Blast furnace protection method

Abstract

The invention belongs to the technical field of blast furnace smelting, and discloses a blast furnace protection method which comprises the following steps: S1, layering a blast furnace along the height direction, and respectively judging the erosion state of each layer of furnace body; s2, respectively preparing a composite furnace protection agent according to the erosion state of each layer of furnace body of the blast furnace; s3, the composite furnace protection agents are put into the corresponding layers of furnace bodies correspondingly, so that furnace protection layers are formed on the inner walls of the furnace bodies after the composite furnace protection agents react; and S4, detecting the furnace protection effect. According to the blast furnace protection method, feeding of the titanium powder can be controlled in a layered mode, it is guaranteed that the hearth part has enough titanium content to form a good protection layer, hearth corrosion is restrained, waste of titanium on the furnace body part is avoided, and the furnace protection cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of blast furnace smelting, in particular to a blast furnace protection method. Background Art

[0002] Blast furnace hearth erosion is a major threat to blast furnace production safety and a major factor in determining blast furnace life. One measure to control abnormal hearth erosion is to add titanium to the blast furnace. This involves adding materials containing titanium oxide (TiO2) to the blast furnace. TiO2 converts these materials into high-melting-point substances such as TiN, TiC, and Ti(CN). These substances adhere to the eroded areas of the blast furnace hearth, forming a protective layer that inhibits erosion and effectively protects the hearth.

[0003] Currently, the most common method for adding titanium to blast furnaces is to add various titanium-containing powders to the top of the furnace. Since the hearth requires protection, adding titanium-containing powders from the top can result in excessive titanium content in the furnace body, causing buildup and adhesion, disrupting smooth operation and increasing costs. However, insufficient titanium content in the hearth results in poor furnace protection. Furthermore, the large amount of titanium-containing powder used increases slag volume and viscosity, increasing energy consumption and making slag-iron removal difficult. Ultimately, this leads to reduced blast furnace output and an increased fuel-to-fuel ratio. Furthermore, the high-melting-point substances produced by adding titanium to the top are evenly distributed throughout the molten iron in the hearth, making localized corrosion repair ineffective and time-consuming.

[0004] Therefore, a blast furnace protection method is needed urgently to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide a blast furnace protection method, which can control the addition of titanium powder in layers, thereby ensuring that the furnace hearth has sufficient titanium content to form a good protective layer and inhibit furnace hearth erosion, while avoiding the waste of titanium in the furnace body and reducing the cost of furnace protection.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The blast furnace protection method comprises the following steps:

[0008] S1. Divide the blast furnace into layers along the height direction and determine the corrosion status of each layer of the furnace body;

[0009] S2. Prepare composite furnace protection agents according to the corrosion status of each layer of the blast furnace;

[0010] S3, respectively adding the composite furnace protection agent into the corresponding layer of the furnace body, so that the composite furnace protection agent reacts to form a furnace protection layer on the inner wall of the furnace body;

[0011] S4. Conduct furnace protection effect test.

[0012] Optionally, in step S1, in the height direction, the blast furnace sequentially includes a furnace top layer, a furnace shaft layer, a furnace waist layer, a furnace belly layer, and a hearth layer from top to bottom.

[0013] Optionally, according to the erosion state of each layer of the furnace body, the titanium load of the corresponding layer of the furnace body is controlled respectively.

[0014] Optionally, in the furnace shaft layer, the titanium load is controlled to be 0.5 - 1.0 kg / t;

[0015] In the hearth layer, the titanium load is controlled to be 2.0 - 3.0 kg / t.

[0016] Optionally, in step S2, the composite furnace protecting agent includes titanomagnetite and vanadium-titanium slag; and / or,

[0017] The composite furnace protecting agent includes titanium-containing concentrate and vanadium-containing tailings.

[0018] Optionally, in step S3, at preset time intervals, titanomagnetite and vanadium-titanium slag are sequentially put into the furnace body.

[0019] Optionally, the content of TiO2 in the composite furnace protecting agent is 20 - 80%.

[0020] Optionally, in step S3, charging ports are arranged at the sides of each layer of the blast furnace body, and the composite furnace protecting agent is put into the corresponding layer of the furnace body through the charging ports.

[0021] Optionally, a sealing cover is provided at the charging port for plugging the charging port.

[0022] Optionally, in step S3, the ways of putting the composite furnace protecting agent into the furnace include one or more of edge charging at the furnace top, composite injection through tuyeres, or injection together with gunite through the taphole.

[0023] Advantages of the present invention:

[0024] In the blast furnace protecting method provided by the present invention, first, the blast furnace is divided into layers in the height direction and the erosion state of each layer of the furnace body is judged respectively, so as to facilitate the separate analysis of different parts of the blast furnace and determine the protecting effect required for each layer of the furnace body. Then, according to the erosion state of each layer of the blast furnace body, a composite furnace protecting agent is prepared respectively. Next, the composite furnace protecting agent is put into the corresponding layer of the furnace body respectively, so that a protecting layer is formed on the inner wall of the furnace body after the reaction of the composite furnace protecting agent. Finally, the protecting effect is detected. With such a setting, corresponding protective layers can be formed for different parts of the blast furnace targeted, which not only avoids the waste of materials, reduces the furnace protecting cost, but also can protect the blast furnace targeted, greatly improving the effect of inhibiting the erosion of the blast furnace. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0026] Figure 1 is the hierarchical structure diagram of the blast furnace provided by the embodiment of the present invention;

[0027] Figure 2 is the step flow chart of the blast furnace hearth protection method provided by the embodiment of the present invention.

[0028] In the figure:

[0029] 1. Furnace top layer; 2. Furnace body layer; 3. Furnace waist layer; 4. Furnace belly layer; 5. Hearth layer. Specific embodiments

[0030] The following will further illustrate the technical solutions of the present invention in conjunction with the drawings and through specific embodiments.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0033] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, 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 should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used for differential description and should not be construed as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0035] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "arranged" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0037] In the description of the present invention, the term "and / or" is merely a description of the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the front and rear associated objects.

[0038] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation on the present invention.

[0039] Embodiment 1

[0040] This embodiment provides a method for protecting a blast furnace, asFigure 1 and Figure 2 As shown in Figure 2 , the blast furnace lining protection method includes the following steps:

[0041] S1. Layer the blast furnace along the height direction and respectively judge the erosion state of each layer of the furnace body.

[0042] As Figure 2 shown in Figure 2 , along the height direction, the blast furnace successively includes a furnace top layer 1, a furnace shaft layer 2, a furnace waist layer 3, a furnace belly layer 4, and a hearth layer 5 from top to bottom. It can be understood that the temperature inside the blast furnace gradually increases from top to bottom. Therefore, the hearth layer 5 is the area with the most serious erosion in the blast furnace and requires key protection for lining protection.

[0043] Specifically, according to the erosion state of each layer of the furnace body, control the titanium load of the corresponding layer of the furnace body respectively, that is, design the titanium load of each layer of the furnace body in a gradient manner. For example, in the furnace shaft layer 2, control the titanium load to be 0.5 - 1.0 kg / t. Because the temperature of the furnace shaft layer 2 is relatively low, a certain protective effect can be achieved without too high a titanium content, and such setting also helps to reduce costs. While in the hearth layer 5, control the titanium load to be 2.0 - 3.0 kg / t. A higher titanium content can generate more high-melting-point substances such as TiC / TiN at high temperatures, forming a thicker and more effective protective layer, thereby inhibiting the erosion of the hearth layer 5.

[0044] S2. Prepare a composite lining protection agent respectively according to the erosion state of each layer of the blast furnace body.

[0045] Specifically, the composite lining protection agent includes titanomagnetite and vanadium-titanium slag. First, conduct component analysis and performance testing on titanomagnetite and vanadium-titanium slag, and determine the component ratio of the two according to the furnace condition. The composite lining protection agent with a synergistic formula improves the compactness of the lining layer. The components in the vanadium-titanium slag can fill the gaps between the reaction products of titanomagnetite, making the lining layer more compact, thereby better blocking the erosion of the hearth layer 5 by the slag and molten iron.

[0046] Optionally, in this embodiment, the content of TiO2 in the composite lining protection agent is 20 - 80%.

[0047] S3. Put the composite lining protection agent into the corresponding layer of the furnace body respectively, so that a lining protection layer is formed on the inner wall of the furnace body after the composite lining protection agent reacts.

[0048] Specifically, in this step, at preset time intervals, titanomagnetite and vanadium-titanium slag are successively charged into the furnace body. When charging the composite furnace lining protecting agent into the furnace body, first charge a part of titanomagnetite to let it start to react in the furnace to form a preliminary furnace lining protection foundation, and then charge vanadium-titanium slag. The components in the vanadium-titanium slag interact with the reaction products of titanomagnetite to improve the compactness of the furnace lining protection layer. This preset time can be determined according to the temperature in the furnace body and the formation state of the furnace lining protection layer, and there is no limitation here. Of course, it can also be adjusted according to different furnace conditions to first charge vanadium-titanium slag and then titanomagnetite. Here, the charging order of the materials needs to be adjusted according to the actual situation.

[0049] More importantly, in this embodiment, in order to specifically charge an appropriate amount of composite furnace lining protecting agent into each layer of the blast furnace body, charging openings are provided on the side of each layer of the blast furnace body, and the composite furnace lining protecting agent is charged into the corresponding layer of the furnace body through the charging openings. With such a setting, separate feeding can be carried out for the furnace shaft layer 2 and the hearth layer 5. On the premise of ensuring the furnace lining protection effect of the furnace lining protection layers formed in the furnace shaft layer 2 and the hearth layer 5, the usage amount of the materials can be accurately controlled to avoid waste.

[0050] Optionally, a sealing cover is provided at the charging opening, and the sealing cover is used to block the charging opening to ensure the sealing performance and use safety of the furnace body.

[0051] Still optionally, in step S3, the ways of charging the composite furnace lining protecting agent include one or several of edge charging at the top of the furnace, composite injection through tuyeres, or injection along with gunite through the taphole.

[0052] S4. Perform furnace lining protection effect detection.

[0053] Specifically, an ultrasonic detection device for the thickness of the blast furnace inner lining can be set up. By measuring the thickness of the blast furnace inner lining, the furnace lining protection effect can be judged. This is the prior art and will not be elaborated in this embodiment.

[0054] Meanwhile, in the blast furnace lining protection method provided in this embodiment, during the smelting process with a large slag volume, by adjusting the component ratio and addition amount of the composite furnace lining protecting agent, it can adapt to the environment of a large slag volume. At the same time, the titanium load distribution in the gradient furnace lining protection technology is optimized to ensure that both the hearth layer 5 and the furnace shaft layer 2 can be effectively protected under the condition of a large slag volume, ensuring the stability of the hearth layer 5 and the furnace shaft layer 2 during the smelting process with a large slag volume, and improving the service life and production efficiency of the blast furnace.

[0055] Embodiment 2

[0056] This embodiment provides a method for protecting the blast furnace lining, which is basically the same as the method for protecting the blast furnace lining provided in Embodiment 1. The difference between this embodiment and Embodiment 1 is that in this embodiment, different combinations of titanium-containing materials can be used to achieve hierarchical control of the titanium load. For example, in addition to titanium-containing ores, titanium-containing pellets can also be used. In terms of the feeding method, a continuously variable feeding device can also be used to dynamically adjust the titanium load according to the real-time situation in the furnace.

[0057] At the same time, other combinations of titanium-containing and vanadium-containing substances can also be tried for the composite furnace lining protection agent, such as titanium-containing concentrate and vanadium-containing tailings, etc.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for protecting a blast furnace, characterized in that, It includes the following steps: S1. Stratify the blast furnace in the height direction and respectively judge the erosion state of each layer of the furnace body; S2. Prepare composite furnace protecting agents respectively according to the erosion state of each layer of the blast furnace body; S3. Put the composite furnace protecting agents into the corresponding layer of the furnace body respectively so that a furnace protecting layer is formed on the inner wall of the furnace body after the reaction of the composite furnace protecting agents; S4. Conduct detection on the furnace protecting effect.

2. The blast furnace hearth protection method according to claim 1, characterized in that, In step S1, in the height direction, the blast furnace sequentially includes a furnace top layer (1), a furnace shaft layer (2), a furnace waist layer (3), a furnace belly layer (4) and a hearth layer (5) from top to bottom.

3. The blast furnace hearth protection method according to claim 2, characterized in that, Control the titanium load of the corresponding layer of the furnace body respectively according to the erosion state of each layer of the furnace body.

4. The blast furnace hearth protection method according to claim 3, characterized in that, In the furnace shaft layer (2), control the titanium load to be 0.5 - 1.0 kg / t; In the hearth layer (5), control the titanium load to be 2.0 - 3.0 kg / t.

5. The blast furnace hearth protection method according to claim 1, characterized in that, In step S2, the composite furnace protecting agent includes titanomagnetite and vanadium-titanium slag; and / or, the composite furnace protecting agent includes titanium-containing concentrate and vanadium-containing tailings.

6. The blast furnace hearth protection method according to claim 5, characterized in that, In step S3, at intervals of a preset time, put titanomagnetite and vanadium-titanium slag into the furnace body in sequence.

7. The blast furnace hearth protection method according to claim 1, characterized in that, The content of TiO2 in the composite furnace protecting agent is 20 - 80%.

8. The blast furnace hearth protection method according to any one of claims 1-7, characterized in that, In step S3, open a feeding port at the side of each layer of the blast furnace body, and the composite furnace protecting agent is put into the corresponding layer of the furnace body through the feeding port.

9. The blast furnace hearth protection method according to claim 8, wherein, A sealing cover is provided at the feeding port for plugging the feeding port.

10. The blast furnace hearth protection method according to any one of claims 1-7, characterized in that, In step S3, the way of putting the composite furnace protecting agent includes one or more of edge feeding at the furnace top, composite injection through tuyeres or injection along with gunite through the taphole.

Images