Method for reducing enrichment of harmful elements in blast furnace

Abstract

The invention discloses a method for reducing enrichment of harmful elements in a blast furnace, which comprises the following steps: adjusting the directions of all tuyeres of the blast furnace to enable the central lines of the tuyeres to deviate from the circle center by 2-5 degrees to form centripetal force, forming spiral airflow in the gas rising process, and bringing nearby dust into the central airflow by the spiral central leading airflow, znO generated after surrounding gaseous Zn encounters dust and is cooled can also be brought into the central airflow; therefore, the spiral center leading airflow is more powerful, and the Zn discharging capacity is improved; changing a material distribution mode, distributing high-Zn furnace burden to the center and a middle annular belt of the blast furnace, and distributing low-Zn furnace burden to the edge of the blast furnace; mgO / Al2O3 in the slag is controlled to be 0.55-0.58, so that alkali removal is facilitated; through the measures, the enrichment rate of harmful elements is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of blast furnace smelting, and in particular relates to a method for reducing the enrichment of harmful elements in a blast furnace. Background Art

[0002] The charge to the blast furnace usually contains a certain amount of harmful elements such as K, Na, Zn, Pb, Cu, As, Sn, etc. These elements circulate and accumulate in the furnace, which will have a certain impact on the blast furnace.

[0003] If there is alkali metal oxidation deposition in the pores of the charge or the gaps in the furnace lining, the expansion caused by carbon precipitation will cause the charge blocks or brick linings to break. After the coke absorbs alkali metals, it will reduce the strength of the coke and increase its reactivity.

[0004] The volatilization temperature of zinc is relatively low, only 907℃. When gaseous zinc encounters mineral powder or coke powder during its rising process, it will generate ZnO after cooling down and adsorbed on the furnace wall. Long-term accumulation will easily cause the furnace wall to thicken and adhere to the charge, blocking the pores of the charge and deteriorating the permeability of the charge column. When the zinc-rich slag skin concentrates on reaching the furnace cylinder, it will also cause the furnace cylinder to cool down or freeze.

[0005] During the iron-making process, lead tends to be deposited at the bottom of the furnace and seep into the brick joints, which has a destructive effect on the bottom of the blast furnace, but has no obvious effect on the normal operation of the furnace.

[0006] Although some methods for smelting low-grade harmful element materials in blast furnaces are disclosed in the prior art, such as CN111733305A discloses a method for smelting in a blast furnace with high zinc load, in which the chemical composition of the high zinc sintered ore entering the furnace is first analyzed to control the zinc content in the high zinc sintered ore to be 0.020% to 0.050%; the high zinc sintered ore, pelletized ore and lump ore are prepared as the charge according to the mass percentage of 60% to 75%: 30% to 15%: 10%; the specific scrap steel material and the above-mentioned high zinc sintered ore are mixed at a mass ratio of 1:25 to 80 to form a mixture; the lump ore, pelletized ore and the mixture are conveyed into a concentrated bucket of a material tank to mix to obtain a mixed ore; then the mixed ore is distributed into the blast furnace through a materialless bell; a distribution mode in which the central coke addition amount is 25% to 30% of the coke batch is adopted, and a blast furnace operation mode in which the air supply area, oxygen enrichment rate, top temperature and CO utilization efficiency are expanded is adopted. Although this method improves the adaptability of blast furnaces to smelt high-zinc-load raw materials, it can only discharge harmful elements such as Zn in the center of the blast furnace through the central airflow, without considering the overall distribution of the blast furnace charge; and it does not effectively eliminate harmful elements such as Zn, K, and Na, resulting in the circulation and enrichment of harmful elements in the furnace, which continuously affects the smooth operation of the blast furnace and increases fuel consumption. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for reducing the enrichment of harmful elements in a blast furnace, which can effectively eliminate the harmful elements in the blast furnace.

[0008] The technical solution adopted by the present invention is as follows:

[0009] The present invention provides a method for reducing the enrichment of harmful elements in a blast furnace, the method comprising:

[0010] (1) Adjust the direction of all tuyere of the blast furnace so that the center line of the tuyere deviates from the center of the circle by 2-5°;

[0011] (2) When charging the blast furnace, the charges entering the blast furnace are lump ore, sintered ore, pelletized ore, and sintered ore from the outer ring to the inner ring. The lump ore with low Zn content is relatively concentrated and distributed closest to the furnace wall, while the sintered ore with high Zn content is distributed to the center and middle ring of the blast furnace. The coke mixed with the lump ore is distributed to the edge of the furnace wall.

[0012] (3) Adopting a blast furnace operation mode with large air volume and low top pressure, increasing the furnace gas volume index, increasing the gas flow rate and raising the furnace top temperature;

[0013] (4) Control the content ratio of MgO to Al2O3 in blast furnace slag between 0.55-0.58.

[0014] In (2), the mass percentages of lump ore, sintered ore and pelletized ore are 8-15%, 75-85% and 5-10% respectively, and the amount of coke used is 20-40 kg / t iron.

[0015] (3) The furnace gas volume index is 60-65m 3 / (min·m 2 ).

[0016] (3), the wind speed is 235-260 m / s.

[0017] (3) The furnace top temperature is controlled at 150-200°C.

[0018] The method for reducing the enrichment of harmful elements in a blast furnace provided by the present invention, on the basis of normal charge distribution, forms a centripetal force by adjusting the directions of all tuyere of the blast furnace so that the center line of the tuyere deviates from the center of the circle by 2-5 degrees, and a spiral airflow is formed in the process of gas rising, the central leading airflow of the spiral will bring nearby dust into the central airflow, and ZnO generated by the surrounding gaseous Zn after the dust is cooled will also be brought into the central airflow; therefore, the spiral central leading airflow is not only stronger, but also improves the ability to discharge Zn; the charge distribution mode is changed, high Zn furnace charge is distributed to the center and middle ring belt of the blast furnace, and low Zn furnace charge is distributed to the edge of the blast furnace; MgO / Al2O3 in the slag is controlled to be 0.55-0.58 to facilitate alkali discharge; the enrichment rate of harmful elements is reduced by the above measures.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The method for reducing the enrichment of harmful elements in a blast furnace provided by the present invention is simple and easy to operate, can effectively exclude harmful elements such as K, Na, Zn, Pb, Cu, etc., and reduces the enrichment rate of the harmful elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the blast furnace tuyere direction after adjustment;

[0022] Figure 2 Schematic diagram of the blast furnace tuyere direction before adjustment;

[0023] Figure 3 This is a corresponding relationship diagram between MgO / Al2O3 in the slag and the amount of K2O and Na2O discharged. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the embodiments.

[0025] Example 1

[0026] A method for reducing the enrichment of harmful elements in a blast furnace, the method comprising:

[0027] (1) Adjust the direction of all tuyere of the blast furnace so that the center line of the tuyere deviates from the center of the circle by 5°, such as Figure 1 As shown;

[0028] (2) When the blast furnace is charged, the charges entering the blast furnace are lump ore, sintered ore, pellet ore, and sintered ore from the outer ring to the inner ring. The lump ore with low Zn content is relatively concentrated and distributed closest to the furnace wall, while the sintered ore with high Zn content is distributed to the center and middle ring of the blast furnace. The coke mixed with the lump ore is distributed to the edge of the furnace wall. The charge matrix is ​​O 38.5 3 36.2 3 33.7 3 31 2C 38 .5 2 36.2 2 36.8 3 33.7 2 31 2 28 2 20 2. The mass percentages of lump ore, sintered ore and pelletized ore are 15%, 75% and 10% respectively, and the amount of coke used is 40kg / t iron;

[0029] (3) Adopt the blast furnace operation mode of high air volume and low top pressure, increase the furnace gas volume index, increase the gas flow rate and increase the furnace top temperature; the furnace gas volume index is controlled at 65m 3 / (min·m 2), the actual wind speed is controlled at 258m / s, and the furnace top temperature is controlled at 192℃;

[0030] (4) The content ratio of MgO to Al2O3 in blast furnace slag is controlled to be 0.58.

[0031] In this embodiment, the enrichment of harmful elements is shown in Table 1.

[0032] Table 1

[0033] parameter <![CDATA[K2O]]> <![CDATA[Na2O]]> Zn Pb Cu <![CDATA[Furnace charge / (kg·t -1 )]]> 1.597 1.548 1.578 0.182 0.483 <![CDATA[Hot metal discharge amount / (kg·t -1 )]]> 0 0 0.00012 0 0.493 <![CDATA[Slag discharge amount / (kg·t -1 )]]> 1.269 1.267 0.00008 0 0 <![CDATA[Gas ash discharge amount / (kg·t -1 )]]> 0.016 0.019 0.082 0.0085 0 <![CDATA[Dust discharge amount of cloth bag / (kg·t -1 )]]> 0.189 0.19 1.329 0.142 0 <![CDATA[Total discharge / (kg·t -1 )]]> 1.474 1.476 1.4112 0.1505 0.493 <![CDATA[Residual amount / (kg·t -1 )]]> 0.123 0.072 0.1668 0.0315 -0.01 Enrichment rate (%) 7.70 4.65 10.57 17.31 -2.07

[0034] It can be seen from Table 1 that after adopting the above measures, compared with Comparative Example 1, the amount of harmful elements such as K, Na, Zn, Pb, Cu discharged increased, the residual amount decreased, and the enrichment rate was significantly reduced.

[0035] Example 2

[0036] A method for reducing the enrichment of harmful elements in a blast furnace, the method comprising:

[0037] (1) Adjust the direction of all tuyere of the blast furnace so that the center line of the tuyere deviates from the center of the circle by 4°;

[0038] (2) When the blast furnace is charged, the charges entering the blast furnace are lump ore, sintered ore, pellet ore, and sintered ore from the outer ring to the inner ring. The lump ore with low Zn content is relatively concentrated and distributed closest to the furnace wall, while the sintered ore with high Zn content is distributed to the center and middle ring of the blast furnace. The coke mixed with the lump ore is distributed to the edge of the furnace wall. The charge matrix is ​​O 38.5 3 36.2 3 33.7 3 31 2C 38 .5 2 36.2 2 36.8 3 33.7 2 31 2 28 2 20 2. The mass percentages of lump ore, sintered ore and pelletized ore are 12%, 80% and 8% respectively, and the amount of coke used is 30kg / t iron;

[0039] (3) Adopt the blast furnace operation mode of high air volume and low top pressure, increase the furnace gas volume index, increase the gas flow rate and increase the furnace top temperature; the furnace gas volume index is controlled at 63m 3 / (min·m 2 ), the actual wind speed is controlled at 247m / s, and the furnace top temperature is controlled at 178℃;

[0040] (4) The content ratio of MgO to Al2O3 in blast furnace slag is controlled to be 0.56.

[0041] In this embodiment, the enrichment of harmful elements is shown in Table 2.

[0042] Table 2

[0043] parameter <![CDATA[K2O]]> <![CDATA[Na2O]]> Zn Pb Cu <![CDATA[Charge into furnace / (kg·t -1 )]]> 1.553 1.503 1.591 0.169 0.446 <![CDATA[Hot metal discharge amount / (kg·t -1 )]]> 0 0 0.00011 0 0.454 <![CDATA[slag discharge amount / (kg·t -1 )]]> 1.23 1.231 0.00007 0 0 <![CDATA[Gas ash discharge amount / (kg·t -1 )]]> 0.014 0.017 0.08 0.008 0 <![CDATA[Discharge amount of cloth bag ash / (kg·t -1 )]]> 0.181 0.179 1.322 0.128 0 <![CDATA[Total discharge / (kg·t -1 )]]> 1.425 1.427 1.4022 0.136 0.454 <![CDATA[Residual amount / (kg·t -1 )]]> 0.128 0.076 0.1888 0.033 -0.008 Enrichment rate (%) 8.24 5.06 11.87 19.53 -1.79

[0044] From the comparison between Table 1 and Table 2, it can be seen that the tuyere centerline deviates from the center of the circle by 2-5°, and the furnace gas volume index is between 60-65m 3 / (min·m 2 ), wind speed is in the range of 235-260m / s, and furnace top temperature is in the range of 150-200℃. As the values ​​decrease, the ability to discharge K, Na, Zn, and Pb decreases, and the enrichment rate increases; MgO / Al2O3 in the slag is in the range of 0.55-0.58. As the values ​​decrease, it may affect the fluidity of slag iron, thereby causing a relative decrease in the amount of Cu discharged from molten iron.

[0045] Example 3

[0046] A method for reducing the enrichment of harmful elements in a blast furnace, the method comprising:

[0047] (1) Adjust the direction of all tuyere of the blast furnace so that the center line of the tuyere deviates from the center of the circle by 2°;

[0048] (2) When the blast furnace is charged, the charges entering the blast furnace are lump ore, sintered ore, pellet ore, and sintered ore from the outer ring to the inner ring. The lump ore with low Zn content is relatively concentrated and distributed closest to the furnace wall, while the sintered ore with high Zn content is distributed to the center and middle ring of the blast furnace. The coke mixed with the lump ore is distributed to the edge of the furnace wall. The charge matrix is ​​O 38.5 3 36.2 3 33.7 3 31 2C 38 .5 2 36.2 2 36.8 3 33.7 2 31 2 28 2 20 2. The mass percentages of lump ore, sintered ore and pelletized ore are 8%, 85% and 7% respectively, and the amount of coke used is 20kg / t iron;

[0049] (3) Adopt the blast furnace operation mode of high air volume and low top pressure, increase the gas volume index of the furnace, increase the gas flow rate and increase the furnace top temperature; the gas volume index of the furnace is controlled at 60m 3 / (min·m 2 ), the actual wind speed is controlled at 236m / s, and the furnace top temperature is controlled at about 152℃;

[0050] (4) The content ratio of MgO to Al2O3 in blast furnace slag is controlled to be 0.55.

[0051] In this embodiment, the enrichment of harmful elements is shown in Table 3.

[0052] Table 3

[0053]

[0054]

[0055] From the comparison between Table 3 and Tables 1 and 2, it can be seen that the tuyere centerline deviates from the center of the circle by 2-5°, and the furnace gas volume index is between 60-65m 3 / (min·m 2 ), wind speed is in the range of 235-260m / s, and furnace top temperature is in the range of 150-200℃. As the values ​​decrease, the ability to discharge K, Na, Zn, and Pb gradually decreases, and the enrichment rate increases; MgO / Al2O3 in the slag is in the range of 0.55-0.58. As the values ​​decrease, it may affect the fluidity of slag iron, thereby causing a relative decrease in the amount of Cu discharged from molten iron.

[0056] Comparative Example 1

[0057] The horizontal directions of all tuyere of blast furnace are aligned with the center of the circle, such as Figure 2 As shown in the figure, the blast furnace iron material layout from the outer ring to the inner ring is sintered ore, lump ore, pelletized ore, sintered ore, coke dicing mixed with lump ore, and the furnace gas volume index is controlled at 56m 3 / (min·m 2 ), the actual wind speed is controlled at 230m / s, the top temperature is controlled at 140°C, MgO / Al2O3 is controlled at 0.52, and the others are the same as in Example 1.

[0058] In this comparative example, the enrichment of harmful elements is shown in Table 4.

[0059] Table 4

[0060]

[0061]

[0062] It can be seen from Table 4 that after adopting the above measures, the proportion of harmful elements such as K, Na, Zn, Pb, Cu discharged is significantly reduced compared with each embodiment, the residual proportion is increased, and the enrichment rate is significantly increased.

[0063] Comparative Example 2

[0064] The rest is the same as in Example 1, except that the horizontal directions of all tuyere of the blast furnace are aligned with the center of the circle.

[0065] In this comparative example, the enrichment of harmful elements is shown in Table 5.

[0066] Table 5

[0067] parameter <![CDATA[K2O]]> <![CDATA[Na2O]]> Zn Pb Cu <![CDATA[Charge into furnace / (kg·t -1 )]]> 1.597 1.548 1.578 0.182 0.483 <![CDATA[Hot metal discharge amount / (kg·t -1 )]]> 0 0 0.0001 0 0.491 <![CDATA[Slag discharge amount / (kg·t -1 )]]> 1.267 1.266 0.00006 0 0 <![CDATA[Gas ash discharge amount / (kg·t -1 )]]> 0.014 0.018 0.076 0.0081 0 <![CDATA[Dust discharge amount of cloth bag / (kg·t -1 )]]> 0.181 0.183 1.265 0.135 0 <![CDATA[Total discharge / (kg·t -1 )]]> 1.462 1.467 1.3411 0.1431 0.491 <![CDATA[Residual amount / (kg·t -1 )]]> 0.135 0.081 0.2369 0.0389 -0.008 Enrichment rate (%) 8.45 5.23 15.01 21.37 -1.66

[0068] It can be seen from Table 5 that compared with Example 1, the blast furnace K2O enrichment rate in Comparative Example 2 increased by 0.75%, Na2O enrichment rate increased by 0.58%, Zn enrichment rate increased by 4.44%, Pb enrichment rate increased by 4.06%, and Cu enrichment rate increased by 0.41%.

[0069] Comparative Example 3

[0070] The rest is the same as Example 1, except that the blast furnace iron materials are arranged from the outer ring to the inner ring in the order of sintered ore, lump ore, pelletized ore, and sintered ore, and coke is mixed into the lump ore.

[0071] In this comparative example, the enrichment of harmful elements is shown in Table 6.

[0072] Table 6 Enrichment of main harmful elements after adopting this scheme

[0073] parameter <![CDATA[K2O]]> <![CDATA[Na2O]]> Zn Pb Cu <![CDATA[Furnace charge / (kg·t -1 )]]> 1.597 1.548 1.578 0.182 0.483 <![CDATA[Hot metal discharge amount / (kg·t -1 )]]> 0 0 0.0001 0 0.492 <![CDATA[Slag discharge amount / (kg·t -1 )]]> 1.268 1.265 0.00005 0 0 <![CDATA[Gas ash discharge amount / (kg·t -1 )]]> 0.015 0.018 0.075 0.0082 0 <![CDATA[Discharge amount of cloth bag ash / (kg·t -1 )]]> 0.187 0.189 1.261 0.137 0 <![CDATA[Total discharge / (kg·t -1 )]]> 1.47 1.472 1.3361 0.1452 0.492 <![CDATA[Residual amount / (kg·t -1 )]]> 0.127 0.076 0.2419 0.0368 -0.009 Enrichment rate (%) 7.95 4.91 15.33 20.22 -1.86

[0074] It can be seen from Table 6 that compared with Example 1, the blast furnace K2O enrichment rate in Comparative Example 3 increased by 0.25%, Na2O enrichment rate increased by 0.26%, Zn enrichment rate increased by 4.76%, Pb enrichment rate increased by 2.91%, and Cu enrichment rate increased by 0.21%.

[0075] Comparative Example 4

[0076] The rest is the same as in Example 1, except that the furnace gas volume index is controlled to 56m 3 / (min·m 2 ), the actual wind speed is controlled at 230m / s and the furnace top temperature is controlled at 140℃.

[0077] In this comparative example, the enrichment of harmful elements is shown in Table 7.

[0078] Table 7 Enrichment of main harmful elements after adopting this scheme

[0079] parameter <![CDATA[K2O]]> <![CDATA[Na2O]]> Zn Pb Cu <![CDATA[Furnace charge / (kg·t -1 )]]> 1.597 1.548 1.578 0.182 0.483 <![CDATA[Hot metal discharge amount / (kg·t -1 )]]> 0 0 0.00011 0 0.493 <![CDATA[Slag discharge amount / (kg·t -1 )]]> 1.268 1.266 0.00007 0 0 <![CDATA[Gas ash discharge amount / (kg·t -1 )]]> 0.012 0.016 0.078 0.0081 0 <![CDATA[Discharge amount of cloth bag ash / (kg·t -1 )]]> 0.174 0.175 1.259 0.13 0 <![CDATA[Total discharge / (kg·t -1 )]]> 1.454 1.457 1.3371 0.1381 0.493 <![CDATA[Residual amount / (kg·t -1 )]]> 0.143 0.091 0.2409 0.0439 -0.01 Enrichment rate (%) 8.95 5.88 15.27 24.12 -2.07

[0080] It can be seen from Table 7 that compared with Example 1, the blast furnace K2O enrichment rate in Comparative Example 4 increased by 1.25%, Na2O enrichment rate increased by 1.23%, Zn enrichment rate increased by 4.7%, Pb enrichment rate increased by 6.81%, and Cu enrichment rate remained unchanged.

[0081] Comparative Example 5

[0082] The rest is the same as in Example 1, except that the MgO / Al2O3 in the slag is controlled at 0.52.

[0083] In this comparative example, the enrichment of harmful elements is shown in Table 8.

[0084] Table 8 Enrichment of main harmful elements after adopting this scheme

[0085]

[0086]

[0087] It can be seen from Table 8 that, compared with Example 1, the blast furnace K2O enrichment rate in Comparative Example 5 increased by 2.01%, Na2O enrichment rate increased by 1.42%, Zn enrichment rate increased by 0.32%, Pb enrichment rate increased by 1.15%, and Cu enrichment rate increased by 0.62%. Screening Example 1

[0088] Under the same conditions as in Example 1, the horizontal directions of all tuyere of the blast furnace were adjusted to deviate from the center of the circle by less than 2°, 2-5°, and greater than 5°, respectively. The changes in the Zn arrangement compared to the horizontal alignment of all tuyere with the center of the circle are shown in Table 9.

[0089] Table 9

[0090]

[0091] As can be seen from Table 9, only when the center line of the tuyere deviates from the center of the circle by an angle of 2-5° can a certain central spiral airflow be generated, and the airflow intensity is enhanced to a certain extent compared with the original airflow, and the zinc discharge is the best. Therefore, during production, the blast furnace tuyere is adjusted so that the center line of the tuyere deviates from the center of the circle by 2-5°.

[0092] Screening Example 2

[0093] The content of MgO / Al2O3 in blast furnace slag has a great relationship with blast furnace alkali removal. The present invention explores the influence of MgO / Al2O3 content in slag on blast furnace alkali removal and finds out suitable MgO / Al2O3. Increasing the MgO content has the effect of reducing the activity and content of alkali metals K2O and Na2O in the slag, which is beneficial to alkali removal. However, too high MgO / Al2O3 will lead to unstable slag, and too low MgO / Al2O3 slag smelting is prone to insufficient heat of slag iron, difficult slag shell in the main groove, large fluctuation of furnace temperature, and difficulty in slag iron discharge. Therefore, controlling suitable MgO / Al2O3 is the key to solving the problem. Through blast furnace practice, under the condition of ensuring that the blast furnace temperature, alkali load and alkalinity are constant, the influence of different MgO / Al2O3 on blast furnace alkali removal is calculated, and the alkali content of the slag discharged from the blast furnace is mainly used to test the alkali content in the blast furnace slag.

[0094] The K2O and Na2O loads entering the furnace are set at 8kg / t, and the amount of K2O and Na2O discharged from the slag is tested. After the data is cleaned, 77 samples that meet the conditions are selected and the results are statistically analyzed. Figure 3As shown in the figure, when MgO / Al2O3 is controlled between 0.55-0.58, the amount of K2O and Na2O discharged is the largest, reaching 7.4-7.5kg / t, and the average can reach 7.24kg / t. Therefore, the MgO / Al2O3 in the blast furnace slag is controlled between 0.55-0.58 during production.

[0095] The above-mentioned detailed description of a method for reducing the enrichment of harmful elements in a blast furnace with reference to the embodiments is illustrative rather than restrictive, and several embodiments can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for reducing the enrichment of harmful elements in a blast furnace, characterized in that: The method comprises: (1) Adjust the direction of all tuyere of the blast furnace so that the center line of the tuyere deviates from the center of the circle by 2-5°; (2) When charging the blast furnace, the charges entering the blast furnace are lump ore, sintered ore, pelletized ore, and sintered ore from the outer ring to the inner ring. The lump ore with low Zn content is relatively concentrated and distributed closest to the furnace wall, while the sintered ore with high Zn content is distributed to the center and middle ring of the blast furnace. The coke mixed with the lump ore is distributed to the edge of the furnace wall. (3) Adopting a blast furnace operation mode with large air volume and low top pressure, increasing the furnace gas volume index, increasing the gas flow rate and raising the furnace top temperature; (4) Control the content ratio of MgO to Al2O3 in blast furnace slag between 0.55-0.

58.

2. The method for reducing the concentration of harmful elements in a blast furnace according to claim 1, characterized in that: (2) 8-15%, 75-85%, 5-10%, and the amount of coke used is 20-40 kg / t iron.

3. The method for reducing the enrichment of harmful elements in a blast furnace according to claim 1, characterized in that: (3) The furnace gas volume index is 60-65m 3 / (min·m 2 ).

4. The method for reducing the concentration of harmful elements in a blast furnace according to claim 1, characterized in that: (3), the wind speed is 235-260 m / s.

5. The method for reducing the enrichment of harmful elements in a blast furnace according to claim 1, characterized in that: (3) The furnace top temperature is controlled at 150-200°C.

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