A ladle lining

Abstract

In order to solve the problems of heavy weight, short life and frequent maintenance of steel ladle, the present invention provides a steel ladle lining, which mainly includes a thermal insulation layer, a permanent layer and a working layer distributed in sequence from the outside to the inside. The inner wall of the steel ladle shell is also fixedly connected with an anchor, one end of the anchor is fixedly connected to the steel ladle, and the other end passes through the thermal insulation layer and the permanent layer in sequence and is located inside the working layer. The thermal insulation layer adopts a composite silicate thermal insulation material, and the working layer is a ceramic fiber high-temperature refractory coating. The overall structure is light in weight, good in thermal insulation effect, resistant to thermal shock, erosion, and easy to maintain.

Description

Technical Field

[0001] The invention relates to the technical field of steel ladles, and in particular to a steel ladle lining. Background Art

[0002] The ladle, also called the steel ladle, is an important container in the metallurgical industry. It plays the role of storing and transporting molten steel, and also has the dual task of refining outside the furnace. With the development of steelmaking technology, the refractory materials used in the ladle in my country have also been well developed. The service life of the ladle is not only related to the consumption of refractory materials, but also directly affects the normal production of steelmaking.

[0003] At present, the lining of domestic ladle is mainly a state of coexistence and use of bricks and amorphous refractory materials. In recent years, especially with the improvement of converter life, the increase of continuous casting ratio and the progress of off-furnace refining technology, the ladle is in increasingly harsh use conditions such as large capacity, multiple steel types, high temperature and long time. The requirements for refractory materials for ladle are also constantly improving. In order to meet these requirements, the domestic refractory industry has also carried out active exploration and attempts, such as the application of integral casting technology, the development and application of permanent castables, the development and application of new insulation materials, the application of low-carbon magnesium carbon bricks, the development and application of ladle repair materials, the application of ladle slag removers, etc., and each has achieved certain results. However, at present, domestic ladles still have problems such as high proportion of brick ladle, heavy weight, low ladle bottom life, short minor repair cycle, poor erosion resistance of high-temperature protective coating of working layer, and slag falling. Summary of the invention

[0004] In order to solve the problems of heavy weight, short service life and frequent maintenance of steel ladle, the present invention provides a steel ladle lining, and the technical solution adopted is as follows:

[0005] A ladle lining, characterized in that it mainly includes an insulation layer, a permanent layer, and a working layer which are distributed in sequence from the outside to the inside. An anchor is also fixedly connected to the inner wall of the ladle shell. One end of the anchor is fixedly connected to the ladle, and the other end passes through the insulation layer and the permanent layer in sequence and is located inside the working layer. The insulation layer adopts a composite silicate insulation material, and the working layer is a ceramic fiber high-temperature refractory coating.

[0006] Preferably, the insulation layer has a thickness of 300-500 mm.

[0007] Preferably, the permanent layer adopts a ceramic fiber section module structure, and the thickness of the permanent layer is 250-350 mm.

[0008] Preferably, the working layer has a coating thickness of 50-200 mm.

[0009] Preferably, the ceramic fiber high temperature refractory coating is made of the following raw materials in parts by weight: 15-25 parts by weight of alumina stabilized emulsion, 10-30 parts by weight of ceramic fibers, 1-5 parts by weight of fiber dispersant solution, 1-5 parts by weight of fiber flocculant solution, 1-3 parts by weight of anti-shrinkage additive and 45-65 parts by weight of water.

[0010] Preferably, the alumina emulsion is prepared by using pseudo-boehmite as the alumina source, preparing the pseudo-boehmite into a 30wt%-50wt% solution, adding a stabilizer to adjust the solution pH to 4-5, and stirring to obtain the solution.

[0011] Preferably, the ceramic fiber is selected from a mixture of one or more of high-aluminum, zirconium-containing, and polycrystalline alumina ceramic fibers; the Al2O3 of the high-aluminum ceramic fiber is ≧52wt%, and Al2O3+SiO2 is ≧98.5wt%; the Al2O3+SiO2+ZrO2 of the zirconium-containing ceramic fiber is ≧99wt%; the Al2O3 of the polycrystalline alumina fiber is ≧72wt%; the diameter of the ceramic fiber is 1-15 microns, and the length is 1-30 mm.

[0012] Preferably, the fiber dispersant solution is a dispersant solution with a solid content of 1%-5%; the dispersant is selected from one or two of polyacrylamide and cellulose; the fiber flocculant solution is a flocculant solution with a solid content of 5%-10%; the flocculant is selected from one or more of polyacrylamide, polyethylene oxide, polyvinyl alcohol and polyethylene glycol; the anti-shrinkage additive is selected from one or more of andalusite, kyanite, spinel, magnesium aluminum silicate and high alumina.

[0013] Preferably, the ceramic fiber high temperature refractory coating also includes a hardener, which is added during spraying, and the added amount is 5%-15% of the coating mass; the hardener is preferably an aluminum-based hardener, and its Al2O3 content is 15%-20%wt.

[0014] The beneficial effects of the present invention are:

[0015] 1. The high-temperature refractory coating made of ceramic fiber is used as the working layer, and the permanent layer is made of ceramic fiber section modules. The two form an overall ceramic fiber structure, which is light in weight, has good thermal insulation effect, is resistant to thermal shock, erosion, and easy to maintain. In addition, the ceramic fiber section module structure coating has good adhesion, and the combination with the high-temperature refractory coating is better;

[0016] 2. The insulation layer adopts composite silicate layer, which replaces ceramic fiberboard, nanoboard and other insulation materials. It is light in weight, low in thermal conductivity and good in thermal shock resistance.

[0017] 3. Ceramic fiber high-temperature refractory coating uses ceramic fiber as the skeleton, pseudo-boehmite to provide alumina, and formulates alumina stabilized emulsion to obtain alumina emulsion with high solid content and stable pH value. Nano alumina is provided by the sol-gel method, which has high activity and can form mullite phase with the fiber as soon as possible, thereby improving the strength and corrosion resistance of the coating. Anti-shrinkage additives are added to alleviate the shrinkage problem caused by high temperature environment. In addition, the content of powder additives in the formula is very low, and powder loss will not occur at low temperature stages, which significantly improves the corrosion resistance, wind speed resistance, and thermal shock resistance of the working layer, improves the problem of severe environmental erosion and easy powder loss of the coating, and significantly improves the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the present invention

[0019] Among them, 1-shell, 2-insulation layer, 3-anchor, 4-permanent layer, 5-working layer. DETAILED DESCRIPTION

[0020] The following will refer to the attached Figure 1 Exemplary embodiments of the present disclosure are described in more detail. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0021] In the description of the invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0022] like Figure 1 The ladle lining shown is mainly composed of a shell 1, an insulation layer 2, a permanent layer 4, and a working layer 5 which are distributed in sequence from the outside to the inside. The inner wall of the shell 1 is fixedly connected with anchors 3 which are distributed radially along the shell 1. One end of the anchor 3 is welded to the inner wall of the shell 1, and the other end passes through the insulation layer 2 and the permanent layer 4 and is located inside the working layer 5, thereby playing the role of fixing the module.

[0023] The anchor 3 is first connected to the ladle shell 1 by welding, and then the insulation layer 2 is constructed inside the ladle shell. The insulation layer 2 adopts a composite silicate insulation material, which is mixed with expanded perlite, sepiolite wool, ceramic fiber, and inorganic binder sodium silicate in a certain proportion. The coating thickness is 400mm, and the surface is smoothed with a mud board. After the composite silicate insulation material is naturally dried and cured for 24 hours, the permanent layer 4 is installed. The permanent layer 4 adopts a ceramic fiber section module with a thickness of 300mm. The ceramic fiber section module is anchored Part 3 is fixed to the shell 1, and the modules are in close contact to avoid large gaps. When gaps exist due to installation problems, ceramic fiber blankets or cotton are used to fill the gaps to ensure that the ceramic fiber modules form a flat overall surface. After the installation is completed, the working layer 5 is constructed. The working layer 5 adopts ceramic fiber high-temperature refractory material. The ceramic fiber high-temperature refractory material uses ceramic fiber as the skeleton and is sprayed onto the surface of the permanent layer 4. Then a mud board is used to smooth the surface. The coating thickness is 80mm. After 2-3 days of natural drying, a hard and erosion-resistant surface coating can be obtained.

[0024] Specifically, the preparation method of ceramic fiber high temperature refractory coating is as follows:

[0025] (1) Prepare a cellulose dispersant solution with a solid content of 5% and a polyacrylamide flocculant solution with a solid content of 10%, with the stirring speed of the stirrer at 800 r / min and the stirring time at 30 min;

[0026] (2) Mixing the raw materials according to weight parts, preparing 16 parts by weight of pseudo-boehmite into a 40% solution, adding HNO3 as a stabilizer, controlling the pH at 4-5, stirring at 600 r / min for 15 minutes, and preparing a stable alumina emulsion; granular nano-alumina with a particle size of 40-50 nm is stacked to form 0.5-2 μm spherical particles, and the 0.5-2 μm spherical particles are further stacked into large alumina particles of about 50 μm;

[0027] (3) Add 3 parts by weight of cellulose dispersant with a solid content of 5% to 15 parts by weight of high-aluminum fibers (Al2O3≧52%wt, Al2O3+SiO2≧98.5%wt, 2-6μm×10-20mm), add 25 parts by weight of water, and stir to disperse the fibers at a stirring speed of 500 r / min for 25 min.

[0028] (4) Mix the samples obtained in step (2) and step (3), add 1 part by weight of a polyacrylamide flocculant solution having a solid content of 10%, and mix and stir at a speed of 500 r / min for 15 min;

[0029] (5) Add 1 part by weight of kyanite powder and 1 part by weight of spinel powder to the sample obtained in step (4), mix and stir evenly at a stirring speed of 600 r / min for 5 min to obtain a finished coating with a moisture content of 65%; the Al2O3 content detected by XRF is 72.35%.

[0030] The permanent layer 4 adopts a ceramic fiber section module structure and the working layer 5 adopts a ceramic fiber high-temperature refractory coating to form a furnace lining with an overall fiber structure. In addition, the insulation layer 2 adopts a composite silicate material. The overall structure has low thermal conductivity, light weight, thermal shock resistance, and strong adhesion to each other, and can form a complete whole, which can reduce heat loss. At the same time, it can provide sufficient protection, is not easy to corrode, ensure the purity of molten steel, reduce the use of refractory materials and the number of maintenance of the ladle, and the maintenance interval time is short, which ensures the turnover of the ladle. In addition, compared with the existing high-temperature refractory coating, the ceramic fiber high-temperature refractory coating used in the working layer 5 has high strength, strong corrosion resistance, is not easy to shrink in high temperature environment, and is not easy to powder fall in low temperature environment, which effectively improves the service life of the ladle lining.

[0031] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A ladle lining, characterized in that: It mainly includes an insulation layer, a permanent layer, and a working layer which are distributed in sequence from the outside to the inside. The inner wall of the ladle shell is also fixedly connected with an anchor. One end of the anchor is fixedly connected to the ladle, and the other end passes through the insulation layer and the permanent layer in sequence and is located inside the working layer. The insulation layer adopts a composite silicate insulation material, and the working layer is a ceramic fiber high-temperature refractory coating. The ceramic fiber high-temperature refractory coating is made of the following raw materials in parts by weight: 15-25 parts by weight of alumina stabilized emulsion, 10-30 parts by weight of ceramic fiber, 1-5 parts by weight of fiber dispersant solution, 1-5 parts by weight of fiber flocculant solution, 1-3 parts by weight of anti-shrinkage additive and 45-65 parts by weight of water.

2. The ladle lining according to claim 1, characterized in that: The thickness of the thermal insulation layer is 300-500 mm.

3. The ladle lining according to claim 1, characterized in that: The permanent layer adopts a ceramic fiber section module structure, and the thickness of the permanent layer is 250-350mm.

4. The ladle lining according to claim 1, characterized in that: The working layer has a coating thickness of 50-200 mm.

5. The ladle lining according to claim 1, characterized in that: The alumina-stabilized emulsion is obtained by using pseudo-boehmite as the alumina source, preparing the pseudo-boehmite into a 30 wt%-50 wt% solution, adding a stabilizer to adjust the solution pH to 4-5, and stirring.

6. The ladle lining according to claim 1, characterized in that: The ceramic fiber is selected from a mixture of one or more of high-aluminum, zirconium-containing, and polycrystalline alumina ceramic fibers; the Al2O3 of the high-aluminum ceramic fiber is ≧52wt%, and Al2O3+SiO2 is ≧98.5wt%; the Al2O3+SiO2+ZrO2 of the zirconium-containing ceramic fiber is ≧99wt%; the Al2O3 of the polycrystalline alumina ceramic fiber is ≧72wt%; the diameter of the ceramic fiber is 1-15 microns, and the length is 1-30 mm.

7. The ladle lining according to claim 1, characterized in that: The fiber dispersant solution is a dispersant solution with a solid content of 1%-5%; the dispersant is selected from one or two of polyacrylamide and cellulose; the fiber flocculant solution is a flocculant solution with a solid content of 5%-10%; the flocculant is selected from one or more of polyacrylamide, polyethylene oxide, polyvinyl alcohol and polyethylene glycol; the anti-shrinkage additive is selected from one or more of andalusite, kyanite, spinel, magnesium aluminum silicate and high-alumina bauxite.

8. The ladle lining according to claim 1, characterized in that: The ceramic fiber high temperature refractory coating also includes a hardener, which is added during spraying, and the added amount is 5%-15% of the coating mass; the hardener is an aluminum-based hardener, and its Al2O3 content is 15%-20%wt.

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