JP2024044434A - Manufacturing method and manufacturing equipment for blast furnace raw materials - Google Patents

Abstract

[Problem] To provide a method and apparatus for producing blast furnace raw materials such as ferro-coke with high quality and high productivity. [Solution] A method for producing blast furnace raw materials using briquettes containing a carbon-containing material and an iron-containing material in a carbonization furnace, the method comprises the steps of charging the briquettes from the top of the carbonization furnace, measuring the height from the top of the carbonization furnace to the top of the piled up briquettes, and sucking gas from the top of the furnace, and it is preferable to control the amount of charging so that the distance (D) from the position of the gas suction port to the top of the piled up briquettes is within the range of 200 to 700 mm. [Selected Figure] Figure 1

Description

The present invention relates to a method and apparatus for producing raw materials for blast furnaces, and particularly to a method and apparatus for producing ferro coke, which is molded coke.

In blast furnace operations, coke produced by carbonizing coal in a coke oven is generally used. In recent years, in order to improve the reactivity of coke, a technology has been developed that uses ferro coke, which is molded coke produced by mixing a certain amount of iron ore with coal, agglomerating it, and then carbonizing it, as a raw material for blast furnaces. Among these, a method using a vertical carbonization furnace has been proposed as a carbonization method for ferro coke. For example, Patent Document 1 discloses a manufacturing method using a vertical carbonization furnace having a carbonization zone in the upper part and a cooling zone in the lower part. This method for producing ferro coke first includes a charging step of charging a molded product made of a carbon-containing material and an iron-containing material into a vertical carbonization furnace. Next, there is a carbonization step in which heating gas is blown into the carbonization zone to carbonize the molded product to produce ferrocoke. The method includes a cooling process in which cooling gas provided in a cooling zone is blown in to cool the ferro coke, and a furnace gas discharge process in which furnace gas is discharged from an exhaust port at the top of the furnace of the vertical carbonization furnace. There is. Finally, there is a ferro coke discharge step for discharging ferro coke from the lower part of the cooling zone. In the carbonization process, low-temperature gas is blown through the low-temperature gas blowing tuyere in the middle part of the carbonization furnace, and high-temperature gas is blown through the high-temperature gas blowing tuyere in the lower part. Here, in order to increase the production amount of ferro coke, it is necessary to increase the capacity of the carbonization furnace. However, the cooling gas and high-temperature gas are injected in the depth direction of the carbonization furnace (direction from the gas injection side to the opposing side surface). Therefore, in order to penetrate into the center of the furnace, the depth direction of the furnace cannot be increased beyond a certain level. That is, the shape of the carbonization furnace needs to be longer in the furnace width direction (direction orthogonal to the depth direction) than in the depth direction.

On the other hand, Patent Document 2 discloses a ferro-coke manufacturing device that has a dispersing material with a slope that becomes wider toward the bottom at the outlet side of the charging chute as a device for uniformly charging molded materials in the furnace width direction.

Japanese Patent Application Publication No. 2011-57970 JP 2014-208768 A

As mentioned above, in a vertical carbonization furnace that has a structure that is longer in the furnace width direction than in the depth direction (see Figure 1 described later), even if multiple rows of charging ports are arranged in the furnace width direction, the furnace width length It is difficult to install a sufficient number of charging ports. If a limited number of charging ports are installed, the charging distribution will depend on the angle of repose of the charged molded product (hereinafter also referred to as the "burden"), making it impossible to obtain a uniform charging shape. There is a problem. Furthermore, if the molded product cannot be charged uniformly in the width direction of the furnace, there will be localized areas in the furnace where the powder pressure is high, and the weight of the charged material may cause cracks in the molded product. Additionally, when the molded products are charged into the furnace, if some parts have more molded parts and some parts have less molded parts in the width direction of the furnace, there is a problem that the gas flow in the furnace becomes uneven, which affects the carbonization of the molded parts. .

On the other hand, the aforementioned Patent Document 2 discloses an apparatus for uniformly charging materials, but the materials contain fine powder, and if the materials are charged in this state, there is a problem that the strength of the molded products after dry distillation varies, making it difficult to obtain molded products with sufficient strength.

The present invention has been made to address the above-mentioned problems, and aims to provide a method and apparatus for producing blast furnace raw materials such as ferrocoke with high quality and high productivity.

As a result of extensive research into solving the various problems described above, the present inventors discovered that when producing molded coke, the position of the gas suction port and the height of the charged material are related to the efficient recovery of fine powder that is mixed in after charging by gas suction. Furthermore, they discovered that it is effective to control the amount of charging while measuring the height of the charged material.

The present invention was completed based on these findings and through further investigation, and the gist of the present invention is as follows.
[1] A method for producing a raw material for a blast furnace by subjecting a molded material containing a carbon-containing material and an iron-containing material to a carbonization furnace,
A step of charging the molded product from the upper part of the carbonization furnace (charging step);
A step of measuring the height from the top of the carbonization furnace to the top of the piled molded products (a measuring step);
a step of aspirating gas from the upper part of the furnace (gas aspirating step);
A method for producing a raw material for a blast furnace, comprising the steps of:
[2] The method for producing raw materials for a blast furnace according to [1], wherein the charging step controls the charging amount of the shaped materials according to the charging height of the shaped materials obtained in the measuring step.
[3] In the method for producing raw materials for a blast furnace according to [1] or [2], the charging amount is controlled so that the distance (D) from the position of the suction port for sucking the gas to the top of the piled up molded products is within the range of 200 mm to 700 mm in the charging step.
[4] A method for producing raw materials for a blast furnace, characterized in that in the charging process described in any one of [1] to [3], there is further provided a step of intermittently charging the shaped materials into the carbonization furnace.
[5] A method for producing raw materials for a blast furnace, characterized in that the charging step described in any one of [1] to [4] above further comprises a step of charging the shaped bodies while dispersing them.
[6] In any one of [1] to [5] above, the method for producing raw materials for a blast furnace is characterized in that the gas suction step comprises suctioning the gas from a plurality of points on the side of the carbonization furnace.
[7] An apparatus for producing a raw material for a blast furnace by using a dry distillation furnace to produce a molded product containing a carbon-containing material and an iron-containing material,
A means for charging the molded material from the upper part of the carbonization furnace (a charging port);
A means for measuring the height from the top of the carbonization furnace to the top of the piled molded products (height gauge);
A means for sucking gas from the upper part of the furnace (gas suction port);
An apparatus for producing raw material for a blast furnace, comprising:
[8] In the above [7], the charging means [charging inlet] has a means [charging amount control device] for controlling the charging amount of the shaped material in accordance with the charging height of the shaped material obtained by the measuring means [height gauge].
[9] In the above [8], the charging amount control means [charging amount control device] is a means for controlling the charging amount so that the distance (D) from the position of the gas suction port to the top of the piled molded products is within the range of 200 mm to 700 mm.
[10] In any one of [7] to [9] above, the charging means [charging inlet] further comprises an opening/closing gate at the outlet of the charging inlet.
[11] In any one of [7] to [10] above, the charging means [charging port] further comprises a diffusion section immediately below the outlet of the charging means [charging port].
[12] In any one of [7] to [11] above, the gas suction means [gas suction ports] are provided at multiple locations on the side of the carbonization furnace.

In the production of shaped coke, the present invention is capable of uniformizing the quality of shaped coke after carbonization in a relatively simple manner by suctioning and removing fine powder together with furnace gas after charging into a vertical carbonization furnace. This has the excellent effect of improving productivity.

1 is a schematic perspective view of an upper part of a furnace showing an outline of an example of a manufacturing apparatus according to the present invention. 1 is a schematic cross-sectional view of the upper part of a furnace showing an outline of an example of a manufacturing apparatus according to the present invention. FIG. 1 is a schematic cross-sectional view showing a test device imitating a manufacturing device according to the present invention. FIG. 3 is a diagram showing the relationship between the position of the gas suction port and the powder ratio of the manufacturing apparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a method and apparatus for producing a raw material for a blast furnace according to the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. Further, since the drawings are for conceptually explaining the present invention, the dimensions of the illustrated members and their ratios may differ from the actual ones.

[Manufacturing method steps (procedures)]
The manufacturing method according to the present invention is a method for producing a raw material for a blast furnace from shaped materials containing a carbon-containing material and an iron-containing material in a carbonization furnace, and is characterized by having the following steps.
(1) A process of charging the molded material from the top of the carbonization furnace [charging process]
(2) A step of measuring the height from the top of the carbonization furnace to the top of the piled molded products [measurement step]
(3) Step of sucking gas from the upper part of the furnace [gas sucking step]
The above steps will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view of the upper part of a ferro coke manufacturing apparatus (vertical carbonization furnace), which is an example of the manufacturing apparatus according to the present invention.

[Charging process]
First, in the charging process, molded products containing carbon-containing materials (coal, etc.) and iron-containing materials (iron ore, etc.), which are raw materials for ferrocoke, are loaded from the charging chute 1 installed in the upper part 5 of the carbonization furnace. This is the process of entering the The furnace upper part 5 is the upper structure of the carbonization furnace, and refers to the area from the furnace top of the carbonization furnace to the area where the molded product is deposited. The installation location of the charging chute 1 for charging the molded product is not particularly limited as long as it is within the upper part of the furnace.

Further, in this charging step, it is preferable to provide either or both of the intermittent charging step and the molded product diffusion charging step described below.

[Intermittent charging step]
The step of intermittently (intermittently) charging the molded product into the carbonization furnace means, for example, providing a retractable gate 2 on the outlet side of the charging chute 1 (the outlet of the charging port) and opening and closing the gate 2. This is a method in which the molded product is intermittently charged into the furnace. The reason for providing this step is to keep the pressure inside the carbonization furnace constant and to reduce fluctuations in the gas concentration inside the furnace.

The molded product is charged into the upper part 5 of the carbonization furnace with fine powder mixed therein. Before charging, the path of the molded material is closed by the gate 2, but when the gate 2 is opened from the closed state, the path of the molded material in the charging chute 1 is opened, and the molded material is charged. . When the gate 2 is closed to close the path of the molded product, one batch of molded products (for example, 600 to 800 kg) can be stored upstream of the gate 2. In normal operation, the gate 2 is opened for each batch and molded products are charged. The process moves on to a measurement process in which the height of the charged material is measured for each charging step.

[Molding diffusion loading step]
Specifically, the step of charging the molded materials while spreading them is a method of spreading them by providing a pyramidal diffusion section 3 immediately below the outlet side (the outlet of the charging inlet) of the charging chute 1. The reason for providing this diffusion charging step is that the shape of the diffusion section 3 allows the molded materials to be charged not only forward but also to the left and right, resulting in a more uniform surface shape of the charged materials.

[Measurement process]
Next, the measurement step is a step of measuring the distance from the top of the carbonization furnace to the top of the deposited molded material after charging (hereinafter also referred to as "height of the charged material" and represented by H). It is.

Here, it is preferable to use a microwave level meter as a measuring device for measuring the charge height. This is because the use of microwaves allows accurate distance measurement even in the furnace environment where fine powder is present. Other examples include laser distance meters and contact distance meters.

In addition, it is preferable to control the amount of molded material (charging amount) charged in the charging process described above according to the height (H) of the charged material measured in this measurement process. The reason for this will be explained in the "Consideration of the gas suction port installation position" section below.

[Gas suction process]
The gas suction step is a step of suctioning fine powder suspended between the upper part of the furnace and the charged materials after charging of the molded materials together with the furnace gas. Here, the fine powder generally means powder having an average particle size of 100 μm or less, but in the present invention, the powder is defined as having an average particle size of less than 20 mm in comparison with the molded materials.

In order to suck in the gas in the furnace, the gas is sucked through a gas suction port 6 provided on the side of the furnace wall of the furnace upper part 5 through a gas suction duct 7 with a suction pump (not shown) installed outside the furnace. ing.

[Study of gas suction port installation position]
Therefore, in order to control the charging amount and reduce the amount of fine powder in the furnace, we considered that it is important to determine the position of the gas suction port, so we considered the position of the gas suction port and the state of powder mixing. I will explain the test conducted.

First, a study was conducted on the appropriate installation position of the gas suction port 6 using a test device (upper structure) 10 simulating the manufacturing device according to the present invention shown in Figure 3.

A mixture of 90 wt % molded material and 10 wt % powder was prepared as a raw material for the test to be charged. This test raw material was charged from charging chute 1, gas suction was performed for a predetermined time, the charge was collected after gas suction, and the weight ratio of powder (powder ratio) in the charge was confirmed. . Then, a similar charging test was conducted by changing the installation position of the gas suction port 6 for gas suction, and the respective powder ratios were confirmed. Here, particles with an average particle size of 20 mm or more are considered to be molded products, and as mentioned above, particles with an average particle size of less than 20 mm are considered to be powder, and the powder ratio is determined from the weight ratio of powder in the sampled charge. Calculated.

The results are shown in FIG. It was found that the powder ratio of the charge was reduced when the gas suction port was installed within a range of 200 mm to 700 mm downstream from the height of the charge (the top of the charge). Ta. More preferably, it is 400 mm to 700 mm.

Based on the above results, the present inventors found that in actual operation, it is difficult to change the installation position of the gas suction port according to the charging amount, so the installation position of the gas suction port is It has been found that it is practical to operate from the viewpoint of how much material should be charged.

That is, by controlling the charging amount while measuring the height position so that the height of the charging material is on the upstream side with respect to the position of the gas suction port, and the distance D is within the range of 200 mm to 700 mm, It becomes possible to efficiently discharge the powder contained in the charge from the side of the furnace.

[Gas suction port and suction method]
Next, the gas suction ports are preferably installed on both sides of the furnace body, on the charging chute 1 side and on the opposite side, and at the above-mentioned height positions. Further, it is desirable to install them at a plurality of locations in the depth direction of the furnace (direction a in FIG. 1). For example, in the case of a furnace with two charging chutes 1 installed, three gas suction ports 6 are installed on the side of the charging chute 1, and three gas suction ports 6 are installed on the opposite side. 6 locations will be installed. By installing the gas suction ports 6 on the side of the charging chute 1 and the opposite side, the powder dispersed near the furnace wall can be efficiently recovered. Further, by installing the gas suction port 6 in the depth direction of the furnace, it becomes possible to collect powder over the entire surface inside the furnace. Furthermore, by installing multiple locations in the furnace, the gas flow in the furnace becomes uniform, and ferro coke having uniform strength can be manufactured.

Note that the shape of the gas suction port is, for example, a rectangle with a length of 100 mm and a width of 1000 mm. When a plurality of suction ports are installed, the distance between adjacent suction ports is, for example, 1200 mm.

Furthermore, a filter (made of metal such as stainless steel and shaped like a grid or slits, the interval between the grids or slits is about 10 mm) is installed at the inlet of the gas suction port to prevent moldings with large particles from being sucked in. It is preferable to provide one.

Further, as for the ability to suction gas, it is preferable to suction only fine powder, and for example, it is preferable that the suction speed is 5 to 10 m/s. This is because if the suction speed is less than 5 m/s, sufficient suction capacity will not be obtained and fine powder will not be suctioned sufficiently, and if it exceeds 10 m/s, particles other than fine powder will stick to the filter part and the suction capacity will decrease. It is. More preferably, it is 7 to 8 m/s.

[Ferro coke manufacturing equipment (carbonization furnace)]
Here, the overall structure of the ferro-coke production apparatus (carbonization furnace) will be described.
As mentioned above, FIG. 1 is a schematic perspective view of the furnace upper part of the manufacturing apparatus according to the present invention. This furnace upper part 5 is also called the charging zone. The shape of the furnace upper part 5 is, for example, a depth a of 1.5 m and a furnace width b of 6 m. The overall height (total length) of the carbonization furnace is, for example, 28 m. The overall structure of the carbonization furnace is composed of a charging zone, a carbonization zone, a cooling zone, and a discharge zone from the top. A carbonization zone 9 for heating and carbonizing the molded material is provided below the charging zone. This carbonization zone 9 is divided into two heating zones depending on the heating temperature, with the upper side (the charging zone side) being a low temperature zone (temperature range: 350 to 500 ° C.) and the lower side being a high temperature zone (temperature range: 700 to 850 ° C.). Each is equipped with a tuyere that blows hot air from the side of the furnace (the side opposite the charging chute side). Further, below the carbonization zone 9, a cooling zone for cooling the molded coke is provided, and a discharge zone for discharging the molded coke from the bottom of the furnace after cooling is provided.

The following provides a more detailed explanation of the embodiments of the present invention, but the present invention is not limited to these examples.

Using the manufacturing apparatus according to the present invention shown in FIG. 1, the relationship between the charging amount and the height position of the charging material was confirmed. Sample No. corresponding to the example of the present invention. 1 to 7 control the charging amount of molded coke while measuring the height position of the charged material during charging, suck the gas in the furnace after charging, and sample the molded coke after carbonization. and confirmed its strength. Sample No. corresponding to a comparative example. Test No. 8 is a case in which no gas suction port was installed and no gas suction was performed, and the strength of the molded coke was also confirmed. The suction speed of gas suction in this example was 8 m/s.

The strength of the sampled molded coke was measured by measuring the DI ¹⁵⁰ ₁₅ using the rotational strength test method described in JIS K 2151, and the average, maximum and minimum strength values were determined. Here, the DI ¹⁵⁰ ₁₅ , which is the strength (surface breaking strength) of the molded product, indicates the mass ratio of molded products having a size of 15 mm or more after applying an impact of 150 rotations with a drum testing machine.

These results are shown in Table 1.

From the results in Table 1, it can be seen that, compared to sample No. 8 (comparative example) where gas suction was not performed, samples No. 1 to 7 (examples of the present invention) had a higher average strength and less variation between the maximum and minimum values. Furthermore, when the charge height position was controlled to the preferred range of 200 to 700 mm (samples No. 1 to 4), the average strength was 75 or higher and the variation between the maximum and minimum values was even less. This made it possible to produce high-quality molded products.

1 Charging chute 2 Gate 3 Diffusion section 4 Charge 5 Furnace upper part 6 Gas suction port 7 Gas suction duct 8 Charge height measuring device 9 Carbonization zone 10 Test device (upper structure)
a Depth b Furnace width H Distance from the top of the furnace to the charge D Distance from the height of the charge to the gas suction port (center)

Claims (20)

A method for producing a raw material for a blast furnace by subjecting a molded material containing a carbon-containing material and an iron-containing material to a dry distillation furnace, comprising:
A step of charging the molded product from the upper part of the carbonization furnace (charging step);
A step of measuring the height from the top of the carbonization furnace to the top of the piled molded products (a measuring step);
a step of aspirating gas from the upper part of the furnace (gas aspirating step);
A method for producing a raw material for a blast furnace, comprising the steps of: The method for producing raw materials for a blast furnace according to claim 1, characterized in that the charging step controls the amount of the shaped material to be charged according to the charging height of the shaped material obtained in the measuring step. The method for producing raw materials for blast furnaces according to claim 2, characterized in that in the charging process, the charging amount is controlled so that the distance (D) from the position of the suction port for sucking in the gas to the top of the piled molded products is within the range of 200 mm to 700 mm. The method for producing raw materials for a blast furnace according to any one of claims 1 to 3, characterized in that the charging process further includes a step of intermittently charging the shaped materials into the carbonization furnace. The method for producing a raw material for a blast furnace according to any one of claims 1 to 3, characterized in that the charging step further includes a step of charging the molded product while diffusing it. The method for producing raw materials for a blast furnace according to claim 4, characterized in that the charging process further includes a step of charging the molded material while dispersing it. 4. The method for producing a raw material for a blast furnace according to claim 1, wherein in the gas suction step, the gas is suctioned from a plurality of locations on a side surface of the carbonization furnace. The method for producing raw materials for a blast furnace according to claim 4, characterized in that the gas suction process involves suctioning gas from multiple points on the side of the carbonization furnace. 6. The method for producing a raw material for a blast furnace according to claim 5, wherein in the gas suction step, the gas is suctioned from a plurality of locations on a side surface of the carbonization furnace. The method for producing raw materials for a blast furnace according to claim 6, characterized in that the gas suction process involves suctioning gas from multiple points on the side of the carbonization furnace. In an apparatus for producing raw material for a blast furnace in a carbonization furnace from a molded product containing a carbon-containing substance and an iron-containing substance,
A means (charging port) for charging the molded product from the upper part of the carbonization furnace;
A means (height measuring device) for measuring the height from the top of the carbonization furnace to the top of the deposited molded product;
means for sucking the gas in the upper part of the furnace [gas suction port];
An apparatus for producing raw materials for a blast furnace, characterized by comprising: The charging means (charging port) is a means for controlling the charging amount of the molded material according to the charging height of the molded material obtained by the measuring means (height measuring device) [charging amount control]. 12. The apparatus for producing raw material for a blast furnace according to claim 11, further comprising: an apparatus for producing a raw material for a blast furnace. The charging amount control means (charging amount control device) charges so that the distance (D) from the position of the gas suction port to the top of the deposited molded product is within a range of 200 mm to 700 mm. 13. The apparatus for producing raw material for a blast furnace according to claim 12, wherein the apparatus is a means for controlling the amount. 14. The apparatus for producing a raw material for a blast furnace according to claim 11, wherein the charging means (charging port) further includes an opening/closing gate at an outlet of the charging port. The blast furnace raw material according to any one of claims 11 to 13, wherein the charging means (charging inlet) further includes a diffusion section immediately below the outlet of the charging means (charging inlet). Manufacturing equipment. The blast furnace raw material manufacturing apparatus according to claim 14, characterized in that the charging means (charging inlet) further includes a diffusion section immediately below the outlet of the charging means (charging inlet). 14. The apparatus for producing a raw material for a blast furnace according to claim 11, wherein the gas suction means (gas suction ports) are provided at a plurality of locations on a side surface of the carbonization furnace. The blast furnace raw material manufacturing apparatus according to claim 14, characterized in that the gas suction means [gas suction ports] are provided at multiple locations on the side of the carbonization furnace. The blast furnace raw material manufacturing apparatus according to claim 15, characterized in that the gas suction means [gas suction ports] are provided at multiple locations on the side of the carbonization furnace. The blast furnace raw material manufacturing apparatus according to claim 16, characterized in that the gas suction means [gas suction ports] are provided at multiple locations on the side of the carbonization furnace.

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