Furnace bottom building method for smelting low-vanadium alloy steel in electric furnace

Abstract

The invention relates to the field of refractory materials of the electric furnace smelting technology, in particular to an electric furnace smelting low-vanadium alloy steel furnace bottom building method which comprises an electric furnace body, the electric furnace body comprises a furnace bottom and a furnace wall, and the furnace bottom and the furnace wall are sequentially provided with a heat preservation layer, a permanent layer and a working layer. The furnace bottom permanent layer comprises a sintered magnesite brick tiled layer and a sintered magnesite brick side tiled layer, and the furnace bottom working layer comprises a carbon magnesite brick tiled layer, a carbon magnesite brick side tiled layer and a carbon magnesite brick vertical tiled layer. Compared with the prior art, the ramming material working layer is replaced by the magnesia carbon brick bricking working layer, and the bricking mode of the magnesia carbon brick working layer is optimized, so that the problem that the normal smelting operation of an electric furnace is influenced by turning over of the ramming material at the bottom of the electric furnace for smelting low-vanadium alloy steel is solved, the service life of the electric furnace is prolonged, smooth production is promoted, and the refractory material cost of the electric furnace is reduced; and technical support is provided for smelting the low-vanadium alloy steel by adopting an electric furnace in iron and steel enterprises.

Description

Technical Field

[0001] The invention relates to the field of refractory materials for electric furnace smelting technology, and in particular to a method for laying a furnace bottom for smelting low-vanadium alloy steel in an electric furnace. Background Art

[0002] Electric furnace smelting is a non-blast furnace ironmaking method that uses electricity as heating energy. The requirements for the furnace bottom are also extremely important. The original electric furnace bottom masonry method is steel structure + fiberboard + fired magnesia bricks (two layers of flat masonry) + ramming material (bulk material). The new furnace must be baked when it is put into use, in order to allow the ramming material at the furnace bottom to sinter and form.

[0003] However, the furnace bottom structure using the above-mentioned existing method has the problem that the sintering and molding effect of the furnace bottom ramming material is not ideal, and part of the ramming material is peeled off, that is, the ramming material is turned over. When smelting low-vanadium alloy steel, it is easy to cause part of the furnace bottom ramming material to peel off, that is, the furnace bottom ramming material is turned over, which leads to safety hazards in the use of the furnace body, resulting in production obstruction and forced offline processing. In actual use, low-vanadium alloy steel is smelted by the furnace bottom ramming material method. The electric furnace is forced to be offline due to the turning over of the furnace bottom ramming material (the furnace age is less than 20 furnaces at a time), which leads to production obstruction and increased refractory costs. Summary of the invention

[0004] The present invention aims to provide a method for building a furnace bottom for smelting low-vanadium alloy steel in an electric furnace, mainly for solving the technical problem in the prior art that part of the furnace bottom ramming material is easily peeled off, i.e., the furnace bottom ramming material is turned over when smelting low-vanadium alloy steel.

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

[0006] A method for laying the bottom of an electric furnace for smelting low-vanadium alloy steel comprises an electric furnace body, wherein the electric furnace body comprises a furnace bottom and a furnace wall, wherein the furnace bottom and the furnace wall are sequentially provided with an insulation layer, a permanent layer and a working layer, wherein the permanent layer of the furnace bottom comprises a flat layer of fired magnesia bricks and a side layer of fired magnesia bricks, and the working layer of the furnace bottom comprises a flat layer of carbon-magnesia bricks, a side layer of carbon-magnesia bricks and a vertical layer of carbon-magnesia bricks, and the flat layer of fired magnesia bricks, the side layer of fired magnesia bricks, the flat layer of carbon-magnesia bricks, the side layer of carbon-magnesia bricks and the vertical layer of carbon-magnesia bricks are sequentially laid layer by layer on the furnace bottom from the outside to the inside.

[0007] Preferably, the upper end face of the thermal insulation layer is laid with a fired magnesia brick flat layer, the upper end face of the fired magnesia brick flat layer is laid with a fired magnesia brick side layer, the upper end face of the fired magnesia brick side layer is laid with a carbon magnesia brick flat layer, the upper end face of the carbon magnesia brick flat layer is laid with a carbon magnesia brick side layer, and the upper end face of the carbon magnesia brick side layer is laid with a carbon magnesia brick vertical layer.

[0008] Preferably, the permanent layer is made of fired magnesia bricks, and the upper end surface of the thermal insulation layer is built in a flat and side manner in sequence.

[0009] Preferably, the dimensions of the fired magnesia brick flat layer and the fired magnesia brick side layer are 230*115*65mm.

[0010] Preferably, the total thickness of the permanent layer after flat and side masonry is 180 mm.

[0011] Preferably, the working layer is made of carbon-magnesia bricks, and the upper end surface of the permanent layer is built in a flat, side and vertical manner in sequence.

[0012] Preferably, the size of the carbon-magnesia brick flat layer, carbon-magnesia brick side layer and carbon-magnesia brick vertical layer is 350*200*100mm.

[0013] Preferably, the total thickness of the working layer after flat, side and vertical masonry is 650mm

[0014] Preferably, the method for building the furnace bottom of an electric furnace for smelting low-vanadium alloy steel comprises the following steps:

[0015] a. First, retain the original insulation material of the furnace bottom. The insulation layer can be made of asbestos board or other alternative materials with a thickness of 10mm. The asbestos board is close to the steel structure of the furnace bottom.

[0016] b. The permanent layer is directly built on the asbestos board. The permanent layer is fired magnesia bricks. The fired magnesia brick flat layer is laid along the asbestos board. After the fired magnesia brick flat layer is laid, the fired magnesia brick side layer is laid sideways on the fired magnesia brick flat layer. After the fired magnesia brick flat layer and the fired magnesia brick side layer are laid, the total thickness of the permanent layer is 180mm. During the laying process, the connection between the furnace bottom and the furnace wall must also be taken into consideration;

[0017] c. Secondly, the working layer is a carbon-magnesia brick working layer. The masonry method of the working layer is flat, side and vertical. Specifically, the magnesia-carbon brick flat layer, magnesia-carbon brick side layer and magnesia-carbon brick vertical layer are laid layer by layer on the permanent layer. After the working layer is built, its total thickness is 650mm. During the building process, the connection between the furnace bottom and the furnace wall must also be taken into consideration;

[0018] d. After the permanent layer and the working layer are completed, the total thickness of the furnace bottom is the insulation layer plus the permanent layer plus the working layer, and the total thickness is 840mm.

[0019] Beneficial effects:

[0020] This solution solves the technical problem of the ramming material turning over at the bottom of the electric furnace during smelting low-vanadium alloy steel, which affects the normal smelting operation of the electric furnace, by replacing the ramming material working layer with a magnesia-carbon brick working layer and optimizing the masonry method of the magnesia-carbon brick working layer. This improves the service life of the electric furnace, promotes smooth production, reduces the cost of refractory materials for the electric furnace, and provides technical support for steel companies to use electric furnaces to smelt low-vanadium alloy steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a three-dimensional structural diagram of a vertical flow sedimentation tank of the patent of this invention.

[0022] The figure numerals in the drawings of the specification include: 1. electric furnace body; 2. furnace bottom; 3. furnace wall; 4. insulation layer; 5. permanent layer; 6. working layer; 7. fired magnesia brick flat layer; 8. fired magnesia brick side layer; 9. carbon magnesia brick flat layer; 10. carbon magnesia brick side layer; 11. carbon magnesia brick vertical layer. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figure 1 As shown, a furnace bottom structure for smelting low-vanadium alloy steel in an electric furnace includes an electric furnace body 1, and the electric furnace body 1 includes a furnace bottom 2 and a furnace wall 3. The furnace bottom 2 and the furnace wall 3 are sequentially installed with an insulation layer 4, a permanent layer 5 and a working layer 6, the permanent layer 5 is made of fired magnesia bricks, and the upper end surface of the insulation layer 4 is sequentially built in a flat and side manner, the permanent layer 5 includes a fired magnesia brick flat layer 7 and a fired magnesia brick side layer 8, the upper end surface of the insulation layer 4 is built with the fired magnesia brick flat layer 7, and the upper end surface of the fired magnesia brick flat layer 7 is built with the fired magnesia brick side layer 8, the size of the fired magnesia brick flat layer 7 and the fired magnesia brick side layer 8 is 230*115*65mm, and the total thickness of the permanent layer 5 after flat and side building is 180mm.

[0025] The upper fired magnesia brick has a high refractoriness under load and is mainly used for the furnace wall and bottom of the basic open hearth and electric furnace for steelmaking, the permanent lining of the oxygen converter, the iron-mixing furnace, the nonferrous smelting furnace, the high-temperature tunnel kiln, the lining of the rotary kiln for calcining magnesia and cement, the upper checker brick of the glass melting furnace, and the bottom and end of the steel rolling soaking furnace and the heating furnace. The existing fired magnesia brick is laid on the furnace bottom in a two-layer flat manner, and the effective thickness of the permanent layer 5 is only 130mm. By laying the fired magnesia brick in a flat and side manner, the effective thickness of the permanent layer 5 is increased to 180mm, which greatly enhances the stability of use.

[0026] The working layer 6 is made of carbon-magnesia bricks, and the upper end surface of the permanent layer 5 is laid in a flat, side and vertical manner in sequence. The working layer 6 includes a carbon-magnesia brick flat layer 9, a carbon-magnesia brick side layer 10 and a carbon-magnesia brick vertical layer 11. The fired magnesia brick flat layer 7, the fired magnesia brick side layer 8, the carbon-magnesia brick flat layer 9, the carbon-magnesia brick side layer 10 and the carbon-magnesia brick vertical layer 11 are sequentially laid in the furnace bottom 2 from the outside to the inside, and the carbon-magnesia brick flat layer 9 is laid layer by layer. The masonry is started along the upper end face of the fired magnesia brick side layer 8, the upper end face of the carbon-magnesia brick flat layer 9 is laid with a carbon-magnesia brick side layer 10, and the upper end face of the carbon-magnesia brick side layer 10 is laid with a carbon-magnesia brick vertical layer 11. The dimensions of the carbon-magnesia brick flat layer 9, the carbon-magnesia brick side layer 10 and the carbon-magnesia brick vertical layer 11 are 350*200*100mm, and the total thickness of the working layer 6 after flat, side and vertical masonry is 650mm.

[0027] By replacing the existing ramming material working layer with a magnesia carbon brick working layer, and laying the carbon-magnesia brick flat layer 9, the carbon-magnesia brick side layer 10 and the carbon-magnesia brick vertical layer 11 in the working layer from the outside to the inside in sequence on the furnace bottom 2 and laying them layer by layer, because the magnesia carbon brick is pressed and formed, the density, strength, high temperature resistance, corrosion, scouring and other properties of the brick are superior to those of the ramming material (bulk material) sintered and formed, and will not cause the furnace bottom to flip over, and the production process will not be interrupted due to the furnace bottom flipping. The multi-layer masonry method also ensures the thickness of the furnace bottom 2, so that the stability of the electric furnace smelting is enhanced, and the problem of the ramming material flipping over at the bottom of the electric furnace smelting low-vanadium alloy steel affecting the normal smelting operation of the electric furnace is solved, thereby increasing the life of the electric furnace, promoting smooth production, and reducing the cost of refractory materials for the electric furnace.

[0028] The method for laying the bottom of an electric furnace for smelting low-vanadium alloy steel comprises the following steps:

[0029] a. First, retain the original insulation material of the furnace bottom. The material of the insulation layer 4 can be asbestos board or other alternative materials with a thickness of 10 mm. The asbestos board is close to the steel structure of the furnace bottom.

[0030] b. A permanent layer 5 is directly built on the asbestos board. The permanent layer 5 is a fired magnesia brick. The fired magnesia brick flat layer 7 is laid flat along the asbestos board. After the fired magnesia brick flat layer 7 is laid, the fired magnesia brick side layer 8 is laid sideways on the fired magnesia brick flat layer 7. After the fired magnesia brick flat layer 7 and the fired magnesia brick side layer 8 are laid, the total thickness of the permanent layer 5 is 180 mm. During the laying process, the connection between the furnace bottom 2 and the furnace wall 3 must also be taken into consideration;

[0031] c. Secondly, the working layer 6 is a carbon-magnesia brick working layer. The working layer 6 is laid in a flat, side and vertical manner. Specifically, a magnesium-carbon brick flat layer 9, a magnesium-carbon brick side layer 10 and a magnesium-carbon brick vertical layer 11 are laid layer by layer on the permanent layer 5. After the working layer 6 is laid, its total thickness is 650 mm. During the laying process, the connection between the furnace bottom 2 and the furnace wall 3 must also be taken into consideration;

[0032] d. After the permanent layer 5 and the working layer 6 are completed, the total thickness of the furnace bottom 2 is the insulation layer 4 plus the permanent layer 5 plus the working layer 6, and the total thickness is 840 mm.

[0033] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A refractory structure for the bottom of an electric furnace for smelting low-vanadium alloy steel, comprising an electric furnace body (1), characterized in that: The electric furnace body (1) comprises a furnace bottom (2) and a furnace wall (3), wherein the furnace bottom (2) and the furnace wall (3) are sequentially provided with an insulation layer (4), a permanent layer (5) and a working layer (6), wherein the furnace bottom permanent layer (5) comprises a fired magnesia brick flat layer (7) and a fired magnesia brick side layer (8), wherein the furnace bottom working layer (6) comprises a carbon magnesia brick flat layer (9), a carbon magnesia brick side layer (10) and a carbon magnesia brick vertical layer (11), wherein the fired magnesia brick flat layer (7), the fired magnesia brick side layer (8), the carbon magnesia brick flat layer (9), the carbon magnesia brick side layer (10) and the carbon magnesia brick vertical layer (11) are sequentially located on the furnace bottom (2) and built layer by layer from the outside to the inside.

2. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 1 is characterized in that: The upper end surface of the thermal insulation layer (4) is built with a fired magnesia brick flat layer (7), the upper end surface of the fired magnesia brick flat layer (7) is built with a fired magnesia brick side layer (8), the upper end surface of the fired magnesia brick side layer (8) is built with a carbon magnesia brick flat layer (9), the upper end surface of the carbon magnesia brick flat layer (9) is built with a carbon magnesia brick side layer (10), and the upper end surface of the carbon magnesia brick side layer (10) is built with a carbon magnesia brick vertical layer (11).

3. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 2, characterized in that: The permanent layer (5) is made of fired magnesia bricks, and the upper end surface of the thermal insulation layer (4) is built in a flat and side manner.

4. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 3, characterized in that: The dimensions of the fired magnesia brick flat layer (7) and the fired magnesia brick side layer (8) are 230*115*65 mm.

5. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 4, characterized in that: The total thickness of the permanent layer (5) after flat and side masonry is 180 mm.

6. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 6, characterized in that: The working layer (6) is made of carbon-magnesia bricks, and the upper end surface of the permanent layer (5) is built in a flat, side and vertical manner in sequence.

7. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 6, characterized in that: The dimensions of the carbon-magnesia brick flat layer (9), the carbon-magnesia brick side layer (10) and the carbon-magnesia brick vertical layer (11) are 350*200*100 mm.

8. The refractory structure of the bottom of the electric furnace for smelting low vanadium alloy steel according to claim 6, characterized in that: The total thickness of the working layer (6) after horizontal, side and vertical masonry is 650 mm.

9. A method for building a furnace bottom for smelting low-vanadium alloy steel in an electric furnace, which is used for the furnace bottom structure for smelting low-vanadium alloy steel in an electric furnace as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: a. First, retain the original insulation material of the electric furnace bottom. The material of the insulation layer (4) can be asbestos board or other alternative materials with a thickness of 10 mm. The asbestos board is close to the steel structure of the furnace bottom; b. A permanent layer (5) is directly built on the asbestos board. The permanent layer (5) is a fired magnesia brick. The fired magnesia brick flat layer (7) is laid flat along the asbestos board. After the fired magnesia brick flat layer (7) is laid, the fired magnesia brick side layer (8) is laid sideways on the fired magnesia brick flat layer (7). After the fired magnesia brick flat layer (7) and the fired magnesia brick side layer (8) are laid, the total thickness of the permanent layer (5) is 180 mm. During the laying process, the connection between the furnace bottom (2) and the furnace wall (3) must also be taken into consideration; c. Secondly, the working layer (6) is a carbon-magnesia brick working layer. The working layer (6) is laid in a flat, side and vertical manner. Specifically, a magnesium-carbon brick flat layer (9), a magnesium-carbon brick side layer (10) and a magnesium-carbon brick vertical layer (11) are laid on the permanent layer (5) layer by layer. After the working layer (6) is laid, its total thickness is 650 mm. During the laying process, the connection between the furnace bottom (2) and the furnace wall (3) must also be taken into consideration. d. After the permanent layer (5) and the working layer (6) are completed, the total thickness of the furnace bottom (2) is the insulation layer (4) plus the permanent layer (5) plus the working layer (6), and the total thickness is 840 mm.

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