL of an aqueous solution of ammonium sulfate having a volume concentration of 1.5 mmol / L to obtain a first mixed solution; A2, aging the first mixed solution obtained in A1 at room temperature for 24 hours, hydrothermally treating it at 110° C. for 24 hours, washing it with deionized water, filtering it for multiple times, obtaining a first solid, and drying it to obtain a precursor powder; A3. Take 5 g of the precursor powder obtained in A2, place it in a 0.25 mol / L phosphoric acid solution for post-treatment modification, and add 1 mol / L calcium nitrate solution dropwise, continue stirring for 3 hours, wash with deionized water, filter several times to obtain a second solid, dry to obtain a third solid, and calcine to obtain the calcium-doped mesoporous zirconium oxide.

2. The method for preparing the nano high-performance iron ditch castable according to claim 1, characterized in that: In A2, the specific operation of drying is: placing the first solid in a drying oven and drying at a temperature of 45-55° C. for 4-4.5 hours.

3. The method for preparing the nano high performance iron ditch castable according to claim 1, characterized in that: In A3, the specific operation of drying is: placing the second solid in a drying oven and drying at a temperature of 55-65° C. for 5-5.5 hours.

4. The method for preparing the nano high-performance iron ditch castable according to claim 1, characterized in that: In A3, the specific operation of calcination is: placing the third solid in a calcination furnace and calcining at a temperature of 490-510° C. for 6-6.5 hours.

5. The method for preparing nano high-performance iron ditch castable according to claim 1, characterized in that: The particle size of the brown corundum is 80-100 meshes, and the particle size of the silicon carbide is 120-150 meshes.

6. The method for preparing nano high-performance iron channel castable according to claim 1, characterized in that: The particle size of the calcium-doped mesoporous zirconia is less than 180 mesh, the particle size of the vermiculite is less than 195 mesh, the particle size of the α-alumina micropowder is less than 2500 mesh, the particle size of the coke powder is less than 180 mesh, the particle size of the aluminum powder is less than 200 mesh, the particle size of the silicon powder is less than 200 mesh, and the particle size of the titanium powder is less than 200 mesh.

7. The method for preparing nano high-performance iron ditch castable according to claim 1, characterized in that: The binder is pure calcium aluminate cement.

8. The method for preparing nano high-performance iron ditch castable according to claim 1, characterized in that: The water reducing agent is sodium hexametaphosphate.

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