An antioxidant BF trough castable and its preparation method

Abstract

The present invention discloses an antioxidant refractory castable for blast furnace troughs and its preparation method, which relates to the technical field of refractory materials. The mass percentages of its raw material components are as follows: brown fused alumina with a particle size of 15 - 8 mm is 10.5 - 12%, brown fused alumina with a particle size of 8 - 5 mm is 14.5 - 16%, brown fused alumina with a particle size of 5 - 3 mm is 10 - 12%, brown fused alumina with a particle size of 3 - 1 mm is 10 - 11%, dense fused alumina with a particle size of 3 - 1 mm is 9 - 10%, dense fused alumina with a particle size of 1 - 0 mm is 4 - 5%, silicon carbide with a particle size of 1 - 0 mm is 11 - 13%, silicon carbide with a particle size of 325 mesh is 9 - 10%, alumina micropowder is 4 - 6%, silica fume is 1.5 - 2.5%, high alumina cement is 1 - 1.5%, ρ - Al 2 O 3 is 1 - 1.5%, andalusite is 0.5 - 1%, spherical pitch is 2 - 2.5%, carbon black is 0.5 - 1%, boron carbide is 0.2 - 0.4%, molybdenum strontium powder is 0.05 - 0.1%, metallic silicon powder is 1.5 - 2.5%, metallic aluminum powder is 0.02 - 0.04%, organic fiber is 0.04 - 0.07%, and water reducer is 0.1 - 0.3%. The present invention has excellent antioxidant performance, can significantly improve the service performance and service life of the refractory castable for troughs, and reduce the maintenance work intensity of the troughs.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory materials, and particularly relates to an antioxidant blast furnace trough castable and a preparation method thereof. Background Art

[0002] The blast furnace trough in an iron-smelting blast furnace is a key facility on the blast furnace platform. It is an important passage for separating molten iron from the molten blast furnace slag floating on the upper part of the molten iron and guiding the molten iron and the blast furnace slag to different downstream processes. The service life of the blast furnace trough castable directly determines the safe and stable production of the blast furnace and belongs to one of the key maintenance parts for the stable operation of the blast furnace.

[0003] Currently, the blast furnace trough castable mainly adopts the Al 2 O 3 -SiC-C system. This castable system has good thermal shock resistance and slag resistance and has become the first choice for refractory materials for the inner lining layer of the blast furnace trough. However, the Al 2 O 3 -SiC-C system contains a large amount of C. These C are under high-temperature conditions during the use of the trough, so they are very easy to oxidize and lose, which in turn leads to a sharp decrease in the thermal shock resistance, high-temperature resistance and oxidation resistance of the blast furnace trough castable, greatly reducing the service life of the refractory. Based on this, there is an urgent need for a new type of blast furnace trough castable to improve the oxidation resistance of the Al 2 O 3 -SiC-C system castable. Summary of the Invention

[0004] Aiming at the defects and problems of the existing trough castable with weak thermal shock resistance, high-temperature resistance and oxidation resistance, the present invention provides an antioxidant blast furnace trough castable and a preparation method thereof.

[0005] The solution adopted by the present invention to solve its technical problems is as follows: An antioxidant blast furnace trough castable is used for the main trough of the blast furnace iron notch. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15 - 8 mm is 10.5 - 12%, brown fused alumina with a particle size of 8 - 5 mm is 14.5 - 16%, brown fused alumina with a particle size of 5 - 3 mm is 10 - 12%, brown fused alumina with a particle size of 3 - 1 mm is 10 - 11%, dense fused alumina with a particle size of 3 - 1 mm is 9 - 10%, dense fused alumina with a particle size of 1 - 0 mm is 4 - 5%, silicon carbide with a particle size of 1 - 0 mm is 11 - 13%, silicon carbide with a mesh size of 325 is 9 - 10%, alumina micropowder is 4 - 6%, silica fume is 1.5 - 2.5%, high alumina cement is 1 - 1.5%, ρ-Al 2 O 3is 1 to 1.5%, andalusite is 0.5 to 1%, spherical asphalt is 2 to 2.5%, carbon black is 0.5 to 1%, boron carbide is 0.2 to 0.4%, molybdenum strontium powder is 0.05 to 0.1%, metallic silicon powder is 1.5 to 2.5%, metallic aluminum powder is 0.02 to 0.04%, organic fiber is 0.04 to 0.07%, and water reducing agent is 0.1 to 0.3%.

[0006] Further, the Al in the brown fused alumina 2 O 3 ≥ 95%, SiO 2 ≤ 1%, Fe 2 O 3 ≤ 0.3%, TiO 2 ≤ 3%, C ≤ 0.1%, powdering rate ≤ 0.02%; the Al in the dense fused alumina 2 O 3 ≥ 99%, Fe 2 O 3 ≤ 0.1%; in the silicon carbide, SiC ≥ 97%, SiO 2 ≤ 0.4%, Fe 2 O 3 ≤ 0.3%, free carbon ≤ 0.5%; the particle size of the alumina micropowder ≤ 1 µm; in the silicon micropowder, SiO 2 ≥ 95%; in the high alumina cement, Al 2 O 3 ≥ 80%; in the ρ - Al 2 O 3 the Al 2 O 3 ≥ 92%; in the andalusite, Al 2 O 3 ≥ 57%, the particle size is 325 mesh; in the spherical asphalt, the fixed carbon ≥ 60%, the ash content ≤ 0.2%, the volatile matter ≤ 40%, the particle size is 1 - 0.2 mm; in the carbon black, the fixed carbon ≥ 95%, the ash content ≤ 0.5%, the volatile matter ≤ 2.5%; in the boron carbide, B 4 C ≥ 95%, SiO 2 ≤ 0.1%, Fe 2 O 3 ≤ 0.25%.

[0007] Further, the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, and the particle sizes are both 500 - 800 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the particle size of the metallic silicon powder is 300 - 400 mesh; the particle size of the metallic aluminum powder is 80 - 200 mesh; the water reducing agent is a polyethylene glycol - based water reducing agent.

[0008] Further, the surface of the carbon black is impregnated with trimethylaluminum, and the ratio of the sites modified by trimethylaluminum to the total carbon edge sites ≥ 60%.

[0009] Further, the mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15 - 8 mm is 11%, brown fused alumina with a particle size of 8 - 5 mm is 15.5%, brown fused alumina with a particle size of 5 - 3 mm is 11%, brown fused alumina with a particle size of 3 - 1 mm is 10.5%, dense fused alumina with a particle size of 3 - 1 mm is 9.5%, dense fused alumina with a particle size of 1 - 0 mm is 4.5%, silicon carbide with a particle size of 1 - 0 mm is 12%, silicon carbide with a particle size of 325 mesh is 9.5%, alumina micropowder is 5.5%, silica fume is 2%, high alumina cement is 1.2%, ρ-Al 2 O 3 is 1.3%, andalusite is 0.8%, spherical asphalt is 2.3%, carbon black is 0.7%, boron carbide is 0.3%, molybdenum strontium powder is 0.07%, metallic silicon powder is 2%, metallic aluminum powder is 0.03%, organic fiber is 0.06%, and water reducing agent is 0.24%.

[0010] The present invention also provides a preparation method of an antioxidant blast furnace trough castable, comprising the following steps:

[0011] S1. Weigh silicon carbide with a particle size of 325 mesh, alumina micropowder, silica fume, high alumina cement, ρ-Al 2 O 3 , andalusite, carbon black, boron carbide, molybdenum strontium powder, metallic silicon powder, metallic aluminum powder, organic fiber, and water reducing agent according to their weight percentages respectively, and add them into a container in sequence for mixing and stirring. The stirring time is 5 - 7 min to obtain a compounded mixture;

[0012] S2. Then weigh brown fused alumina with a particle size of 15 - 8 mm, brown fused alumina with a particle size of 8 - 5 mm, brown fused alumina with a particle size of 5 - 3 mm, brown fused alumina with a particle size of 3 - 1 mm, dense fused alumina with a particle size of 3 - 1 mm, dense fused alumina with a particle size of 1 - 0 mm, silicon carbide with a particle size of 1 - 0 mm, and spherical asphalt according to their weight percentages respectively, and add them into another container in sequence for mixing and stirring. The stirring time is 3 - 5 min to obtain a compounded granular material;

[0013] S3. Continuously and uniformly add the compounded mixture to the container while stirring the compounded granular material. The addition time of the compounded mixture is 3 - 5 min. After the addition is completed, stir the mixture of the two again evenly for 3 - 5 min to obtain the blast furnace trough castable.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] The antioxidant blast furnace trough castable and its preparation method provided by the present invention, after performance index tests, have relatively excellent bulk density, flexural strength, compressive strength, and linear change rate, and have excellent antioxidant performance, thereby being able to significantly improve the service performance and service life of the trough castable, reduce the maintenance cost of the trough and the working intensity of employees.

[0016] By introducing molybdenum strontium powder, the antioxidant performance of the trough castable is improved, thereby increasing the service life of the trough; by adding andalusite, during the use of the trough castable, a liquid phase rich in SiO 2 is generated under high-temperature conditions, which penetrates into small pores under the action of capillary force, blocks the pores, and prevents the reaction of oxygen with the internal materials of the castable. And the liquid phase rich in SiO 2 reacts with Al 2 O 3 in the castable to form mullite, making the structure more dense and blocking the penetration of oxygen into the interior of the castable, thereby improving the antioxidant performance of the castable. Embodiment

[0017] The present invention will be further described below in conjunction with embodiments.

[0018] The present invention provides a technical solution for an antioxidant blast furnace trough castable and its preparation method, which is used to improve the antioxidant performance of the Al 2 O 3 -SiC-C system castable. Embodiment

[0019] This embodiment provides an antioxidant blast furnace trough castable for the main trough of the blast furnace tapping trough. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15-8 mm is 11%, brown fused alumina with a particle size of 8-5 mm is 15.5%, brown fused alumina with a particle size of 5-3 mm is 11%, brown fused alumina with a particle size of 3-1 mm is 10.5%, dense fused alumina with a particle size of 3-1 mm is 9.5%, dense fused alumina with a particle size of 1-0 mm is 4.5%, silicon carbide with a particle size of 1-0 mm is 12%, silicon carbide with a particle size of 325 mesh is 9.5%, alumina micropowder is 5.5%, silica fume is 2%, high alumina cement is 1.2%, ρ-Al 2 O 3 is 1.3%, andalusite is 0.8%, spherical asphalt is 2.3%, carbon black is 0.7%, boron carbide is 0.3%, molybdenum strontium powder is 0.07%, metallic silicon powder is 2%, metallic aluminum powder is 0.03%, organic fiber is 0.06%, and water reducer is 0.24%.

[0020] In the above-mentioned brown fused alumina, Al 2 O 3 ≥95%, SiO 2 ≤1%, Fe 2 O 3 ≤0.3%, TiO 2 ≤3%, C≤0.1%, pulverization rate ≤0.02%; in the dense fused alumina, Al 2 O 3 ≥99%, Fe 2 O 3 ≤0.1%; in the silicon carbide, SiC≥97%, SiO2 ≤0.4%, Fe 2 O 3 ≤0.3%, free carbon ≤0.5%; the particle size of alumina micropowder ≤1 µm; SiO in silica micropowder 2 ≥95%; Al in high alumina cement 2 O 3 ≥80%; Al in ρ-Al 2 O 3 Al in 2 O 3 ≥92%; Al in andalusite 2 O 3 ≥57%, the particle size is 325 mesh; the fixed carbon in spherical asphalt ≥60%, the ash content ≤0.2%, the volatile matter ≤40%, the particle size is 1 - 0.2 mm; the fixed carbon in carbon black ≥95%, the ash content ≤0.5%, the volatile matter ≤2.5%; B in boron carbide 4 C ≥95%, SiO 2 ≤0.1%, Fe 2 O 3 ≤0.25%.

[0021] Among them, molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, and the particle size of both is 800 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the particle size of the above-mentioned metallic silicon powder is 325 mesh, the particle size of metallic aluminum powder is 200 mesh, and the water reducing agent used is polyethylene glycol based water reducing agent.

[0022] In the present invention, to improve the antioxidant performance of carbon black, trimethylaluminum is used to impregnate the surface of carbon black, and the ratio of the sites modified by trimethylaluminum to the total carbon edge sites after treatment ≥60%, which specifically includes the following process:

[0023] ① Add carbon black into the reactor, add an appropriate amount of n-hexane, toluene, etc., and stir evenly;

[0024] ② Add 4% of the weight of carbon black of trimethylaluminum into the reactor, and continue to stir evenly;

[0025] ③ Heat the reactor, keep the temperature at 100 - 110 °C, and stir and react for 3 - 4 h to make trimethylaluminum react with the hydroxyl or carbonyl groups on the surface of carbon black to form chemical bonds, and tightly combine trimethylaluminum with carbon black;

[0026] ④ After the reaction is completed, wash with a solvent to remove unreacted trimethylaluminum and other impurities;

[0027] ⑤ Place the washed carbon black in a ventilated and dry room to dry it and remove the residual solvent to obtain trimethylaluminum-modified carbon black.

[0028] The ratio of the sites modified by trimethylaluminum to the total carbon edge sites ≥ 60%, and the modified carbon black has excellent antioxidant performance under high-temperature conditions.

[0029] In the present invention, the antioxidant performance of the iron runner castable is improved by adding molybdenum-strontium powder. Molybdenum oxide and strontium oxide can react with oxygen, and the reaction products are oxides in a stable state under high-temperature conditions, forming a stable protective film layer on the surface of the castable to prevent oxygen from reacting with other materials in the castable. At the same time, molybdenum oxide and strontium oxide can be adsorbed on the surface of the castable to prevent oxygen from reacting with other chemical substances in the castable. Through this physical reaction, the antioxidant performance of the castable can be improved, and it has good stability under high-temperature conditions.

[0030] In addition, in the present invention, by adding andalusite, during the use of the iron runner castable, a liquid phase rich in SiO 2 can be generated under high-temperature conditions. Under the action of capillary force, it infiltrates into small pores, blocks the pores, and prevents oxygen from reacting with the internal materials of the castable. And the liquid phase rich in SiO 2 can react with Al 2 O 3 in the castable to generate mullite, making the structure more dense and blocking the infiltration of oxygen into the interior of the castable, thereby improving the antioxidant performance of the castable.

[0031] Based on the above antioxidant blast furnace iron runner castable, the present invention also provides a preparation method of the antioxidant blast furnace iron runner castable, which specifically includes the following steps:

[0032] S1. Weigh 325-mesh silicon carbide, alumina micropowder, silicon micropowder, high-alumina cement, ρ-Al 2 O 3 , andalusite, carbon black, boron carbide, molybdenum-strontium powder, metallic silicon powder, metallic aluminum powder, organic fiber, water reducer according to the above weight percentages respectively, and add them into a container in sequence for mixing and stirring. The stirring time is 7 min to obtain a compounded mixture;

[0033] S2. Then weigh brown fused alumina of 15 - 8 mm, brown fused alumina of 8 - 5 mm, brown fused alumina of 5 - 3 mm, brown fused alumina of 3 - 1 mm, dense fused alumina of 3 - 1 mm, dense fused alumina of 1 - 0 mm, silicon carbide of 1 - 0 mm, spherical pitch according to the above weight percentages respectively, and add them into another container in sequence for mixing and stirring. The stirring time is 3 min to obtain a compounded granular material;

[0034] S3. While stirring the above compounded granular material, continuously and evenly add the compounded mixture into this container. The addition time of the compounded mixture is 5 min. After the addition is completed, stir the mixture of the two evenly again for 3 min to obtain the blast furnace iron runner castable.

[0035] The antioxidant blast furnace trough castable provided by the present invention and its preparation method can prepare a trough castable with excellent antioxidant performance, which is mainly used for the main trough of the blast furnace tapping trough. The trough castable prepared by the method of the present invention can significantly improve the service performance and service life of the trough castable, and effectively reduce the maintenance cost and working intensity of the trough. Example

[0036] This example provides an antioxidant blast furnace trough castable for the main trough of the blast furnace tapping trough. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina of 15 - 8 mm is 11.8%, brown fused alumina of 8 - 5 mm is 14.5%, brown fused alumina of 5 - 3 mm is 11.6%, brown fused alumina of 3 - 1 mm is 10.3%, dense fused alumina of 3 - 1 mm is 10%, dense fused alumina of 1 - 0 mm is 4.8%, silicon carbide of 1 - 0 mm is 12.5%, silicon carbide of 325 mesh is 10%, alumina micropowder is 4.6%, silica fume is 1.5%, high alumina cement is 1.4%, ρ - Al 2 O 3 is 1%, andalusite is 0.6%, spherical asphalt is 2.2%, carbon black is 0.6%, boron carbide is 0.36%, molybdenum strontium powder is 0.05%, metallic silicon powder is 1.8%, metallic aluminum powder is 0.04%, organic fiber is 0.05%, and water reducer is 0.3%.

[0037] Among them, the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, and the particle sizes are both 800 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the particle size of the above - mentioned metallic silicon powder is 325 mesh, the particle size of the metallic aluminum powder is 200 mesh, and the water reducer used is a polyethylene glycol - based water reducer. In this example, to improve the antioxidant performance of carbon black, trimethylaluminum is used to impregnate the surface of carbon black, and the treatment process is the same as that in Example 1. After treatment, the ratio of the sites modified by trimethylaluminum to the total carbon edge sites is ≥60%.

[0038] The preparation method of the above - mentioned antioxidant blast furnace trough castable specifically includes the following steps:

[0039] S1. Weigh silicon carbide of 325 mesh, alumina micropowder, silica fume, high alumina cement, ρ - Al 2 O 3 , andalusite, carbon black, boron carbide, molybdenum strontium powder, metallic silicon powder, metallic aluminum powder, organic fiber, and water reducer according to the above weight percentages, and add them into a container in sequence for mixing and stirring. The stirring time is 5 min to obtain a compounded mixture;

[0040] S2. Then, respectively weigh brown fused alumina of 15 - 8 mm, brown fused alumina of 8 - 5 mm, brown fused alumina of 5 - 3 mm, brown fused alumina of 3 - 1 mm, dense fused alumina of 3 - 1 mm, dense fused alumina of 1 - 0 mm, silicon carbide of 1 - 0 mm, and spherical pitch according to the above weight percentages, and sequentially add them into another container for mixing and stirring. The stirring time is 5 min to obtain the compound aggregate;

[0041] S3. While stirring the above compound aggregate, continuously and evenly add the compound mixture into the container. The adding time of the compound mixture is 3 min. After the addition is completed, stir the mixture of the two evenly for another 3 min to obtain the blast furnace trough castable. Example

[0042] This example provides an antioxidant blast furnace trough castable for the main trough of the blast furnace iron notch. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina of 15 - 8 mm is 12%, brown fused alumina of 8 - 5 mm is 14.7%, brown fused alumina of 5 - 3 mm is 12%, brown fused alumina of 3 - 1 mm is 10.2%, dense fused alumina of 3 - 1 mm is 9.2%, dense fused alumina of 1 - 0 mm is 4.2%, silicon carbide of 1 - 0 mm is 11%, silicon carbide of 325 mesh is 9.8%, alumina micropowder is 6%, silicon micropowder is 1.7%, high alumina cement is 1.3%, ρ - Al 2 O 3 is 1.5%, andalusite is 0.7%, spherical pitch is 2%, carbon black is 0.7%, boron carbide is 0.2%, molybdenum strontium powder is 0.08%, metallic silicon powder is 2.5%, metallic aluminum powder is 0.03%, organic fiber is 0.04%, and water reducing agent is 0.15%.

[0043] Among them, the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, and the particle size is 500 mesh. The ratio of molybdenum oxide to strontium oxide is 7:3; the particle size of the above metallic silicon powder is 300 mesh, the particle size of the metallic aluminum powder is 100 mesh, and the water reducing agent used is a polyethylene glycol - based water reducing agent.

[0044] In this example, to improve the antioxidant performance of carbon black, trimethylaluminum is used to impregnate the surface of carbon black. The treatment process is the same as that in Example 1. After treatment, the ratio of the sites modified by trimethylaluminum to the total carbon edge sites is ≥60%; and the preparation method of the antioxidant blast furnace trough castable in this example is prepared according to the above weight ratio and the steps of Example 1. Example

[0045] This embodiment provides an antioxidant blast furnace trough castable for the main trough of the blast furnace iron notch. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina of 15 - 8 mm is 11.3%, brown fused alumina of 8 - 5 mm is 16%, brown fused alumina of 5 - 3 mm is 10.7%, brown fused alumina of 3 - 1 mm is 10%, dense fused alumina of 3 - 1 mm is 9%, dense fused alumina of 1 - 0 mm is 4.4%, silicon carbide of 1 - 0 mm is 12.3%, silicon carbide of 325 mesh is 9%, alumina micropowder is 5.4%, silica fume is 2.5%, high alumina cement is 1.2%, ρ - Al 2 O 3 is 1.4%, andalusite is 1%, spherical asphalt is 2.4%, carbon black is 0.5%, boron carbide is 0.37%, molybdenum strontium powder is 0.1%, metallic silicon powder is 2.1%, metallic aluminum powder is 0.02%, organic fiber is 0.06%, and water reducer is 0.25%.

[0046] Among them, the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, and the particle sizes are both 500 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the particle size of the above - mentioned metallic silicon powder is 400 mesh, the particle size of the metallic aluminum powder is 200 mesh, and the water reducer used is a polyethylene glycol - based water reducer.

[0047] In this embodiment, to improve the antioxidant performance of carbon black, trimethylaluminum is used to impregnate the surface of carbon black. The treatment process is the same as that in Embodiment 1, and the ratio of the sites modified by trimethylaluminum to the total carbon edge sites after treatment is ≥60%; and the preparation method of the antioxidant blast furnace trough castable in this embodiment is prepared according to the above weight ratio following the steps of Embodiment 1. Embodiment

[0048] This embodiment provides an antioxidant blast furnace trough castable for the main trough of the blast furnace iron notch. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina of 15 - 8 mm is 10.5%, brown fused alumina of 8 - 5 mm is 14.6%, brown fused alumina of 5 - 3 mm is 11.4%, brown fused alumina of 3 - 1 mm is 11%, dense fused alumina of 3 - 1 mm is 9.2%, dense fused alumina of 1 - 0 mm is 4%, silicon carbide of 1 - 0 mm is 12.7%, silicon carbide of 325 mesh is 9.4%, alumina micropowder is 5.8%, silica fume is 1.8%, high alumina cement is 1%, ρ - Al 2 O 3 is 1.3%, andalusite is 0.8%, spherical asphalt is 2.5%, carbon black is 1%, boron carbide is 0.26%, molybdenum strontium powder is 0.07%, metallic silicon powder is 2.3%, metallic aluminum powder is 0.03%, organic fiber is 0.07%, and water reducer is 0.27%.

[0049] Among them, the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, both with a particle size of 800 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the above-mentioned metallic silicon powder has a particle size of 300 mesh, the metallic aluminum powder has a particle size of 80 mesh, and the water reducing agent used is a polyethylene glycol-based water reducing agent.

[0050] In this example, to improve the antioxidant performance of carbon black, trimethylaluminum is used to impregnate the surface of carbon black. The treatment process is the same as that in Example 1, and the ratio of the sites modified by trimethylaluminum to the total carbon edge sites after treatment is ≥60%; and in this example, the preparation method of the antioxidant blast furnace trough castable is prepared according to the above weight ratio following the steps of Example 1. Example

[0051] This example provides an antioxidant blast furnace trough castable for the main trough of the blast furnace iron notch. The mass percentages of the raw material components in this iron notch castable are as follows: brown fused alumina of 15 - 8 mm is 11.6%, brown fused alumina of 8 - 5 mm is 15.8%, brown fused alumina of 5 - 3 mm is 10%, brown fused alumina of 3 - 1 mm is 10.6%, dense fused alumina of 3 - 1 mm is 9.4%, dense fused alumina of 1 - 0 mm is 5%, silicon carbide of 1 - 0 mm is 13%, silicon carbide of 325 mesh is 9.7%, alumina micropowder is 4%, silica fume is 2.4%, high alumina cement is 1.5%, ρ - Al 2 O 3 is 1.2%, andalusite is 0.5%, spherical asphalt is 2.3%, carbon black is 0.85%, boron carbide is 0.4%, molybdenum strontium powder is 0.06%, metallic silicon powder is 1.5%, metallic aluminum powder is 0.03%, organic fiber is 0.06%, and water reducing agent is 0.1%.

[0052] Among them, the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, both with a particle size of 800 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the above-mentioned metallic silicon powder has a particle size of 400 mesh, the metallic aluminum powder has a particle size of 80 mesh, and the water reducing agent used is a polyethylene glycol-based water reducing agent.

[0053] In this example, to improve the antioxidant performance of carbon black, trimethylaluminum is used to impregnate the surface of carbon black. The treatment process is the same as that in Example 1, and the ratio of the sites modified by trimethylaluminum to the total carbon edge sites after treatment is ≥60%; and in this example, the preparation method of the antioxidant blast furnace trough castable is prepared according to the above weight ratio following the steps of Example 1.

[0054] Comparative Example 1:

[0055] This comparative example provides an antioxidant blast furnace trough castable and its preparation method. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15 - 8 mm is 11.5%, brown fused alumina with a particle size of 8 - 5 mm is 15.5%, brown fused alumina with a particle size of 5 - 3 mm is 11%, brown fused alumina with a particle size of 3 - 1 mm is 10.5%, dense fused alumina with a particle size of 3 - 1 mm is 9.5%, dense fused alumina with a particle size of 1 - 0 mm is 4.5%, silicon carbide with a particle size of 1 - 0 mm is 12%, silicon carbide with a particle size of 325 mesh is 9.5%, alumina micropowder is 5.5%, silica fume is 2%, high alumina cement is 1.2%, ρ - Al 2 O 3 is 1.3%, andalusite is 0.8%, spherical asphalt is 2.3%, carbon black is 0.2%, boron carbide is 0.3%, molybdenum strontium powder is 0.07%, metallic silicon powder is 2%, metallic aluminum powder is 0.03%, organic fiber is 0.06%, and water reducer is 0.24%. The preparation method of the above antioxidant blast furnace trough castable is the same as that described in Example 1.

[0056] Comparative Example 2:

[0057] This comparative example provides an antioxidant blast furnace trough castable and its preparation method. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15 - 8 mm is 11.8%, brown fused alumina with a particle size of 8 - 5 mm is 15%, brown fused alumina with a particle size of 5 - 3 mm is 11.6%, brown fused alumina with a particle size of 3 - 1 mm is 10.3%, dense fused alumina with a particle size of 3 - 1 mm is 10%, dense fused alumina with a particle size of 1 - 0 mm is 4.8%, silicon carbide with a particle size of 1 - 0 mm is 12.5%, silicon carbide with a particle size of 325 mesh is 10%, alumina micropowder is 4.6%, silica fume is 1.5%, high alumina cement is 1.4%, ρ - Al 2 O 3 is 0.5%, andalusite is 0.6%, spherical asphalt is 2.2%, carbon black is 0.6%, boron carbide is 0.36%, molybdenum strontium powder is 0.05%, metallic silicon powder is 1.8%, metallic aluminum powder is 0.04%, organic fiber is 0.05%, and water reducer is 0.3%. The preparation method of the above antioxidant blast furnace trough castable is the same as that described in Example 1.

[0058] Comparative Example 3:

[0059] This comparative example provides an antioxidant BF trough castable and its preparation method. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina of 15 - 8 mm is 12%, brown fused alumina of 8 - 5 mm is 14.78%, brown fused alumina of 5 - 3 mm is 12%, brown fused alumina of 3 - 1 mm is 10.2%, dense fused alumina of 3 - 1 mm is 9.2%, dense fused alumina of 1 - 0 mm is 4.2%, silicon carbide of 1 - 0 mm is 11%, silicon carbide of 325 mesh is 9.8%, alumina micropowder is 6%, silica fume is 1.7%, high alumina cement is 1.3%, ρ - Al 2 O 3 is 1.5%, andalusite is 0.7%, spherical asphalt is 2%, carbon black is 0.7%, boron carbide is 0.2%, molybdenum strontium powder is 0%, metallic silicon powder is 2.5%, metallic aluminum powder is 0.03%, organic fiber is 0.04%, water reducer is 0.15%. The preparation method of the above - mentioned antioxidant BF trough castable is the same as that described in Example 1. The content ratio of molybdenum strontium powder in this comparative example is 0.

[0060] Comparative Example 4:

[0061] This comparative example provides an antioxidant BF trough castable and its preparation method. The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina of 15 - 8 mm is 11.3%, brown fused alumina of 8 - 5 mm is 16%, brown fused alumina of 5 - 3 mm is 10.72%, brown fused alumina of 3 - 1 mm is 10%, dense fused alumina of 3 - 1 mm is 9%, dense fused alumina of 1 - 0 mm is 4.4%, silicon carbide of 1 - 0 mm is 12.3%, silicon carbide of 325 mesh is 9%, alumina micropowder is 5.4%, silica fume is 2.5%, high alumina cement is 1.2%, ρ - Al 2 O 3 is 1.4%, andalusite is 1%, spherical asphalt is 2.4%, carbon black is 0.5%, boron carbide is 0.37%, molybdenum strontium powder is 0.1%, metallic silicon powder is 2.1%, metallic aluminum powder is 0%, organic fiber is 0.06%, water reducer is 0.25%. The content ratio of metallic aluminum powder in this comparative example is 0.

[0062] By detecting the qualified performance indexes of the antioxidant BF trough castables prepared with different ratios in the above - mentioned Examples 1 - 6 and Comparative Examples 1 - 4, the detection index ranges are shown in the following table:

[0063] Table 1 Detection Index Ranges of Qualified Products

[0064] The detection results are shown in the following table:

[0065]

[0066] Table 2 Test Results of Performance Indicators of Examples 1-6 and Comparative Examples 1-4

[0067]

[0068] It can be obtained from the above table that the antioxidant BF trough castable prepared according to the component ratios of Examples 1-6 of the present invention meets the requirements of the test range in terms of bulk density, flexural strength, compressive strength and linear change rate under different high-temperature calcination. However, for the BF trough castable prepared according to the component ratios in Comparative Examples 1-4, its flexural strength and compressive strength are relatively weak when calcined at 110°C. After calcination at 1450°C, neither its flexural strength, compressive strength nor linear change rate meets the requirements of the index test range, and its performance strength is relatively weak.

[0069] In summary, the antioxidant BF trough castable and its preparation method provided by the present invention have excellent bulk density, flexural strength, compressive strength and linear change rate after performance index tests, and have excellent antioxidant performance, thus significantly improving the service performance and service life of the trough castable.

[0070] The above are only the preferred embodiments of the present invention and do not limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An antioxidant refractory castable for the main trough of the blast furnace iron runner, characterized in that: The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15 - 8 mm is 10.5 - 12%, brown fused alumina with a particle size of 8 - 5 mm is 14.5 - 16%, brown fused alumina with a particle size of 5 - 3 mm is 10 - 12%, brown fused alumina with a particle size of 3 - 1 mm is 10 - 11%, dense fused alumina with a particle size of 3 - 1 mm is 9 - 10%, dense fused alumina with a particle size of 1 - 0 mm is 4 - 5%, silicon carbide with a particle size of 1 - 0 mm is 11 - 13%, silicon carbide with a particle size of 325 mesh is 9 - 10%, alumina micropowder is 4 - 6%, silica fume is 1.5 - 2.5%, high alumina cement is 1 - 1.5%, ρ-Al 2 O 3 is 1 - 1.5%, andalusite is 0.5 - 1%, spherical asphalt is 2 - 2.5%, carbon black is 0.5 - 1%, boron carbide is 0.2 - 0.4%, molybdenum strontium powder is 0.05 - 0.1%, metallic silicon powder is 1.5 - 2.5%, metallic aluminum powder is 0.02 - 0.04%, organic fiber is 0.04 - 0.07%, water reducing agent is 0.1 - 0.3%; the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide; the carbon black surface is impregnated with trimethylaluminum, and the ratio of the sites modified by trimethylaluminum to the total carbon edge sites is ≥60%; including the following process: ① Add carbon black to the reactor, add an appropriate amount of n-hexane and toluene, and stir evenly; ② Add 4% of the weight of carbon black of trimethylaluminum to the reactor and continue to stir evenly; ③ Heat the reactor, keep the temperature at 100-110 °C, stir and react for 3-4 h, so that trimethylaluminum reacts with the hydroxyl or carbonyl groups on the carbon black surface to form chemical bonds, and tightly combine trimethylaluminum and carbon black together; ④ After the reaction is completed, wash with a solvent to remove unreacted trimethylaluminum and other impurities; ⑤ Place the washed carbon black in a ventilated and dry room to dry it and remove the residual solvent to obtain trimethylaluminum-modified carbon black.

2. The antioxidant refractory castable for the blast furnace iron runner according to claim 1, characterized in that: In the brown fused alumina, Al 2 O 3 ≥ 95%, SiO 2 ≤ 1%, Fe 2 O 3 ≤ 0.3%, TiO 2 ≤ 3%, C ≤ 0.1%, powdering rate ≤ 0.02%; In the dense fused alumina, Al 2 O 3 ≥ 99%, Fe 2 O 3 ≤ 0.1%; In the silicon carbide, SiC ≥ 97%, SiO 2 ≤ 0.4%, Fe 2 O 3 ≤ 0.3%, free carbon ≤ 0.5%; The particle size of the alumina micropowder ≤ 1 µm; In the silica fume, SiO 2 ≥ 95%; In the high alumina cement, Al 2 O 3 ≥ 80%; In ρ-Al 2 O 3 Al 2 O 3 ≥ 92%; In the andalusite, Al 2 O 3 ≥ 57%, the particle size is 325 mesh; In the spherical asphalt, the fixed carbon ≥ 60%, the ash content ≤ 0.2%, the volatile content ≤ 40%, the particle size is 1 - 0.2 mm; In the carbon black, the fixed carbon ≥ 95%, the ash content ≤ 0.5%, the volatile content ≤ 2.5%; In the boron carbide, B 4 C ≥ 95%, SiO 2 ≤ 0.1%, Fe 2 O 3 ≤ 0.25%.

3. The antioxidant refractory castable for the blast furnace iron runner according to claim 1, characterized in that: the molybdenum strontium powder is composed of molybdenum oxide and strontium oxide, and the particle sizes are both 500-800 mesh, and the ratio of molybdenum oxide to strontium oxide is 7:3; the particle size of the metallic silicon powder is 300-400 mesh; the particle size of the metallic aluminum powder is 80-200 mesh; the water reducer is a polyethylene glycol-based water reducer.

4. The antioxidant refractory castable for the blast furnace iron runner according to claim 1, characterized in that: The mass percentages of the raw material components in the trough castable are as follows: brown fused alumina with a particle size of 15 - 8 mm is 11%, brown fused alumina with a particle size of 8 - 5 mm is 15.5%, brown fused alumina with a particle size of 5 - 3 mm is 11%, brown fused alumina with a particle size of 3 - 1 mm is 10.5%, dense fused alumina with a particle size of 3 - 1 mm is 9.5%, dense fused alumina with a particle size of 1 - 0 mm is 4.5%, silicon carbide with a particle size of 1 - 0 mm is 12%, silicon carbide with a particle size of 325 mesh is 9.5%, alumina micropowder is 5.5%, silica fume is 2%, high alumina cement is 1.2%, ρ-Al 2 O 3 is 1.3%, andalusite is 0.8%, spherical asphalt is 2.3%, carbon black is 0.7%, boron carbide is 0.3%, molybdenum strontium powder is 0.07%, metallic silicon powder is 2%, metallic aluminum powder is 0.03%, organic fiber is 0.06%, water reducing agent is 0.24%.

5. A preparation method of the antioxidant refractory castable for the blast furnace iron runner according to any one of claims 1-4, characterized in that: including the following steps: S1. Weigh silicon carbide, alumina fine powder, silicon fine powder, high alumina cement, ρ-Al 2 O 3 , andalusite, carbon black, boron carbide, molybdenum strontium powder, metallic silicon powder, metallic aluminum powder, organic fiber, water reducing agent by weight percentage respectively, and add them into a container in sequence for mixing and stirring. The stirring time is 5 - 7 min to obtain a compounded mixture; S2. Then, respectively weigh brown fused alumina of 15-8 mm, brown fused alumina of 8-5 mm, brown fused alumina of 5-3 mm, brown fused alumina of 3-1 mm, dense fused alumina of 3-1 mm, dense fused alumina of 1-0 mm, silicon carbide of 1-0 mm, and spherical pitch according to weight percentages, and add them to another container in sequence for mixing and stirring. The stirring time is 3-5 min to obtain a mixed aggregate; S3. While stirring the above-mentioned mixed aggregate, continuously and evenly add the mixed compound to the container. The addition time of the mixed compound is 3-5 min. After the addition is completed, stir the mixture of the two evenly for 3-5 min again to obtain the refractory castable for the blast furnace iron runner.

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