Method for judging stacking degree of vanadium titano-magnetite smelting hearth under condition of high pellet proportion

Abstract

The invention provides a method for judging the stacking degree of a vanadium titano-magnetite smelting hearth under the condition of high pellet proportion, which comprises the following steps: monitoring the center temperature of a furnace top charge level, the center temperature characterizing the intensity of blast furnace center airflow; calculating the blast furnace zinc discharge rate; and the hearth stacking degree is determined according to the calculated blast furnace zinc discharge rate data and the furnace top charge level center temperature data. Compared with the prior art, the method for judging the stacking degree of the vanadium titano-magnetite smelting blast furnace hearth under the high pellet proportion condition provided by the invention has the advantages that the stacking condition of the vanadium titano-magnetite smelting blast furnace hearth is judged according to the change of the furnace top temperature and the blast furnace zinc discharge rate, and the method is simple, convenient, efficient and reliable; therefore, the problem of how to judge hearth accumulation during blast furnace smelting of the vanadium titano-magnetite can be solved, and early warning is provided for a blast furnace operator so as to take measures in time.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and more specifically to a method for judging the accumulation degree of a vanadium-titanium magnetite smelting furnace under high pellet ratio conditions. Background Art

[0002] During the blast furnace smelting process, the blast furnace hearth is the area where the main heat is brought into and generated by the blast furnace, and it is the power source for the descent and reduction of the blast furnace charge. Therefore, the working state of the blast furnace hearth is the basis for the stable and efficient production of the blast furnace. Hearth accumulation is often caused by abnormal distribution of the temperature field or gas flow field in the blast furnace. When the heat and gas flow cannot effectively reach its area, the slag iron and coke mixture are mixed together and cannot be effectively melted in time to form a mass, which leads to the inactivity of the blast furnace hearth and the loss of the original stability of the hearth heat, causing the blast furnace to malfunction and smelting to be unsmooth. If the hearth accumulation is not handled properly, it will affect the discharge of slag iron, damage the hearth cooling equipment, and cause damage to the refractory materials at the bottom of the hearth. In China, multiple sensors for detecting temperature, flow, etc. are generally installed at the bottom of the hearth of large blast furnaces. Due to the large amount of data, it is difficult to accurately diagnose the hearth accumulation condition in a short time. In response to these problems, steel companies have explored many methods in practice, such as using a model to evaluate the amount of slag and iron remaining in the hearth to ensure the normal operation of the hearth; the application of the inverse solution of heat transfer boundaries in the diagnosis of blast furnace hearth erosion; the technical idea of ​​using mathematical models to manage the working state of the blast furnace hearth, and constructing mathematical models to ensure hearth accumulation and stability. Some companies also evaluate the accumulation of blast furnace hearths from the water temperature difference and heat load, but this method is relatively extensive.

[0003] In the blast furnace smelting of vanadium-titanium magnetite, there is also the heat transfer and reduction reaction between the downward iron-containing charge and the upward high-temperature coal gas in the reverse movement process. As the reduction reaction goes on, while the iron is reduced, elements such as Ti, Si, and V are also reduced into the molten iron. Not only does the problem of hearth accumulation occur in the blast furnace smelting of ordinary ore exist, but it is more serious. This is mainly due to the over-reduction of TiO2 in the hearth during the blast furnace smelting of vanadium-titanium magnetite, generating high-melting-point TiC and TiN, which will cause hearth accumulation and unstable furnace conditions. The accumulation in the hearth manifests itself in different ways, such as the water temperature difference of each layer of cooling water wall and the furnace body temperature being higher or lower than normal, the throat temperature being lower or higher than normal, and the temperature band becoming narrower. Especially under the condition of high pellet ratio, the pellets have the effect of inhibiting the central airflow. Based on these phenomena, it is difficult to determine whether it is caused by hearth accumulation or other reasons.

[0004] Therefore, it is very necessary to explore a method that can more realistically feedback the thermal status of the blast furnace hearth, especially when slight accumulation begins to gradually appear in the center of the blast furnace hearth and the accumulation behavior worsens, and can also effectively and timely feedback the hearth accumulation, so as to deal with the hearth accumulation as soon as possible. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for judging the degree of accumulation in the furnace of vanadium-titanium magnetite smelting under high pellet ratio conditions, which can solve the problem of how to judge the accumulation in the furnace during blast furnace smelting of vanadium-titanium magnetite, and provide early warning for blast furnace operators so that timely measures can be taken.

[0006] The present invention provides a method for determining the accumulation degree of a vanadium-titanium magnetite smelting furnace under a high pellet ratio condition, comprising the following steps:

[0007] Monitor the center temperature of the furnace top material surface, which indicates the strength of the central airflow in the blast furnace;

[0008] Calculate the zinc discharge rate of the blast furnace;

[0009] The degree of accumulation in the furnace is determined by calculating the blast furnace zinc discharge rate data and the center temperature data of the furnace top material surface.

[0010] Preferably, the calculation formula of the blast furnace zinc discharge rate is:

[0011] Blast furnace zinc discharge rate = zinc discharged from blast furnace / zinc entered into blast furnace.

[0012] Preferably, the zinc-containing materials entering the blast furnace include: sintered ore, pelletized ore, coke, and pulverized coal injection. The amount of zinc of each material entering the blast furnace every day is first calculated.

[0013] Preferably, the amount of zinc of each material entering the blast furnace every day = G burn × % burn + G balls × % balls + G coke × % coke + G coal × % G coal;

[0014] Among them, Gburn is the weight of sintered ore, %burn is the zinc content of sintered ore, Gball is the weight of pelletized ore, %ball is the zinc content of pelletized ore, Gcoke is the weight of coke, %coke is the zinc content of coke, Gcoal is the weight of pulverized coal, and %coal is the zinc content of pulverized coal.

[0015] Preferably, the zinc-containing materials discharged from the blast furnace include: blast furnace slag, molten iron, gravity dust ash, furnace top and furnace front dust ash, and then the amount of zinc discharged from the blast furnace by each material every day is calculated.

[0016] Preferably, the amount of zinc discharged from the blast furnace by each material every day = G slag × % slag + G iron × % iron + G weight × % weight + G top × % G top;

[0017] Among them, G slag is the weight of blast furnace slag, % slag is the zinc content of blast furnace slag, G iron is the weight of molten iron, % iron is the zinc content of molten iron, G weight is the weight of gravity dust ash, % weight is the zinc content of gravity dust ash, G top is the weight of furnace top and furnace front dust ash, % top is the zinc content of furnace top and furnace front dust ash.

[0018] Preferably, the furnace accumulation degree is specifically divided into five levels: normal, slight, slightly, severe, and extremely severe.

[0019] Preferably, the furnace state of the normal gear is: the blast furnace zinc discharge rate data is greater than 90% and the center temperature data of the furnace top material surface is greater than 350°C;

[0020] The furnace state of the mild gear: the blast furnace zinc discharge rate data is greater than 90% and the furnace top material surface center temperature data is 300°C to 350°C; or, the blast furnace zinc discharge rate data is 70% to 90% and the furnace top material surface center temperature data is greater than 350°C;

[0021] The slightly geared furnace state: the blast furnace zinc discharge rate data is greater than 90% and the furnace top material surface center temperature data is greater than or equal to 250°C and less than 300°C; or, the blast furnace zinc discharge rate data is 80% to 90% and the furnace top material surface center temperature data is 250°C to 350°C; or, the blast furnace zinc discharge rate data is greater than or equal to 70% and less than 80% and the furnace top material surface center temperature data is 300°C to 350°C;

[0022] The furnace state of the severe gear: the blast furnace zinc discharge rate data is greater than or equal to 70% and less than 80% and the furnace top material surface center temperature data is greater than or equal to 250°C and less than 300°C;

[0023] The extremely serious furnace state is as follows: the blast furnace zinc discharge rate data is less than 70% and the center temperature data of the furnace top material surface is less than 250°C.

[0024] Preferably, the determination process determines the degree of accumulation in the center of the hearth by observing the same hearth state for three consecutive days.

[0025] Preferably, the furnace hearth state of the minor grade does not require intervention and is in the observation stage; the furnace hearth state of the slightly severe grade requires certain intervention measures; the furnace hearth state of the severe grade requires strong intervention, such as increasing the center temperature of the furnace top charge surface and increasing the zinc discharge rate; the furnace hearth state of the extremely severe grade means that the blast furnace is on the verge of collapse and the blast furnace condition is seriously abnormal.

[0026] The present invention provides a method for judging the degree of accumulation in the furnace hearth of vanadium-titanium magnetite smelting under the condition of high pellet ratio, comprising the following steps: monitoring the center temperature of the furnace top charge surface, the center temperature characterizing the strength of the central airflow of the blast furnace; calculating the blast furnace zinc discharge rate; determining the degree of accumulation in the furnace hearth by calculating the blast furnace zinc discharge rate data and the center temperature data of the furnace top charge surface. Compared with the prior art, the method for judging the degree of accumulation in the furnace hearth of vanadium-titanium magnetite smelting under the condition of high pellet ratio provided by the present invention judges the accumulation of the furnace hearth of the vanadium-titanium magnetite smelting blast furnace according to the changes of the furnace top temperature and the blast furnace zinc discharge rate, and the method is simple, efficient and reliable, so as to solve the problem of how to judge the accumulation of the furnace hearth during the blast furnace smelting of vanadium-titanium magnetite, and provide an early warning for the blast furnace operator so that timely measures can be taken. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be clearly and completely described below in conjunction with 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.

[0028] The present invention provides a method for determining the accumulation degree of a vanadium-titanium magnetite smelting furnace under a high pellet ratio condition, comprising the following steps:

[0029] Monitor the center temperature of the furnace top material surface, which indicates the strength of the central airflow in the blast furnace;

[0030] Calculate the zinc discharge rate of the blast furnace;

[0031] The degree of accumulation in the furnace is determined by calculating the blast furnace zinc discharge rate data and the center temperature data of the furnace top material surface.

[0032] The present invention first monitors the center temperature of the furnace top material surface, and the center temperature represents the strength of the central airflow of the blast furnace; the present invention has no special limitation on the monitoring method, and the temperature monitoring technical means familiar to those skilled in the art can be used.

[0033] Secondly, the present invention calculates the blast furnace zinc discharge rate; the calculation formula of the blast furnace zinc discharge rate is preferably:

[0034] Blast furnace zinc discharge rate = zinc discharged from blast furnace / zinc entered into blast furnace.

[0035] In the present invention, the zinc-containing materials entering the blast furnace include: sintered ore, pelletized ore, coke, and PCI. The amount of zinc of each material entering the blast furnace every day is calculated first; on this basis, the amount of zinc of each material entering the blast furnace every day = G burn × % burn + G pellet × % pellet + G coke × % coke + G coal × % G coal;

[0036] Among them, Gburn is the weight of sintered ore, %burn is the zinc content of sintered ore, Gball is the weight of pelletized ore, %ball is the zinc content of pelletized ore, Gcoke is the weight of coke, %coke is the zinc content of coke, Gcoal is the weight of pulverized coal, and %coal is the zinc content of pulverized coal.

[0037] In the present invention, the zinc-containing materials discharged from the blast furnace include: blast furnace slag, molten iron, gravity dust removal ash, furnace top and furnace front dust removal ash, and then the amount of zinc discharged from the blast furnace by each material every day is calculated; on this basis, the amount of zinc discharged from the blast furnace by each material every day = G slag × % slag + G iron × % iron + G weight × % weight + G top × % G top;

[0038] Among them, G slag is the weight of blast furnace slag, % slag is the zinc content of blast furnace slag, G iron is the weight of molten iron, % iron is the zinc content of molten iron, G weight is the weight of gravity dust ash, % weight is the zinc content of gravity dust ash, G top is the weight of furnace top and furnace front dust ash, % top is the zinc content of furnace top and furnace front dust ash.

[0039] Finally, the present invention determines the degree of accumulation in the furnace by calculating the blast furnace zinc discharge rate data and the center temperature data of the furnace top material surface.

[0040] In the present invention, the furnace accumulation degree is preferably specifically divided into five levels: normal, slight, slightly, severe, and extremely severe.

[0041] In the present invention, the furnace state of the normal gear is: the blast furnace zinc discharge rate data is greater than 90% and the center temperature data of the furnace top material surface is greater than 350°C;

[0042] The furnace state of the mild gear: the blast furnace zinc discharge rate data is greater than 90% and the furnace top material surface center temperature data is 300°C to 350°C; or, the blast furnace zinc discharge rate data is 70% to 90% and the furnace top material surface center temperature data is greater than 350°C;

[0043] The slightly geared furnace state: the blast furnace zinc discharge rate data is greater than 90% and the furnace top material surface center temperature data is greater than or equal to 250°C and less than 300°C; or, the blast furnace zinc discharge rate data is 80% to 90% and the furnace top material surface center temperature data is 250°C to 350°C; or, the blast furnace zinc discharge rate data is greater than or equal to 70% and less than 80% and the furnace top material surface center temperature data is 300°C to 350°C;

[0044] The furnace state of the severe gear: the blast furnace zinc discharge rate data is greater than or equal to 70% and less than 80% and the furnace top material surface center temperature data is greater than or equal to 250°C and less than 300°C;

[0045] The extremely serious furnace state is as follows: the blast furnace zinc discharge rate data is less than 70% and the center temperature data of the furnace top material surface is less than 250°C.

[0046] For details, please refer to Table 1 below.

[0047] Table 1

[0048]

[0049]

[0050] Note: If there is an intersection between endpoint values, please refer to the above text description. The table is for the convenience of expression.

[0051] In the present invention, the determination process preferably determines the accumulation degree in the center of the hearth by observing the same hearth state for three consecutive days.

[0052] In the present invention, the furnace hearth state of the minor grade does not need intervention and is in the observation stage; the furnace hearth state of the slightly severe grade needs certain intervention measures; the furnace hearth state of the severe grade needs strong intervention, such as increasing the center temperature of the furnace top material surface and increasing the zinc discharge rate; the furnace hearth state of the extremely severe grade means that the blast furnace is on the verge of collapse and the blast furnace condition is seriously abnormal.

[0053] In the present invention, the high pellet ratio specifically refers to: blast furnace charge structure: sintered ore 70wt%~30wt% + pellet ratio 30wt%~70wt% condition. The present invention is conducive to judging the degree of furnace accumulation under the high pellet ratio condition.

[0054] The present invention provides a method for judging the degree of accumulation in the furnace hearth of vanadium-titanium magnetite smelting under the condition of high pellet ratio, comprising the following steps: monitoring the center temperature of the furnace top charge surface, the center temperature characterizing the strength of the central airflow of the blast furnace; calculating the blast furnace zinc discharge rate; determining the degree of accumulation in the furnace hearth by calculating the blast furnace zinc discharge rate data and the center temperature data of the furnace top charge surface. Compared with the prior art, the method for judging the degree of accumulation in the furnace hearth of vanadium-titanium magnetite smelting under the condition of high pellet ratio provided by the present invention judges the accumulation of the furnace hearth of the vanadium-titanium magnetite smelting blast furnace according to the changes of the furnace top temperature and the blast furnace zinc discharge rate, and the method is simple, efficient and reliable, so as to solve the problem of how to judge the accumulation of the furnace hearth during the blast furnace smelting of vanadium-titanium magnetite, and provide an early warning for the blast furnace operator so that timely measures can be taken.

[0055] In order to further illustrate the present invention, the following examples are provided for detailed description.

[0056] Benchmark Example

[0057] Blast furnace charge structure: Under the condition of sinter ore 50wt% + pellet ratio 50wt%, blast furnace smelting vanadium-titanium magnetite, the furnace hearth is under normal working conditions, the zinc discharge rate is 94% (92% on the first day, 102% on the second day, 97% on the third day), and the center temperature of the furnace top charge surface is 360℃ (378℃ on the first day, 369℃ on the second day, 371℃ on the third day). The furnace condition is normal, the gas utilization rate is high, the fuel ratio is low, the iron loss is low, and the material is evenly discharged.

[0058] Comparative Example 1

[0059] Blast furnace charge structure: Under the conditions of sintered ore 50wt% + pellet ratio 50wt%, the blast furnace is used to smelt vanadium-titanium magnetite, the center temperature of the furnace top charge surface is 265°C (275°C on the first day, 254°C on the second day, and 267°C on the third day), the zinc discharge rate is 73% (72% on the first day, 75% on the second day, and 71% on the third day), and a serious accumulation state occurs in the center of the hearth. The hearth does not accept air volume, the wind pressure is high, the gas utilization rate is low, the iron loss is high, the material discharge is uneven, and phenomena such as collapse and sliding occur.

[0060] Comparative Example 2

[0061] Blast furnace charge structure: Under the conditions of sintered ore 50wt% + pellet ratio 50wt%, the blast furnace is used to smelt vanadium-titanium magnetite, the center temperature of the furnace top charge surface is 330℃ (348℃ on the first day, 324℃ on the second day, 318℃ on the third day), the zinc discharge rate is 84% ​​(81% on the first day, 88% on the second day, 83% on the third day), there is a slight accumulation in the center of the furnace hearth, the wind pressure is high, the gas utilization rate is sometimes high and sometimes low, the iron loss is slightly higher than normal, the material discharge is uneven, and occasional collapse and sliding of the material occur.

[0062] The experimental data table is shown in Table 2 below.

[0063] Table 2

[0064]

[0065] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the degree of accumulation in a furnace of vanadium-titanium magnetite smelting under high pellet ratio conditions, comprising the following steps: Monitor the center temperature of the furnace top material surface, which indicates the strength of the central airflow in the blast furnace; Calculate the blast furnace zinc discharge rate; The degree of accumulation in the furnace is determined by calculating the blast furnace zinc discharge rate data and the center temperature data of the furnace top material surface.

2. The method for judging the degree of accumulation in the furnace of vanadium-titanium magnetite smelting under high pellet ratio conditions according to claim 1, characterized in that: The calculation formula of the blast furnace zinc discharge rate is: Blast furnace zinc discharge rate = zinc discharged from blast furnace / zinc entered into blast furnace.

3. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 2, characterized in that: The zinc-containing materials entering the blast furnace include: sintered ore, pelletized ore, coke, and PCI. The amount of zinc of each material entering the blast furnace every day is first calculated.

4. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 3 is characterized in that: The amount of zinc entering the blast furnace from each material every day = G burn × % burn + G balls × % balls + G coke × % coke + G coal × % G coal; Among them, Gburn is the weight of sintered ore, %burn is the zinc content of sintered ore, Gball is the weight of pelletized ore, %ball is the zinc content of pelletized ore, Gcoke is the weight of coke, %coke is the zinc content of coke, Gcoal is the weight of pulverized coal, and %coal is the zinc content of pulverized coal.

5. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 2, characterized in that: The zinc-containing materials discharged from the blast furnace include: blast furnace slag, molten iron, gravity dust removal ash, furnace top and furnace front dust removal ash, and then the amount of zinc discharged from the blast furnace by each material every day is calculated.

6. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 5, characterized in that: The amount of zinc discharged from the blast furnace by each material every day = G slag × % slag + G iron × % iron + G weight × % weight + G top × % G top; Among them, G slag is the weight of blast furnace slag, % slag is the zinc content of blast furnace slag, G iron is the weight of molten iron, % iron is the zinc content of molten iron, G weight is the weight of gravity dust ash, % weight is the zinc content of gravity dust ash, G top is the weight of furnace top and furnace front dust ash, % top is the zinc content of furnace top and furnace front dust ash.

7. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 1, characterized in that: The degree of furnace accumulation is specifically divided into five levels: normal, slight, slightly, severe, and extremely severe.

8. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 7, characterized in that: The furnace state of the normal gear: the blast furnace zinc discharge rate data is greater than 90% and the center temperature data of the furnace top material surface is greater than 350°C; The furnace state of the mild gear: the blast furnace zinc discharge rate data is greater than 90% and the furnace top material surface center temperature data is 300°C to 350°C; or, the blast furnace zinc discharge rate data is 70% to 90% and the furnace top material surface center temperature data is greater than 350°C; The slightly geared furnace state: the blast furnace zinc discharge rate data is greater than 90% and the furnace top material surface center temperature data is greater than or equal to 250°C and less than 300°C; or, the blast furnace zinc discharge rate data is 80% to 90% and the furnace top material surface center temperature data is 250°C to 350°C; or, the blast furnace zinc discharge rate data is greater than or equal to 70% and less than 80% and the furnace top material surface center temperature data is 300°C to 350°C; The furnace state of the severe gear: the blast furnace zinc discharge rate data is greater than or equal to 70% and less than 80% and the furnace top material surface center temperature data is greater than or equal to 250°C and less than 300°C; The extremely serious furnace state is as follows: the blast furnace zinc discharge rate data is less than 70% and the center temperature data of the furnace top material surface is less than 250°C.

9. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 8, characterized in that: The determination process determines the accumulation degree in the center of the hearth by the same hearth state occurring for three consecutive days.

10. The method for judging the accumulation degree of vanadium-titanium magnetite smelting furnace under high pellet ratio conditions according to claim 9, characterized in that: The furnace hearth status of the described minor level does not require intervention and is in the observation stage; the furnace hearth status of the described slightly severe level requires certain intervention measures; the furnace hearth status of the described severe level requires strong intervention, such as increasing the center temperature of the furnace top material surface and increasing the zinc discharge rate; the furnace hearth status of the described extremely severe level means that the blast furnace is on the verge of collapse and the blast furnace condition is seriously abnormal.

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