阅读说明：本技术 一种高炉开炉快速喷煤、富氧的方法 (Method for quickly spraying coal and enriching oxygen during blow-in of blast furnace ) 是由 吴泽勇 刘永辉 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种高炉开炉快速喷煤、富氧的方法,该方法先通过对填充料的合理配料,使焦炭负荷缓慢而稳步上升,保障开炉过程中炉缸热量充沛,炉况稳步向好,风量逐渐接受,为正常负荷料的加入奠定基础。并通过大幅度提高填充料装入完毕后的第一批正常料的焦炭负荷,实现在半个冶炼周期后即完成喷煤、富氧以迎接负荷料。从而避免长时间全焦冶炼,有利于高炉气流稳定和灵活调剂炉温,使铁水[si]平稳下降,减轻炉前工作量。之后按每个冶炼周期提高0.2～0.3的调整力度继续提高焦炭负荷,提升幅度稳步均匀,以利于实现高炉开炉顺行、快速达产达效的目的。(The invention discloses a method for quickly spraying coal and enriching oxygen during the blow-in of a blast furnace, which comprises the steps of firstly reasonably preparing a filler, slowly and stably increasing the coke load, ensuring the abundant heat of a furnace hearth in the blow-in process, ensuring the stable and good furnace condition and gradually accepting the air quantity, and laying a foundation for adding a normal load material. And the coke load of the first batch of normal materials after the filling material is completely filled is greatly improved, so that coal injection and oxygen enrichment can be completed to meet the load material after a half smelting period. Thereby avoiding long-time full coke smelting, being beneficial to the stable and flexible adjustment of the furnace temperature of blast furnace gas flow, leading the molten iron [ si ] to stably descend and reducing the workload in front of the furnace. And then, the coke load is continuously increased according to the adjustment force of 0.2-0.3 per smelting period, and the increase amplitude is stable and uniform, so that the purposes of realizing smooth blast furnace opening and quickly achieving the effect are achieved.)

1. A method for quickly spraying coal and enriching oxygen during the blow-in of a blast furnace is characterized in that the blast furnace is blown in by full coke or a furnace hearth is filled with sleepers or miscellaneous trees; dividing the filling material into a plurality of sections, keeping the coke batch weight of each section consistent, and ensuring that the coke layer thickness at the furnace waist part reaches 0.2-0.3 m;

wherein, when the full coke blow-in is adopted, the first section of the filling material is clean coke and is filled from the hearth to the upper edge of the furnace bosh; the second section is empty coke, and is filled to the lower part of the furnace body from the furnace waist, and the height filled in the furnace body accounts for 20 +/-5% of the height of the furnace body; adding ore from the third section, and increasing the coke load section by section in a rhythm that the coke load of each section of material is 0.2-0.3 heavier than that of the previous section of material;

after the blast furnace is ignited and air is supplied, filling the last section of filler, and changing the first batch of normal materials after the filler to improve the coke load by taking the coal injection amount of 80-100 kg/t as a reference;

coal injection and oxygen enrichment are carried out at the same time in a half smelting period after ignition, then the coke load is continuously increased according to the adjustment force of increasing 0.2-0.3 in each smelting period, and the physical heat is kept at 1480 ℃ or higher in the process, so that the furnace temperature is ensured to be sufficient;

and carrying out gas guiding operation 2-3 hours after air supply and ignition.

2. The method of claim 1, wherein Al is present in the second section of the charge material₂O₃The mass percent of the Al content is not more than 13 percent, and the Al content is gradually increased from the second section material to each section material₂O₃In order to reduce the slag ratio, Al₂O₃The highest mass percentage content of the component (A) is not more than 14.5 percent.

3. The method of claim 2, wherein the MgO content of the slag is determined according to MgO and Al from the second stage₂O₃The mass ratio of (A) to (B) is controlled to be 0.6-0.65; the alkalinity of the slag is controlled to be 0.95 +/-0.05.

4. The method of claim 3, wherein the filling material controls [ Si ] in the molten iron to 2.5% -3.5% and [ Mn ] to 0.8 + -0.1%.

5. The method for blast furnace blowing-in fast coal injection and oxygen enrichment as claimed in claim 2, characterized in that, from the second section of the charge, fluorite is added to each batch, and the amount of fluorite is 5 plus or minus 1 percent of the weight of the batch.

6. The method of claim 1, wherein the distribution matrix is adjusted during the charging of the filling material so that the filling material forms a level of the platform + the central funnel in the furnace after charging.

7. The method of claim 1, wherein the total dry-to-coke ratio of the charge material is 3.0-4.0 t/t.

8. The method of claim 1, wherein the actual charging volume of the charge material into the blast furnace deviates from the planned charging volume by less than 4%.

9. The method of claim 1, wherein after the blast furnace is opened, a coal gas sample is taken to perform a coal gas explosion test when the tuyere is completely ignited, the test is passed, and when the top pressure of the furnace is greater than 0.008MPa, the furnace condition is smooth, the charging equipment is normally operated, and the hot air pressure is greater than 0.06MPa, the coal gas introduction operation is performed.

10. The method for fast injecting coal and oxygen for the blast furnace blowing-in according to any one of claims 1 to 9 is suitable for the blowing-in of newly built, medium and after-overhaul blast furnaces.

Technical Field

The invention relates to a blast furnace blow-in method, in particular to a method for quickly injecting coal and enriching oxygen during blow-in of a blast furnace.

Background

The blow-in of the blast furnace is a complicated system project and is a relatively complex practical operation in iron-making production. The blast furnace condition and the blow-in condition before blow-in are different, and the blow-in condition is also different greatly. The furnace opening modes adopted at present mainly comprise two main types, wherein the furnace opening is carried out by filling a hearth with sleepers mostly, and the furnace opening is carried out by fully coking a small part of the hearth.

In a traditional furnace opening mode, after the ignition and the furnace opening of a blast furnace, the initial O/C is about 2.20, the increase of the O/C after air supply is gentle, if the furnace condition is smooth and good, the O/C is increased according to the amplitude of 0.1/6 hour in the early stage, the O/C is increased according to the amplitude of 0.1/8 hour in the later stage, when the air volume is full, the load is increased to 3.5, and the coal injection is considered, and the coal injection time is generally that the coal injection is carried out after the ignition and the air supply are carried out for. Therefore, the traditional coke load increasing method is slow after the blast furnace is opened, the coal injection and oxygen enrichment time is late, and long-time full coke smelting is not beneficial to flexibly adjusting the furnace temperature and stably and quickly reducing molten iron [ si ], so that the front work and the quick yield of the furnace are influenced.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects of the prior art, the invention provides a method for quickly spraying coal and enriching oxygen when a blast furnace is opened, which can ensure the stable airflow of the blast furnace, realize the flexible adjustment of the furnace temperature, stably lower the molten iron [ si ], reduce the workload in front of the furnace and realize the quick production of the blast furnace.

The technical scheme is as follows: the invention relates to a method for quickly spraying coal and enriching oxygen during the blow-in of a blast furnace, which adopts the full coke blow-in, or adopts sleepers or miscellaneous trees to fill a hearth blow-in; dividing the filling material into a plurality of sections, keeping the coke batch weight of each section consistent, and ensuring that the coke layer thickness at the furnace waist part reaches 0.2-0.3 m; wherein, when the full coke blow-in is adopted, the first section of the filling material is clean coke and is filled from the hearth to the upper edge of the furnace bosh; the second section is empty coke, and is filled to the lower part of the furnace body from the furnace waist, and the height filled in the furnace body accounts for 20 +/-5% of the height of the furnace body; adding ore from the third section, and increasing the coke load section by section in a rhythm that the coke load of each section of material is 0.2-0.3 heavier than that of the previous section of material;

after the blast furnace is ignited and air is supplied, filling the last section of filler, and changing the first batch of normal materials after the filler to improve the coke load by taking the coal injection amount of 80-100 kg/t as a reference;

coal injection and oxygen enrichment are carried out at the same time in a half smelting period after ignition, then the coke load is continuously increased according to the adjustment force of increasing 0.2-0.3 in each smelting period, and the physical heat is kept at 1480 ℃ or higher in the process, so that the furnace temperature is ensured to be sufficient;

and carrying out gas guiding operation 2-3 hours after air supply and ignition.

Wherein, Al in the second section of the filler₂O₃The mass percent of the Al content is not more than 13 percent, and the Al content is gradually increased from the second section material to each section material₂O₃In order to reduce the slag ratio, Al₂O₃The highest mass percentage content of the component (A) is not more than 14.5 percent.

Further, from the second stage, the MgO content of the slag is determined according to MgO and Al₂O₃The mass ratio of (A) to (B) is controlled to be 0.6-0.65; the alkalinity of the slag is controlled to be 0.95 +/-0.05.

Furthermore, the filling material controls the [ Si ] in the molten iron to be 2.5-3.5% and the [ Mn ] to be 0.8 +/-0.1%.

Further, from the second stage, fluorite is added into each batch, and the fluorite is used in an amount of 5 +/-1 percent of the weight of the batch.

Further, the actual loading volume of the fill material into the furnace deviates from the planned loading volume by less than 4%.

Specifically, after air supply, when the air ports are completely ignited, a coal gas sample is taken to perform a coal gas explosion test, the test is qualified, and when the furnace top pressure is greater than 0.008MPa, the furnace condition is smooth, the charging equipment operates normally, and the hot air pressure is greater than 0.06MPa, the coal gas introduction operation is performed.

Has the advantages that: the method firstly reasonably mixes the filling material to ensure that the coke load slowly and stably rises, ensures that the heat of a furnace hearth is abundant in the blow-in process, ensures that the furnace condition is stable and good, gradually accepts the air volume, and lays a foundation for adding the normal load material. And the coke load of the first batch of normal materials after the filling material is completely filled is greatly improved, so that coal injection and oxygen enrichment can be completed to meet the load material after a half smelting period. Thereby avoiding long-time full coke smelting, being beneficial to the stable and flexible adjustment of the furnace temperature of blast furnace gas flow, leading the molten iron [ si ] to stably descend and reducing the workload in front of the furnace. And then, the coke load is continuously increased according to the adjustment force of 0.2-0.3 per smelting period, and the increase amplitude is stable and uniform, so that the purposes of realizing smooth blast furnace opening and quickly achieving the effect are achieved.

Detailed Description

The method for quickly spraying coal and enriching oxygen during the blow-in of the blast furnace disclosed by the invention can be applied to the blow-in production process of all blast furnaces.

Specifically, the production control process comprises the following steps:

1) and under the condition of permission of enterprise resources, selecting raw fuel and auxiliary materials with good quality as much as possible and blowing the raw fuel and the auxiliary materials into the furnace.

2) And under the condition of permission of enterprise resources, the ore-using structure with higher clinker rate (more than or equal to 90%) is selected to blow in the furnace as much as possible.

3) Blowing-in filling material ingredient

The blast furnace filling material is divided into a plurality of sections according to the requirement, and the total dry-coke ratio of the filling material is 3.0-4.0 t/t. The batch weight of each section of coke is kept consistent, and the coke batch weight ensures that the thickness of the coke layer at the furnace waist part reaches 0.2-0.3 m.

When the full coke blow-in is adopted, the first section of the filling material is clean coke and is filled from the hearth to the upper edge of the furnace bosh; when the furnace is opened by filling the furnace cylinder with the sleepers or the miscellaneous trees, the first section is the sleepers/miscellaneous trees plus the clean coke, namely the furnace cylinder is filled with the sleepers or the miscellaneous trees, and the clean coke is filled to the upper edge of the furnace belly.

The second section is empty coke slag making material which is filled to the lower part of the furnace body from the furnace waist, and the height filled in the furnace body accounts for 20 +/-5 percent of the height of the furnace body. Among them, the air coke is slag forming material including coke, alkaline flux (e.g., limestone, dolomite), acid flux (e.g., silica), stone material for improving slag fluidity such as fluorite. Considering that the temperature of the first slag tapping iron furnace is lower, Al in the air coke is required₂O₃The mass percentage content of the Al is not more than 13 percent, and the Al is gradually increased from the second section of empty coke slag-making material to each section of material₂O₃In order to reduce the slag ratio, Al₂O₃The highest mass percentage content of the component (A) is not more than 14.5 percent.

The ore is added into the third section of the filling material, the coke load of the third section is controlled to be 0.2, and then the coke load of each section of the filling material is gradually increased by 0.2-0.3 compared with the coke load of the previous section of the filling material and shows a smooth rising trend. The load is particularly increased in a manner that increases ore batch weight and fixes coke batch weight.

From the second section, the MgO content of the slag is determined according to MgO and Al₂O₃The mass ratio of the slag is controlled to be 0.6-0.65, and the alkalinity of the slag is controlled to be 0.95 +/-0.05. And, starting from the second section, each batch is prepared with fluorite, and the dosage of the fluorite is 5 +/-1% of the batch weight. In addition, the filler is [ Si ] in molten iron]Controlled to be 2.5-3.5%, [ Mn%]The control is 0.8 +/-0.1%.

The proportion of the iron materials for normal production, including sintered ore, pellet ore and lump ore, is kept stable according to the needs, the coke load and the slag iron components gradually tend to be normalized through sectional batching, and the temperature field, the pressure field and the concentration field in the blast furnace gradually transition to normal levels.

4) The requirement for the filling material in the blast furnace

Firstly, adjusting a material distribution matrix in the process of filling materials. After the filling process is finished, the charge level in the furnace is required to form a platform and a central funnel charge level with proper width and depth.

② the difference between the actual material volume loaded into the furnace and the planned loading volume is less than 4 percent.

5) Before air supply and ignition, oxygen lances are arranged on all iron holes to supply oxygen to burn coke in a furnace hearth, and the furnace hearth is heated to facilitate smooth operation of the blast furnace and smooth iron tapping for the first time.

6) And coal injection and oxygen enrichment equipment is well debugged before ignition and blow-in, and the coal injection and oxygen enrichment capacity is realized.

7) And igniting, blowing in and blowing in, after the blowing-in filler is filled, greatly increasing the coke load of the first batch of normal material to prepare for 80-100 kg/t of coal injection, exiting the full coke smelting as soon as possible to be beneficial to airflow stabilization and flexible adjustment of the furnace temperature, enabling the molten iron [ si ] to stably descend and reducing the workload in front of the furnace. And coal injection and oxygen enrichment are carried out in a half smelting period after ignition. And then according to the smelting period, continuously increasing the coke load according to the adjustment force of increasing 0.2-0.3 per smelting period, wherein the temperature of molten iron is 1480 ℃ or more, the furnace temperature must be kept sufficient, and the rapid furnace cooling and the yield reaching in advance are facilitated.

8) The method meets the conditions, the coal gas is introduced as early as possible (2-3 hours after air supply ignition), the furnace condition is smooth, the environmental pollution is reduced, and specifically, after air supply, a coal gas sample is taken to perform a coal gas explosion test after all air ports are ignited. The test is qualified, and when the pressure of the furnace top is more than 0.008MPa, the furnace condition is smooth, the charging equipment operates normally, and the pressure of hot air is more than 0.06MPa, the hot air furnace technician contacts to send gas according to the gas sending procedure.

9) In order to realize successful blow-in, a blast furnace operation parameter adjustment operation schedule (quantification and modeling) 72 hours after blow-in ignition is also established and implemented according to the schedule

The air quantity (properly controlled during the formation period of the soft melting zone), the air temperature, the top pressure, the coal injection, the oxygen enrichment, the number of working air ports, the load variation (according to the smelting period), the slag iron components and other operation parameters are adjusted to make system arrangement, so that the air quantity, the air speed and the blast kinetic energy are stably increased to a set level, the blanking is smooth, the molten iron [ si ] is stably reduced, the molten iron temperature is sufficient (not lower than 1480 ℃), the slag iron has good fluidity, the coal gas utilization rate is gradually increased and stabilized, the furnace condition is smooth, the coal injection and the oxygen enrichment are quickly realized, and the purpose of quickly achieving the yield is achieved.

Next, 2550m at a certain domestic factory³The present invention will be described in further detail with reference to a blast furnace as an example.

1) Before the blast furnace is opened

The diameter of 2550m³The blast furnace is subjected to furnace shutdown and cooling wall replacement after two times of water pumping and material emptying lines reach the position below a furnace hearth tuyere.

The 1 st item repair is 4 months, 30 days, 2:23 ignition blow-in 2009. Residual broken coke in the furnace is basically cleaned out before the furnace is opened, two of three iron openings are burnt out of the furnace, and 4 air openings are provided with hot air guide pipes. The blast furnace is opened for 2 blast furnaces for production, the self-production dry quenching of the blast furnace is sufficient, the full self-production dry quenching can be kept after the blast furnace is opened, but the first slag iron production is difficult after the blast furnace is opened, and the time for production is long; coal injection and oxygen enrichment are delayed: the time from ignition blow-in to coal injection is 54.65 hours; the oxygen enrichment time from the ignition furnace opening to the beginning is 62.78 h.

The 2 nd project repair is 2019, 4 months, 30 days, 19:16 ignition blow-in. 4, 1 day, blowing out the furnace through an empty stockline for 29 days, and replacing 176 blocks of copper cooling walls and 99 blocks of cast iron cooling walls. Due to the limitation of the time of blowing in, the furnace is raked to the average 2.59 meters below the central line of the tuyere before the furnace is blown in, and three iron openings are basically dug out (the direction of the three iron openings is 4.14 meters, 3.88 meters and 4.48 meters below the central line of the tuyere at the deepest position of digging), but are not communicated, and the furnace cylinder is about 166m³The residual coke and slag iron condensate are not removed. The self-produced dry quenching coke of the factory is only enough for 2 blast furnaces to produce. The self-production dry quenching amount of 3 blast furnaces is insufficient during the 2 nd repair blow-in, and the self-production dry quenching proportion is reduced from 100% to 55% after ignition blow-in. The difficulty of opening the furnace for the 2 nd time of project repair is greater than that of the last time.

The blast furnace blow-in of the 2 nd time repair adopts the method for quickly spraying coal and enriching oxygen for the blast furnace blow-in, the time from ignition blow-in to start of coal spraying and oxygen enrichment is 13.73 hours, the slag iron is smoothly discharged after the blast furnace is blown in, and the yield is high.

2) And the blowing-in filling material is a self-produced dry quenching full coke blowing-in furnace.

3) And the structure of the ore for opening the furnace is a structure of 84.2 percent of sinter and 15.8 percent of pellet fully-cooked material.

4) And blowing-in raw fuel quality:

the components of the raw fuel are shown in Table 1

TABLE 1 blow-in raw Fuel composition

Wherein, the raw materials such as PB blocks are not in the ingredients of the filling material, and are ingredients in the loading coal injection oxygen-enriched smelting period.

② blow-in raw material strength indexes are shown in Table 2

TABLE 2 blow-in raw Fuel Strength index

5) And measuring the filling volume of the blast furnace.

Before charging, the filling volume of the blast furnace is measured by a 3D scanner, and the total volume of the blast furnace is calculated to be 2492.2m according to the measurement results of each part³Working volume is 2182.6m³。

6) Blow-in charge filling

The blowing-in filler has a 10-section structure. The coke batch is fixed to 17 tons, the first stage material 30 batches of clean coke are totally added to the upper edge of the furnace belly, the second stage material 18 batches of empty coke are added to the position 3.4 meters below the furnace body, wherein the clean coke is 306 tons, the fluorite is 5.4 tons, the limestone is 45 tons, the dolomite is 41.4 tons, and the silica is 21.6 tons. The third to tenth sections are 30 normal batches of materials, the number of the batches is respectively as follows: 5. 5, 4, 3 and 2, wherein the ore batches are respectively as follows: 3.4t, 6.8t, 11.9t, 17t, 22.1t, 27.3t, 32.3t and 37.4t, and the O/C is respectively 0.2, 0.4, 0.7, 1.0, 1.3, 1.6, 1.9 and 2.2. And stopping filling the furnace burden after the ninth section of the material is added, wherein the material lines of the south mechanical stock rod and the north mechanical stock rod are 3.24 meters and 2.92 meters respectively, and the tenth section of the material is remained, and the ignition air supply material is added after the ignition air supply material is moved. The normal material line is set to be 1.5 meters, the coke ratio of the whole furnace is 3.82t/t, the O/C is 0.407, 440 tons of sintered ore, 82.7 tons of pellet ore, 23.3 tons of manganese ore, 14.7 tons of fluorite, 88 tons of limestone, 92.6 tons of dolomite and 78.3 tons of silica. Finally, the material distribution matrix of the 2 cans is shown in table 1.

TABLE 1 Final 2 pots of Filler distribution matrix

The strand was 3.45m, the platform width 1.1m, the funnel depth 1.4m, the funnel diameter 2.67m, and no segregation in the circumferential direction, measured according to the final charge level. Theoretically calculating that the stockline is 3.8 meters after the 9 th section of material is filled, the average stockline of the mechanical stock rod is 3.08 meters after the 9 th section of material is actually filled, and the difference between the volume of the material actually filled into the furnace and the planned filling volume is 2115-2075-40 m³The error is 1.93%.

7) 3 oxygen lances are installed on the iron notch to deliver oxygen to burn coke in the hearth and heat the hearth

Oxygen supplying is well carried out on the No. 5 and No. 6 iron mouth oxygen lances 15: 334 after 4 months and 30 days, and oxygen supplying is well carried out on the No. 5 and No. 6 iron mouths before air supplying and ignition, and coke is burnt by supplying oxygen into a furnace hearth.

8) And after ignition and air supply, the 1 st batch of normal material starts to greatly adjust the coke load to the coal injection coke load.

After ignition and air supply, after the 10 th section of the blast furnace is filled with the filling material, the coke load of the 1 st normal batch is greatly adjusted to be coal injection coke load, the coke load is adjusted to 2.933 from 2.2, and the coke ratio is reduced to 554kg/t from 728 kg/t. And then continuously increasing the coke load according to the adjustment force of 0.2-0.3 in each smelting period. The coke load adjustment after ignition blow-in is shown in tables 2 and 3:

TABLE 2 Coke load adjustment after ignition blow-in

TABLE 3 Coke load adjustment after ignition blow-in

9) Ignition blow-on process

19:16 air supply ignition blow-on in 2019, 4 month, 30 days and 823m air supply volume³And the air ports of 20: 0113 # and 15# are firstly lightened at the air temperature of 805 ℃, all the air ports of 21:00 are lightened, the coal gas explosion test of the furnace top is qualified, and the coal gas is guided successfully at 22: 27.

Adding 3:38 min of wind amount to 2711m in 1 day and 5 months³Min, 6:00 air volume has been added to 2977m³And/min. And drawing the No. 6 iron notch oxygen lance to discharge iron slag at a ratio of 6:55 in 1 day, wherein the second section of empty coke section is delivered to the hearth, the iron slag smoothly flows out and has good fluidity, mainly comprising slag and a small amount of molten iron, and the slag is blocked after 40 minutes. Slag composition: r₂＝0.87、Al₂O₃＝11.56％、MgO＝7.33％，MgO/Al₂O₃0.63; 7:36 drawing the No. 6 iron-mouth oxygen lance, smoothly tapping for 10 minutes, then plugging the mouth, wherein the slag components are as follows: r₂＝0.92、Al₂O₃12.3%, 7.9% MgO, 0.64% MgO/Al2O 3; 7:49 drawing 5# iron mouth oxygen lance, smoothly discharging slag for 2 minutes, then blocking the iron mouth by large jet, and obtaining slag component R₂＝0.94、Al₂O₃＝12.71％、MgO＝8.12％，MgO/Al₂O₃0.63. Opening the No. 6 taphole for 3 times respectively at the ratio of 8:33, 9:40 and 11:18, continuously discharging slag, and discharging a small amount of molten iron into a dry slag pit.

9:00 initial coal injection 12t/h and oxygen enrichment 2000m³H is used as the reference value. 12:10 oxygen enrichment to 3500m³/h。

13:09, arranging the No. 6 tap hole to discharge the first iron (which is different from the slag tapping link, namely the formal tapping), wherein the time from the blow-in of the furnace is 17.88 hours. At the moment, the charge is discharged into the hearth in the eighth stage, the tapping amount is 70.45 tons in 47 minutes of tapping, the temperature of the molten iron is 1400 ℃, and the molten iron [ Si ] is]＝2.62％、[Mn]＝0.71％、[S]0.009%, slag composition: r₂＝0.97、Al₂O₃＝13.85％、MgO＝8.39％，MgO/Al₂O₃When the slag iron is 0.61, the slag iron flows smoothly, the slag iron groove does not form a groove and is not slagged, the iron groove does not stick iron, and the furnace is opened successfully.

The 14:06 air quantity is added to 3454m³Permin, oxygen enrichment of 3647m³/h。

Opening the taphole at the ratio of 15:21 of the No. 2 furnace iron, delivering the filler to the hearth at the tenth section (coke load of 2.20), tapping 103.05 tons at the molten iron temperature of 1430 ℃, and discharging the molten iron [ Si]＝2.18％、[Mn]＝0.71％、[S]0.005%, slag composition: r₂＝0.97、Al₂O₃＝13.93％、MgO＝8.55％，MgO/Al₂O₃And (5) 0.61, till all the blowing-in filling materials are completely burnt through the tuyere, smoothly entering a loading coal injection oxygen-enriched smelting period. 17:51 air volume is added to 3665m³And/min. 20:15 oxygen addition 1000m³H to 5000m³/h。

5 months and 2 days with 1:00 air volume 4026m³Permin, oxygen enrichment of 5160m³H is used as the reference value. The charging material with the coke load of 2.933 (coal injection ratio of 89kg/t) is the coal injection material which is added from the 1 st batch after ignition and air supply, the produced molten iron is the 3 rd to 8 th furnaces (5 months, 1 day, 16:46 to 2 days, 3:48), and the molten iron [ Si ] is]Gradually reduced from 2.22% to 1.42%, molten iron [ Mn%]0.7% -1.06% of slag R₂1.09 to 1.12, Al₂O₃14.37-14.84% and MgO 8.81-9.06%. The temperature of the molten iron in the furnace 3 to 8 is raised to 1496 to 1515 ℃. Molten iron generated by furnace burden with coke load of 3.205 (coal injection ratio of 99kg/t) is from the 9 th furnace to the 11 th furnace (3: 56-9: 42 in 2 days), and the molten iron [ Si ] is]Gradually decrease to 1.06 percent, molten iron [ Mn%]0.87% -1.04% of slag R₂Increase to 1.22, Al₂O₃14.65-14.93%, 9.11-9.42% MgO, and 1507-1522 deg.c molten iron temperature. Molten iron generated by a charging material with a coke load of 3.418 (coal injection ratio of 101kg/t) is from the 12 th furnace to the 15 th furnace (2 days 9: 59-9: 42), and the molten iron [ Si [ [ Si ] is]Gradually decrease to 0.83%, molten iron [ Mn%]0.94% -0.96% of slag R₂Is 1.21, Al₂O₃14.54-13.99%, 9.10-9.29% of MgO, and the temperature of molten iron is 1498-1515 ℃. When tapping 13 furnaces, the molten iron contains [ Si ]]The reduction to below 1.0% is 0.96%, and the time for opening the furnace from the ignition is 40 h. Molten iron [ Si ] produced from a charge with a coke load of 3.755 (coal injection ratio of 101kg/t)]Gradually reduced to 0.6 percent, and the molten iron contains [ Mn ]]0.65%, slag R₂Is 1.25, Al₂O₃＝14.27％、MgO＝9.16Percent, molten iron temperature 1494 ℃.

3 days 2:00 air volume 4166m³Min, oxygen enrichment 5963m³H is used as the reference value. 6:00 oxygen up to 9000m³At this time, the air volume is 4658m³And/min. 10:00 air quantity added to 4751m³At/min (63 h after ignition), the oxygen enrichment was 9652m3/h, so far the air volume had been added to the full air volume. The coal injection amount and the oxygen enrichment amount 4 days before the furnace is opened are shown in Table 4.

TABLE 4 coal injection and oxygen enrichment 4 days before opening

	5 months and 1 day	5 months and 2 days	5 months and 3 days	5 months and 4 days
					Coal injection quantity (t)	175	397.8	556.9	546.8
Oxygen-rich quantity (m)3)	55348	112446	186206	252410

Yield on day 3: the blast furnace utilization coefficient is 2.1t/m³d; the yield of molten iron on day 4 is 6279 tons, and the utilization coefficient of the blast furnace is 2.46t/m³d (see table 5), the normal production level is reached, and the goal of rapidly reaching the production by opening the furnace is realized.

TABLE 5 molten iron yield 4 days before opening the furnace

Date	5 months and 1 day	5 months and 2 days	5 months and 3 days	5 months and 4 days
					Molten iron yield (t)	1021.6	2987.2	5358.3	6279.3
Blast furnace utilization factor (t/m)3d)	0.40	1.17	2.10	2.46

Therefore, by adopting the method, the coal can be injected and the oxygen can be enriched as soon as possible after the furnace is opened, the content of Si in the molten iron can be reduced rapidly and stably, the smooth operation of the furnace condition is promoted, and the condition is created for achieving the effect rapidly.