JPS63140007A - Method for charging raw material into bell type blast furnace - Google Patents

Abstract

PURPOSE:To stabilize blast furnace operation without requiring new devices and intensification of control sequence by segmenting and depositing main raw materials and different raw materials to a laminar state on a large bell, then charging said raw materials into a blast furnace at the time of charging the main raw materials and different raw material into the furnace. CONSTITUTION:The main raw materials which are ore, sintered ore pellets and coke and the different raw materials which are different in component or characteristic from the main raw materials are charged into the blast furnace. The main raw materials and different raw materials are segmented and laminated to the stepped layer state on the large bell and after the above-mentioned different raw materials are laminated on the prescribed position, the large bell is opened to charge the raw materials into the furnace. The distribution in the in-furnace radial direction of the raw materials after charging into the furnace has the specific pattern according to the position of the step layer of the raw materials to be laminated on the large bell. The main raw materials and different raw material are, therefore, distributed and charged to the desired position in the furnace. Since an operation for intentionally forming ruggedness on the surface of the deposits in the furnace prior to charging different raw materials into the furnace is not carried out, the weight ratio distribution of the ore and the coke does not degrade. Also since there is no need for increasing the number of the batches for charging to the large bell in order to charge the different raw material, the need for providing the intricate charging sequence is eliminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for charging different types of raw materials into a bell type blast furnace. Specifically, the present invention relates to a method for charging different types of raw materials into a bell-type blast furnace. The present invention relates to a method for charging raw materials into a blast furnace that can accurately control the distribution of raw materials in the radial direction within the furnace.

[Conventional technology and problems]

In blast furnace operation, raw materials such as ore, sintered ore, or pellets and coke are alternately charged into the furnace from furnace m, and
Pig iron is produced by blowing hot air through the tuyeres to reduce and melt raw materials.

The charging of the raw materials and the like will be explained using FIG. 5. First, the raw material (2) conveyed to the m section of the furnace by the belt conveyor (1) is temporarily stored in a fixed hopper (3).

The raw material is then uniformly charged onto the small bell (6) via the seal valve (4) and the rotating chute (2).

Next, the raw material ■ is passed through a small bell (
6) is opened and dropped onto the thick bell (8). Furthermore, when the level of the charge reaches a predetermined stock level in the blast furnace,
The large bell (8) is opened by operating the large bell rod (9), and the raw material (2) on the large bell (8) is charged into the blast furnace. At that time, operate the movable armor (1) and move the raw material (2).
The distribution of raw materials in the radial direction in the furnace is controlled by controlling the falling position of the raw materials in the furnace.

Now, the main object of charge distribution control in a blast furnace is the ff1ffi ratio distribution (hereinafter referred to as O/C) of ore and coke in the radial direction within the furnace. However, in recent blast furnace operations, there are strong demands for the use of inexpensive raw materials, stable production of high-quality pig iron, and flexible pig iron production ratios. In order to meet this requirement, along with the main raw materials (here iron source raw materials and coke),
The main raw materials and ingredients, or properties (excluding ingredients here)
Various methods have been proposed in which different types of raw materials with different particle sizes, strength, softening and fusion properties, reactivity, etc. are charged together.

For example, the methods disclosed in JP-A-59-150003 and JP-A-61-56212 use auxiliary raw materials such as limestone or silica stone to adjust the basicity of the ore. The methods disclosed in Japanese Patent Application Laid-open No. 150003 and Japanese Patent Application Laid-Open No. 61-15904 deposit sintered ores having different basicities at different positions in the radial direction of the furnace.

Also, JP-A-55-28308 and JP-A-55
The method disclosed in Japanese Patent No. 62106 is called a grain-size charging method, and is a charging method in which sintered ore or coke of different grain sizes are deposited at different positions in the furnace.

By the way, in the above-mentioned method for charging different materials into a blast furnace,
The important points are as follows. That is, (a) it is possible to accurately charge the material into the desired position in the furnace.

(b) O/C distribution controllability in the radial direction within the furnace is not deteriorated by charging different types of raw materials.

That's true. Conventionally, the following methods have been employed to achieve the above (a) and (b).

(1) A method of charging different AA materials in different batches.

For example, JP-A No. 55-283085;
As in JP-A-132106 and JP-A-61-56212, when charging different U raw materials, a movable armor is operated, and by this operation, the different kinds of raw materials can be distributed at desired positions in the furnace. However, due to the accumulation of different materials OD as shown in FIG. 6, new irregularities are formed on the charging surface, which deteriorates the O/C distribution control in the radial direction within the furnace. Additionally, in general, the charging amount of different a raw materials is at most 30% of the main raw material, and if a new batch is created for different raw materials and a movable armor is operated, the raw material charging sequence becomes extremely difficult. It becomes complicated.

■Method of charging different raw materials in the same batch as the main raw material.

This method has different main ingredients! It is possible to grasp in advance the change in the particle size of the raw material discharged from the bell over time, as in the mixed charging method in which the raw material is mixed with the IT material before charging into the furnace and then charged, as in JP-A-60-174808. Based on this, we tried to operate the movable armor over time during raw material charging to deposit raw materials with different particle sizes at different positions in the radial direction inside the furnace, and also to control the O/C distribution. It is something to do.

These methods do not adversely affect radial O/C distribution control. However, the mixed charging method requires a mixing operation of the raw materials, and the premixing operation is usually performed at the time of cutting the raw materials from the raw material storage tank to the charging conveyor. In the process of transporting the raw materials, the mixed raw materials are reclassified and cannot necessarily be charged into the furnace in a uniformly mixed state. Also, JP-A-60-1
The method of Japanese Patent No. 74808 requires a complicated charging sequence of controlling the movable armor over time. As mentioned above, the conventional method of charging different types of raw materials cannot be said to fully satisfy the above (a) and (b), and also requires a complicated charging sequence in terms of cleaning efficiency. There was a problem.

[Means for solving problems]

The present invention addresses the above two important points when charging different types of raw materials into a blast furnace: (a) Different! 1 Raw material can be charged to a desired position in the furnace.

(b) The radial direction inside the furnace due to the charging of different materials. 70 Distribution controllability does not deteriorate.

This was obtained as a result of numerous tests using a 1/7 scale model of the top of a blast furnace to determine what measures should be taken to achieve this.

That is, when charging raw materials into a bell-type blast furnace, the present invention combines ore, sintered ore pellets, and coke (hereinafter referred to as main raw materials) and raw materials with different components or properties from these main raw materials (hereinafter referred to as these). When charging different types of raw materials (referred to as different types of raw materials) into a blast furnace, the main raw materials and different type of raw materials are layered on a large bell in a stacked manner, and after stacking the different types of raw materials at predetermined positions, This method involves opening and loading the container.

[For production]

The present invention will be explained below with reference to the drawings.

Sintered ore, which is one of the main raw materials, is colored red, blue, and yellow. (A) in the lower layer,
The blue sintered ore (B) was layered in the middle layer, and the yellow sintered ore (C) was layered in the upper layer, each layer being divided into three layers with equal volume. Thereafter, the large bell (8) was opened and the material was charged into a scaled-down model blast furnace. The results are shown in FIG. As you can see from this result, the red sintered layer is laminated in the lower layer! ! In (A), the deposition rate is high in the center of the furnace, and gradually decreases toward the furnace wall.

The blue sintered ore (B) layered in the middle layer has a high deposition rate between the furnace center and the furnace wall. Yellow sintered ore (
C) is largely deposited on the furnace wall side.

In this way, it has been found that the distribution of the raw material in the radial direction inside the furnace after being charged into the furnace forms a unique pattern depending on the position of the stages stacked on the large bell of the raw material.

The present invention was made based on this knowledge and has the following features.

(1) Different types of raw materials with different components or properties from the main raw materials can be distributed and charged at desired locations within the plant.

(11) Prior to charging different raw materials, in order to avoid operations that intentionally create unevenness on the surface of deposits in the furnace, 070
Distribution controllability does not deteriorate.

(+i) Since there is no need to increase the number of large bell charging batches due to charging different materials, there is no need to provide a complicated charging sequence.

According to the present invention, since it has the above-mentioned features, it can sufficiently contribute to the adjustment of blast furnace furnace conditions.

For example, if during blast furnace operation, the ore on the wall side of the furnace does not drain well and slips occur frequently, then a different type of raw material with high basicity that can improve the pouring properties is laminated in the upper layer of the large bell, and then By charging the raw material inside the furnace, the raw material with high basicity is distributed in large quantities on the furnace wall side, which improves the furnace condition.

[Example 1] An example will be shown in which a 177 m small crosspiece type at the top of a blast furnace is used to use a material having different properties from the main material as a different material.

Three cases shown in Table 1 were tested using sintered ore of normal particle size as the main raw material and fine-grained sintered ore as a different raw material.

Table 1 (Inspection) In accordance with the reduction ratio of the model, grain sizes of 1 to 3 were used as fine sintered ore, and grain sizes of 3 to 15 to 1 were used as normal sintered ore.

In case (a) of Table 1, different raw materials (fine-grained sintered ore) are stacked in the lower layer on the large bell, and the main raw material (normal grained sintered ore) is layered in the middle and upper layers. When charged into the furnace after 15 cm of each was deposited.

Case (b) is a case in which different raw materials are stacked in a 3 cm layer in the middle layer, and the main raw material is deposited in 151 layers each in the lower layer and then charged into the furnace. Case (C) shows a case in which 1.51 layers of the different 1a raw materials were stacked in the upper layer, and 15c11 layers of the main raw material were deposited in the lower and middle layers, respectively, and then charged into the furnace.

The results are shown in FIG. As you can see from the figure, the case (
In all cases a), (b), and (c), the fine sinter deposition rate gradually increases from the furnace center toward the furnace wall. However, in case (C) The case where different types of raw materials are arranged in the upper layer shows much more deposited patterns on the furnace wall side than the other two cases.Therefore, when using fine sintered ore in blast furnace operation or When using fine-grained sintered ore to improve furnace conditions, utilizing this pattern will enable smooth blast furnace operation.

[Example 2] As in Example 1, an example will be shown in which a reduced model of furnace O1 is used to use a raw material different in composition from the main raw material as a different raw material.

Three cases shown in Table 2 were tested using sinter as the main raw material and limestone as a different raw material.

Table 2 (Notes) In accordance with the model reduction ratio of 1/7, the grain size of the sintered ore was set to 1 to 15 cm.11 The grain size of the limestone was set to 3 to 6 nm.

In case (d) of Table 2, different 11 raw materials (limestone) are laminated in 4.51 layers in the lower layer above the bell, and the main raw material (sintered ore) is deposited 15 cm each in the middle and upper layers. If you enter In case (e), 31 different materials are stacked in the middle layer,
When the main raw material is charged after depositing 15 cm in each of the lower and upper layers.

Case <r> is a case where 1.5 times of different raw materials are stacked in the upper layer, and the main raw material is charged after being deposited in the lower layer and the middle layer.

The results are shown in Figure 4. As can be seen from the figure, the pattern in case (d) when different types of raw materials are stacked in the lower layer is that there is a lot of deposition in the center of the furnace (gradually towards the furnace wall). In case (e), when different types of raw materials are arranged in the middle layer, a pattern is shown in which the deposition rate is high in the middle part between the furnace center and the furnace wall. When placed in the upper stage, the deposition rate is low in the center of the furnace, but shows a pattern that rises steeply toward the furnace wall.

In the above two embodiments, the raw materials are arranged in three layers on a large bell, but the present invention is not limited to these embodiments. In addition, for actual blast furnace operation, patterns for combining various raw materials and different types of silk materials are created, and the optimal ingredients and
Stable blast furnace operation can be achieved by adopting a flexible rod and pattern.

In addition, in the present invention, as a method of layering the main raw material and different types of raw materials on the large bell, it is sufficient to adopt a method in which the main raw materials and different types of raw materials are received separately on the small bell and then dropped onto the large bell. .

〔Effect of the invention〕

As explained above, the present invention has a main material and a different U material on a large bell.
All you have to do is separate the raw materials, pile them up, and then charge them.
Different types of raw materials can be distributed and charged at desired positions in the radial direction of the furnace, and since different types of raw materials are not charged locally, O/C does not deteriorate, allowing stable blast furnace operation. And different! Another advantage is that there is no need to install new equipment or to enhance the control sequence for charging the material.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a state in which sintered ore according to the method of the present invention is stacked on a large bell. FIG. 2 is a diagram showing the distribution of deafness after the sintered ore shown in FIG. 1 is charged into a furnace. FIG. 3 is a diagram showing the distribution in the furnace when fine-grained sintered ore is used as the different raw material. FIG. 4 is a diagram showing the distribution in the furnace when limestone is used as a different raw material. FIG. 5 is a sectional view of the m-section of the blast furnace, and FIG. 6 is a sectional view of the upper part of the furnace. 1...Belt conveyor 3...Fixed hopper-6.
...Small bell 8...Large bell ■...Different raw materials

Claims (1)

[Claims] In a method of charging a main raw material and a different type of raw material with different components or properties from the main raw material into a bell-type blast furnace, when the main raw material and the different type of raw material are deposited on a large bell, the main raw material and the different type of raw material are A method for charging raw materials into a bell-type blast furnace, which comprises dividing and stacking raw materials and loading the different kinds of raw materials in a height direction so as to form a predetermined layer thickness, and then opening a large bell and charging the raw materials into the plant.