A method for removing zinc from blast furnace based on vanadium titano-magnetite

Abstract

The present application relates to the technical field of vanadium-titanium magnetite blast furnace smelting, and discloses a blast furnace zinc removal method based on vanadium-titanium magnetite, which comprises the following steps: obtaining the zinc charging load for blast furnace smelting of iron ore, wherein the iron ore contains vanadium-titanium magnetite; adjusting the burden angle, blast furnace batch weight and coke load in the burden system according to the zinc charging load, wherein the adjustment range of the burden angle increases with the increase of the zinc charging load, and the blast furnace batch weight and coke load decrease with the increase of the zinc charging load; obtaining the types of furnace charges and the weight and zinc content of each furnace charge to determine the zinc removal rate; and adjusting the structure of the charging raw material in the burden system and the air supply system according to the zinc removal rate. Through the above scheme, the blast furnace center airflow is stabilized, the zinc circulation enrichment in the blast furnace is reduced, the zinc removal capacity of the blast furnace is enhanced, and the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite is facilitated.

Description

Technical Field

[0001] This invention relates to the field of blast furnace smelting technology for vanadium-titanium magnetite, and particularly to a blast furnace zinc removal method based on vanadium-titanium magnetite. Background Technology

[0002] Titanium magnetite is a complex iron ore primarily composed of iron, titanium, and vanadium, along with various other valuable elements. As rare metals, vanadium and titanium have a wide range of applications, thus vanadium-titanium magnetite possesses very high comprehensive utilization value. The vanadium-titanium magnetite deposits in the Panxi region are an important strategic mineral resource in my country and a crucial foundation for Sichuan Province's vanadium-titanium steel industry cluster. While direct reduction technology for vanadium-titanium magnetite needs further development, blast furnace smelting remains the primary technological approach.

[0003] Panzhihua Iron and Steel Group Xichang Steel & Vanadium mainly uses vanadium-titanium concentrate and surrounding ordinary ores, which have high levels of harmful elements. In addition, the plant uses recycled materials such as blast furnace gas ash, converter dust, sludge, and iron oxide powder, resulting in a high zinc load (zinc load > 1 kg / t·iron) brought into the blast furnace. As a result, the blast furnace has insufficient zinc removal capacity (zinc removal rate is less than 100%), which affects the long-term stable operation of the blast furnace. Summary of the Invention

[0004] In view of this, the present invention proposes a blast furnace zinc removal method based on vanadium-titanium magnetite, which can solve the technical problems of poor zinc removal capacity and impact on the stable operation of blast furnace when using vanadium-titanium magnetite for blast furnace smelting in the prior art.

[0005] On one hand, embodiments of the present invention provide a blast furnace zinc discharge method based on vanadium-titanium magnetite. This method includes: obtaining the zinc load for blast furnace smelting of iron ore containing vanadium-titanium magnetite; adjusting the charging angle, blast furnace batch weight, and coke load in the charging system according to the zinc load, wherein the adjustment range of the charging angle increases with the increase of the zinc load, and the blast furnace batch weight and coke load decrease with the increase of the zinc load; obtaining the type of furnace charge and the weight and zinc content of each charge to determine the zinc discharge rate; and adjusting the structure of the raw materials and the blast ventilation system in the charging system according to the zinc discharge rate.

[0006] In some embodiments, adjusting the charging angle, blast furnace batch weight, and coke load in the charging system according to the zinc load includes: adjusting the charging angle, blast furnace batch weight, and coke load according to the zinc load level to which the zinc load belongs. The zinc load level is divided into three levels: the first zinc load level is zinc load < 1.0 kg / t•iron, the second zinc load level is 1.0 kg / t•iron ≤ zinc load < 1.5 kg / t•iron, and the third zinc load level is zinc load ≥ 1.5 kg / t•iron.

[0007] In some embodiments, adjusting the charging angle, blast furnace batch weight, and coke load according to the zinc load level to which the zinc load belongs includes: if the zinc load belongs to the first zinc load level, controlling the distance between the outermost ore landing point and the furnace wall to be ≥80mm, and controlling the outer angle difference between ore and coke to be within the range of 0-1.5°, and the inner angle difference between ore and coke to be within the range of 5°~6°; if the zinc load belongs to the second zinc load level, controlling the distance between the outermost ore landing point and the furnace wall to be ≥1.5mm. The blast furnace load and coke load are controlled to be reduced by 1% to 5% if the zinc load is within the third zinc load level, the distance between the outermost ring ore drop point and the furnace wall is controlled to be ≥150mm, the outer angle difference between ore and coke is controlled to be within the range of 1-2.5°, the inner angle difference between ore and coke is controlled to be within the range of 5° to 7.5°, and the blast furnace load and coke load are controlled to be reduced by ≥5%.

[0008] In some embodiments, the raw materials fed into the furnace include vanadium-titanium sinter and vanadium-titanium pellets. Adjusting the structure of the raw materials and the air supply system in the feeding system according to the zinc discharge rate includes: adjusting the proportion and order of the vanadium-titanium pellets in the raw materials fed into the furnace according to the zinc discharge rate, wherein the proportion of the vanadium-titanium pellets decreases as the zinc discharge rate decreases, and the order of the vanadium-titanium pellets advances as the zinc discharge rate decreases; and adjusting the blast kinetic energy according to the zinc discharge rate, wherein the blast kinetic energy increases as the zinc discharge rate decreases.

[0009] In some embodiments, adjusting the proportion and order of vanadium-titanium pellets in the furnace feed material according to the zinc discharge rate includes: if 80% ≤ the zinc discharge rate < 100%, controlling the proportion of vanadium-titanium pellets to decrease by 0-5% and advancing the order of vanadium-titanium pellets by 1 position; if the zinc discharge rate < 80%, controlling the proportion of vanadium-titanium pellets to decrease by 1-10% and advancing the order of vanadium-titanium pellets by 1-2 positions.

[0010] In some embodiments, adjusting the blower kinetic energy according to the zinc removal rate includes: if 80% ≤ the zinc removal rate < 100%, adjusting the vent area and the air volume to increase the blower kinetic energy by 1% to 5%; if the zinc removal rate < 80%, adjusting the vent area and the air volume to increase the blower kinetic energy by 5% to 20%.

[0011] In some embodiments, the blast furnace zinc removal method based on vanadium-titanium magnetite provided by the present invention further includes: controlling the average value of the total titanium and silicon content in the molten iron and the frequency of low furnace temperature according to the zinc removal rate, wherein the average value of the total titanium and silicon content in the molten iron increases as the zinc removal rate decreases, and the frequency of low furnace temperature decreases as the zinc removal rate decreases.

[0012] In some embodiments, controlling the average value of the total titanium and silicon content in the molten iron and the frequency of low furnace temperature includes: if 80% ≤ the zinc removal rate < 100%, controlling the average value of the total titanium and silicon content in the molten iron to be ≥ 0.25%, and the proportion of the total titanium and silicon content ≤ 0.2% < 20%; if the zinc removal rate < 80%, controlling the average value of the total titanium and silicon content in the molten iron to be ≥ 0.3%, and the proportion of the total titanium and silicon content ≤ 0.2% < 10%.

[0013] In some embodiments, the blast furnace zinc removal method based on vanadium-titanium magnetite provided by the present invention further includes: controlling the slag basicity, the aluminum-magnesium ratio and titanium dioxide content in the slag according to the zinc removal rate, wherein the slag basicity and the titanium dioxide content in the slag decrease as the zinc removal rate decreases, and the aluminum-magnesium ratio in the slag increases as the zinc removal rate decreases.

[0014] In some embodiments, the blast furnace zinc removal method based on vanadium-titanium magnetite provided by the present invention further includes: adjusting the furnace body pressurized water inlet temperature in the cooling system according to the zinc removal rate, wherein the furnace body pressurized water inlet temperature increases as the zinc removal rate decreases.

[0015] The present invention has at least the following beneficial effects: This invention provides a blast furnace zinc removal method based on vanadium-titanium magnetite. By adjusting the charging angle, blast furnace batch weight, and coke load in the charging system according to the zinc load, and adjusting the structure of the raw materials and the blasting system in the charging system according to the zinc removal rate, and by adjusting the charging angle adjustment range as the zinc load increases, while the blast furnace batch weight and coke load decrease as the zinc load increases, this blast furnace adjustment scheme stabilizes the central airflow of the blast furnace, reduces zinc circulation and enrichment within the blast furnace, enhances the zinc removal capacity of the blast furnace, and facilitates the stable and smooth operation of blast furnaces smelting vanadium-titanium magnetite. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 embodiments can be obtained based on these drawings without creative effort.

[0017] Figure 1A flowchart of a blast furnace zinc grate method based on vanadium-titanium magnetite is provided for an embodiment of the present invention; Figure 2 This is a flowchart illustrating an adjustment of the charging angle, blast furnace batch weight, and coke load in a blast furnace zinc discharge method based on vanadium-titanium magnetite, according to the zinc load entering the furnace, as provided in an embodiment of the present invention. Figure 3 A schematic diagram illustrating the order of raw materials and fuels fed into the blast furnace in the zinc discharge method based on vanadium-titanium magnetite provided in an embodiment of the present invention; Figure 4 A flowchart of another blast furnace zinc grate method based on vanadium-titanium magnetite provided for embodiments of the present invention. Detailed Implementation

[0018] 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.

[0019] 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. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” indicate orientations or positions based on the orientations or positions shown in the accompanying drawings and are for ease of description only, and should not be construed as limiting the technical solution.

[0020] 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.

[0021] In the description and claims of this invention and the foregoing drawings, when an element is referred to as "fixed to," "mounted to," "disposed on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0022] Panzhihua Iron and Steel Group Xichang Steel & Vanadium mainly uses vanadium-titanium concentrate and surrounding ordinary ores, which have high levels of harmful elements. In addition, the use of recycled materials from the plant area, such as blast furnace gas ash, converter dust, sludge, and iron oxide powder, results in a high zinc load (zinc load > 1 kg / t·iron) entering the blast furnace. This leads to insufficient zinc removal capacity (zinc removal rate less than 100%). High zinc levels also have several adverse effects on the long-term stable operation of the blast furnace, primarily: firstly, zinc vapor condenses and accumulates in the furnace throat and riser pipes, adhering to the furnace charge powder and forming lumps, causing blockages. First, the gas passage causes thickening and nodules on the upper and middle parts of the blast furnace wall, disrupting the normal distribution of the burden and gas flow. Second, it damages the thermal strength of the raw materials and fuels, exacerbates the pulverization of the raw materials and fuels, and worsens the permeability of the burden column, causing suspension, collapse, and other problems in the pipeline. Third, zinc circulates and accumulates in the furnace, seeps into the brick joints, and oxidizes with the slag or corundum-mullite bricks, forming a series of solid solution phase deposits, causing the brick lining to expand and resulting in deformation or upturning of the tuyeres. Fourth, the high-zinc nodules fall off on their own, easily causing severe heat loss in the hearth, which in turn leads to furnace cooling.

[0023] Therefore, in order to solve the problem of insufficient zinc removal capacity of blast furnace when smelting vanadium-titanium magnetite, this invention proposes a blast furnace zinc removal method based on vanadium-titanium magnetite. This method can stabilize the central airflow of the blast furnace through blast furnace adjustment, reduce the circulation and enrichment of zinc in the blast furnace, enhance the zinc removal capacity of the blast furnace, and facilitate the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite.

[0024] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0025] The first aspect of this invention provides a blast furnace zinc grate method based on vanadium-titanium magnetite, such as... Figure 1 As shown, the blast furnace zinc discharge method based on vanadium-titanium magnetite includes steps S10 to S40.

[0026] S10. Obtain the zinc load for blast furnace smelting of iron ore.

[0027] The iron ore used in this invention contains vanadium-titanium magnetite, with the total proportion of vanadium-titanium magnetite being greater than 60%.

[0028] S20. Adjust the charging angle, blast furnace weight, and coke load in the charging system according to the zinc load.

[0029] The range of adjustment for the feeding angle increases with the increase of the zinc load in the furnace, while the blast furnace batch weight and coke load decrease with the increase of the zinc load in the furnace.

[0030] The blast furnace zinc removal method based on vanadium-titanium magnetite provided by this invention is applicable to blast furnace batch weights of 41-44t and coke loads of 4.3-4.7t / t, but is not limited thereto. The blast furnace zinc removal method provided by this invention is also applicable to other blast furnace batch weights and coke loads.

[0031] S30. Obtain the type of furnace charge and the weight and zinc content of each charge to determine the zinc removal rate.

[0032] Specifically, the furnace charge can include raw materials and fuel. Raw materials can include vanadium-titanium magnetite, and fuel can include coke and coal. The zinc discharge rate can be calculated using the following formula, based on the type of furnace charge and the weight and zinc content of each type of charge.

[0033]

[0034] Where m represents the type of dust collected; This indicates the weight of a single type of dust collector ash, expressed in tons. The value indicates the Zn content of the dust, expressed in %; P indicates the type of blast furnace product (i.e., the slag discharged from blast furnace smelting). This indicates the weight of blast furnace products, in tons. This indicates the Zn content of the product, expressed in %; n represents the type of raw material and fuel fed into the blast furnace. This indicates the weight of a single type of raw material or fuel fed into the furnace, in tons. This indicates the Zn content of raw materials and fuels fed into the furnace individually, expressed in %.

[0035] S40. Adjust the structure of the raw materials entering the furnace and the air supply system in the feeding system according to the zinc discharge rate.

[0036] Specifically, vanadium-titanium magnetite includes vanadium-titanium sinter and vanadium-titanium pellets. In some specific embodiments, the vanadium-titanium magnetite may contain 35%–60% vanadium-titanium sinter and 40%–65% vanadium-titanium pellets. In this embodiment of the invention, by configuring 40%–65% vanadium-titanium pellets in the vanadium-titanium magnetite, the feeding regime is optimized. The high proportion of vanadium-titanium pellets ensures the flow of the central airflow, thereby reducing the cyclic enrichment of zinc.

[0037] In this embodiment of the invention, when the zinc removal rate decreases, the proportion of all-vanadium-titanium pellets in vanadium-titanium magnetite can be adjusted within the range of 40%-65%, thereby further ensuring the flow of central airflow, reducing the cyclic enrichment of zinc, and achieving an increase in the zinc removal rate.

[0038] In this embodiment of the invention, the blast kinetic energy can be changed by adjusting the air supply system, thereby reducing the circulating load of zinc in the blast furnace and improving the zinc discharge rate.

[0039] In this embodiment of the invention, the proportion of vanadium-titanium pellets and the blast furnace kinetic energy can be adjusted according to different zinc removal rates. Specifically, the proportion of vanadium-titanium pellets decreases as the zinc removal rate decreases, while the blast furnace kinetic energy increases as the zinc removal rate decreases, but the increase in blast furnace kinetic energy does not exceed 20% of the normal control level. In other words, the lower the zinc removal rate, the greater the decrease in the proportion of vanadium-titanium pellets, and the greater the increase in blast furnace kinetic energy, limited to 20% of the normal control level. This further ensures the circulation of the central airflow, reduces the recycling and enrichment of zinc, and achieves a significant increase in the zinc removal rate.

[0040] The blast furnace zinc discharge method based on vanadium-titanium magnetite provided by this invention is applicable when the tuyeres area can be maintained at 0.261 m². 2 -0.283m 2 Air volume ≥ 4000m³ 3 The method for removing zinc from blast furnaces with a blast rate of / min is applicable to blast furnaces, but not limited to this. The method is also applicable to blast furnaces with other tuyeres and blast rates.

[0041] This invention adjusts the charging angle, blast furnace batch weight, and coke load in the charging system according to the zinc load, and adjusts the structure of the raw materials and the air supply system in the charging system according to the zinc discharge rate. The adjustment range of the charging angle increases with the increase of the zinc load, while the blast furnace batch weight and coke load decrease with the increase of the zinc load. This blast furnace adjustment scheme stabilizes the central airflow, reduces the accumulation of zinc in the blast furnace, enhances the zinc discharge capacity of the blast furnace, and is conducive to the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite.

[0042] In some embodiments, adjusting the charging angle, blast furnace weight, and coke load in the charging system according to the zinc load includes: adjusting the charging angle, blast furnace weight, and coke load according to the zinc load level to which the zinc load belongs. The zinc load level is divided into three levels: the first zinc load level is zinc load < 1.0 kg / t•iron, the second zinc load level is 1.0 kg / t•iron ≤ zinc load < 1.5 kg / t•iron, and the third zinc load level is zinc load ≥ 1.5 kg / t•iron.

[0043] Different zinc load levels correspond to different blast furnace load classes, resulting in different adjustments to the charging angle, blast furnace batch weight, and coke load. The adjustment ranges for each of these parameters are related to the zinc load class to which the zinc load belongs. The higher the zinc load class (the third zinc load class is the highest), the greater the adjustment ranges for each of these parameters. Thus, by adjusting the charging system, the blast furnace zinc discharge rate can be increased.

[0044] like Figure 2As shown, the process of adjusting the charging angle, blast furnace batch weight, and coke load in the charging system according to the zinc load includes steps S210 to S240.

[0045] S210. Determine the zinc load level to which the zinc load entering the furnace belongs.

[0046] The zinc load is divided into three levels: Level 1 is zinc load < 1.0 kg / t•iron, Level 2 is 1.0 kg / t•iron ≤ zinc load < 1.5 kg / t•iron, and Level 3 is zinc load ≥ 1.5 kg / t•iron. If the zinc load entering the furnace belongs to Level 1, proceed to step S220; if it belongs to Level 2, proceed to step S230; and if it belongs to Level 3, proceed to step S240.

[0047] S220, control the distance between the outermost ring ore landing point and the furnace wall to be ≥80mm, and control the outer angle difference between ore and coke to be within the range of 0-1.5°, and the inner angle difference between ore and coke to be within the range of 5°~6°.

[0048] When the zinc load in the furnace is <1.0 kg / t•iron, the charging system is as follows: the cross-sectional area of ​​the furnace throat is divided into 11 concentric rings of equal width. The landing point of the ore (vanadium-titanium sinter + full vanadium-titanium pellets) is controlled to be located in rings 5-11. The distance between the landing point of the ore in the outermost ring and the furnace wall is controlled to be ≥80 mm. The maximum coke angle is maintained > the maximum ore angle, and the minimum coke angle is maintained < the minimum ore angle. The outer angle difference between ore and coke is controlled to be 0-1.5°, and the inner angle difference between ore and coke is controlled to be 5-6°. This can enhance the central and peripheral airflow of the blast furnace, making the airflow distribution of the blast furnace more reasonable and improving the zinc discharge rate of the blast furnace.

[0049] It should be noted that, in this embodiment of the invention, the outer angle difference between the ore and coke refers to the difference between the maximum coke placement angle and the maximum ore placement angle. The inner angle difference between the ore and coke refers to the difference between the minimum coke placement angle and the minimum ore placement angle.

[0050] S230, control the distance between the outermost ring ore landing point and the furnace wall to be ≥100mm, control the outer angle difference between ore and coke to be within the range of 0.5-2°, and the inner angle difference between ore and coke to be within the range of 5°~7°, and control the blast furnace batch weight and coke load to be reduced by 1%~5%.

[0051] When 1.0 kg / t•iron ≤ zinc load < 1.5 kg / t•iron, the charging system is as follows: control the ore drop point to be in the 5th-10th ring, control the distance between the outermost ring ore drop point and the furnace wall to be ≥ 100 mm, and maintain the maximum coke angle > the maximum ore angle and the minimum coke angle < the minimum ore angle. Control the outer angle difference between ore and coke to be 0.5-2°, control the inner angle difference between ore and coke to be 5-7°, and control the batch weight and load to be reduced by 1%-5%. This can enhance the central and peripheral airflow of the blast furnace when the zinc load increases, making the blast furnace airflow distribution more in line with the actual smelting conditions and improving the blast furnace zinc discharge rate.

[0052] S240, control the distance between the outermost ring ore landing point and the furnace wall to be ≥150mm, control the outer angle difference between ore and coke to be within the range of 1-2.5°, control the inner angle difference between ore and coke to be within the range of 5°~7.5°, and control the reduction of blast furnace batch weight and coke load to be ≥5%.

[0053] When the zinc load in the furnace is ≥1.5kg / t•iron, the charging system is as follows: control the ore landing point to be in the 5th-9th ring, control the distance between the outermost ring ore landing point and the furnace wall to be ≥150mm, maintain the maximum coke angle > the maximum ore angle, and the minimum coke angle < the minimum ore angle, control the outer angle difference between ore and coke to be 1-2.5°, control the inner angle difference between ore and coke to be 5-7.5°, and control the batch weight and load reduction to be ≥5%. This can enhance the central and peripheral airflow of the blast furnace when the zinc load in the furnace increases, making the airflow distribution of the blast furnace more in line with the actual smelting conditions and improving the zinc discharge rate of the blast furnace.

[0054] In this embodiment of the invention, by developing a charging scheme for different zinc load levels, the zinc discharge capacity of the blast furnace can be enhanced, the zinc circulation and enrichment within the blast furnace can be reduced, and the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite can be facilitated.

[0055] In some embodiments, adjusting the structure of the raw materials and the air supply system in the feeding system according to the zinc discharge rate includes: adjusting the proportion and arrangement order of the vanadium-titanium pellets in the raw materials according to the zinc discharge rate; and adjusting the blast kinetic energy according to the zinc discharge rate.

[0056] The proportion of all-vanadium-titanium pellets decreases as the zinc removal rate decreases, the position of all-vanadium-titanium pellets advances as the zinc removal rate decreases, and the blast furnace energizing capacity increases as the zinc removal rate decreases, but the increase in blast furnace energizing capacity does not exceed 20% of the normal control level. Specifically, the greater the decrease in the zinc removal rate, the greater the increase in the proportion of all-vanadium-titanium pellets, the more advanced the position of all-vanadium-titanium pellets, and the greater the increase in blast furnace energizing capacity, limited to 20% of the normal control level.

[0057] This embodiment enhances the zinc removal capacity of the blast furnace through the above-mentioned scheme, reduces the circulation and enrichment of zinc within the blast furnace, and is conducive to the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite.

[0058] In one specific embodiment, such as Figure 3 The diagram shows the arrangement of raw materials and fuels entering the furnace. Vanadium-titanium sinter is present in all seven arrangement sequences, while whole vanadium-titanium pellets are arranged from the 2nd to the 6th positions, with coke following the whole vanadium-titanium pellets. The purpose of having vanadium-titanium sinter present in all seven arrangement sequences is to serve as a bottom layer to reduce the sliding of whole vanadium-titanium pellets towards the rear end during belt transport, thereby reducing the rolling of whole vanadium-titanium pellets towards the center during charging. This stabilizes the central airflow, reduces the circulation and enrichment of zinc within the blast furnace, and promotes the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite.

[0059] In some specific embodiments, adjusting the proportion and order of all-vanadium-titanium pellets in the raw materials fed into the furnace according to the zinc discharge rate includes: if 80% ≤ zinc discharge rate < 100%, controlling the proportion of all-vanadium-titanium pellets to decrease by 0~5% and advancing the order of all-vanadium-titanium pellets by 1 position; if the zinc discharge rate < 80%, controlling the proportion of all-vanadium-titanium pellets to decrease by 1~10% and advancing the order of all-vanadium-titanium pellets by 1~2 positions.

[0060] In some specific embodiments, adjusting the blower kinetic energy according to the zinc removal rate includes: if 80% ≤ zinc removal rate < 100%, adjusting the vent area and air volume to increase the blower kinetic energy by 1% to 5%; if the zinc removal rate < 80%, adjusting the vent area and air volume to increase the blower kinetic energy by 5% to 20%.

[0061] This embodiment enhances the zinc removal capacity of the blast furnace through the above-mentioned scheme, reduces the circulation and enrichment of zinc within the blast furnace, and is conducive to the stable and smooth operation of the blast furnace for smelting vanadium-titanium magnetite.

[0062] In some embodiments, such as Figure 4 As shown, the blast furnace zinc discharge method based on vanadium-titanium magnetite provided by the present invention may include steps S10 to S40, and may also include steps S50 and / or S60 and / or S70 and / or S80. Figure 4 The case that includes steps S50, S60, S70 and S80 simultaneously is shown.

[0063] S50. Based on the zinc discharge rate, control the slag basicity, aluminum-magnesium ratio, and titanium dioxide content in the slag.

[0064] The basicity of the slag and the titanium dioxide content in the slag decrease as the zinc removal rate decreases, while the aluminum-magnesium ratio in the slag increases as the zinc removal rate decreases. Specifically, the lower the zinc removal rate, the greater the decrease in slag basicity and titanium dioxide content, and the higher the aluminum-magnesium ratio in the slag.

[0065] In one specific embodiment, if the zinc discharge rate is 80% ≤ Zinc removal rate < 100%, the slag Ro is reduced by 1%-2%, the magnesium-aluminum ratio is maintained at 0.60±0.3, and the slag TiO2 is reduced by 1%-2%.

[0066] If the zinc discharge rate is between 80% and 100%, the zinc discharge capacity of the blast furnace can be improved by reducing the slag basicity (Ro) by 1%-2%, maintaining the magnesium-aluminum ratio at 0.60±0.3, and reducing the slag TiO2 by 1%-2%, thereby reducing the zinc circulation and enrichment within the blast furnace.

[0067] In one specific embodiment, if the zinc discharge rate is <80%, the slag Ro is reduced by 2%-4%, the magnesium-aluminum ratio is maintained at 0.62±0.3, and the slag TiO2 is reduced by 2%-5%.

[0068] If the zinc discharge rate is less than 80%, the zinc discharge capacity of the blast furnace can be improved by reducing the slag Ro by 2%-4%, maintaining the magnesium-aluminum ratio at 0.62±0.3, and reducing the slag TiO2 by 2%-5%, thereby reducing the zinc circulation and enrichment within the blast furnace.

[0069] In one specific embodiment, the slag basicity, aluminum-magnesium ratio, and titanium dioxide content in the slag can be controlled by adjusting the proportion of vanadium-titanium pellets in the raw materials fed into the furnace.

[0070] S60. Based on the zinc discharge rate, control the average value of the total titanium and silicon content in the molten iron and the frequency of low furnace temperature.

[0071] The average total titanium and silicon content in molten iron increases as the zinc removal rate decreases, while the frequency of low furnace temperatures decreases as the zinc removal rate decreases. Specifically, the lower the zinc removal rate, the higher the average total titanium and silicon content in the molten iron, and the lower the frequency of low furnace temperatures.

[0072] In one specific embodiment, if 80% ≤ zinc removal rate < 100%, the average value of the total titanium and silicon content in the molten iron is controlled to be ≥ 0.25%, and the proportion of the total titanium and silicon content ≤ 0.2% is < 20%.

[0073] The frequency of low furnace temperatures can be obtained by statistically analyzing the proportion of total titanium and silicon content over a period of time. The average value of total titanium and silicon content and the molten iron temperature represent the average furnace temperature. If the zinc discharge rate is 80% ≤ zinc discharge rate < 100%, the zinc discharge capacity of the blast furnace can be improved and the accumulation of zinc in the blast furnace can be reduced by controlling the molten iron temperature above 1430℃, controlling the average value of total titanium and silicon content in the molten iron to ≥ 0.25%, and controlling the proportion of total titanium and silicon content ≤ 0.2% to < 20%.

[0074] In one specific embodiment, if the zinc removal rate is <80%, the average value of the total titanium and silicon content in the molten iron is controlled to be ≥0.3%, and the proportion of titanium and silicon content ≤0.2% is <10%.

[0075] If the zinc removal rate is less than 80%, the zinc removal capacity of the blast furnace can be improved and the accumulation of zinc in the blast furnace can be reduced by controlling the molten iron temperature above 1440℃, controlling the average total content of titanium and silicon in the molten iron to be ≥0.3%, and controlling the proportion of total titanium and silicon content ≤0.2% to be <10%.

[0076] In one specific embodiment, the total content of titanium and silicon in molten iron can be controlled by adjusting the coke load and the air supply system.

[0077] S70. Control the proportion of coke at the edge and center based on the zinc discharge rate.

[0078] Specifically, the proportion of coke at the edges and center increases as the zinc discharge rate decreases.

[0079] In one specific embodiment, if the zinc discharge rate is 80% ≤ Zinc discharge rate < 100%, the sum of the proportions of edge and center coke should be ≥ 50%, of which the proportion of center coke should be ≥ 25%. This improves the zinc discharge capacity of the blast furnace and reduces the accumulation of zinc in the blast furnace.

[0080] In one specific embodiment, if the zinc discharge rate is <80%, the sum of the proportions of edge and center coke should be ≥65%, of which the proportion of center coke should be ≥30%, thereby improving the blast furnace's zinc discharge capacity and reducing the accumulation of zinc in the blast furnace.

[0081] S80. Adjust the temperature of the pressurized water inlet in the furnace body during the cooling process according to the zinc discharge rate.

[0082] Specifically, the inlet temperature of the pressurized water in the furnace increases as the zinc discharge rate decreases. In other words, the lower the zinc discharge rate, the higher the inlet temperature of the pressurized water in the furnace.

[0083] In one specific embodiment, if the zinc discharge rate is 80% ≤ Zinc discharge rate < 100%, the water temperature difference between different sections of the furnace body is increased by 1℃-5℃, based on the criterion that it does not exceed the design value. This reduces the zinc circulation and enrichment in the blast furnace and improves the zinc discharge capacity of the blast furnace.

[0084] In one specific embodiment, if the zinc discharge rate is <80%, the water temperature difference between different sections of the furnace body is not more than the design value. The inlet temperature of the medium-pressure water in the furnace body is increased by 5°C-10°C. This reduces the accumulation of zinc in the blast furnace and improves the zinc discharge capacity of the blast furnace.

[0085] The following specific embodiments illustrate the optimization process of zinc removal using the blast furnace zinc removal method based on vanadium-titanium magnetite described in this invention under different zinc removal rates. It should be understood that the following embodiments are only used to explain this invention and are not intended to limit this invention.

[0086] 1) When the zinc removal rate is ≥100%, the zinc removal problem is not considered.

[0087] 2) When the zinc discharge rate is between 80% and 100%, zinc discharge is optimized by adjusting the proportion of vanadium-titanium pellets, the discharge sequence, the blast energy, the proportion of slag, edge and center coke, and the temperature of the medium-pressure water inlet in the furnace. Specifically: the proportion of vanadium-titanium pellets is reduced by 0-5%, and the pellets are moved forward one position to reduce the amount of pellets rolling towards the center, stabilize the central airflow, and improve the zinc discharge rate; the blast energy is increased by 1%-5%; and the [Ti]+[Si] in the molten iron is controlled to be ≥0.2. The proportion of [Ti]+[Si]≤0.20% is less than 20%, and the molten iron temperature is controlled above 1430℃, thereby improving the furnace temperature control level and reducing the frequency of low furnace temperatures; the slag Ro is reduced by 1%-2%, the magnesium-aluminum ratio is maintained at 0.60±0.3, and the slag TiO2 is reduced by 1%-2%; the sum of the proportion of coke at the edge and center is ≥50%, of which the proportion of coke at the center should be ≥25%; the water temperature difference between different sections of the furnace body does not exceed the design value, and the inlet temperature of the medium-pressure water in the furnace body is increased by 1℃-5℃.

[0088] 3) When the zinc discharge rate is <80%, zinc discharge can be optimized by further adjusting the proportion of vanadium-titanium pellets, the discharge sequence, the blast energy, the slag, the proportion of coke at the edge and center, and the temperature of the medium-pressure water inlet in the furnace. Specifically, the proportion of vanadium-titanium pellets should be reduced by 1-10%, and the pellets should be moved forward 1-2 positions to reduce the amount of pellets rolling towards the center, stabilize the central airflow, and improve the zinc discharge rate; the blast energy should be increased by 5%-20%; and the [Ti]+[Si] content in the molten iron should be ≥0.30%. Furthermore, the proportion of [Ti]+[Si]≤0.20% is <10%, and the furnace temperature of molten iron is controlled above 1440℃, thereby improving the furnace temperature control level and reducing the frequency of low furnace temperatures; the slag Ro is controlled to decrease by 2%-4%, the magnesium-aluminum ratio is maintained at 0.62±0.3, and the slag TiO2 is controlled to decrease by 2%-5%; the sum of the proportion of coke at the edge and center should be ≥65%, of which the proportion of coke at the center should be ≥30%; the water temperature difference between different sections of the furnace body should not exceed the design value, and the inlet temperature of the medium-pressure water in the furnace body is increased by 5℃-10℃.

[0089] Using a 1750m high-titanium vanadium-titanium magnetite as an example 3 Taking a blast furnace (a bell-less top blast furnace) for smelting high-titanium vanadium-titanium magnetite, with a material structure of 60-35% vanadium-titanium sinter and 40-65% pure vanadium-titanium pellets as an example, this invention illustrates the blast furnace zinc removal method based on vanadium-titanium magnetite. This 1750m³... 3When the blast furnace smelting material structure consists of 60-35% vanadium-titanium sinter and 40-65% high-titanium vanadium-titanium magnetite, the blast furnace feed contains high levels of harmful elements, typically with a zinc load exceeding 1.0 kg / t and a zinc removal rate below 100%. By using the method described in this invention, the zinc removal rate can be increased in a shorter time, effectively reducing the circulating load of zinc within the blast furnace, minimizing furnace wall nodules and damage to coke strength, thus laying an important foundation for the long-term stable operation of the blast furnace. The specific implementation is as follows: Taking a certain month as an example, the blast furnace batch load was 42t and 4.45t / t, the material structure was: 44% vanadium-titanium sinter + 56% vanadium-titanium pellets, and the zinc load into the furnace was 1.143kg / t. The zinc content of the materials entering the blast furnace is shown in Table 1. The zinc content of the gravity dust, cyclone dust, and bag filter dust discharged from the furnace top was tested, and the results are shown in Table 2.

[0090] Table 1 Blast furnace material quantity and zinc content

[0091] Table 2 Weight and Zinc Content of Blast Furnace Dust, Molten Iron, and Slag

[0092] The zinc discharge rate was calculated to be 78.39% = ∑(dust weight × Zn content in the dust) / ∑(weight of raw material entering the furnace × Zn content in the raw material) × 100%. This indicates that the amount of zinc circulating and accumulating in the furnace is relatively large, which poses a significant threat to the stable and smooth operation of the blast furnace.

[0093] For a zinc load of 1.143 kg / t, which falls between 1.0 and 1.5 kg / t, and a zinc discharge rate of 73.76%, the following adjustments are made: First, reduce the proportion of all-vanadium-titanium pellets by 2% and optimize the discharge sequence, changing the discharge order of all-vanadium-titanium pellets from third to sixth to second to fifth, and the coking coal from fourth to third. Second, adjust the batch load, reducing it by approximately 3%, from 42t and 4.45t / t to 41t and 4.35t / t. Third, adjust the charging system according to Table 3 as follows: Table 3 Adjustment of the charging system

[0094] After three adjustments to the charging system, the ore platform remained largely unchanged. The outer angle difference was adjusted from 1° to 2°, the inner angle difference from 5° to 6.5°, and the combined percentage of coke at the edge and center was adjusted from 62.5% to 73.3%, with the percentage of coke at the center increasing from 25% to 31.25%.

[0095] The lower-level regulation includes the air supply system, heating system, slagging system, and cooling system, as detailed below: Air supply system adjustment: The air outlet area was changed from 0.2714m². 2 Adjusted to 0.2665m 2 Under normal furnace conditions, the oxygen enrichment rate is not significantly adjusted, and the air volume is increased from 4230 m³ / h. 3 / min increased to 4260m 3 / min, the blower kinetic energy increased from 167KJ / S to 176KJ / S, an increase of 5.38%.

[0096] Thermal regime adjustment: Improve furnace temperature control level, increase the average furnace temperature [Ti]+[Si] from 0.27% to 0.32%, decrease the proportion of furnace temperature [Ti]+[Si]≤0.20% from 14.3% to 8.9%, and increase the average molten iron temperature from 1439℃ to 1446℃.

[0097] Adjustments to the slag-forming system: The slag Ro was reduced from 1.10 to 1.07 in stages, a total reduction of 2.7%; the magnesium-aluminum ratio was adjusted from 0.59 to 0.61; and the slag TiO2 was reduced from 22.54% to 21.95%, a total reduction of 2.6%.

[0098] Cooling system adjustment: Based on the principle that the water temperature difference in each section of the furnace body does not exceed the design value, the inlet temperature of the medium-pressure water in the furnace body will be gradually increased from 35.4℃ to 41℃. Specifically, the cooling water temperature difference in section 9 of the furnace body will increase from 2.04℃ to 3.33℃, the cooling water temperature difference in section 10 of the furnace body will increase from 2.15℃ to 2.91℃, the cooling water temperature difference in section 11 of the furnace body will increase from 2.11℃ to 2.72℃, and the cooling water temperature difference in sections 12-16 of the furnace body will increase from 2.17℃ to 2.21℃.

[0099] Following the above adjustments, after 15 days of stable operation of the blast furnace, the zinc removal rate significantly increased, reaching 105%. See Tables 4 and 5 for details.

[0100] Table 4 Blast Furnace Material Quantity and Zinc Content

[0101] Table 5 Weight and Zinc Content of Blast Furnace Dust, Molten Iron, and Slag

[0102] The zinc removal rate is calculated as follows: Zinc removal rate = ∑(dust weight × Zn content in the dust) / ∑(weight of raw material entering the furnace × Zn content in the raw material) × 100% = 101.79%.

[0103] As can be seen from the above embodiments, by using the zinc removal method described in this invention, the zinc removal rate can be increased in a short time, so that the zinc removal rate reaches 100%, effectively reducing the circulating load of zinc in the blast furnace, reducing furnace wall nodules and damage to coke strength, and laying an important foundation for the long-term stable operation of the blast furnace.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A blast furnace zinc discharge method based on vanadium-titanium magnetite, characterized in that, include: Obtain the zinc load for blast furnace smelting of iron ore, wherein the iron ore contains vanadium-titanium magnetite; The charging angle, blast furnace batch weight, and coke load in the charging system are adjusted according to the zinc load. The adjustment range of the charging angle increases with the increase of the zinc load, while the blast furnace batch weight and coke load decrease with the increase of the zinc load. Obtain the types of furnace charge, as well as the weight and zinc content of each charge, to determine the zinc removal rate; The structure of the raw materials fed into the furnace and the air supply system in the feeding system are adjusted according to the zinc discharge rate.

2. The method according to claim 1, characterized in that, Adjustments to the charging angle, blast furnace batch weight, and coke load in the charging system based on the zinc load include: According to the zinc load level to which the zinc load belongs, the charging angle, the blast furnace batch weight and the coke load are adjusted. The zinc load level is divided into three levels: the first zinc load level is zinc load < 1.0 kg / t•iron, the second zinc load level is 1.0 kg / t•iron ≤ zinc load < 1.5 kg / t•iron, and the third zinc load level is zinc load ≥ 1.5 kg / t•iron.

3. The method according to claim 2, characterized in that, Adjustments to the charging angle, blast furnace batch weight, and coke load based on the zinc load level to which the furnace feed load belongs include: If the zinc load entering the furnace belongs to the first zinc load level, the distance between the outermost ring ore landing point and the furnace wall shall be controlled to be ≥80mm, and the outer angle difference between ore and coke shall be controlled within the range of 0-1.5°, and the inner angle difference between ore and coke shall be controlled within the range of 5°~6°. If the zinc load entering the furnace belongs to the second zinc load level, the distance between the outermost ring ore landing point and the furnace wall shall be controlled to be ≥100mm, and the outer angle difference between ore and coke shall be controlled within the range of 0.5-2°, and the inner angle difference between ore and coke shall be controlled within the range of 5°~7°, and the blast furnace batch weight and the coke load shall be reduced by 1%~5%; If the zinc load entering the furnace belongs to the third zinc load level, the distance between the outermost ring ore landing point and the furnace wall shall be controlled to be ≥150mm, and the outer angle difference between ore and coke shall be controlled within the range of 1-2.5°, and the inner angle difference between ore and coke shall be controlled within the range of 5°~7.5°, and the blast furnace batch weight and the coke load shall be reduced by ≥5%.

4. The method according to claim 1, characterized in that, The raw materials fed into the furnace include vanadium-titanium sinter and vanadium-titanium pellets. Adjustments to the structure of the raw materials and the air supply system in the charging procedure based on the zinc discharge rate include: The proportion and order of the vanadium-titanium pellets in the furnace feed are adjusted according to the zinc discharge rate. The proportion of the vanadium-titanium pellets decreases as the zinc discharge rate decreases, and the order of the vanadium-titanium pellets advances as the zinc discharge rate decreases. The blowing energy is adjusted according to the zinc removal rate, wherein the blowing energy increases as the zinc removal rate decreases.

5. The method according to claim 4, characterized in that, Adjusting the proportion and order of vanadium-titanium pellets in the furnace feed material according to the zinc discharge rate includes: If 80%≤the zinc removal rate<100%, the proportion of all vanadium-titanium pellets is reduced by 0~5%, and the ranking of all vanadium-titanium pellets is advanced by 1 place. If the zinc discharge rate is less than 80%, the proportion of vanadium-titanium pellets should be reduced by 1-10%, and the ranking of vanadium-titanium pellets should be advanced by 1-2 places.

6. The method according to claim 4, characterized in that, Adjusting the blower kinetic energy based on the zinc discharge rate includes: If 80% ≤ the zinc removal rate < 100%, the area of ​​the air outlet and the air volume are adjusted to increase the blowing energy by 1% to 5%. If the zinc removal rate is less than 80%, the area of ​​the air outlet and the air volume are adjusted to increase the blowing power by 5% to 20%.

7. The method according to claim 1, characterized in that, Also includes: Based on the zinc discharge rate, the average value of the total titanium and silicon content in the molten iron and the frequency of low furnace temperature are controlled. The average value of the total titanium and silicon content in the molten iron increases as the zinc discharge rate decreases, and the frequency of low furnace temperature decreases as the zinc discharge rate decreases.

8. The method according to claim 7, characterized in that, Controlling the average total titanium and silicon content in molten iron and the frequency of low furnace temperatures includes: If 80% ≤ the zinc removal rate < 100%, the average value of the total titanium and silicon content in the molten iron should be ≥ 0.25%, and the proportion of titanium and silicon content ≤ 0.2% should be < 20%. If the zinc removal rate is <80%, the average value of the total titanium and silicon content in the molten iron should be ≥0.3%, and the proportion of titanium and silicon content ≤0.2% should be <10%.

9. The method according to claim 1, characterized in that, Also includes: Based on the zinc discharge rate, the slag basicity, the aluminum-magnesium ratio, and the titanium dioxide content in the slag are controlled. The slag basicity and the titanium dioxide content in the slag decrease as the zinc discharge rate decreases, while the aluminum-magnesium ratio in the slag increases as the zinc discharge rate decreases.

10. The method according to claim 1, characterized in that, Also includes: The temperature of the pressurized water inlet in the furnace body during the cooling process is adjusted according to the zinc discharge rate, wherein the temperature of the pressurized water inlet increases as the zinc discharge rate decreases.

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