Mullite-based high-strength wear-resistant anti-erosion castable for coke oven top and preparation method thereof

Abstract

The invention relates to the field of castable, in particular to mullite-based high-strength wear-resistant anti-erosion castable for a coke oven top and a preparation method of the mullite-based high-strength wear-resistant anti-erosion castable. Comprising the following raw materials in parts by mass: 45-60 parts of mullite aggregate, 8-15 parts of bauxite, 3-6 parts of crystal whiskers, 6-9 parts of calcium aluminate cement, 1-3 parts of an additive, 1-2 parts of a water reducing agent, 0.1-0.2 part of steel fibers and 3-5 parts of water, the preparation method comprises the following steps: S1, putting the mullite raw material, the bauxite, the whisker, the calcium aluminate cement, the additive, the water reducing agent and the steel fiber into a stirrer, and stirring to obtain a mixture; and S2, putting the mixture into a stirrer, adding water while stirring, and stirring to obtain the mullite-based high-strength wear-resistant anti-erosion castable for the coke oven top. The prepared castable has excellent characteristics of high strength, good wear resistance, high temperature resistance and strong erosion resistance.

Description

Technical Field

[0001] The invention relates to the field of castables, and in particular to a mullite-based high-strength, wear-resistant and erosion-resistant castable for a coke oven top and a preparation method thereof. Background Art

[0002] Coke ovens play a vital role in the steel production process, and the coke oven roof, as an important part of the coke oven, is exposed to harsh environments such as high temperature, charge impact, and gas erosion for a long time. Under such working conditions, the refractory materials used for the roof need to have high strength, high wear resistance, and excellent corrosion resistance to ensure the stable operation and long service life of the coke oven.

[0003] Traditional castables for coke oven roofs have certain limitations in terms of strength, wear resistance and corrosion resistance. For example, some castables have a significant decrease in strength at high temperatures and are easily damaged by the impact of falling furnace charges; some castables have insufficient wear resistance, and in the long-term use process, the surface is severely worn, resulting in damage to the roof structure; and some castables have weak corrosion resistance to harmful components in coal gas, which will reduce the service life of the castables after being corroded, increasing the maintenance cost and downtime of the coke oven.

[0004] Mullite has high refractoriness, good chemical stability and certain mechanical strength, and is an ideal raw material for preparing high-performance castables. However, castables based solely on mullite still cannot fully meet the stringent requirements of coke oven tops in terms of performance. Therefore, it is of great practical significance to develop a mullite-based high-strength, wear-resistant and erosion-resistant castable and its preparation method for coke oven top working conditions. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned technology, the present invention provides a mullite-based high-strength wear-resistant and erosion-resistant castable for a coke oven roof and a preparation method thereof.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: A mullite-based high-strength, wear-resistant and erosion-resistant castable for a coke oven roof, comprising the following raw materials in parts by weight: 45-60 parts of mullite aggregate, 8-15 parts of bauxite, 3-6 parts of whiskers, 6-9 parts of calcium aluminate cement, 1-3 parts of admixture, 1-2 parts of water reducer, 0.1-0.2 parts of steel fiber and 3-5 parts of water.

[0007] Preferably, the whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir for 25 - 35 min, add cerium nitrate and yttrium nitrate, continue to stir for 10 - 15 min, then add tetraethyl orthosilicate, stir for 10 - 20 min, subsequently add p-toluenesulfonic acid, stir and react for 1 - 2 h, transfer to a sealed container, age for 10 - 15 h, take out and place in a drying oven, dry for 6 - 10 h, and finally calcine to obtain whiskers; among them, 28 - 40 parts of aluminum isopropoxide, 18 - 25 parts of tetraethyl orthosilicate, 0.2 - 0.4 part of p-toluenesulfonic acid, 0.1 - 0.3 part of cerium nitrate, 0.1 - 0.3 part of yttrium nitrate, and 150 - 220 parts of ethanol.

[0008] Preferably, the admixture is prepared by mixing 3 - 5 parts of silica fume and 1 - 2 parts of modified bentonite.

[0009] Preferably, the silica fume is prepared by calcining at 1000 - 1200 °C for 1 - 3 h.

[0010] Preferably, the modified bentonite is prepared by the following method: Mix sodium sarcosinate and deionized water, heat and stir for 20 - 35 min, add sodium tripolyphosphate, stir for 20 - 30 min, then add bentonite, ultrasonically disperse for 15 - 20 min, heat and stir for 3 - 5 h, centrifuge for 5 - 8 min, wash, and dry to obtain modified bentonite; among them, 1 - 3 parts of sodium sarcosinate, 0.1 - 0.2 part of sodium tripolyphosphate, 15 - 25 parts of bentonite, and 150 - 180 parts of deionized water.

[0011] Preferably, the water reducing agent is sodium hexametaphosphate and / or sodium pyrophosphate.

[0012] A preparation method of a mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven roof includes the following steps: S1. Put the mullite raw material, bauxite, whiskers, calcium aluminate cement, admixture, water reducing agent and steel fiber into a mixer, stir for 20 - 30 min to obtain a mixture. S2. Place the mixture in a mixer, add water while stirring, control the stirring rate at 100 - 200 rpm, and stir for 10 - 15 min to obtain the mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven roof.

[0013] In summary, the present invention has the following beneficial effects: In the present invention, aluminum isopropoxide and tetraethyl orthosilicate are mixed, and cerium nitrate, yttrium nitrate and p-toluenesulfonic acid are added to prepare whiskers. The introduction of rare earth elements cerium and yttrium changes the crystal structure and electronic structure of the whiskers, thereby improving the mechanical properties, high-temperature resistance and oxidation resistance of the whiskers. The introduction of p-toluenesulfonic acid can accelerate the hydrolysis and polycondensation reactions of aluminum isopropoxide and tetraethyl orthosilicate, shorten the reaction time, improve the reaction efficiency, and enable the reaction to achieve the desired effect within a shorter time. When added to the castable, it can form a three-dimensional network structure in the castable, improve the overall structural strength and load-bearing capacity, and can play a role in blocking and bridging on the path of crack propagation, change the crack propagation direction, and consume the energy of crack propagation, thereby inhibiting the further development of cracks.

[0014] In the present invention, bentonite is treated with sodium sarcosinate, and then sodium tripolyphosphate is added to prepare modified bentonite. The introduction of sodium sarcosinate can improve the surface properties of bentonite, enhance its hydrophilicity. After being mixed with silica powder after high-temperature calcination, an admixture is prepared. The modified bentonite has good adhesiveness and filling properties, and the silica powder has high activity and fine particle characteristics. When the two are mixed and added to the castable, they can fill the pores in the castable, make the structure of the castable more dense, and thus improve the mechanical properties of the castable. The modified bentonite can fill some of the pores in the castable, and the introduction of silica powder can further fill into finer voids and the gaps between bentonite particles, make the structure of the castable more dense, and thus improve the wear resistance. Detailed implementation manners

[0015] The present invention will be further described below in conjunction with the specific implementation manners, but the embodiments do not limit the present invention in any form.

[0016] Mullite aggregate, purchased from Zhengzhou Dongze Foundry Materials Co., Ltd., 200 mesh; bauxite, purchased from Hebei Hengguang Mineral Products Co., Ltd., particle size: 150 nm; calcium aluminate cement, purchased from Zhengzhou Shengshi Jinding Thermal Insulation and Refractory Materials Co., Ltd.; steel fiber, purchased from Baoding Shengtaiyuan Metal Products Co., Ltd., product type: milled steel fiber; silica powder, purchased from Shouluanshan Mineral Products Processing Factory, Lingshou County, 325 mesh; bentonite, purchased from Bosheng Mineral Products Processing Factory, Lingshou County, content ≥ 97%.

[0017] Example 1 A mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven roof, comprising the following raw materials in parts by mass: 45 parts of mullite aggregate, 8 parts of bauxite, 3 parts of whiskers, 6 parts of calcium aluminate cement, 1 part of admixture, 1 part of water reducer, 0.1 part of steel fiber and 3 parts of water.

[0018] Among them, the whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir at 150 rpm for 25 min, add cerium nitrate and yttrium nitrate, continue stirring for 10 min, then add tetraethyl orthosilicate, stir at 80 rpm for 10 min, subsequently add p-toluenesulfonic acid, stir and react at 200 rpm for 1 h, transfer to a sealed container, carry out aging treatment, the aging temperature is 60 °C, the aging time is 10 h, take out and place in a drying oven, the drying temperature is 80 °C, dry for 6 h, and finally carry out calcination. The calcination system is: heat up to 800 °C at a rate of 5 °C / min, hold for 1 h, then heat up to 1400 °C at a rate of 3 °C / min, hold for 2 h, and cool to room temperature with the furnace to obtain whiskers; among them, 28 parts of aluminum isopropoxide, 18 parts of tetraethyl orthosilicate, 0.2 part of p-toluenesulfonic acid, 0.1 part of cerium nitrate, 0.1 part of yttrium nitrate, and 150 parts of ethanol.

[0019] Among them, the admixture is prepared by mixing 3 parts of silica fume and 1 part of modified bentonite.

[0020] Among them, the silica fume is held at 80 °C for 3 h, then heated up to 1000 °C at a rate of 5 °C / min, held for 1 h, and cooled with the furnace to obtain it.

[0021] The modified bentonite is prepared by the following method: Mix sodium sarcosinate and deionized water, stir at 30 °C for 20 min, control the stirring rate at 100 rpm, add sodium tripolyphosphate, stir at 100 rpm for 200 min, then add bentonite, ultrasonically disperse at 20 kHz for 15 min, heat to 45 °C and stir for 3 h, control the stirring rate at 150 rpm, centrifuge at 4000 rpm for 5 min, wash 3 times with deionized water, and dry at 80 °C for 4 h to obtain the modified bentonite; among them, 1 part of sodium sarcosinate, 0.1 part of sodium tripolyphosphate, 15 parts of bentonite, and 150 parts of deionized water.

[0022] A preparation method of a mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven top includes the following steps: S1. Put the mullite raw material, bauxite, whiskers, calcium aluminate cement, admixture, water reducer and steel fiber into a mixer, stir at 200 rpm for 20 min to obtain a mixture; among them, the water reducer is sodium hexametaphosphate; S2. Place the mixture in a mixer, add water while stirring, control the stirring rate at 100 rpm, and stir for 10 min to obtain the mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven top.

[0023] Example 2 A mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven top, comprising the following raw materials in parts by mass: 60 parts of mullite aggregate, 15 parts of bauxite, 6 parts of whiskers, 9 parts of calcium aluminate cement, 3 parts of admixture, 2 parts of water reducer, 0.2 parts of steel fiber and 5 parts of water.

[0024] Among them, the whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir at 200 rpm for 35 min, add cerium nitrate and yttrium nitrate, continue to stir for 15 min, then add tetraethyl orthosilicate, stir at 100 rpm for 20 min, then add p-toluenesulfonic acid, stir and react at 300 rpm for 2 h, transfer to a sealed container, carry out aging treatment, the aging temperature is 70 °C, the aging time is 15 h, take out and place in a drying oven, the drying temperature is 100 °C, dry for 10 h, and finally carry out calcination. The calcination system is: heat up to 1000 °C at a rate of 10 °C / min, hold for 3 h, then heat up to 1600 °C at a rate of 6 °C / min, hold for 4 h, and cool to room temperature with the furnace to obtain whiskers; among them, 40 parts of aluminum isopropoxide, 25 parts of tetraethyl orthosilicate, 0.4 part of p-toluenesulfonic acid, 0.3 part of cerium nitrate, 0.3 part of yttrium nitrate, and 220 parts of ethanol.

[0025] Among them, the admixture is prepared by mixing 5 parts of silica fume and 2 parts of modified bentonite.

[0026] Among them, the silica fume is held at 100 °C for 5 h, then heated up to 1200 °C at a rate of 8 °C / min, held for 3 h, and cooled with the furnace to obtain it.

[0027] The modified bentonite is prepared by the following method: Mix sodium sarcosinate and deionized water, stir at 40 °C for 35 min, control the stirring rate at 150 rpm, add sodium tripolyphosphate, stir at 150 rpm for 30 min, then add bentonite, ultrasonically disperse at 30 kHz for 20 min, heat to 60 °C and stir for 5 h, control the stirring rate at 200 rpm, centrifuge at 6000 rpm for 8 min, wash with deionized water 3 times, and dry at 100 °C for 6 h to obtain modified bentonite; among them, 3 parts of sodium sarcosinate, 0.2 part of sodium tripolyphosphate, 25 parts of bentonite, and 180 parts of deionized water.

[0028] A preparation method of a mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven top, comprising the following steps: S1. Put the mullite raw material, bauxite, whiskers, calcium aluminate cement, admixture, water reducer and steel fiber into a mixer, stir at 300 rpm for 30 min to obtain a mixture; among them, the water reducer is sodium hexametaphosphate; S2. Place the mixture in a mixer, add water while stirring, control the stirring rate at 200 rpm, and stir for 15 min to obtain a mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven top.

[0029] Example 3 A mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof, comprising raw materials in the following parts by mass: 55 parts of mullite aggregate, 12 parts of bauxite, 5 parts of whiskers, 8 parts of calcium aluminate cement, 2 parts of admixture, 1.5 parts of water reducer, 0.1 part of steel fiber and 4 parts of water.

[0030] Among them, the whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir at 180 rpm for 30 min, add cerium nitrate and yttrium nitrate, continue stirring for 12 min, then add tetraethyl orthosilicate, stir at 90 rpm for 15 min, then add p-toluenesulfonic acid, stir and react at 250 rpm for 1.5 h, transfer to a sealed container, carry out aging treatment, the aging temperature is 65 °C, the aging time is 12 h, take out and place in a drying oven, the drying temperature is 90 °C, dry for 8 h, and finally carry out calcination. The calcination system is: heat up to 900 °C at a rate of 8 °C / min, hold for 2 h, then heat up to 1500 °C at a rate of 5 °C / min, hold for 3 h, and cool to room temperature with the furnace to obtain whiskers; among them, 34 parts of aluminum isopropoxide, 22 parts of tetraethyl orthosilicate, 0.3 part of p-toluenesulfonic acid, 0.2 part of cerium nitrate, 0.2 part of yttrium nitrate, and 190 parts of ethanol.

[0031] Among them, the admixture is prepared by mixing 4 parts of silica fume and 1.5 parts of modified bentonite.

[0032] Among them, the silica fume is held at 90 °C for 4 h, then heated up to 1100 °C at a rate of 7 °C / min, held for 2 h, and cooled with the furnace to obtain.

[0033] The modified bentonite is prepared by the following method: Mix sodium sarcosinate and deionized water, stir at 35 °C for 30 min, control the stirring rate at 130 rpm, add sodium tripolyphosphate, stir at 130 rpm for 25 min, then add bentonite, ultrasonically disperse at 25 kHz for 18 min, heat to 55 °C and stir for 4 h, control the stirring rate at 180 rpm, centrifuge at 5000 rpm for 7 min, wash 3 times with deionized water, and dry at 90 °C for 5 h to obtain modified bentonite; among them, 2 parts of sodium sarcosinate, 0.1 part of sodium tripolyphosphate, 20 parts of bentonite, and 170 parts of deionized water.

[0034] A preparation method of a mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof, comprising the following steps: S1. Put the mullite raw material, bauxite, whiskers, calcium aluminate cement, admixture, water reducer and steel fiber into a mixer, stir at 260 rpm for 25 min to obtain a mixture; among them, the water reducer is sodium pyrophosphate; S2. Place the mixture in a blender, add water while stirring, control the stirring rate at 150 rpm, and stir for 13 min to obtain a mullite-based high-strength, wear-resistant and erosion-resistant castable for the coke oven roof.

[0035] Comparative Example 1 Comparative Example 1 is the same as Example 1, except that the preparation method of the whiskers is different, which is specifically as follows: The whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir at 150 rpm for 25 min, add tetraethyl orthosilicate, stir at 80 rpm for 10 min, then add p-toluenesulfonic acid, stir and react at 200 rpm for 1 h, transfer to a closed container, carry out aging treatment, the aging temperature is 60 °C, the aging time is 10 h, take out and place in a drying oven, the drying temperature is 80 °C, dry for 6 h, and finally carry out calcination. The calcination system is: heat up to 800 °C at a rate of 5 °C / min, hold for 1 h, then heat up to 1400 °C at a rate of 3 °C / min, hold for 2 h, and cool to room temperature with the furnace to obtain whiskers; among them, 28 parts of aluminum isopropoxide, 18 parts of tetraethyl orthosilicate, 0.2 part of p-toluenesulfonic acid, and 150 parts of ethanol.

[0036] Comparative Example 2 Comparative Example 2 is the same as Example 1, except that the preparation method of the whiskers is different, which is specifically as follows: The whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir at 150 rpm for 25 min, add cerium nitrate and yttrium nitrate, continue to stir for 10 min, then add tetraethyl orthosilicate, stir and react at 200 rpm for 1 h, transfer to a closed container, carry out aging treatment, the aging temperature is 60 °C, the aging time is 10 h, take out and place in a drying oven, the drying temperature is 80 °C, dry for 6 h, and finally carry out calcination. The calcination system is: heat up to 800 °C at a rate of 5 °C / min, hold for 1 h, then heat up to 1400 °C at a rate of 3 °C / min, hold for 2 h, and cool to room temperature with the furnace to obtain whiskers; among them, 28 parts of aluminum isopropoxide, 18 parts of tetraethyl orthosilicate, 0.1 part of cerium nitrate, 0.1 part of yttrium nitrate, and 150 parts of ethanol.

[0037] Comparative Example 3 Comparative Example 3 is the same as Example 1, except that the silica fume is not subjected to high-temperature calcination treatment.

[0038] Comparative Example 4 Comparative Example 4 is the same as Example 1, except that the admixture is prepared by mixing 3 parts of silica fume and 1 part of bentonite.

[0039] Performance Test Sample preparation: Add 10 parts of water to the castables prepared in Examples 1-3 and Comparative Examples 1-4, stir well, then perform vibration casting, molding, and demolding. After baking at 110°C for 24 h and calcining at 1500°C for 3 h, and then cooling naturally, Samples 1-3 and Comparative Samples 1-4 are obtained. Perform the following performance tests on Samples 1-3 and Comparative Samples 1-4: Flexural strength: Test according to GB / T 50081-2002, using specimens of 150 mm×150 mm×600 mm. Compressive strength: Test according to GB / T 5072-2008, using cubes with a side length of 50 mm. Thermal shock resistance test: Conduct thermal shock resistance experiments on Samples 1-3 and Comparative Samples 1-4 respectively, and evaluate with the retention rate (%) of the room temperature flexural strength of the samples after thermal shock; the thermal shock resistance is 1300°C, 30 min, and air cooling 5 times. Erosion resistance test: Conduct erosion experiments on Samples 1-3 and Comparative Samples 1-4 respectively, and evaluate the erosion resistance with the average thickness of the castable crucible sample damaged by the slag reaction; the test conditions are 1600°C, 3 h. Wear resistance: Test according to the standard GB / T18301-2012; after heating the sample to 500°C, wear it at a pressure of 10 kg for 30 min each time. Change the wear position and perform wear treatment 3 times, then measure the depth of the wear marks generated on the test block and take the average value to obtain it.

[0040] Table 1 Performance test results of the samples

[0041] As can be seen from the results in Table 1, Samples 1-3 exhibit excellent performance, indicating that the castables prepared in Examples 1-3 have excellent mechanical properties, wear resistance, and erosion resistance; from Samples 1 and Comparative Samples 1 and 2, it can be seen that the introduction of rare earth elements significantly improves the mechanical properties and antioxidant properties of the castable, and the introduction of p-toluenesulfonic acid accelerates the polycondensation reaction between aluminum isopropoxide and tetraethyl orthosilicate. The acceleration of this reaction process makes the whisker cross-linking more compact, the cross-linking density is significantly increased, and the internal structural defects of the castable are thus greatly reduced; from Samples 1 and Comparative Samples 3 and 4, it can be seen that the mixed introduction of silica fume after high-temperature calcination and bentonite treated with sodium sarcosinate into the castable makes the internal structure of the castable more compact and orderly, promoting the improvement of the mechanical properties of the castable. In addition, due to its small particle size, silica fume can just fill the tiny gaps between bentonite particles, further enhancing its wear resistance and enabling it to maintain good use in a long-term friction environment.

[0042] This specific embodiment is only an interpretation of the present invention and does not limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A mullite-based high-strength, wear-resistant and erosion-resistant castable for a coke oven roof, characterized in that: The invention comprises the following raw materials in parts by weight: 45-60 parts of mullite aggregate, 8-15 parts of bauxite, 3-6 parts of whiskers, 6-9 parts of calcium aluminate cement, 1-3 parts of admixture, 1-2 parts of water reducer, 0.1-0.2 parts of steel fiber and 3-5 parts of water.

2. The mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof according to claim 1, characterized in that: The whiskers are prepared by the following method: Add aluminum isopropoxide to ethanol, stir for 25-35 minutes, add cerium nitrate and yttrium nitrate, continue stirring for 10-15 minutes, then add tetraethyl orthosilicate, stir for 10-20 minutes, then add p-toluenesulfonic acid, stir and react for 1-2 hours, transfer to a sealed container, age for 10-15 hours, take out and place in a drying oven, dry for 6-10 hours, and finally calcine to obtain whiskers; wherein, aluminum isopropoxide 28-40 parts, tetraethyl orthosilicate 18-25 parts, p-toluenesulfonic acid 0.2-0.4 parts, cerium nitrate 0.1-0.3 parts, yttrium nitrate 0.1-0.3 parts, ethanol 150-220 parts.

3. The mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof according to claim 1, characterized in that: The admixture is prepared by mixing 3-5 parts of silicon micropowder and 1-2 parts of modified bentonite.

4. The mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof according to claim 3, characterized in that: The silicon micropowder is prepared by calcining at 1000-1200° C. for 1-3 hours.

5. The mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof according to claim 3, characterized in that: The modified bentonite is prepared by the following method: Mix sodium sarcosinate and deionized water, heat and stir for 20-35 minutes, add sodium tripolyphosphate, stir for 20-30 minutes, then add bentonite, ultrasonically disperse for 15-20 minutes, heat and stir for 3-5 hours, centrifuge for 5-8 minutes, wash, and dry to obtain modified bentonite; wherein, sodium sarcosinate is 1-3 parts, sodium tripolyphosphate is 0.1-0.2 parts, bentonite is 15-25 parts, and deionized water is 150-180 parts.

6. The mullite-based high-strength, wear-resistant and erosion-resistant castable for coke oven roof according to claim 1, characterized in that: The water reducing agent is sodium hexametaphosphate and / or sodium pyrophosphate.

7. A method for preparing the mullite-based high-strength wear-resistant and erosion-resistant castable for coke oven top according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Put mullite raw material, bauxite, whisker, calcium aluminate cement, admixture, water reducing agent and steel fiber into a mixer and stir for 20-30 minutes to obtain a mixture; S2. Put the mixture in a mixer, add water while stirring, control the stirring rate to 100-200 rpm, stir for 10-15 minutes, and obtain a mullite-based high-strength, wear-resistant and corrosion-resistant castable for coke oven roof.

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