Method for extending service life of molten iron ladle

Abstract

A method for extending the service life of a hot metal ladle, the method comprising the steps of: emptying the remaining slag iron in the hot metal ladle; taking the hot metal ladle offline; cleaning the residual slag iron on the wall surface of the hot metal ladle; baking the hot metal ladle; adding a deoxidizer to the hot metal ladle; and putting the hot metal ladle online. The present application provides a method for extending the service life of a hot metal ladle, wherein a deoxidizer is added to the hot metal ladle, and the added deoxidizer reacts with oxides such as FeO in the high-temperature slag iron molten in the hot metal ladle, and forms a carbon excess state, so as to prevent the oxides in the slag iron from reacting with the carbon in the hot metal and the carbon element in the refractory material, completely solving the violent reaction in the hot metal ladle connection process and the iron leakage accident of the hot metal ladle, and extending the service life of the hot metal ladle.

Description

Technical Field

[0001] The invention belongs to the technical field of molten iron smelting, and particularly relates to a method for extending the service life of a molten iron ladle. Background Art

[0002] The iron ladle "one ladle to the end" mode of steel enterprises is specifically: the iron ladle stores and transports molten iron, and uses CaO+CaF2 composite desulfurizer for KR desulfurization. The "one ladle to the end" mode means that the blast furnace iron, KR desulfurization slag, and converter iron are all contained and transported by the iron ladle. Due to the elimination of the tank dumping station, the temperature loss of molten iron is reduced, creating a good molten iron temperature condition for steelmaking production.

[0003] In the daily production process, slag iron is easily stuck to the ladle from the upper edge of the ladle mouth to the slag line of the side wall (hereinafter referred to as the ladle edge). When the ladle needs to be taken offline for cold inspection after a long period of use, or when the molten iron output decreases due to blast furnace maintenance, equipment failure, etc., and some ladles need to be temporarily offline, they must be baked to above 800℃ with coke oven gas before they are put online again. During the baking process, the slag iron mixture adhered to the ladle mouth and the ladle wall melts and gathers at the bottom of the ladle and cannot be removed. The molten slag iron mixture has a high content of highly oxidizing FeO (16% to 45%), which is deposited on the bottom of the ladle for a long time and reacts with [C] in the molten iron and the carbon element in the refractory to generate CO or CO2, which destroys the brick structure and deteriorates the strength of the brick, causing the slag iron to penetrate along the cracks on the surface of the refractory bricks and then cause the refractory to peel off. The chemical reaction formula is as follows:

[0004] [FeO]+C→[Fe]+CO↑

[0005] 2[FeO]+C→2[Fe]+CO2↑

[0006] Especially in the initial stage of blast furnace receiving molten iron, high-temperature molten iron (temperature ≥1500℃) flows into the ladle from the swinging groove at a faster speed (due to a certain height difference), which is similar to strong mechanical stirring and enhances the kinetic conditions of the chemical reaction. The FeO in the slag-iron mixture accumulated at the bottom of the ladle reacts violently with the molten iron and the refractory materials of the ladle, instantly producing a large amount of gas, causing the molten iron to churn violently, resulting in ladle overturning and abnormal erosion of the ladle, which often causes molten iron to churn and overflow and iron leakage from the ladle in severe cases. Summary of the invention

[0007] In view of the above problems, the present invention provides a method for extending the service life of a ladle which overcomes the above problems or at least partially solves the above problems.

[0008] In order to solve the above technical problems, the present invention provides a method for extending the service life of a ladle, the method comprising the steps of:

[0009] Empty the remaining slag in the ladle;

[0010] The molten iron ladle is offline;

[0011] Cleaning the residual iron on the wall surface of the molten iron ladle;

[0012] baking the ladle;

[0013] Adding a deoxidizer into the ladle;

[0014] Put the ladle online.

[0015] Preferably, the cleaning of residual iron on the wall surface of the molten iron ladle comprises the steps of:

[0016] Prepare cleaning tools;

[0017] The cleaning tool is used to clean the residual iron on the wall surface of the molten iron ladle.

[0018] Preferably, the step of using the cleaning tool to clean the residual iron on the wall surface of the molten iron ladle comprises the following steps:

[0019] Determining whether the cleaning tool is close to the wall refractory material on the surface of the ladle;

[0020] If so, reducing the cleaning force of the cleaning tool;

[0021] If not, maintain current cleaning efforts.

[0022] Preferably, the baking of the ladle comprises the steps of:

[0023] Prepare baking line;

[0024] placing the ladle on the baking line;

[0025] The ladle is baked to a preset temperature using coke oven gas.

[0026] Preferably, the preset temperature is greater than or equal to 800°C.

[0027] Preferably, the step of adding a deoxidizer into the ladle comprises the following steps:

[0028] Obtaining the amount of slag iron oxide remaining at the bottom of the molten iron ladle;

[0029] A preset amount of deoxidizer is added according to the amount of iron oxides in the slag.

[0030] Preferably, the deoxidizer is coke diced from blast furnace raw material undersize.

[0031] Preferably, the particle size of the chopped coke from the blast furnace raw material undersize is 10 mm to 17 mm.

[0032] Preferably, the carbon content of the blast furnace raw material undersize coke is greater than or equal to 85%.

[0033] Preferably, the amount of coke diced in the blast furnace raw material undersize satisfies the formula:

[0034]

[0035] Among them, A represents the amount of coke pieces in the blast furnace raw material undersize, B represents the carbon content of coke pieces in the blast furnace raw material undersize, C represents the amount of slag iron, and D represents the oxide content of slag iron.

[0036] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages: The present application provides a method for extending the service life of a ladle, in which a deoxidizer is added into the ladle, and the added deoxidizer reacts with oxides such as FeO in the molten high-temperature slag iron in the ladle to form an excess carbon state, so as to prevent the oxides in the slag iron from reacting with the carbon in the molten iron and the carbon element in the refractory material, thereby completely solving the violent reaction in the iron connection process of the ladle and the iron leakage accident of the ladle, and extending the service life of the ladle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 It is a schematic diagram of slag iron attachments on the ladle wall when the ladle is offline in a method for extending the service life of a ladle provided by an embodiment of the present invention;

[0039] Figure 2 It is a schematic diagram of residual iron on the wall surface of a molten iron ladle in a method for extending the service life of a molten iron ladle provided by an embodiment of the present invention;

[0040] Figure 3 It is a schematic diagram of baking a molten iron ladle on a baking table in a method for extending the service life of a molten iron ladle provided in an embodiment of the present invention;

[0041] Figure 4 It is a schematic diagram of adding a deoxidizer into a molten iron ladle in a method for extending the service life of a molten iron ladle provided in an embodiment of the present invention;

[0042] Figure 5 It is a schematic diagram of the reaction between the residual slag iron in the ladle and the deoxidizer in a method for extending the service life of the ladle provided by an embodiment of the present invention;

[0043] Figure 6It is a schematic diagram of putting an iron ladle online in a method for extending the service life of an iron ladle provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be described in detail below in conjunction with specific implementations and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific implementations and examples are used to illustrate the present invention, rather than to limit the present invention.

[0045] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0046] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0047] like Figure 1-6 In an embodiment of the present application, the present invention provides a method for extending the service life of a molten iron ladle, the method comprising the steps of:

[0048] Empty the remaining slag in the ladle;

[0049] The molten iron ladle is offline;

[0050] Cleaning the residual iron on the wall surface of the molten iron ladle;

[0051] baking the ladle;

[0052] Adding a deoxidizer into the ladle;

[0053] Put the ladle online.

[0054] In an embodiment of the present application, the remaining slag in the ladle is emptied before the ladle is taken off the line, and then the slag on the surface of the ladle wall is cleaned, the ladle is baked on a baking line, and a deoxidizer is added to clean the oxides in the slag at the bottom of the ladle.

[0055] In an embodiment of the present application, the cleaning of residual iron on the wall surface of the molten iron ladle comprises the steps of:

[0056] Prepare cleaning tools;

[0057] The cleaning tool is used to clean the residual iron on the wall surface of the molten iron ladle.

[0058] In the embodiment of the present application, residual iron on the wall surface of the molten iron ladle can be cleaned by a special cleaning tool.

[0059] In an embodiment of the present application, the step of using the cleaning tool to clean the residual iron on the wall surface of the molten iron ladle comprises the following steps:

[0060] Determining whether the cleaning tool is close to the wall refractory material on the surface of the ladle;

[0061] If so, reducing the cleaning force of the cleaning tool;

[0062] If not, maintain current cleaning efforts.

[0063] In an embodiment of the present application, in order to prevent damage to the refractory materials of the wall on the surface of the ladle, when using a cleaning tool to clean the residual iron on the surface of the ladle, it is necessary to determine whether the cleaning tool is close to the refractory materials of the wall on the surface of the ladle. When it is close, it is necessary to reduce the cleaning force of the cleaning tool to prevent the cleaning tool from damaging the refractory materials of the wall.

[0064] In an embodiment of the present application, the step of baking the ladle comprises the following steps:

[0065] Prepare baking line;

[0066] placing the ladle on the baking line;

[0067] The ladle is baked to a preset temperature using coke oven gas.

[0068] In the embodiment of the present application, the ladle is baked by using a baking line to reach a preset temperature.

[0069] In the embodiment of the present application, the preset temperature is greater than or equal to 800°C.

[0070] In the embodiment of the present application, the benefits of baking the ladle to 800°C are: on the one hand, the refractory material can be preheated to a predetermined temperature in advance, so as to prevent the refractory material from being damaged by a sudden change in temperature after the molten iron ladle receives iron; and the residual slag iron in the ladle wall can be melted, thereby facilitating the addition of a deoxidizer for reaction.

[0071] In an embodiment of the present application, the step of adding a deoxidizer into the ladle comprises the following steps:

[0072] Obtaining the amount of slag iron oxide remaining at the bottom of the molten iron ladle;

[0073] A preset amount of deoxidizer is added according to the amount of iron oxides in the slag.

[0074] In the embodiment of the present application, after the iron ladle is baked, the slag iron oxides on the wall of the iron ladle melt and gather at the bottom of the iron ladle. At this time, a deoxidizer is required to react with the slag iron oxides.

[0075] In the embodiment of the present application, the deoxidizer is coke diced from blast furnace raw material undersize.

[0076] In the embodiments of the present application, the advantages of using diced coke, which is the undersize of the blast furnace raw material, as a deoxidizer are as follows: diced coke is the undersize of the coke entering the blast furnace, which can achieve resource recycling; diced coke has a certain particle size, which is conducive to controlling its addition into the molten iron ladle during the production process; diced coke has a high carbon content, which can fully meet the demand for removing FeO from the residual slag.

[0077] In the embodiment of the present application, the particle size of the coke diced from the blast furnace raw material undersize is 10mm-17mm.

[0078] In the embodiment of the present application, the particle size of the chopped coke of the blast furnace raw material screen is 10mm-17mm. The advantage is that it will not generate a lot of dust during the addition process, and will not be burned up quickly in large quantities after being added to the molten iron ladle, which can maximize the reduction reaction.

[0079] In an embodiment of the present application, the carbon content of the blast furnace raw material undersize coke is greater than or equal to 85%.

[0080] In the embodiment of the present application, the advantage of the carbon content of the blast furnace raw material undersize coke being greater than or equal to 85% is that the carbon content is high and the composition is relatively stable.

[0081] In the embodiments of the present application, considering that part of the char diced from the blast furnace raw material undersize will be burned and consumed in a high temperature environment, it is necessary to add additional char diced from the blast furnace raw material undersize under ideal conditions according to the specific situation of the slag iron to ensure complete reaction with the slag iron.

[0082] In the embodiment of the present application, the amount of coke cubes in the blast furnace raw material undersize satisfies the formula:

[0083]

[0084] Among them, A represents the amount of coke pieces in the blast furnace raw material undersize, B represents the carbon content of coke pieces in the blast furnace raw material undersize, C represents the amount of slag iron, and D represents the oxide content of slag iron.

[0085] The present application provides a method for extending the service life of a ladle, in which a deoxidizer is added into the ladle, and the added deoxidizer reacts with oxides such as FeO in the molten high-temperature slag iron in the ladle to form an excess carbon state, so as to prevent the oxides in the slag iron from reacting with the carbon in the molten iron and the carbon element in the refractory material, thereby completely solving the violent reaction in the iron connection process of the ladle and the iron leakage accident of the ladle, and extending the service life of the ladle.

[0086] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. The various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied for herein.

[0087] In short, the above is only a preferred embodiment of the technical solution of the present invention, and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for extending the service life of a ladle, characterized in that: The method comprises the steps of: Empty the remaining slag in the ladle; The molten iron ladle is offline; Cleaning the residual iron on the wall surface of the molten iron ladle; baking the ladle; Adding a deoxidizer into the ladle; Put the ladle online; The adding of deoxidizer into the ladle comprises the steps of: Obtaining the amount of slag iron oxide remaining at the bottom of the molten iron ladle; Adding a preset amount of deoxidizer according to the amount of iron oxides in the slag, wherein the deoxidizer is coke diced from the blast furnace raw material undersize; The particle size of the coke diced material of the blast furnace raw material undersize is 10 mm-17 mm, the carbon content of the coke diced material of the blast furnace raw material undersize is greater than or equal to 85%, and the amount of the coke diced material of the blast furnace raw material undersize satisfies the formula: ， Among them, A represents the amount of coke pieces in the blast furnace raw material undersize, B represents the carbon content of coke pieces in the blast furnace raw material undersize, C represents the amount of slag iron, and D represents the oxide content of slag iron.

2. The method for extending the service life of a ladle according to claim 1, characterized in that: The cleaning of residual iron on the wall surface of the molten iron ladle comprises the following steps: Prepare cleaning tools; The cleaning tool is used to clean the residual iron on the wall surface of the molten iron ladle.

3. The method for extending the service life of a ladle according to claim 2, characterized in that: The use of the cleaning tool to clean the residual iron on the wall surface of the molten iron ladle comprises the following steps: Determining whether the cleaning tool is close to the wall refractory material on the surface of the ladle; If so, reducing the cleaning force of the cleaning tool; If not, maintain current cleaning efforts.

4. The method for extending the service life of a ladle according to claim 1, characterized in that: The baking of the ladle comprises the steps of: Prepare baking line; placing the ladle on the baking line; The ladle is baked to a preset temperature using coke oven gas.

5. The method for extending the service life of a ladle according to claim 4, characterized in that: The preset temperature is greater than or equal to 800°C.

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