A method for quick recovery of blast furnace condition for smelting vanadium titano-magnetite

Abstract

The present application provides a kind of for smelting vanadium-titanium magnetite blast furnace condition quick recovery method, when abnormal situation appears in blast furnace, the following steps are carried out: ore is with first material distribution mode is distributed in blast furnace;First coke with first average particle size is with first weight ratio is with second material distribution mode is distributed in blast furnace;Second coke with second average particle size is with second weight ratio is with third material distribution mode is distributed in blast furnace.The method of the present application can quickly improve the permeability and liquid permeability of the blast furnace center column, thereby effectively shortening the time for recovering the blast furnace smelting condition after the fluctuation of vanadium-titanium magnetite blast furnace, preventing further deterioration of the blast furnace condition, promoting the recovery and rapid stabilization of the blast furnace condition.

Description

Technical Field

[0001] This invention belongs to the field of ironmaking technology, specifically relating to a method for rapidly restoring the furnace condition of a blast furnace used in smelting vanadium-titanium magnetite. Background Technology

[0002] In the blast furnace smelting process of vanadium-titanium magnetite, especially the blast furnace smelting of high-titanium vanadium-titanium magnetite, due to its resource characteristics, the TiO2 load in the furnace is high, and the TiO2 content in the slag generated in the blast furnace is as high as 15%-25%. Under the condition of a large amount of hot coke, the reaction temperature is too high and the reaction time is prolonged, which will lead to the reduction of TiO2 in the furnace to TiC, TiN and its solid solution Ti(C,N) and Ti(C,N) with melting points of up to 2900℃. This will increase the amount of high-melting-point substances, resulting in the deterioration of slag-iron separation effect and fluidity. Since a blast furnace can be roughly considered as an irregular cylindrical vertical furnace, the solid materials filled from the top of the blast furnace exchange heat with the reducing gases generated by the burning coke and pulverized coal and the hot blast blown in the lower part during the downward process. The minerals are heated, melted and reduced, and the coke, which plays a supporting role in the skeleton, gradually decreases in particle size. In the high-temperature softening zone and the hearth, the coke particle size is even less than 1 / 2 of the original size when it enters the furnace. Since the coke particle size directly determines the porosity, air permeability and liquid permeability of the material, the coke particle size becomes the most important factor determining the air permeability and liquid permeability of the blast furnace charge in the high-temperature softening zone and in the hearth.

[0003] Furthermore, due to the structural characteristics of the blast furnace, the length of the tuyere swirling zone generated by the high-speed airflow blowing in from the tuyere is between 1.0 and 2.0 meters. Modern large blast furnaces often have a hearth diameter exceeding 9 meters, making it difficult for the airflow to reach the central burden column. Therefore, the blast furnace center is often a relatively inactive area, hence the term "central dead burden column." In vanadium-titanium magnetite blast furnace smelting, the increased mass of high-melting-point substances such as Ti(C,N) leads to increased slag-iron viscosity, making it even more difficult for slag and iron to penetrate the central burden column. Conversely, slag and iron trapped in the central burden column cannot flow out in time, prolonging the reaction time. Under the direct reduction of coke, even more Ti(C,N) is generated, further reducing the permeability and liquid permeability of the central burden column. When the furnace condition becomes inactive in the center and the blast volume decreases, the swirling zone length further decreases, the central burden column becomes larger, and the blast furnace center becomes even more inactive. This vicious cycle often leads to a more severe deterioration of the blast furnace condition.

[0004] For the reasons mentioned above, maintaining the permeability of the central charge column in the blast furnace during vanadium-titanium magnetite smelting is fundamental to ensuring stable operation and high productivity during blast furnace operation. Preventing a decrease in the permeability and liquid permeability of the central charge column is crucial. If central accumulation, a large dead charge column, or increased titanium carbonitride production occur in the blast furnace, the furnace condition will deteriorate, significantly extending the time required to restore furnace condition and resulting in a substantial increase in wasted mineral resources and energy consumption.

[0005] Therefore, there is a need to provide a method that can quickly improve the condition of a blast furnace. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for rapidly restoring the furnace condition of a blast furnace used in smelting vanadium-titanium magnetite.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides a rapid method for restoring the blast furnace condition in vanadium-titanium magnetite smelting. When an abnormal situation occurs in the blast furnace, the following steps are performed:

[0009] The ore is fed into the blast furnace using the first feeding method;

[0010] The first coke with a first average particle size is fed into the blast furnace according to a first weight ratio and a second feeding method.

[0011] The second coke with the second average particle size is fed into the blast furnace in a third feeding method according to the second weight ratio.

[0012] Furthermore, compared to normal blast furnace operation, when an abnormal situation occurs in the blast furnace:

[0013] The first feeding angle of the first feeding method is reduced by 1-2° compared with that of the blast furnace during normal operation, and the first feeding angle of the first feeding method is ≥23°.

[0014] Furthermore,

[0015] The first average particle size of the first coke is 48mm-52mm, and the first weight ratio of the first coke is 85%-90%.

[0016] Furthermore, compared to normal blast furnace operation, when an abnormal situation occurs in the blast furnace:

[0017] The second feeding angle of the second feeding method is reduced by 1-2° compared with that of the blast furnace during normal operation, and the second feeding angle of the second feeding method is ≥23°.

[0018] Furthermore,

[0019] The second average particle size of the second coke is 60mm-80mm, and the second weight ratio of the second coke is 10%-15%.

[0020] Furthermore,

[0021] The second batch of coke is placed into the central area of ​​the blast furnace throat at a third feeding angle of 12°-16° using the third feeding method.

[0022] Furthermore, compared to normal blast furnace operation, when an abnormal situation occurs in the blast furnace:

[0023] The ore batch weight was reduced by 5%, and the first coke load was reduced to 4.0-4.2 t / t.

[0024] Furthermore, compared to normal blast furnace operation, when an abnormal situation occurs in the blast furnace:

[0025] Reduce the air intake area of ​​the air vent;

[0026] Maintain the blower speed and blower kinetic energy by ≤10%, or maintain the blower speed and blower kinetic energy unchanged.

[0027] Furthermore,

[0028] After 2-5 days of smelting, the blast furnace condition improved, and then the smelting continued for 3-7 days using the method described above.

[0029] Furthermore,

[0030] The ore, first coke, and second coke are fed in an alternating manner.

[0031] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0032] The rapid recovery method for blast furnace conditions in vanadium-titanium magnetite smelting of the present invention can quickly improve the air permeability and liquid permeability of the central burden in the blast furnace, thereby effectively shortening the recovery time after fluctuations in blast furnace conditions in vanadium-titanium magnetite smelting, preventing further deterioration of blast furnace conditions, and promoting the recovery and rapid stabilization of blast furnace conditions. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic flowchart of the rapid recovery method for blast furnace conditions in vanadium-titanium magnetite smelting according to the present invention.

[0035] Figure 2 This is another schematic flowchart of the method for rapid recovery of blast furnace conditions for smelting vanadium-titanium magnetite according to the present invention.

[0036] Figure 3 This is a schematic diagram of the blast furnace charging method for the rapid recovery of blast furnace conditions in vanadium-titanium magnetite smelting, as described in this invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0038] This invention relates to a rapid recovery method for blast furnace conditions in vanadium-titanium magnetite smelting. The method targets blast furnaces using vanadium-titanium magnetite as the main feedstock, with a blast furnace slag TiO2 content ≥20% during normal production, and a top structure employing a rotating chute-type, bell-less charging system. The average coke particle size is 48mm-52mm. When an abnormal situation occurs in the blast furnace, specifically when the central airflow is significantly weakened and the blast furnace's wind resistance is significantly reduced, the specific manifestation is: blast furnace top burden level 4 ( Figure 3 The area of ​​the flame region observed by imaging has shrunk significantly or even disappeared; or there is a flame in the center, but the flame is weak and flickering; the temperature at the center of the blast furnace top has decreased by more than 20% compared to normal production and has stabilized thereafter; production is carried out according to the normal charging system, but the blast furnace blast pressure gradually increases, the pressure difference increases, and the permeability index decreases. In order to match the relationship between blast volume and blast pressure, it is necessary to reduce the blast volume, and the reduction is more than 5% of the normal blast volume, and production has continued for ≥7 days after the reduction; the temperature monitored by the thermocouple at the center of the blast furnace bottom shows a significant downward trend.

[0039] After the above-mentioned comprehensive situation occurs in the blast furnace, such as Figure 1 As shown, this invention provides a method for rapidly restoring the blast furnace condition in vanadium-titanium magnetite smelting. When an abnormal situation occurs in the blast furnace, the following steps are performed:

[0040] The ore is fed into the blast furnace using the first feeding method;

[0041] The first coke with a first average particle size is fed into the blast furnace according to a first weight ratio and a second feeding method.

[0042] The second coke with the second average particle size is fed into the blast furnace in a third feeding method according to the second weight ratio.

[0043] In one embodiment of the present invention, when an abnormal situation occurs in the blast furnace, compared with the normal operation of the blast furnace: the first feeding angle of the first feeding method is reduced by 1-2° compared with the normal operation of the blast furnace, and the first feeding angle of the first feeding method is ≥23°.

[0044] In one embodiment of the present invention, the first average particle size of the first coke is 48mm-52mm, and the first weight ratio of the first coke is 85%-90%. Compared with the normal operation of the blast furnace, when the blast furnace is in an abnormal situation: the second feeding angle of the second feeding method is reduced by 1-2° compared with the normal operation of the blast furnace, and the second feeding angle of the second feeding method is ≥23°.

[0045] In one embodiment of the present invention, the second average particle size of the second coke is 60mm-80mm, and the second weight ratio of the second coke is 10%-15%. The second coke is distributed into the central region of the blast furnace throat at a third distribution angle of 12°-16° using a third distribution method.

[0046] In one embodiment of the present invention, compared with the normal operation of the blast furnace, when an abnormal situation occurs in the blast furnace: the ore batch weight is reduced by 5%, and the first coke load is reduced to 4.0-4.2 t / t. Further, the tuyeres inlet area is reduced, and the reduction in blast speed and blast kinetic energy is maintained at ≤10%, or the blast speed and blast kinetic energy are maintained unchanged.

[0047] The following combination Figure 2 and Figure 3 This invention provides a method for rapidly restoring the condition of a blast furnace.

[0048] A portion of the coke is centrally graded and screened to separate a second coke with a particle size of 60mm-80mm. In the event of an anomaly in the blast furnace, the ore, the first coke (first average particle size 48mm-52mm), and the second coke (second average particle size 60mm-80mm) are fed alternately. Figure 3 As shown, during the charging process, based on coke load and coke batch weight parameters, 10%–15% of the second coke by weight is loaded into the left charging hopper 1, which has just finished charging ore at the top of the furnace, while 85%–90% of the first coke by weight is loaded into the right charging hopper 2 on the other side of the furnace top. Specifically, after the ore is charged into the left charging hopper 1, the valve below the left charging hopper 1 is closed. The first coke in the right charging hopper 2 is then charged, while the second coke is loaded into the left charging hopper 1. After the first coke in the right charging hopper 2 is charged, the valve below the right charging hopper 2 is closed, and then the second coke in the left charging hopper 1 is charged. The second coke is then fed into the center through the rotating chute 3, ensuring that it is distributed into the central area of ​​the blast furnace throat.

[0049] In one embodiment of the present invention, a second coke with a particle size of 60mm to 80mm is distributed into the central region of the blast furnace throat at a third distribution angle of 12° to 16°. In a preferred embodiment, it is distributed into the central region of the burden surface in the blast furnace throat. The large-particle second coke added to the central region of the blast furnace improves the overall permeability of the burden layer in the central region. As the blast furnace smelting and burden descend, it gradually replaces the original small-particle first coke in the center of the blast furnace, thereby increasing the coke particle size and porosity of the central burden column, forming a coke burden column with better air permeability and liquid permeability. This gradually guides the blast furnace gas flow towards the center for penetration and development, thus improving the central region.

[0050] In one embodiment of the present invention, to ensure the rapid formation of airflow in the center of the blast furnace, the ore batch weight is reduced by 5% and the first coke load is reduced to 4.0-4.2 t / t in the upper part of the blast furnace, compared with the normal operation of the blast furnace. This reduces the overall pressure difference of the entire blast furnace charge column, improves permeability, and prevents poor permeability in other areas from causing excessive airflow to be drawn to the center, resulting in pipe formations in the center that are detrimental to blast furnace smelting. Furthermore, to avoid insufficient airflow at the blast furnace edges, leading to thickening of the furnace wall and edge adhesion in the hearth, the first ore charging angle and the second coke charging angle are reduced by 1-2° respectively in the abnormal operation of the blast furnace, compared with the normal operation of the blast furnace. This ensures adequate edge airflow.

[0051] In one embodiment of the present invention, in the lower adjustment of the blast furnace, the tuyeres are enclosed by adding rings during the shutdown period to reduce the air inlet area of ​​the tuyeres, maintain the blast speed and blast kinetic energy unchanged, or reduce them by ≤10%, thereby ensuring that the depth of the blast furnace tuyeres swirling zone 5 is equivalent to that during normal blast furnace production, so that the gas flow can easily reach the center of the blast furnace.

[0052] In one embodiment of the present invention, under the conditions described above, smelting for 2-5 days allows for the gradual replacement of the coke column in the center of the blast furnace and the gradual development of the gas flow in the center. This effectively avoids the situation where insufficient central gas flow leads to excessive reduction of titanium oxide slag into high-melting-point substances, resulting in poor air permeability and liquid permeability of the central burden in the blast furnace. Furthermore, it avoids the vicious cycle of inactive central gas flow → reduced blast capacity → forced further reduction in blast → even more inactive central gas flow.

[0053] In one embodiment of the present invention, those skilled in the art should understand that when smelting using the method of the present invention, the activity of the blast furnace hearth center lags behind the activity of the upper central airflow. As the central airflow becomes more active, parameters such as ore batch weight, coke load, and blast furnace air volume will return to normal. However, at this time, the dead material column in the hearth center has not been completely replaced. Therefore, after smelting using the above-mentioned method of the present invention for 2-5 days, the above-mentioned method of the present invention should continue to be used to grade and feed the coke into the furnace and perform central coke smelting for 3-7 days to ensure that the blast furnace condition is completely stable.

[0054] Example 1

[0055] The method of this invention is applied to blast furnace A, which uses high-titanium vanadium-titanium magnetite as the main raw material. During normal blast furnace operation, the average TiO2 content in the slag is 21.8%, and the blast furnace utilization coefficient is between 2.30 t / (m³). 3 ·d)-2.60t / (m 3 Between ·d), the fabric used is as follows:

[0056]

[0057] Where α represents the chute angle, which decreases sequentially after the material is laid. O and C represent the number of chute rotations required for the ore and first coke at each chute angle, respectively; one rotation of the chute is considered one rotation. 2.0m represents the material level depth, meaning that material laying begins when the material level drops to 2.0m from the zero material level. During normal blast furnace production, the ore batch weight is between 42-45t / batch, the first coke load is between 4.35-4.55t / t, the gas utilization rate is between 43.5-45.0%, and the average furnace top temperature is around 180℃-200℃.

[0058] After blast furnace A had been operating for a period of time, the proportion of water-quenched coke increased significantly due to the maintenance of the dry-quenching coke oven, resulting in a decrease in the coke CSR. Blast furnace A gradually experienced reduced permeability, a strained relationship between blast volume and pressure, and a gradual weakening of the central airflow. At one point, the central airflow was even unobservable in the infrared imaging of the furnace top, and the central temperature of the furnace top gradually decreased to around 150℃. During this period, to alleviate the imbalance between blast volume and pressure, a slight reduction in blast volume was implemented, and the oxygen enrichment rate was reduced from approximately 3.0% to approximately 1.8%. The blast furnace utilization coefficient also decreased and remained at 2.20 t / (m³). 3 Approximately d). Under these conditions, the blast furnace operated for nearly 10 days. The dry-quenched coke oven maintenance was completed, but after switching to dry-quenched coke for more than 3 days, the blast furnace condition did not improve. The temperature at the center of the blast furnace hearth had dropped by more than 10°C, and the phenomenon of small-scale material slippage in the blast furnace had increased. It was determined that under the long-term reduced-blast operation, a slight central accumulation had formed in the center of the hearth.

[0059] When the aforementioned abnormal situation occurs in blast furnace A, the method of this invention is used to prevent the blast furnace condition from deteriorating further, so as to restore the blast furnace condition as soon as possible. The coke from the top-charged coke oven is screened using a grading vibrating screen to obtain a second coke with an average particle size of 60mm-80mm, which is then stored separately in a blast furnace trough charging bin. Simultaneously, regarding the top-loading system, the ore batch weight is reduced to 41t / batch, the first coke load is reduced to 4.15t / t, and the charging system is changed to:

[0060]

[0061] The ore and the first coke are distributed according to the modified distribution system. That is, compared with the distribution system during normal blast furnace production, when the above-mentioned abnormal situation occurs in the blast furnace, the first distribution angle of the ore and the second distribution angle of the first coke are reduced by 1.5°, 1.5°, 1.5°, 2°, 2° and 2° respectively.

[0062] The first average particle size of the first coke is 50 mm, and the first coke's batch weight ratio is 90%.

[0063]

[0064] Furthermore, the second coke was distributed into the central area of ​​the blast furnace throat at a third charging angle of 16°. The second average particle size of the second coke was 70mm, and its batch weight ratio was 10%. Simultaneously, before changing the charging method, a tuyeres ring was added during a shutdown, increasing the tuyeres' air inlet area from 0.2714m². 2 Reduced to 0.2612m 2 Under the above adjustments, after two days of blast furnace smelting, the relationship between blast furnace blast volume and blast pressure was alleviated, and the airflow in the center of the blast furnace gradually increased; by the third day of smelting, the airflow in the center of the blast furnace further increased, and parameters such as blast volume, blast pressure, and furnace top temperature returned to normal; after the fifth day of smelting, the temperature at the center of the blast furnace bottom began to rise, and the blast furnace condition was further stabilized.

[0065] Example 2

[0066] The method of this invention is applied to blast furnace B, which uses high-titanium vanadium-titanium magnetite as the main raw material. During normal blast furnace operation, the average TiO2 content in the slag is 22.3%, and the blast furnace utilization coefficient is between 2.50 t / (m³). 3 ·d)-2.750t / (m 3 Between ·d), the fabric used is as follows:

[0067]

[0068] Where α represents the chute angle, which decreases sequentially after the material is laid. O and C represent the number of chute rotations required for the ore and first coke at each chute angle, respectively; one rotation of the chute is considered one rotation. 1.8m represents the material level depth, meaning that material laying begins when the material level drops to 1.8m from the zero material level. During normal blast furnace production, the ore batch weight is between 32-33.5t / batch, the first coke load is between 4.40-4.60t / t, the gas utilization rate is between 42.5-44.0%, and the average furnace top temperature is around 140℃-160℃.

[0069] After operating for a period of time, Blast Furnace B was forced to reduce the proportion of its main coking coal due to a short-term shortage in the supply of coking coal resources. The coke CSR decreased from an average of 62% to 59%. As a result, Blast Furnace B gradually experienced reduced permeability, a strained relationship between blast volume and pressure, and a gradual weakening of the central airflow. Infrared imaging of the furnace top showed intermittent central airflow, and the furnace top center temperature gradually decreased to around 110℃. During this period, a slight reduction in blast volume was implemented to alleviate the pressure imbalance, with the blast volume reduced from an average of 3300 m³ / h. 3 / min decreased to 3100m 3 The oxygen enrichment rate decreased from approximately 4.5% to approximately 3.0% per minute, and the blast furnace utilization coefficient also decreased and remained at 2.30 t / (m³). 3 Approximately d). Under these conditions, the blast furnace operated for nearly 7 days, the supply of major coking coal types resumed, and the coke CSR gradually improved and increased to 63%. However, after 3 days of continuous smelting, the condition of blast furnace B still showed no improvement. The center temperature of the blast furnace bottom had dropped by more than 10°C and showed no signs of recovery. The overall pressure and flow of the blast furnace remained relatively tight. It was determined that under prolonged reduced blast operation, a slight central buildup had formed in the center of the hearth of blast furnace B.

[0070] When the aforementioned abnormal situation occurs in blast furnace B, the method of this invention is used to prevent the blast furnace condition from deteriorating further, so as to restore the blast furnace condition as soon as possible. The coke from the top-charged coke oven is screened using a grading vibrating screen to obtain a second coke with an average particle size of 60mm-80mm, which is then stored separately in a blast furnace trough charging bin. Simultaneously, regarding the top-loading system, the ore batch weight is reduced to 31t / batch, the first coke load is reduced to 4.20t / t, and the charging system is changed to:

[0071]

[0072] The ore and the first coke are charged according to the modified charging system. That is, compared to the charging system during normal blast furnace production, when the above-mentioned abnormal situation occurs in the blast furnace, the first charging angle of the ore and the second charging angle of the first coke are reduced by 1°, 2°, 2°, 2°, 2°, and 2° respectively. The first average particle size of the first coke is 48mm, and the batch weight ratio of the first coke is 85%.

[0073]

[0074] Furthermore, the second coke was distributed into the central area of ​​the blast furnace throat at a third charging angle of 12°. The second average particle size of the second coke was 60mm, and its batch weight ratio was 15%. Simultaneously, before changing the charging method, a tuyeres ring was added during a shutdown, increasing the tuyeres' air inlet area from 0.2625m². 2 Reduced to 0.2556m 2 Under the above adjustments, after 3 days of blast furnace smelting, the relationship between blast furnace blast volume and blast pressure was alleviated, and the airflow in the center of the blast furnace gradually increased; by the 4th day of smelting, the airflow in the center of the blast furnace further increased, and parameters such as blast volume, blast pressure, and furnace top temperature returned to normal; after the 6th day of smelting, the temperature in the center of the blast furnace bottom began to rise, and the blast furnace condition was further stabilized.

[0075] Example 3

[0076] The method of this invention is applied to a C-type blast furnace using high-titanium vanadium-titanium magnetite as the main raw material. During normal blast furnace operation, the average TiO2 content in the slag is 21.5%, and the blast furnace utilization coefficient is between 2.40 t / (m³). 3 ·d)-2.60t / (m 3 Between ·d), the fabric used is as follows:

[0077]

[0078] Where α represents the chute angle, which decreases sequentially after the material is laid. O and C represent the number of chute rotations required for the ore and first coke at each chute angle, respectively; one rotation of the chute is considered one rotation. 2.0m represents the material level depth, meaning that material laying begins when the material level drops to 2.0m from the zero material level. During normal blast furnace production, the ore batch weight is between 42-43.5t / batch, the first coke load is between 4.30-4.45t / t, the gas utilization rate is between 44.0-45.0%, and the average furnace top temperature is around 170℃-180℃.

[0079] After operating for a period of time, Blast Furnace C experienced a significant increase in the proportion of water-quenched coke due to maintenance of the dry-quenching coke oven, leading to a decrease in coke CSR. This resulted in reduced permeability, a strained relationship between blast furnace airflow and pressure, and a gradual weakening of the central airflow. At one point, the central airflow was even undetectable in infrared imaging of the furnace top, and the furnace top center temperature gradually decreased to around 140℃. During this period, to alleviate the airflow and pressure imbalance, a slight reduction in airflow was implemented, and the oxygen enrichment rate was lowered from approximately 3.5% to approximately 2.0%. The blast furnace utilization coefficient also decreased and remained at 2.20 t / (m³). 3Approximately d). Under these conditions, the blast furnace operated for nearly 7 days. The dry-quenched coke oven maintenance was completed, but after switching to dry-quenched coke smelting for more than 3 days, the blast furnace condition still did not improve. The center temperature of the blast furnace bottom had dropped by more than 10°C, and the phenomenon of small-scale material slippage in the blast furnace had increased. It was determined that under the long-term reduced-blast operation, a slight central accumulation had formed in the center of the hearth.

[0080] When the aforementioned abnormal situation occurs in blast furnace C, the method of this invention is used to prevent the blast furnace condition from deteriorating further, so as to restore the blast furnace condition as soon as possible. The coke from the top-charged coke oven is screened by a grading vibrating screen to obtain a second coke with an average particle size of 60mm-80mm, which is then stored separately in a blast furnace trough charging bin. Simultaneously, regarding the top-loading system, the ore batch weight is reduced to 41t / batch, the first coke load is reduced to 4.10t / t, and the charging system is changed to:

[0081]

[0082] The ore and the first coke are charged according to the modified charging system. That is, compared to the charging system during normal blast furnace production, when the above-mentioned abnormal situation occurs in the blast furnace, the first charging angle of the ore and the second charging angle of the first coke are reduced by 2°, 2°, 2°, 2°, 2°, 2°, and 2° respectively. The first average particle size of the first coke is 52mm, and the batch weight ratio of the first coke is 87%.

[0083]

[0084] Furthermore, the second coke was distributed into the central area of ​​the blast furnace throat at a third charging angle of 14°. The second average particle size of the second coke was 80mm, and its batch weight ratio was 13%. Simultaneously, before changing the charging method, a tuyeres ring was added during a shutdown, increasing the tuyeres' air inlet area from 0.2612m². 2 Reduced to 0.2566m 2 Under the above adjustments, after 3 days of blast furnace smelting, the relationship between blast furnace blast volume and blast pressure was alleviated, and the airflow in the center of the blast furnace gradually increased; by the 5th day of smelting, the airflow in the center of the blast furnace further increased, and parameters such as blast volume, blast pressure, and furnace top temperature returned to normal; after the 6th day of smelting, the temperature in the center of the blast furnace bottom began to rise, and the blast furnace condition was further stabilized.

[0085] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0086] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “lateral,” “longitudinal,” and “vertical” indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the purpose of facilitating the description of the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0088] It should be noted that the components or steps in the above embodiments can be interchanged, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of this invention, and the protection scope of this invention should not be limited to the above embodiments.

[0089] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for rapidly restoring the furnace condition of a blast furnace used in smelting vanadium-titanium magnetite, characterized in that, When an abnormal situation occurs in the blast furnace, perform the following steps: The ore is fed into the blast furnace using the first feeding method; A first coke with a first average particle size is fed into the blast furnace according to a first weight ratio and a second feeding method. The first average particle size of the first coke is 48mm-52mm, and the first weight ratio of the first coke is 85%-90%. A second coke with a second average particle size of 60mm-80mm is fed into the blast furnace according to a second weight ratio using a third feeding method. The second coke has a second average particle size of 60mm-80mm and a second weight ratio of 10%-15%. The second coke is fed into the central area of ​​the blast furnace throat at a third feeding angle of 12°-16° using the third feeding method. The ore, first coke, and second coke are then fed sequentially using an alternating feeding method. Compared with the normal operation of the blast furnace, when the blast furnace is in an abnormal situation: the first charging angle of the first charging method is reduced by 1-2° compared with the normal operation of the blast furnace, and the first charging angle of the first charging method is ≥23°; Compared with the normal operation of the blast furnace, when the blast furnace is in an abnormal situation: the second charging angle of the second charging method is reduced by 1-2° compared with the normal operation of the blast furnace, and the second charging angle of the second charging method is ≥23°; Compared to normal blast furnace operation, when abnormal conditions occur in the blast furnace: ore batch weight decreases by 5%, and the first coke load decreases to 4.0-4.2 t / t; Compared to normal blast furnace operation, when an abnormal situation occurs in the blast furnace: Reduce the air intake area of ​​the air vent; Maintain the blower speed and blower kinetic energy by ≤10%, or maintain the blower speed and blower kinetic energy unchanged.

2. The method according to claim 1, characterized in that, After 2-5 days of smelting, the blast furnace condition improved, and then the smelting continued for 3-7 days using the method described above.

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