JP7533501B2 - Apparatus and method for producing raw materials for blast furnaces - Google Patents

Description

The present invention relates to an apparatus and method for producing raw materials for blast furnaces.

In recent years, the steel industry has been required to reduce _CO2 gas emissions from the viewpoint of preventing global warming, and it is urgent to reduce the amount of fossil fuel used. In the steel industry, molten iron is produced in a blast furnace by reducing iron ore with carbon, i.e., coke produced by carbonizing coal in a coke oven. To reduce the coke consumption, technology is being developed to use ferro-coke as a raw material for blast furnaces. Ferro-coke is a molded coke made by mixing a certain amount of iron ore with coal, forming agglomerates, and then carbonizing the mixture to disperse fine metallic iron particles in the coke, thereby increasing the reactivity of the coke through the catalytic action of the metallic iron.

A method for carbonizing ferro-coke using a vertical carbonization furnace (hereinafter, simply referred to as a carbonization furnace) has been proposed. For example, Patent Document 1 discloses a method for producing ferro-coke using a carbonization furnace having a carbonization zone at the top and a cooling zone at the bottom. This method includes a charging step in which molded materials made of carbon-containing materials and iron-containing materials are charged into the carbonization furnace from the top of the furnace, a carbonization step in which heated gas is blown into the molded materials to produce ferro-coke in the carbonization zone, a cooling step in which cooling gas is blown into the molded materials to cool the ferro-coke, an in-furnace gas discharge step in which furnace gas is discharged from an outlet at the top of the furnace, and a ferro-coke discharge step in which ferro-coke is discharged from the bottom of the cooling zone. In the carbonization step, the molded materials are heated by blowing low-temperature gas into the furnace from a low-temperature gas blowing tuyere in the middle of the carbonization zone and high-temperature gas into the furnace from a high-temperature gas blowing tuyere in the bottom of the carbonization zone. In the cooling process, the ferro-coke is cooled by injecting cooling gas from the cooling gas injection tuyeres at the bottom of the cooling zone. In order to increase the production volume of ferro-coke, the volume of the carbonization furnace must be increased, but the heating gas and cooling gas are injected in the depth direction of the carbonization furnace, that is, parallel to the horizontal component of the direction in which the molded materials are charged, in other words, in the thickness direction of the carbonization furnace. Therefore, in order to allow the above-mentioned gases to penetrate to the center of the furnace in the depth direction, the internal dimensions in the depth direction must be kept below a certain level. Therefore, the carbonization furnace has a shape in which the furnace width direction (the direction perpendicular to the depth direction in the cross section of the carbonization furnace) is longer than the depth direction.

JP 2011-57970 A JP 2011-162271 A

As described above, in a carbonization furnace having a structure in which the furnace width direction is longer than the depth direction, it is difficult to obtain a uniform distribution of the molded materials even if multiple rows of molded material charging inlets are arranged in the furnace width direction. In particular, the powder generated by the collision of the molded materials with the wall surface of the chute through which the molded materials are inserted into the carbonization furnace, or the collision of the molded materials with each other during the process of transporting the molded materials into the carbonization furnace including the chute, tends to segregate and tend to concentrate at the charging inlet side of the carbonization furnace. This is because most of the powder slips through the molded materials and settles, and the molded materials are separated into two layers by the time they reach the carbonization furnace: a layer of molded material particles with a particle size larger than the powder (hereinafter referred to as the molded material layer) and a powder layer located below the molded material layer. Specifically, when 1 ton of molded materials is charged into the carbonization furnace, the thickness of the charged materials when entering the carbonization furnace, that is, the combined thickness of the molded material layer and the powder layer, is about 150 mm at most. Because the compact particles are charged into the carbonization furnace from a high position due to the powder present below them, they tend to fly to a position far from the charging port, while the powder in the lower layer falls near the charging port. Compact particles form mountains according to their angle of repose, making them less likely to segregate than powder, but in the carbonization furnace, the compact particles tend to accumulate in a biased manner in the depth direction away from the charging port. In addition, because the position of the powder is fixed by slipping between the compacts, if the powder falls concentrated at one point, for example near the charging port mentioned above, significant powder segregation will occur. Problems caused by the segregation of compacts and powder include uneven gas flow in the furnace, which affects the carbonization of the compacts.

As an example of a method for uniformly charging materials, Patent Document 2 discloses a method for dispersing materials radially by providing a dispersion induction section in a conveying furnace, which has an inclined surface that slopes radially downward from the widthwise center of the conveying path toward the exit side. This technology is specialized for improving dispersion in the furnace width direction. The presence or absence of a dispersion induction section does not affect the flying distance of the powder, so the installation of a dispersion induction section cannot eliminate segregation of powder or molding particles.

The present invention has been made to solve the above problems, and aims to propose an apparatus and method for producing blast furnace raw materials that improve the distribution of blast furnace raw materials in a carbonization furnace during the production of blast furnace raw materials such as ferro coke, i.e., to suppress the segregation of powder and molded particles that are larger in diameter than the powder, thereby achieving high quality and high productivity.

In order to achieve the above object, the present invention provides
[1] In an apparatus for producing raw materials for a blast furnace, the raw materials for a blast furnace are produced by carbonizing molded materials loaded into a furnace through a chute, the molded materials have a powder and molded material particles having a particle size larger than that of the powder, and a guide section is provided protruding into the furnace on at least a part of a furnace wall facing a charging port to which the chute is connected, the guide section contacting the molded material particles loaded into the furnace through the chute and pushing them back toward the charging port.

[2] In the manufacturing apparatus for raw materials for a blast furnace described in [1] above, the guide portion is located below the lower end of the charging port, a first ratio (d/W) between the height difference d between the guide portion and the lower end of the charging port and the inner dimension W in the depth direction of the furnace is 0.65 to 0.80, and a second ratio (w/W) between the protruding length w of the guide portion in the depth direction and the inner dimension W is 0.35 to 0.50.

[3] In the manufacturing apparatus for raw materials for a blast furnace described in [1] or [2] above, the chute is provided with a diffusion section that diffuses the molded material in the width direction of the furnace when the molded material is charged into the furnace.

[4] In the blast furnace raw material manufacturing apparatus described in any one of [1] to [3] above, the guide portion is in the shape of a flat plate.

[5] In the apparatus for producing raw materials for a blast furnace described in any one of [1] to [4] above, the molded product is an apparatus for producing raw materials for a blast furnace that contains a carbon-containing material and an iron-containing material as components.

[6] A method for producing raw materials for a blast furnace, characterized in that raw materials for a blast furnace are produced using the manufacturing apparatus for raw materials for a blast furnace described in any one of [1] to [5] above.

[7] In the method for producing raw materials for a blast furnace described in [6] above, the shaped materials are charged into the furnace while monitoring the accumulation level of the shaped materials in the furnace so that the distance D from the lower end of the charging port to the upper end portion of the shaped materials accumulated in the furnace always satisfies the following formula:
0.1≦(D-d)/W

According to the present invention, it is possible to suppress the segregation of the molded product particles and powder in the furnace. In addition, it is possible to suppress the adverse effects on the carbonization of the molded product caused by the segregation of the molded product particles and powder. As a result, it is possible to improve the quality of the raw material for the blast furnace charged into the blast furnace and to increase the productivity of the raw material for the blast furnace.

FIG. 1 is a side view of a ferro-coke producing apparatus according to the present invention, in which (a) of FIG. 1 is a view for explaining a state in which charging of molded materials into a furnace has just begun, and (b) of FIG. 1 is a view for explaining a state in which charging of molded materials into a furnace is just about to be completed. FIG. 11 is a graph showing the correlation between the maximum powder rate, the maximum molded particle weight, and the first ratio. FIG. 13 is a graph showing the correlation between the maximum powder rate, the maximum molded particle weight, and the second ratio. FIG. 11 is a graph showing the correlation between the maximum powder rate, the maximum molded particle weight, and the third ratio.

The molded product in the embodiment of the present invention is carbonized to become a raw material for a blast furnace, and an example of the raw material for a blast furnace is molded coke. Specifically, ferro coke, which is a type of molded coke, can be mentioned. Below, one embodiment of the present invention will be described using the manufacturing process of ferro coke as an example. Note that the drawings in the following description are schematic and may differ from the actual product. In addition, the following embodiment is an example of an apparatus and method for embodying the technical idea of the present invention, and the present invention is not limited to the embodiment described below. In other words, the present invention can be modified in various ways within the technical scope of the present invention described in the claims.

Figure 1 is a side view of a ferro-coke manufacturing apparatus (hereinafter, simply referred to as the manufacturing apparatus) according to the present invention. The manufacturing apparatus shown in Figure 1 is a carbonization furnace 1 that carbonizes molded materials in an upper carbonization zone and cools the ferro-coke produced by carbonizing the molded materials in a lower cooling zone (not shown), and a charging port 2 is formed on the side of the upper part of the carbonization furnace 1. The left-right direction in Figure 1 indicates the depth direction and thickness direction of the carbonization furnace 1, and the up-down direction in Figure 1 indicates the up-down direction of the carbonization furnace 1.

As described above, the molded product in the embodiment of the present invention is turned into ferro-coke by carbonization, and contains carbon-containing materials (such as coal) and iron-containing materials (such as iron ore) as components. The molded product is made by agglomerating the above-mentioned materials using an agglomeration device (not shown), and is transported in this state to the carbonization furnace 1 by a transport device (not shown). During the transport process, the molded product may collide with the transport device due to vibration, or with each other, and may become partly powdered. Therefore, when the molded product is charged into the carbonization furnace 1, it contains powder SP and molded product particles LP with a particle size larger than that of the powder SP. The agglomeration device and transport device may be configured in the same manner as conventionally known agglomeration devices and transport devices.

A chute 3 is connected to the inlet 2, which charges a preset amount of molded material into the carbonization furnace 1. The above-mentioned unillustrated conveying device is connected to the chute 3. In the example shown in FIG. 1, the chute 3 has an inclined surface that slopes downward from above, and the molded material conveyed by the conveying device is charged into the carbonization furnace 1 along the inclined surface. Specifically, the chute 3 shown in FIG. 1 has two inclined surfaces with different inclination angles in the charging direction of the molded material. The inclination angle of the second inclined surface 3B on the downstream side with respect to the horizontal plane (not shown) is set smaller than that of the first inclined surface 3A on the upstream side in the charging direction. This is to make it easier to charge the molded material on the side opposite the inlet 2 in the depth direction of the carbonization furnace 1. The inclination angles of these inclined surfaces 3A and 3B are preset. In addition, a gate 4 is provided on the upstream side of the chute 3 in the charging direction of the molded material to the carbonization furnace 1, that is, on the inlet side of the chute 3.

The gate 4 is a mechanism for charging the molded material into the carbonization furnace 1, or a mechanism for adjusting the amount of molded material to be charged into the carbonization furnace 1. In other words, the gate 4 is not particularly limited as long as it can charge the molded material into the carbonization furnace 1 or can adjust the amount of molded material to be charged. In the example shown here, the gate 4 is in the form of a door configured to rotate around a predetermined rotation axis. Specifically, it is provided on the upper inner surface of the inner surface of the chute 3, and is configured to open toward the carbonization furnace 1 side by receiving torque transmitted from an actuator (not shown). This is to avoid the possibility that the gate 4 may obstruct the charging of the molded material when opening the gate 4 to charge the molded material into the carbonization furnace 1 if the gate 4 is provided on the lower inner surface of the inner surface of the chute 3. In addition, the gate 4 may be configured to be able to change its opening degree continuously or in stages. If the opening degree of the gate 4 is configured to be changeable, the amount of molded material to be charged into the carbonization furnace 1 can be controlled by controlling the opening degree of the gate 4.

The diffusion section 5 is provided downstream of the gate 4 in the charging direction of the molded material. The diffusion section 5 diffuses or disperses the molded material that has passed through the gate 4 in the width direction of the dry distillation furnace 1 (hereinafter referred to as the furnace width direction) when the molded material is charged into the inside of the dry distillation furnace 1. Specifically, the diffusion section 5 is provided between the first inclined surface 3A and the second inclined surface 3B of the chute 3 in the charging direction of the molded material. Although not shown in detail, the diffusion section 5 has a quadrangular pyramid shape as an example, and has a triangular front inclined surface facing the dry distillation furnace 1 and triangular side inclined surfaces located on both sides of the front inclined surface. Each of the front inclined surface and the two side inclined surfaces descends from the chute 3 toward the charging port 2 side, and is the passing surface of the molded material. The furnace width direction is a direction perpendicular to the vertical direction and the depth direction of the dry distillation furnace 1.

Among the furnace walls in the carbonization furnace 1, the furnace wall facing the charging port 2 is provided with a guide section 6 that, when the molded material is charged into the carbonization furnace 1, mainly comes into contact with the molded material particles LP in the molded material and pushes them back toward the charging port 2 side to guide the accumulation position of the molded material particles LP toward the charging port 2 side. In the example shown here, the guide section 6 is in the form of a flat plate that protrudes almost horizontally toward the inside of the carbonization furnace 1. Specifically, the protruding length in the depth direction and the installation height in the vertical direction are set so that the tip portion 6A of the guide section 6 is mainly located at the boundary between the powder SP and the molded material particles LP when the molded material is charged into the carbonization furnace 1. The protruding length and the installation height in the vertical direction of the guide section 6 can each be determined in advance by experiment. Also, as an example, the guide section 6 may extend in the furnace width direction over at least a portion of the furnace wall facing the charging port 2, i.e., over a length approximately equal to the width of the molded product diffused in the furnace width direction by the diffusion section 5. Alternatively, it may extend over the entire range (total length) in the furnace width direction.

In addition, instead of installing the guide part 6 horizontally, it may be installed at an angle toward the bottom of the dry distillation furnace 1. When installing the guide part 6 at an angle toward the bottom of the dry distillation furnace 1, it is preferable that the angle between the horizontal plane (not shown) and the guide part 6 is less than 30 degrees. This is because, as will be described later, when the molded products are loaded into the dry distillation furnace 1, a certain amount of the molded products are piled up on the guide part 6, and this pile functions as a buffer for the molded products that are loaded one after another. Also, as an example, the guide part 6 may be made of an iron-based material.

Next, the operation of the manufacturing apparatus shown in Figure 1 will be described. Molded products containing carbon-containing materials (coal, etc.) and iron-containing materials (iron ore, etc.) that are the raw materials for ferro-coke are supplied from a conveying device to the chute 3. Here, as described above, a part of the molded product becomes powder SP during the conveying process, and the powder SP moves to the lower side of the molded product particles LP through the gaps between the molded product particles LP. Therefore, when the molded product reaches the chute 3, it is supplied to the chute 3 in a double layer state, with a layer of molded product particles LP (hereinafter referred to as the molded product particle layer) and a layer of powder SP (hereinafter referred to as the powder layer) below it.

When the molded material is supplied to the chute 3, the gate 4 installed on the inlet side of the chute 3 is closed, and one batch of molded material is piled up upstream of the gate 4. Next, the gate 4 is opened, and the molded material is charged into the carbonization furnace 1 installed at a lower position than the chute 3. At this time, the molded material passes over the diffusion section 5 that promotes dispersion in the furnace width direction, and is thus diffused or dispersed in the furnace width direction and charged into the carbonization furnace 1. Of the molded material, the molded material particles LP come into contact with the guide section 6 installed in part or the entire range of the furnace width direction of the furnace wall facing the charging inlet 2 of the carbonization furnace 1 and fall into the carbonization furnace 1. The diffusion section 5 is structured so that its length in the furnace width direction is longer than that of the chute 3.

As described above, in conventional operations, that is, when the guide portion 6 of the present invention is not provided, the molding particles LP in the moldings fly to a position away from the inlet 2 of the carbonization furnace 1, while the powder SP in the moldings tends to segregate near the inlet 2 of the carbonization furnace 1. One method for improving such segregation of the powder SP is to extend the flying distance of the powder SP by lowering the level of the deposit DM in the carbonization furnace 1 (hereinafter referred to as the deposit level), that is, the height of the moldings deposited in the carbonization furnace 1. However, when the deposit level is lowered, the flying distance of the molding particles LP also increases, and the peak of the mountain formed by the molding particles LP also moves away from the inlet 2 of the carbonization furnace 1. In other words, the molding particles LP segregate near the furnace wall facing the inlet 2 of the carbonization furnace 1. The deposit DM refers to the molded material that is loaded into the dry distillation furnace 1 and deposited there, and the molded material that is deposited on the guide section 6.

The molded material particles LP form mountains according to their angle of repose, so the degree of segregation is smaller than that of the powder SP, but the segregation, like that of the powder SP, causes the gas flow in the furnace to become uneven, adversely affecting the carbonization of the molded material. Therefore, in the present invention, in order to suppress the segregation of the molded material particles LP when inserting molded materials into the carbonization furnace 1 with the accumulation level in the carbonization furnace 1 lowered, the above-mentioned guide section 6 is provided over a part or the entire range of the furnace width direction of the furnace wall facing the charging port 2 of the carbonization furnace 1. The guide section 6 pushes the molded material particles LP back to the charging port 2 side of the carbonization furnace 1, guiding the accumulation position of the molded material particles LP to the charging port 2 side, thereby suppressing the segregation of the molded material particles LP.

As described above, the protruding length and installation height of the guide section 6 are set so that the tip 6A of the guide section 6 is positioned between the layer of molded particles and the powder layer that are loaded into the dry distillation furnace 1 via the chute 3. Therefore, the molded particles LP mainly come into contact with the guide section 6, and the molded particles LP are temporarily retained on the guide section 6. The guide section 6 may be inclined toward the bottom of the dry distillation furnace 1, but it is preferable to install it parallel to the cross section of the dry distillation furnace 1 to retain the molded particles LP on the guide section 6.

The molded particles LP that remain on the guide section 6 come into contact with the molded particles LP that are being charged one after another. In other words, the molded particles LP that remain on the guide section 6, i.e., the deposit DM, function as a buffer material that suppresses contact and collision between the molded particles LP that are being charged one after another and the guide section 6, and are designed to prevent or suppress both the powdering of the molded particles LP and the wear and damage of the guide section 6. In the embodiment of the present invention, since the guide section 6 mainly comes into contact with the molded particles LP, the dispersion of the powder SP is not particularly hindered. Therefore, the powder SP falls and accumulates in the approximate center in the depth direction of the dry distillation furnace 1, as shown in (a) of FIG. 1. In addition, since the guide section 6 is made of an iron-based material as an example, when it comes into direct contact or collides with the molded products charged from the chute 3, it is more likely to be powdered than when the molded products come into contact or collide with each other.

Here, the size of the guide section 6 will be specifically described. In the example shown in FIG. 1, the guide section 6 is located below the lower end 2A of the inlet 2 of the carbonization furnace 1, and the first ratio (d/W) between the height difference d between the lower end 2A of the inlet 2 and the guide section 6 and the inner dimension W of the carbonization furnace 1 in the depth direction is preferably set to 0.65 or more and 0.80 or less (0.65≦d/W≦0.80). In addition, the second ratio (w/W) between the depth direction length of the guide section 6, i.e., the above-mentioned protruding length w, and the inner dimension W of the carbonization furnace 1 in the depth direction is preferably set to 0.35 or more and 0.50 or less (0.35≦w/W≦0.50).

The molded products that have fallen onto the guide section 6 do not have the momentum to break through the molded flow that is being charged from the charging port 2 of the carbonization furnace 1, that is, to move to the opposite side of the molded flow, or to change the trajectory of the molded flow. This is because the kinetic energy of the molded products when they fall from the chute 3 into the carbonization furnace 1 is greatly reduced by the fall of the molded products onto the guide section 6. Therefore, as shown in (a) of FIG. 1, while the molded flow is occurring, the molded products on the guide section 6 are held on the guide section 6 and do not break through the molded flow from above the guide section 6 and fall below the carbonization furnace 1. Therefore, the molded products on the guide section 6 fall below the carbonization furnace 1 from above the guide section 6 and accumulate in the carbonization furnace 1 only after almost all of the molded products that did not come into contact with the guide section 6 have fallen into the carbonization furnace 1, that is, after the molded flow has disappeared, as shown in (b) of FIG. 1. Note that the guide section 6 does not adversely affect the charging trajectory of the powder SP as long as the powder layer does not come into contact with the guide section 6.

In the embodiment of the present invention, the installation of the guide portion 6 is premised on lowering the accumulation level in the carbonization furnace 1, as described above. Regarding the accumulation level in the carbonization furnace 1, it is preferable that the distance D from the lower end 2A of the inlet 2 of the carbonization furnace 1 to the upper end portion of the accumulation DM in the carbonization furnace 1 always satisfies the following formula:
0.1≦(D-d)/W...(1)
In order to always satisfy the relationship of the above formula (1), the accumulation level in the carbonization furnace 1 is monitored and the molded material is intermittently charged into the carbonization furnace 1. In this way, the dispersibility, i.e., segregation, of both the powder SP and the molded material particles LP in the carbonization furnace 1 can be improved.

Next, an example carried out to confirm the action and effect of the present invention will be described. In this example, a test device simulating the ferro-coke manufacturing device shown in FIG. 1 was used, and the distribution of molded materials in the depth direction of the test device when the molded materials were charged into the test device was investigated. Specifically, the molded material charging device, i.e., the chute, was of approximately the same shape as the chute actually installed in the carbonization furnace 1, and a collection box was installed on the outlet side of the chute to resemble the carbonization furnace 1. A flat guide portion 6 was installed on at least a portion of the inner surface of the collection box in the width direction (corresponding to the furnace width direction of the carbonization furnace 1 described above) facing the inlet of the collection box.

A predetermined amount of molded products was loaded into the collection box from the chute. The collection box was divided into four equal parts in the depth direction and five equal parts in the width direction, for a total of twenty sections. The particle size of the molded products present in each of the divided spaces was investigated. Specifically, the molded products in each space were collected and sieved, the molded products remaining on the sieve were designated as molded product particles LP, and the molded products below the sieve were designated as powder SP, and the weights of the molded product particles LP and the powder SP were measured. A sieve with 20 mm mesh was used to sieve the molded products. Therefore, the particle size of the molded product particles LP was 20 mm or more in diameter, and the particle size of the powder SP was less than 20 mm in diameter. The powder ratio, that is, the weight ratio of the powder SP to the total amount of molded products in each space, was also calculated. The weight of the molded particles LP and the powder ratio are obtained for each of the twenty spaces described above, but in the following explanation, the "maximum powder ratio" is used as an index of the segregation of the powder SP, and the "maximum molded particle weight" is used as an index of the segregation of the molded particles LP. The "maximum powder ratio" is the maximum value of the powder ratio obtained by comparing the powder ratios of each of the twenty spaces. Also, the "maximum molded particle weight" is the maximum value of the molded particle weight obtained by comparing the molded particle weights of each of the twenty spaces.

[Example 1]
In Example 1, the influence of the installation height of the guide section 6 on the maximum powder ratio and the maximum weight of the molded product particles was investigated. The amount of molded product charged was set to 250 kg, the depth direction length w of the guide section 6 was set to 600 mm, and the second ratio (w/W) was set to 0.4, and the height difference d between the lower end 2A of the inlet 2 of the carbonization furnace 1 and the guide section 6 was changed. The results are shown in FIG. 2. After the molded product was charged, the third ratio ((D-d)/W) of the height difference between the upper end portion of the deposit DM in the carbonization furnace 1 and the guide section 6 to the inner dimension W in the depth direction was 0.15 to 0.18, which satisfied the above-mentioned formula (1).

As shown in FIG. 2, it was confirmed that the dispersibility of both the powder SP and the molded particles LP improved when the first ratio (d/W) was in the range of 0.65 to 0.80 (0.65≦d/W≦0.80). When the first ratio (d/W) was less than 0.65 (d/W<0.65), there was insufficient contact between the guide section 6 and the molded particles LP charged from the chute, and the segregation of the molded particles LP was not improved. When the first ratio (d/W) was greater than 0.80 (0.80<d/W), the guide section 6 came into contact with the powder layer, pushing the powder layer back toward the charging inlet 2 of the dry distillation furnace 1, and the segregation of the powder SP was not improved.

[Example 2]
In Example 2, the influence of the depth direction length w of the guide section 6 on the maximum powder ratio and the maximum molded particle weight was investigated. The amount of molded material charged was set to 250 kg, the height difference d between the lower end 2A of the inlet 2 of the carbonization furnace 1 and the guide section 6 was set to 1200 mm, and the first ratio (d/W) was set to 0.80. The results are shown in FIG. 3. After the molded material was charged, the third ratio ((D-d)/W) of the height difference between the upper end portion of the deposit DM in the carbonization furnace 1 and the guide section 6 to the inner dimension W in the depth direction was 0.14 or more and 0.19 or less, which satisfies the above-mentioned formula (1).

As shown in FIG. 3, it was confirmed that the dispersibility of both the powder SP and the molded particles LP improved when the second ratio (w/W) was in the range of 0.35 or more and 0.50 or less (0.35≦w/W≦0.50). When the second ratio (w/W) was less than 0.35 (w/W<0.35), the guide portion 6 and the molded particles LP did not come into sufficient contact with each other, and the segregation of the molded particles LP was not improved. When the second ratio (w/W) was greater than 0.50 (0.50<w/W), the guide portion 6 came into contact with the powder layer, and the powder layer was pushed back toward the inlet 2 of the dry distillation furnace 1, and the segregation of the powder SP was not improved.

[Example 3]
In Example 3, the influence of the accumulation level in the carbonization furnace 1 on the maximum powder ratio and the maximum weight of the molded product particles was investigated. The charging amount of the molded product was 250 kg, the height difference d between the lower end 2A of the charging port 2 of the carbonization furnace 1 and the guide section 6 was set to 1200 mm, the first ratio (d/W) was set to 0.80, the depth direction length w of the guide section 6 was set to 600 mm, and the second ratio (w/W) was set to 0.40. The results are shown in FIG. 4.

As shown in FIG. 4, it was confirmed that the dispersibility of both the powder SP and the molded material particles LP is improved by satisfying the third ratio ((D-d)/W) of the height difference between the upper end of the deposit DM in the carbonization furnace 1 and the guide section 6, and the inner dimension W in the depth direction, of 0.1 or more, i.e., the above-mentioned formula (1), when the third ratio ((D-d)/W) is less than 0.1 ((D-d)/W<0.1) after the molded material is charged, the drop when the molded material deposited on the guide section 6 falls toward the inside of the carbonization furnace 1 is small, i.e., the kinetic energy of the molded material is small, so the molded material particles LP cannot be pushed back sufficiently toward the charging port 2, and segregation of the molded material particles LP is not eliminated.

REFERENCE SIGNS LIST 1 Carbonization furnace 2 Charging inlet 3 Chute 4 Gate 5 Diffusion section 6 Guide section SP Powder LP Molded particle DM Sediment

Claims (6)

In an apparatus for producing raw materials for a blast furnace, raw materials for a blast furnace are produced by carbonizing shaped materials charged into a furnace through a chute,
The molded product has a powder and molded product particles having a particle size larger than that of the powder,
A guide portion is provided protruding into the furnace on at least a portion of the furnace wall facing the charging port to which the chute is connected, the guide portion contacting the molding particles charged into the furnace through the chute and pushing the molding particles back toward the charging port ,
The guide portion is located below the lower end portion of the charging port,
A first ratio (d/W) between a height difference d between the guide portion and a lower end portion of the charging port and an inner dimension W in the depth direction of the furnace is 0.65 or more and 0.80 or less,
A manufacturing apparatus for blast furnace raw material , wherein a second ratio (w/W) of a protruding length w of the guide portion in the depth direction to the inner dimension W is 0.35 or more and 0.50 or less . In the apparatus for producing blast furnace raw material according to claim 1 ,
A manufacturing apparatus for producing raw materials for a blast furnace, wherein the chute is provided with a diffusion section for diffusing the molded materials in the width direction of the furnace when the molded materials are charged into the furnace. In the apparatus for producing blast furnace raw material according to claim 1 or 2 ,
The guide portion of this device for manufacturing raw materials for a blast furnace is in the shape of a flat plate. In the apparatus for producing blast furnace raw material according to any one of claims 1 to 3 ,
The molded product is an apparatus for manufacturing raw material for a blast furnace, the raw material containing a carbon-containing material and an iron-containing material as components. A method for producing raw materials for a blast furnace, comprising producing raw materials for a blast furnace by using an apparatus for producing raw materials for a blast furnace according to any one of claims 1 to 4 . In the method for producing a blast furnace raw material according to claim 5 ,
The accumulation level of the molded products in the furnace is monitored so that the distance D from the lower end of the charging port to the upper end of the molded products accumulated in the furnace always satisfies the following formula:
The method for producing raw material for a blast furnace comprises charging the molded material into the furnace.
0.1≦(D-d)/W

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