A method for regulating stable smelting of a blast furnace

Abstract

The present application provides a kind of blast furnace stable smelting regulating method, comprising: detecting the stability of blast furnace, and obtaining the proportion of silicon in blast furnace molten iron;The proportion of silicon in blast furnace molten iron is less than or equal to 0.3%, it is determined that the comprehensive load of blast furnace is increased, reduce the speed of ore batch feeding, or increase the proportion of ore batch coke;The proportion of silicon in blast furnace molten iron is greater than 0.5%, it is determined that the working condition of blast furnace is stable, speed up the feeding speed, or reduce the proportion of ore coke;The proportion of silicon in blast furnace molten iron is greater than 0.3% and less than or equal to 0.5%, it is determined that the working condition of blast furnace is stable, stabilize the feeding speed and stabilize the proportion of ore coke, the beneficial effects brought by the technical scheme in the present application include at least: by the proportion of silicon in blast furnace molten iron, the load level in blast furnace is determined, the working condition of blast furnace is predicted in advance, the situation of blast furnace energy overflow is avoided, the efficiency of generation can be improved, at the same time, it can be known in advance that the load of blast furnace is too large, the problem of causing blast furnace ore fluctuation, recovery difficulty and long recovery time is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of iron-making blast furnace, in particular to a kind of blast furnace stable smelting adjustment method. BACKGROUND

[0002] The steel plate is used as the furnace shell of the iron-making shaft furnace, and the refractory brick lining is built in the shell. The blast furnace body is divided into five parts from top to bottom, i.e. the furnace throat, the furnace shaft, the furnace waist, the furnace belly and the furnace hearth. Because of the good technical and economic indicators of the blast furnace iron-making technology, simple process, large production capacity, high labor productivity and low energy consumption, etc., the iron produced by this method accounts for a large part of the total iron output in the world.

[0003] During the production of the blast furnace, iron ore, coke and flux (limestone) for slagging are charged from the top of the furnace, and preheated air is blown into the tuyere located at the lower part of the furnace along the circumference of the furnace. At high temperatures, the carbon in the coke (some blast furnaces also spray coal powder, heavy oil, natural gas and other auxiliary fuels) burns with the oxygen in the air to generate carbon monoxide and hydrogen, which removes the oxygen in the iron ore during the upward process in the furnace, thereby reducing the iron. The molten iron is discharged from the iron tap hole.

[0004] The un-reduced impurities in the iron ore and the flux such as limestone combine to form slag, which is discharged from the slag tap hole. The generated coal gas is discharged from the top of the furnace and used as fuel for hot blast furnaces, heating furnaces, coke ovens and boilers after dust removal. The main product of blast furnace smelting is pig iron, and the by-products are blast furnace slag and blast furnace gas.

[0005] The blast furnace production is in a state of tension in terms of raw and fuel materials, and the quality fluctuates frequently. The thermal load fluctuates frequently, and the slag skin is frequently dropped. This makes the blast furnace unable to run stably for a long time or the technical and economic indicators of the blast furnace production are poor. Each time the furnace condition fluctuates, it is difficult to recover, a large amount of coke needs to be added, and a long recovery time is needed, which directly affects the production capacity and technical and economic indicators of the blast furnace production. The traditional technology is to analyze the causes of the abnormality after the blast furnace is abnormal. SUMMARY

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a kind of blast furnace stable smelting adjustment method, to solve the problems of furnace condition fluctuation, difficult recovery, the need to add a large amount of coke, and the need for a long recovery time in the prior art, which directly affects the production capacity and technical and economic indicators of the blast furnace production.

[0007] To achieve the above-mentioned purpose and other related purposes, the present application provides a kind of blast furnace stable smelting adjustment method, comprising:

[0008] detecting the stability of the blast furnace, and obtaining the proportion of silicon in the blast furnace molten iron;

[0009] if the proportion of silicon in the blast furnace molten iron is less than or equal to 0.3%, it is determined that the comprehensive load of the blast furnace is increased, and the mineral batch feeding speed is reduced or the mineral batch coke proportion is increased.

[0010] If the proportion of silicon in the molten iron of the blast furnace is greater than 0.5%, the blast furnace is considered to be operating stably. In this case, the feeding speed should be increased or the proportion of ore and coke should be reduced.

[0011] If the proportion of silicon in the molten iron of the blast furnace is greater than 0.3% and less than or equal to 0.5%, the blast furnace is considered to be operating stably, with stable feeding rate and stable ore-coke ratio.

[0012] Optionally, the adjustment method further includes:

[0013] If external factors affect the blast furnace operating conditions, the proportion of raw materials and fuels should be monitored and appropriate adjustments made.

[0014] Optionally, when the quality of raw materials fluctuates, load reduction or batch withdrawal can be implemented to control the pressure differential.

[0015] Optionally, if the blast furnace pressure is too tight and full ventilation cannot be maintained, the gas pipes can be diverted, or the ore batch can be withdrawn, or the load can be reduced.

[0016] Optionally, when gas utilization and furnace temperature fluctuate significantly, the air volume should be controlled to be 50-150 Nm lower than the normal air volume. 3 / min.

[0017] Optionally, for sinter with FeO ≤ 7 or FeO ≥ 11.5, increase the fuel ratio by 10-15 kg / t Fe based on the furnace temperature.

[0018] Alternatively, if 2500 m 3 The physical heat of molten iron in the blast furnace is below 1490℃. The proportion of raw coal is increased by 5-8 kg / t·Fe, and the load is reduced by 0.05-0.1 t / t.

[0019] If 1750m 3 The physical heat of molten iron in the blast furnace is below 1480℃, the proportion of raw coal is increased by 5-8 kg / t·Fe, and the load is reduced by 0.05-0.1 t / t.

[0020] Alternatively, if 2500m 3 If the physical heat of molten iron in the blast furnace remains below 1490℃, the blast volume will be reduced to 200 Nm³. 3 / min, oxygen enrichment reduced by 5000-8000 Nm 3 / h, while simultaneously reducing the load by 0.1-0.15t / t;

[0021] If 1750m 3 If the physical heat of molten iron in the blast furnace remains below 1480℃, the blast volume will be reduced to 200 Nm³. 3 / min, oxygen enrichment reduced by 5000-8000 Nm 3 / h, while simultaneously reducing the load by 0.1-0.15t / t.

[0022] Optionally, the cooling wall heat load fluctuation: cooling wall water temperature difference increases 1℃, the fuel ratio increases 5-10kg / t·Fe; the cooling wall water temperature difference increases 2℃ or more and the silicon proportion in molten iron is less than 0.3%, and 10-15 tons of clean coke is added, while the material speed is controlled to be 1 to 2 batches lower than the normal material speed, and the lower limit of oxygen enrichment is 8000Nm 3 / h.

[0023] Optionally, if 2500m 3 The average coal ratio of the blast furnace is higher than or equal to 170kg / t·Fe, and the furnace temperature is not up to standard, and the load is reduced.

[0024] If 1750m 3 The average coal ratio of the blast furnace is higher than or equal to 165kg / t·Fe, and the furnace temperature is not up to standard, and the load is reduced.

[0025] As described above, the technical scheme in the present application brings at least the following beneficial effects: by determining the load level in the blast furnace according to the proportion of silicon in the molten iron in the blast furnace, the working condition of the blast furnace is predicted in advance, the situation of energy overflow of the blast furnace is avoided, the efficiency of generation is improved, and the problem of causing blast furnace ore fluctuation and difficulty in recovery and long recovery time is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A flowchart of the adjusting method for stable smelting of a blast furnace according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0027] The embodiments of the present application will be described in detail with specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied in different specific embodiments, and various modifications or changes can be made to the details in the specification without departing from the spirit of the present application.

[0028] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present application, and the diagrams only show the components related to the present application, not the number, shape and size of the components when actually implemented. The actual implementation of each component may be arbitrarily changed in type, number and proportion, and the component layout pattern may be more complex.

[0029] Figure 1 A flowchart of the adjusting method for stable smelting of a blast furnace according to an exemplary embodiment of the present application is shown. Please refer to Figure 1 The present application provides an adjusting method for stable smelting of a blast furnace, comprising:

[0030] Step 110, detecting the stability of the blast furnace and obtaining the proportion of silicon in the molten iron of the blast furnace;

[0031] Step 120, judging the proportion of silicon in the molten iron;

[0032] Step 130, if the proportion of silicon in the molten iron of the blast furnace is less than or equal to 0.3%, it is determined that the comprehensive load of the blast furnace is heavy, and the feeding speed of the ore batch is reduced or the proportion of coke in the ore batch is increased;

[0033] Step 140, if the proportion of silicon in the molten iron of the blast furnace is greater than 0.5%, it is determined that the working condition of the blast furnace is stable, and the feeding speed is increased or the proportion of coke in the ore is reduced;

[0034] Step 150, if the proportion of silicon in the molten iron of the blast furnace is greater than 0.3% and less than or equal to 0.5%, it is determined that the working condition of the blast furnace is stable, and the feeding speed and the proportion of coke in the ore are stable.

[0035] In an embodiment of the present application, specifically, the adjusting method further comprises: if the blast furnace working condition is caused by external factors, detecting the proportion of raw fuel and making corresponding adjustment.

[0036] When the quality of raw fuel fluctuates, the load is reduced or the ore batch is reduced to control the pressure difference, specifically:

[0037] 1. Coke quality: M40 ≤ 85.5 or M10 ≥ 6.8 or CSR ≤ 63 or CRI ≥ 29:

[0038] ① Reduce the coke load by 0.2 to 0.5 t / t;

[0039] ② Reduce the ore batch by 2 to 4 t;

[0040] ③ Control the pressure difference to be 5 to 10 kPa lower than normal;

[0041] ④ Increase the silicon control standard in molten iron by 0.3% to 0.5%.

[0042] 2. Sinter RDI+3.15 ≤ 55:

[0043] ① Reduce the coke load by 0.2 t / t;

[0044] ② Reduce the ore batch by 2 to 4 t;

[0045] ③ Control the pressure difference to be 5 to 10 kPa lower than normal.

[0046] 3. Sinter drum strength ≤ 76.5:

[0047] ① Reduce the coke load by 0.2 t / t;

[0048] ② Reduce the ore batch by 2 to 4 t;

[0049] ③ Control the pressure difference 5 to 10 kPa lower than normal.

[0050] 4. The average particle size of sintered ore into the furnace is ≤15;

[0051] ① Reduce the coke load by 0.2 t / t;

[0052] ② Remove 2 to 4 t of ore;

[0053] ③ Increase the frequency of checking the material under the tank, once every 4 hours.

[0054] 5. The Al2O3 content of sintered ore is ≥2.4;

[0055] ① Control the magnesium-aluminum ratio of slag to 0.55 to 0.6, and if necessary, add serpentine under the blast furnace tank;

[0056] ② Remove 2 to 4 t of ore;

[0057] ③ Increase the [Si] control standard in molten iron by 0.3% to 0.5%, and the physical heat of molten iron is >1500℃;

[0058] ④ The charging system is appropriately loose at the edge and center, and the overall reduction of ore and coke is recommended by 0.5°, and if necessary, add half a circle of medium coke.

[0059] In an embodiment of the present application, specifically, if the blast furnace pressure volume relationship is tight, and full wind cannot be maintained for 4 hours continuously, the gas pipe is dredged or the ore batch is removed or the load is removed.

[0060] In an embodiment of the present application, specifically, when the gas utilization rate and the furnace temperature fluctuate greatly, the wind volume can be controlled to be 50-150 Nm 3 / min lower than the normal wind volume to stabilize the furnace temperature and dredge the gas.

[0061] In an embodiment of the present application, specifically, when the FeO content in sintered ore is ≤7 or ≥11.5: according to the furnace temperature basis, increase the fuel ratio by 10-15 kg / t·Fe.

[0062] If the physical heat of molten iron in a 2500 m 3 high blast furnace is lower than 1490℃, increase the raw coal ratio by 5-8 kg / t·Fe, and remove the load by 0.05-0.1 t / t;

[0063] If the physical heat of molten iron in a 1750 m 3 high blast furnace is lower than 1480℃, increase the raw coal ratio by 5-8 kg / t·Fe, and remove the load by 0.05-0.1 t / t.

[0064] If the physical heat of molten iron in a 2500 m 3 high blast furnace is continuously lower than 1490℃, the wind volume is 200 Nm 3 / min, reduce oxygen enrichment 5000-8000Nm 3 / h, while reducing load 0.1-0.15t / t;

[0065] If 1750m 3 If the physical heat of molten iron in the blast furnace is continuously lower than 1480℃, the air volume is up to 200Nm 3 / min, reduce oxygen enrichment 5000-8000Nm 3 / h, while reducing load 0.1-0.15t / t.

[0066] Cooling wall heat load fluctuation: increase fuel ratio by 5 to 10 kg / t·Fe when cooling wall water temperature difference increases by 1℃; increase clean coke by 10 to 15 tons when cooling wall water temperature difference increases by more than 2℃ and silicon content in molten iron is lower than 0.3%, while controlling the material speed to be lower than the normal material speed by 1 to 2 batches, and the lower limit of oxygen enrichment is 8000Nm 3 / h.

[0067] If 2500m 3 If the average coal ratio of the blast furnace is higher than or equal to 170kg / t·Fe and the furnace temperature is not up to standard, reduce the load, and if 1750m 3 If the average coal ratio of the blast furnace is higher than or equal to 165kg / t·Fe and the furnace temperature is not up to standard, reduce the load, and if the furnace temperature is within the specified range for one smelting period, adjust the coal gas as appropriate.

[0068] When the comprehensive load has a significant increasing trend and [Si] is at the upper limit, consider measures to dredge coal gas to stabilize the comprehensive load when the total air rate decreases.

[0069] FeO in sinter ≤7 or ≥11.5: increase fuel ratio by 10 to 15 kg / t·Fe according to the furnace temperature basis.

[0070] If [Si] in molten iron is continuously lower than 0.3% for one smelting period and does not reach the specified range, increasing the injection amount to raise the temperature may affect the smooth running, so consider adding coke to reduce the load or (and) the ore batch.

[0071] The above examples are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method of regulating the stable smelting of a blast furnace, characterized in that, Comprise: Detect the stability of the blast furnace, and obtain the proportion of silicon in the molten iron of the blast furnace; If the proportion of silicon in the molten iron of the blast furnace is less than or equal to 0.3%, it is determined that the comprehensive load of the blast furnace is heavy, and the feeding speed of the ore batch is reduced or the proportion of ore batch coke is increased; If the proportion of silicon in the molten iron of the blast furnace is greater than 0.5%, it is determined that the working condition of the blast furnace is stable, and the feeding speed is increased or the proportion of ore coke is reduced; If the proportion of silicon in the molten iron of the blast furnace is greater than 0.3% and less than or equal to 0.5%, it is determined that the working condition of the blast furnace is stable, and the feeding speed and the proportion of ore coke are stable; When the quality of raw fuel fluctuates, the load or ore batch is reduced to control the pressure difference; If the blast furnace pressure volume relationship is tight and cannot maintain full wind, the gas pipe is dredged or the ore batch is reduced or the load is reduced; If 2500 m 3 The physical heat of the blast furnace molten iron is lower than 1490℃, the proportion of raw material coal is increased by 5-8 kg / t·Fe, and the load is reduced by 0.05-0.1 t / t. If 1750 m 3 The physical heat of the blast furnace molten iron is lower than 1480℃, the proportion of raw material coal is increased by 5-8 kg / t·Fe, and the load is reduced by 0.05-0.1 t / t. If 2500m 3 The physical heat of the blast furnace iron is continuously lower than 1490℃, the air volume is up to 200Nm 3 / min, the oxygen is reduced by 5000-8000Nm 3 / h, and the load is reduced by 0.1-0.15t / t simultaneously. If 1750 m 3 The physical heat of the blast furnace iron is continuously lower than 1480℃, the air volume is up to 200 Nm 3 / min, the oxygen is reduced by 5000-8000 Nm 3 / h, and the load is reduced by 0.1-0.15 t / t simultaneously. Cooling wall heat load fluctuation: the cooling wall water temperature difference increases by 1℃, the fuel ratio increases by 5-10 kg / t·Fe; the cooling wall water temperature difference increases by more than 2℃ and the silicon content in molten iron is less than 0.3%, add 10-15 tons of clean coke, and control the material speed to be 1 to 2 batches lower than the normal material speed, and the lower limit of rich oxygen is 8000 Nm 3 / h.

2. The adjusting method for stable smelting of a blast furnace according to claim 1, characterized in that: When the gas utilization rate and the furnace temperature fluctuate greatly, the air volume is controlled to be 50-150 Nm 3 / min lower than the normal air volume.

3. The adjusting method for stable smelting of a blast furnace according to any one of claims 1-2, characterized in that: If FeO in the sinter is less than or equal to 7% or greater than or equal to 11.5%, the fuel ratio is increased by 10-15 kg / t·Fe based on the furnace temperature.

4. The adjusting method for stable smelting of a blast furnace according to claim 1, characterized in that: If 2500 m 3 If the average coal ratio of the blast furnace is higher than or equal to 170 kg / t·Fe and the furnace temperature still does not meet the standard, the load is reduced. If 1750 m 3 If the average coal ratio of the blast furnace is higher than or equal to 165 kg / t·Fe and the furnace temperature still does not meet the standard, the load is reduced.

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