Method for improving charging ore batch of blast furnace smelting

Abstract

The invention belongs to the field of blast furnace smelting, and relates to a method for increasing blast furnace smelting charging ore batch, which can enlarge blast furnace charging ore batch, increase coal ratio and increase blast furnace daily output. According to the technical scheme, in the blast furnace smelting process, a feeding skip car circularly feeds materials to a blast furnace according to a first feeding sequence; the first feeding sequence comprises A + nB, A comprises cokes of x feeding skip cars and ores of m feeding skip cars, B comprises cokes of x feeding skip cars and ores of 2m feeding skip cars, and n represents that operation B is repeated for n times after operation A is completed in the first feeding sequence. Less than or equal to y first feeding sequences are completed within one hour, and the number of feeding skip cars for feeding the blast furnace in the y first feeding sequences is less than or equal to k. Wherein k, x, m and n are all positive integers.

Description

Technical Field

[0001] The invention belongs to the field of blast furnace smelting and relates to a method for improving ore batches fed into the blast furnace for smelting. Background Art

[0002] In the current technology, a blast furnace for iron smelting has a furnace capacity of 1080m3, and the charging method is inclined bridge and charge car charging, and the volume of the blast furnace charge car is 9.0m3. The blast furnace charging mode adopts coke ore alternating charging, for example, two cars of coke are loaded on the charge car, and then two cars of ore are loaded, and so on. The blast furnace can load up to 36 cars per hour, and the maximum daily output of the blast furnace is 4100 tons.

[0003] As the blast furnace strength increases and the coal ratio increases, problems in the blast furnace smelting process are gradually exposed: (1) The mode of alternating coke and ore loading is adopted, with the maximum ore batch feeding into the furnace being 31.0 tons / batch. The maximum daily output of the blast furnace is 4,100 tons / day, which cannot meet the demand for increasing the production of the blast furnace.

[0004] (2) The maximum ore batch that can be fed into the furnace can only be maintained at 31.0 tons / batch. However, as the coal ratio increases, the coke layer in the soft melting zone of the blast furnace becomes thinner and thinner, and the coke-ore interface effect increases, which reduces the stability of the furnace condition in the blast furnace and causes large fluctuations in the furnace condition, thus restricting the increase of the coal ratio in the blast furnace.

[0005] (3) The hourly charging speed of the blast furnace is maintained at a maximum of 9 batches / hour. Once the material preparation under the trough is slightly delayed, the blast furnace material line is prone to a shortage of material, which affects the blast furnace matrix distribution, affects the gas utilization, and causes fluctuations in the stability of the furnace condition, affecting production. Summary of the invention

[0006] In order to overcome the defects in the above-mentioned related technologies, the present invention proposes a method for increasing the ore batches fed into the blast furnace for smelting, which can expand the ore batches fed into the blast furnace, improve the coal ratio, and increase the daily output of the blast furnace.

[0007] To achieve the above technical objectives, the present invention provides a method for increasing the number of ore batches fed into a blast furnace for smelting. The blast furnace is fed with a feeding car, and the maximum feeding speed of the blast furnace is k cars / h.

[0008] The method for improving the ore batches fed into the blast furnace for smelting includes: during the blast furnace smelting process, the charging car cyclically charges the blast furnace in a first charging sequence. The first charging sequence includes: A+nB, wherein A includes coke from x charging cars and ore from m charging cars, B includes coke from x charging cars and ore from 2m charging cars, and n means that in the first charging sequence, after completing operation A, operation B is repeated n times. Less than or equal to y first charging sequences are completed within one hour, and the number of charging cars for charging the blast furnace in the y first charging sequences is less than or equal to k. Wherein, k, x, m, and n are all positive integers.

[0009] Preferably, the method for improving the ore batches entering the blast furnace for smelting also includes: controlling the loading car to complete g first loading sequences within one hour, wherein g is less than or equal to y, and when the loading car completes greater than or equal to g first loading sequences within one hour, the thickness of the coke layer at the throat of the blast furnace is maintained at Q.

[0010] Preferably, the method for improving the ore batch entering the blast furnace for smelting also includes: completing g first loading sequences according to the loading vehicle within one hour, obtaining the mass of coke added to the blast furnace per hour, and controlling the air volume entering the blast furnace according to the mass of coke added to the blast furnace per hour.

[0011] Preferably, according to the air volume entering the blast furnace, the cross-sectional area of ​​the air inlet is controlled so that the wind speed at the air inlet entering the blast furnace is greater than or equal to 255 m / s.

[0012] Preferably, the combustion temperature of the blast furnace is adjusted so that the temperature of the tuyere of the blast furnace is between 2340°C and 2370°C.

[0013] Preferably, the method for increasing the ore batch for blast furnace smelting further comprises: gradually increasing the mass of coke or ore in the charging car every day, and counting the daily molten steel output of smelting, when the ratio of the daily molten steel output to the mass of coke or ore in the corresponding charging car is the largest, the mass of coke or ore in the charging car is the optimal amount. The charging car adds coke or ore in the optimal amount.

[0014] The beneficial effects of the present invention are: The present invention improves the blast furnace coal ratio, increases the ore input per unit time of the blast furnace, and improves the steelmaking output by adjusting the feeding method of coke and ore under the premise that the feeding car and the feeding mechanism remain unchanged.

[0015] The present invention adopts the first charging sequence, which can stabilize the coke layer thickness in the blast furnace, increase the ore layer thickness, reduce the number of coke and ore layers, reduce the coke-ore interface effect, and improve the stability of the furnace condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A flow chart of the present invention; Figure 2 Another flow chart of the present invention. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0019] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0021] like Figure 1 As shown, some embodiments of the present invention provide a method for increasing the ore batches fed into a blast furnace for smelting. The blast furnace is fed with a charging car, and the maximum feeding speed of the blast furnace is k cars / h.

[0022] The method for improving the ore batch entering the blast furnace for smelting comprises: S1. During the blast furnace smelting process, the charging car cyclically charges the blast furnace in the first charging sequence.

[0023] S2. The first loading sequence includes: A+nB, wherein A includes the coke from x loading cars and the ore from m loading cars, B includes the coke from x loading cars and the ore from 2m loading cars, and n means that in the first loading sequence, after completing operation A, operation B is repeated n times.

[0024] S3. Complete less than or equal to y first loading sequences within one hour, and the number of loading vehicles for loading the blast furnace in the y first loading sequences is less than or equal to k.

[0025] Among them, k, x, m, and n are all positive integers.

[0026] For example, a loading vehicle has a volume of 9m 3 Due to the limitations of the feeding machinery and equipment, the blast furnace can be fed with 36 loaders per hour, that is, k can be 36.

[0027] The first loading sequence includes A+nB, A can be the coke from two of the loading cars, B can be the coke from two of the loading cars and the ore from four of the loading cars, that is, x can be 2, and m can be 2.

[0028] The first charging sequence can be A+2B, that is, n can be 2, that is, the first charging sequence can be to add the following sequence to the blast furnace: one charging carload of coke, one charging carload of coke, one charging carload of ore, one charging carload of ore; one charging carload of coke, one charging carload of coke, one charging carload of ore, one charging carload of ore, one charging carload of ore, one charging carload of ore; one charging carload of coke, one charging carload of coke, one charging carload of ore, one charging carload of ore, one charging carload of ore, one charging carload of ore. In this way, the blast furnace is cyclically charged using the first charging sequence.

[0029] Or n can be 3, x can be 2, and m can be 2; the first loading order is A+3B, wherein A represents the coke from 2 of the loading cars and the ore from 2 of the loading cars, and B includes the coke from 2 of the loading cars and the ore from 4 of the loading cars.

[0030] That is to say, the first charging sequence can be to add the following sequence to the blast furnace: one charging carload of coke, one charging carload of coke, one charging carload of ore, and one charging carload of ore; one charging carload of coke, one charging carload of coke, one charging carload of ore, one charging carload of ore, one charging carload of ore, and one charging carload of ore. Stone; one loading car of coke, one loading car of coke, one loading car of ore, one loading car of ore, one loading car of ore, one loading car of ore; one loading car of coke, one loading car of coke, one loading car of ore, one loading car of ore, one loading car of ore, one loading car of ore. In this way, the blast furnace is cyclically charged using the first charging sequence.

[0031] In the present application, the blast furnace can adopt an inclined bridge type loading machine, which includes: an inclined bridge, a loading car and a winch, and the winch drives the loading car to lift coke or ore from the ground to the top of the blast furnace and load it into the blast furnace. The process of completing less than or equal to y first loading sequences within one hour can be that the loading car is driven by the winch to smoothly load the blast furnace according to the first loading. Of course, it is understandable that in order to ensure the stability of the furnace condition during the blast furnace smelting process, when the loading car completes y first loading sequences within one hour, the number of loading cars should be evenly distributed within one hour.

[0032] When the first loading sequence is A+2B, and A is coke from two of the loading cars, and B is coke from two of the loading cars and ore from four of the loading cars, the first loading sequence includes 10 loading cars. When the blast furnace is loaded by loading cars, the loading cars per hour are less than or equal to 36, that is, y first loading sequences can be completed for the blast furnace within one hour, and y is less than or equal to 3.6.

[0033] Preferably, the method for improving the ore batches entering the blast furnace for smelting also includes: controlling the loading car to complete g first loading sequences within one hour, wherein g is less than or equal to y, and when the loading car completes greater than or equal to g first loading sequences within one hour, the thickness of the coke layer at the throat of the blast furnace is maintained at Q.

[0034] The blast furnace capacity is 1080m 3 , the thickness of the coke layer at the throat of the blast furnace is maintained at 560mm~580mm, which can keep the furnace condition in the blast furnace stable. After experiments, when the loading car keeps the loading car rate at 32.5 cars / hour~32.9 cars / hour, the thickness of the coke layer at the throat of the blast furnace is maintained at 560mm~580mm, the loading car rate of the loading car is less than 32.5 cars / hour, the thickness of the coke layer at the throat of the blast furnace is lower than 560mm, and the loading car rate of the loading car is greater than 32.9 cars / hour, the thickness of the coke layer at the throat of the blast furnace is higher than 580mm. That is to say, for a furnace capacity of 1080m 3 For the blast furnace, the thickness of the coke layer at the throat of the blast furnace is maintained at Q, and Q is the range value: 560mm~580mm. The charging car maintains a loading rate of 32.5 cars / hour~32.9 cars / hour. The charging car completes g first loading sequences within one hour, and g is 3.25~3.29.

[0035] Preferably, the method for improving the ore batch entering the blast furnace for smelting also includes: completing g first loading sequences according to the loading vehicle within one hour, obtaining the mass of coke added to the blast furnace per hour, and controlling the air volume entering the blast furnace according to the mass of coke added to the blast furnace per hour.

[0036] In the present application, the mass of coke or ore loaded in each loading car is fixed, and the loading car number of the loading car in one hour can be calculated according to the first loading sequence. For example, if x is 2, m is 2, and n is 2, it can be known that the first loading sequence includes coke from six loading cars. When g first loading sequences are completed in one hour, the mass of coke from six loading cars, which is g times the mass of coke added to the blast furnace in one hour, can be obtained.

[0037] The blast furnace includes an air inlet device, which includes a plurality of blowers and a blast furnace tuyere, the blowers are connected to the blast furnace tuyere, and the blast furnace tuyere is connected to the inside of the blast furnace. There are many ways to control the amount of air entering the blast furnace, among which it can be adjusted by controlling the number and working power of the blowers, or by controlling the area of ​​the blast furnace tuyere.

[0038] Preferably, according to the air volume entering the blast furnace, the cross-sectional area of ​​the air inlet is controlled so that the wind speed at the air inlet entering the blast furnace is greater than or equal to 255 m / s.

[0039] The product of the wind speed at the tuyere of the blast furnace and the cross-sectional area of ​​the air inlet is the air intake volume of the blast furnace per unit time. That is to say, when the air intake volume per unit time of the blast furnace and the cross-sectional area of ​​the air inlet are known, the wind speed at the tuyere of the blast furnace can be calculated.

[0040] For example: the ratio of the hourly air intake of a blast furnace to the cross-sectional area of ​​the air inlet is the hourly wind speed at the tuyere of the blast furnace. The wind speed per second at the tuyere of the blast furnace can be obtained by converting the time unit.

[0041] Under the premise that the air volume entering the blast furnace is determined, the cross-sectional area of ​​the air inlet can be controlled to adjust the wind speed at the blast furnace tuyere. Of course, the reduction or increase of the cross-sectional area of ​​the air inlet will inevitably affect the air volume entering the blast furnace. The air volume can be compensated by adjusting the power of the blower. The specific compensation method belongs to the conventional technical means of those skilled in the art and will not be elaborated here.

[0042] The loading car frequency is maintained at 32.5 cars / hour to 32.9 cars / hour, and the mass of coke added to the blast furnace per hour is reduced. In order to make the hearth of the blast furnace active, the blast furnace tuyere wind speed should be greater than or equal to 255m / s. In the present application, the mass of coke added to the blast furnace per hour is substantially reduced. In order to ensure the blast furnace tuyere wind speed, the blast furnace tuyere area can be reduced to increase the tuyere wind speed to meet the requirement that the wind speed at the tuyere entering the blast furnace is greater than or equal to 255m / s.

[0043] For example, after adopting the first charging sequence, the blast furnace air volume can be 3050m 3 / min or more, the blast furnace tuyere wind speed ≥255m / s, the previous 11 Φ115 tuyere and 9 Φ110 tuyere can be adjusted to 11 Φ110 tuyere and 9 Φ115 tuyere. The tuyere area is increased from 0.1997m 2 Shrink to 0.1979m 2 , ensure that the wind speed at the blast furnace tuyere is greater than or equal to 255m / s.

[0044] Preferably, the combustion temperature of the blast furnace is adjusted so that the temperature of the tuyere of the blast furnace is between 2340°C and 2370°C.

[0045] Preferably, if Figure 2 As shown, the method for improving the ore batch entering the blast furnace for smelting also includes: S4. The mass of the coke or ore in the charging car is gradually increased every day, and the daily molten steel output is counted. When the ratio of the daily molten steel output to the mass of the coke or ore in the corresponding charging car is the largest, the mass of the coke or ore in the charging car is the optimal amount. The charging car adds coke or ore in the optimal amount.

[0046] In other embodiments of the present application except for this embodiment, the mass of coke or ore loaded in the charging car is 31 tons. After adopting the first charging sequence, the mass of the charging car can be gradually increased under the premise of ensuring stable generation. For example, the mass of coke or ore loaded in the charging car can be 44 tons, 45 tons, 46 tons, 47 tons, 48 ​​tons, 49 tons and 50 tons, and the daily output of the blast furnace under different loading amounts of the charging car is obtained. When the ratio of the daily output of the blast furnace to the loading amount of the charging car is the largest, the optimal loading amount of the charging car can be obtained. At this loading amount, the output ratio of the blast furnace is the largest.

[0047] The air volume entering the blast furnace changes adaptively with the different loading amounts of the charging car. Estimating the air volume entering the blast furnace based on the amount of coke is a technical means well known to those skilled in the art and will not be elaborated here.

[0048] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0049] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for increasing the ore batches fed into a blast furnace for smelting, wherein the blast furnace is fed with a feeding car, and the maximum feeding speed of the blast furnace is k cars / h, characterized in that: The method for improving the ore batch entering the blast furnace for smelting comprises: During the blast furnace smelting process, the charging car cyclically charges the blast furnace in the first charging sequence; The first loading sequence includes: A+nB, wherein A includes the coke from x loading carts and the ore from m loading carts, B includes the coke from x loading carts and the ore from 2m loading carts, and n means that in the first loading sequence, after completing operation A, operation B is repeated n times; Complete less than or equal to y first loading sequences within one hour, and the number of loading vehicles for loading the blast furnace in the y first loading sequences is less than or equal to k; Among them, k, x, m, and n are all positive integers.

2. The method for improving the ore batch for blast furnace smelting according to claim 1, characterized in that: The method for improving the ore batches entering the blast furnace for smelting also includes: controlling the loading car to complete g first loading sequences within one hour, wherein g is less than or equal to y, and when the loading car completes greater than or equal to g first loading sequences within one hour, the thickness of the coke layer at the throat of the blast furnace is maintained at Q.

3. The method for improving the ore batch for blast furnace smelting according to claim 2, characterized in that: The method for improving the ore batch entering the blast furnace for smelting also includes: According to the loading vehicle completing g first loading sequences within one hour, the mass of coke added into the blast furnace per hour is obtained, and the air volume entering the blast furnace is controlled according to the mass of coke added into the blast furnace per hour.

4. The method for improving the ore batch for blast furnace smelting according to claim 3, characterized in that: According to the air volume entering the blast furnace, the cross-sectional area of ​​the air inlet is controlled so that the wind speed at the air inlet entering the blast furnace is greater than or equal to 255m / s.

5. The method for improving the ore batch for blast furnace smelting according to claim 4, characterized in that: The combustion temperature of the blast furnace is adjusted so that the temperature of the tuyere of the blast furnace is between 2340°C and 2370°C.

6. The method for improving the ore batch for blast furnace smelting according to claim 5, characterized in that: The method for improving the ore batch entering the blast furnace for smelting also includes: The quality of the coke or ore in the loading car is gradually increased every day, and the daily molten steel output is counted. When the ratio of the daily molten steel output to the quality of the coke or ore in the corresponding loading car is the largest, the quality of the coke or ore in the loading car is the optimal amount; The charging car adds coke or ore in optimum amounts.

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