Raw material manufacturing apparatus for blast furnace and raw material manufacturing method for blast furnace

Abstract

To provide a method and an apparatus for manufacturing a raw material for a blast furnace by which it is possible to enhance quality and productivity of the raw material for the blast furnace, such as ferro coke.SOLUTION: An apparatus for manufacturing a raw material for a blast furnace includes a pyrolysis furnace body and a charging chute that is disposed above the pyrolysis furnace body and supplies a carbon-containing material to the pyrolysis furnace body. The pyrolysis furnace body includes a leveled part including: a stationary part fixed to a wall part of the body; a telescopic part that has a base end fixed to the stationary part and is formed telescopically in a separating direction from the wall part; and a plate part disposed at a front end of the telescopic part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an apparatus for manufacturing raw materials for a blast furnace and a method for manufacturing raw materials for a blast furnace, which are used in a blast furnace such as formed coke, particularly ferrocoke.

Background Art

[0002] In recent years, from the perspective of global warming, the steel industry has been required to reduce the amount of CO2 gas generated. For this reason, it has become an urgent task to reduce the use of fossil fuels. In the steel industry, hot metal is produced by reducing iron ore with carbon (coke produced by carbonizing coal in a coke oven) in a blast furnace. And, in order to reduce the coke unit, the development of a technology using ferrocoke as a raw material for a blast furnace has been carried out. Ferrocoke is obtained by mixing a certain amount of iron ore with coal, forming it into lumps, and then subjecting it to carbonization treatment to disperse fine metallic iron particles in the coke. It is a formed coke with enhanced reactivity of the coke due to the catalytic action of metallic iron.

[0003] As a carbonization method for ferrocoke, a method using a vertical carbonization furnace has been proposed. Patent Document 1 discloses a vertical carbonization furnace having a carbonization zone at the upper part and a cooling zone at the lower part. The method for manufacturing ferrocoke in a vertical carbonization furnace includes a charging step of charging a formed product composed of a carbon-containing substance and an iron-containing substance into the vertical carbonization furnace using a charging device, a carbonization step of blowing a heating gas into the carbonization zone and carbonizing the formed product to produce ferrocoke, a cooling step of cooling the ferrocoke by blowing a cooling gas into the cooling zone, a furnace gas discharge step of discharging the furnace gas from the discharge port at the top of the vertical carbonization furnace, and a ferrocoke discharge step of discharging the ferrocoke from the lower part of the cooling zone.

[0004] In the carbonization step, the formed product is heated by blowing a low-temperature gas from the low-temperature gas blowing port in the middle part of the carbonization zone and a high-temperature gas from the high-temperature gas blowing port in the lower part of the carbonization zone into the furnace. In the cooling step, the ferrocoke is cooled by blowing a cooling gas from the cooling gas blowing port in the lower part of the cooling zone.

[0005] Here, in order to increase the production amount of ferrocoke, it is necessary to increase the volume of the vertical retort furnace. Generally, the charged material is charged in an inclined direction using an inclined charging chute with the inclined direction as the charging direction. However, since the heating gas and the cooling gas are injected in the depth direction of the vertical retort furnace (parallel to the horizontal component of the charging direction of the charged material), it is necessary to keep the inner dimension in the depth direction below a certain level in order to allow the gas to penetrate to the central part of the furnace. Therefore, the vertical retort furnace is configured to have a longer inner dimension in the furnace width direction (the direction orthogonal to the depth direction in the cross-section of the retort furnace) than in the depth direction, and a large volume is ensured.

[0006] Also, Patent Document 2 discloses a method of uniformly charging (conveying) a material by providing a dispersion guiding portion having an inclined surface that slopes radially downward from the central portion in the width direction of the conveying path toward the outlet side to disperse the material radially.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in a vertical retort furnace having a structure with a larger size in the furnace width direction than in the depth direction, it is difficult to arrange a large number of charging shoots corresponding to all positions in the furnace width direction in order to evenly disperse the carbon-containing material corresponding to the size in the furnace width direction. On the other hand, the powder generated by the collision between the molded product and the wall surface of the charging shoot or the collision between the molded products is likely to segregate, and tends to gather on the charging shoot side at the bottom of the furnace inside the vertical retort furnace. This is because most of the powder in the charged material passes through the gaps between the molded products and settles during the process of passing through the charging shoot, causing the charged material to separate into two layers, namely, a molded product layer (upper layer) and a powder layer (lower layer) before reaching the retort furnace. When 1 ton of molded product is charged, the thickness of the charged material when entering the retort furnace is at most about 150 mm. However, since the molded product is charged from a position higher than the powder existing below it, it is likely to fly to a position far from the charging port, while the powder in the lower layer falls near the charging port.

[0009] Also, at the bottom of the furnace inside the vertical retort furnace, the accumulated molded products form a mountain-shaped slope formed according to the angle of repose. And the formed mountain-shaped slope has a greater inclination as it gets closer to the top. Therefore, even when the powder lands at a position far from the charging port, it is slightly pushed back toward the charging port side and comes to rest. Thus, the moving distance of the powder from landing to coming to rest becomes large. That is, the mountain-shaped slope formed by the molded products reduces the dispersion in the depth direction of the retort furnace and causes significant uneven distribution of the powder. Due to the segregation of the powder, the gas flow inside the furnace becomes non-uniform, causing problems such as poor carbonization of the molded products.

[0010] In addition, since the dispersion guiding part disclosed in Patent Document 2 does not affect the flying distance of the powder, even if the dispersion guiding part is installed, the powder segregation on the charging port side cannot be eliminated.

[0011] The present invention has been made in view of such circumstances, and an object thereof is to provide a raw material manufacturing apparatus for a blast furnace and a raw material manufacturing method for a blast furnace that improve the distribution of the charged material in the furnace of a vertical retort furnace, particularly the distribution of the powder contained in the charged material.

Means for Solving the Problems

[0012] To solve the above problems, the present invention has the following features.

[0013] [1] In a raw material manufacturing apparatus for a blast furnace, comprising a carbonization furnace body and a charging chute provided above the carbonization furnace body for supplying a carbon-containing substance to the carbonization furnace body, the carbonization furnace body has a leveling portion including a fixing portion fixed to its wall portion, a telescopic portion having a proximal end fixed to the fixing portion and formed to be telescopically extendable in a direction away from the wall portion, and a plate portion provided at the tip of the telescopic portion. [2] The telescopic portion of the raw material manufacturing apparatus for a blast furnace according to [1] extends and contracts along the horizontal direction. [3] The carbonization furnace body has a pair of wall portions arranged to face each other in its depth direction, The telescopic portion of the raw material manufacturing apparatus for a blast furnace according to [1] or [2] extends and contracts in the depth direction. [4] The charging chute is provided on one of the pair of wall portions, The telescopic portion of the raw material manufacturing apparatus for a blast furnace according to [3] extends and contracts from the wall portion provided with the charging chute in a direction in which the pair of wall portions face each other. [5] The raw material manufacturing apparatus for a blast furnace according to [4], wherein the relationship between the height from the charging chute to the apex of the charge of the carbon-containing substance supplied to the carbonization furnace body and the distance between the pair of wall portions satisfies the following formula. D / WA≦0.5 D: Height from the opening end of the charging chute to the apex of the charge WA: Distance between the pair of wall portions [6] The raw material manufacturing apparatus for a blast furnace according to any one of [3] to [5], wherein the distance between the pair of wall portions and the distance from the plate portion to the wall portion facing the plate portion when the leveling portion extends satisfy the following formula. 0.2≦WB / WA≦0.4 WA: Distance between a pair of wall portions WB: Distance from the plate portion to the wall portion facing the plate portion when the leveling portion extends [7] The height from the lower end of the plate portion to the apex of the charge of the carbon-containing substance supplied to the retort furnace body and the distance between the pair of wall portions satisfy the following formula, The raw material manufacturing apparatus for blast furnaces according to any one of [3] to [6]. 0.05 ≦ d / WA ≦ 0.15 d: Height from the lower end of the plate portion to the apex of the charge WA: Distance between a pair of wall portions [8] A method for manufacturing a raw material for a blast furnace, which manufactures a raw material for a blast furnace using the raw material manufacturing apparatus for a blast furnace according to any one of [1] to [7]. [9] A supply step of supplying the carbon-containing substance to the retort furnace body, A leveling step of expanding and contracting the leveling portion, and having, The supply step is executed two or more times, The leveling step is executed between the execution of the supply step and the execution of the next supply step. The method for manufacturing a raw material for a blast furnace according to [8].

Effect of the Invention

[0014] According to the present invention, it is possible to improve the distribution of the charge in the retort furnace, particularly the distribution of the powder contained in the charge.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0016] Hereinafter, taking the case of manufacturing ferrocoke, which is a kind of formed coke obtained by mixing a certain amount of iron ore with coal and forming it into lumps, as an example, the present invention will be described through embodiments of the present invention. Here, each drawing is schematic and may differ from the actual one. Further, the following embodiments illustrate devices and methods for embodying the technical idea of the present invention, and do not specify the configuration to be the following. That is, various changes can be made to the technical idea of the present invention within the technical scope described in the claims.

[0017] Referring to FIG. 1, the configuration of a conventional vertical retort furnace 100 will be described. FIG. 1 shows a side schematic view of the vertical retort furnace 100. In the following description, the "charged material" is not limited to the "formed product containing a carbon-containing substance and an iron-containing substance" for manufacturing ferrocoke, and may also include the "formed product containing a carbon-containing substance". That is, any formed product containing at least a carbon-containing substance may be used. The "charged material" includes a "formed product" and a "powder" attached to or separated from the "formed product". Further, the "blast furnace raw material" means "coke" containing ferrocoke.

[0018] The vertical retort furnace 100 has a charging chute 10, a charging gate 20, a diffusing section 30, and a retort furnace body 70. First, the charge containing the molded product containing the carbon-containing substance (coal) and the iron-containing substance (iron ore) is supplied to the charging chute 10 provided above the retort furnace body. The charge is temporarily accumulated inside the charging chute 10 (in the middle of the charging chute 10) due to the closing of the charging gate 20 (refer to the dashed line in the figure). The charge passes through the inside of the charging chute 10 toward the retort furnace body 70 when the charging gate 20 is opened (shown by the solid line in the figure). The charge is dispersed so as to spread inside the charging chute 10 by passing through the diffusing section 30 of the charging chute 10. After passing through the inside of the charging chute 10, the charge accumulates inside the retort furnace body 70. The charge forms a mountain shape according to the angle of repose inside the retort furnace body 70.

[0019] Here, as described above, the charge charged into the retort furnace body 70 is separated into two layers, a molded product layer (upper layer) and a powder layer (lower layer), inside the charging chute 10 before reaching the retort furnace body 70. Therefore, as shown in FIG. 1, the charge charged into the retort furnace body 70 falls inside the retort furnace body 70 while separating into the molded product layer 40 and the powder layer 50. For this reason, the charge 60 accumulated inside the retort furnace body 70 is in a state where the molded product and the powder are unevenly distributed. Due to this uneven distribution, in the conventional vertical retort furnace 100, the gas flow inside the retort furnace body 70 becomes non-uniform, and problems such as poor carbonization of the molded product have occurred.

[0020] <Configuration of leveling section etc.> Next, with reference to FIG. 2, the configuration of the vertical retort furnace 11 which is an embodiment of the present invention will be described. FIG. 2 is a side schematic view of the vertical retort furnace 11 as a raw material manufacturing apparatus 12 for a blast furnace. The vertical retort furnace 11 shown in FIG. 2 further includes a leveling section 80 with respect to the vertical retort furnace 100 shown in FIG. 1.

[0021] Fig. 2(a) shows the state where the prior charge is charged into the vertical retort furnace 11. Fig. 2(b) shows the operation mode of the leveling part 80 of the vertical retort furnace 11. Fig. 2(c) shows the mode in which the subsequent charge is charged onto the prior charge on which the leveling operation of the leveling part 80 has been performed.

[0022] As shown in Fig. 2, the retort furnace main body 7 has a pair of wall parts 7a facing each other in the depth direction S. A leveling part 80 is provided on one wall part 7a of the retort furnace main body 7. The leveling part 80 includes a fixing part 81 fixed to the wall part 7a, a telescopic part 82 whose base end is fixed to the fixing part 81 and is formed to be telescopically extendable in a direction away from the wall part 7a, and a plate part 83 provided at the tip of the telescopic part 82. Incidentally, it is preferable that the telescopic part 82 expands and contracts along the horizontal direction toward the charge 6.

[0023] The leveling part 80 can level the charge 6 formed in a mountain shape by moving the plate part 83 toward the charge 6. And by leveling the charge 6 formed in a mountain shape, the "formed product" and "powder" of the charge 6 are mixed in the vertical direction and the horizontal direction. Thereby, the distribution of the charge 6 in the furnace of the vertical retort furnace 11, particularly the distribution of the powder contained in the charge 6, can be improved.

[0024] The leveling part 80 is preferably provided so as to satisfy the following formula (1) when the height from the opening end of the charging chute 1 to the apex of the charge is D and the distance between the pair of wall parts 7a is WA. By providing the leveling part 80 at a position satisfying the relationship of the following formula (1), the charge 6 formed in a mountain shape can be efficiently leveled (collapsed). D / WA ≦ 0.5 (1)

[0025] When D / WA exceeds 0.5, since the flying distance of the charge tends to be long, it is considered that the apex of the charge 6 formed in a mountain shape is biased toward the wall part 7a facing the charging chute 10. In such a case, the leveling part 80 may expand and contract from the wall part 7a facing the charging chute 10 toward the wall part 7a where the charging chute 10 is provided.

[0026] Similarly, when D / WA is 0.5 or less, since the flying distance of the charged material tends to be short, it is considered that the apex of the charged material 6 formed in a mountain shape is either at the middle between the wall portions 7a in the depth direction S or biased toward the wall portion 7a side where the charging chute 10 is provided. In such a case, the leveling portion 80 may expand and contract from the wall portion 7a where the charging chute 10 is provided toward the wall portion 7a facing the charging chute 10.

[0027] Further, the leveling portion 80 is preferably provided so as to satisfy the following formula (2) when the distance from the plate portion 83 to the wall portion 7a facing the plate portion 83 when the leveling portion 80 extends is defined as WB. By providing the leveling portion 80 at a position satisfying the relationship of the following formula (2), the charged material 6 formed in a mountain shape can be efficiently leveled (collapsed). 0.2 ≦ WB / WA ≦ 0.4 (2)

[0028] When WB / WA exceeds 0.4, the stop position of the plate portion 83 when the leveling portion 80 is extended becomes closer to the wall portion 7a side where the fixing portion 81 is provided than the middle of the distance WA, and the charged material 6 formed in a mountain shape cannot be sufficiently leveled.

[0029] When WB / WA is less than 0.2, there is a risk that the charged material will be pinched between the plate portion 83 and the wall portion 7a when the leveling portion 80 is extended. If the leveling portion 80 further extends in such a state, pressure is applied to the charged material 6, and as a result, there is a risk of generating powder.

[0030] Furthermore, the leveling portion 80 is preferably provided so as to satisfy the following formula (3) when the height from the lower end of the plate portion 83 to the apex of the charged material is defined as d. 0.05 ≦ d / WA ≦ 0.15 (3)

[0031] When d / WA is less than 0.05, the resistance received by the leveling portion 80 due to contact with the charged material becomes small, and the charged material 6 in a mountain shape cannot be sufficiently leveled.

[0032] When d / WA exceeds 0.15, the resistance that the leveling part 80 receives due to contact with the charged material becomes larger than expected, and the lifespan of the leveling part 80 may be shortened.

[0033] WB / WA and d / WA may be set to be constant. By setting them in this way, even if the operating speed when expanding and contracting the leveling part 80 is changed, the influence can be reduced. In addition, if the expansion and contraction direction of the plate part 83, and WB / WA and d / WA are constant, there is no difference in the leveling effect due to the difference in the operating speed when expanding and contracting the leveling part 80.

[0034] <Method for manufacturing raw materials for blast furnace> Next, a method for manufacturing raw materials for a blast furnace that levels the mountain-shaped charged material 6 deposited inside the dry distillation furnace body 7 by means of the vertical dry distillation furnace 11 having the leveling part 80 will be described.

[0035] The method for manufacturing raw materials for a blast furnace includes a supply step of supplying a carbon-containing substance to the dry distillation furnace body 7 and a leveling step of expanding and contracting the leveling part 80. The supply step is executed two or more times, and the leveling step is executed after one supply step is executed and before the next supply step is executed.

[0036] Figure 3 shows the operating mode of the leveling part 80 in the leveling step. As shown in Figure 3, in the leveling step, the plate part 83 of the leveling part 80 expands and contracts in the horizontal direction with respect to the charged material 6 deposited inside the dry distillation furnace body 7. Thereby, it becomes possible to efficiently level (collapse) the charged material 6 formed in a mountain shape.

[0037] Here, as described above, the charge (hereinafter also referred to as "preceding charge") that is first charged into the vertical retort furnace 11 is formed in a mountain shape and deposited inside the retort furnace body 7. Then, the charge (hereinafter also referred to as "subsequent charge") that is subsequently charged into the vertical retort furnace 11 is in a state of being separated into two layers, namely, the molded product layer 4 and the powder layer 5, when it falls from the charging chute 1 into the retort furnace body 7. And when the powder layer 5 of the subsequent charge lands near the top of the mountain shape formed by the preceding charge, the moving distance until it moves along the slope of the mountain shape and comes to rest becomes large. For this reason, the moving distance of the powder contained in the powder layer 5 of the subsequent charge becomes large, and the uneven distribution of the powder in the charge 6 deposited inside the retort furnace body 7 becomes remarkable.

[0038] On the other hand, in the present embodiment, when the preceding charge previously charged into the vertical retort furnace 11 is deposited in a mountain shape inside the retort furnace body 7, the leveling part 80 is expanded and contracted with respect to the preceding charge to level the charge.

[0039] FIG. 4 shows the mode of the supply step after the leveling step is executed. As shown in FIG. 4, after the leveling step is executed, the subsequent charge is charged into the vertical retort furnace 11. Thereby, when the subsequent charge falls toward the inside of the retort furnace body 7, since the preceding charge is not formed in a mountain shape, uneven distribution of the powder contained in the subsequent charge due to moving along the slope does not occur, and powder segregation can be alleviated.

[0040] As described above, according to the present invention, by providing the leveling part 80 on the wall part 7a of the retort furnace body 7, the distribution of the charge 6 in the furnace of the vertical retort furnace 11, particularly the distribution of the powder contained in the charge 6, can be improved.

Example

[0041] (Test Example 1: Test on the expansion and contraction direction of the leveling part) For a plurality of examples in which the expansion and contraction direction of the leveling part was changed, the standard deviation of the height of the charge and the maximum powder ratio in a test system imitating a retort furnace were confirmed.

[0042] (Raw material manufacturing device for blast furnace) A test device that simulated a ferrocoke manufacturing device was used as a test system. Specifically, a charging chute and the like having the same shape as those installed in the actual machine were used, and a recovery box having the same shape as a retort furnace was installed at the tip side of the charging chute, with the retort furnace regarded as a reference.

[0043] A leveling section was provided in the recovery box, and the operation mode thereof was changed. Specifically, cases were as follows: when the leveling section was not operated (none); when the leveling section was provided on one of a pair of wall portions provided in a direction orthogonal to the depth direction of the recovery box and extended toward the other wall portion (B1); when the leveling section was provided on the other of a pair of wall portions provided in a direction orthogonal to the depth direction of the recovery box and extended toward the one wall portion (B2); when the leveling section was provided on one of a pair of wall portions provided in the depth direction of the recovery box and extended toward the other wall portion (A1); when the leveling section was provided on the other of a pair of wall portions provided in the depth direction of the recovery box and extended toward the one wall portion (A2); and a test was conducted for an example in which the leveling section was provided on the other of a pair of wall portions provided in the depth direction of the recovery box, extended toward the one wall portion, and was inclined so that the angle θ formed by the horizontal direction and the expansion and contraction section was 30° (A3).

[0044] In addition, D / WA: (height from the opening end of the charging chute to the apex of the charged material) / (distance between wall portions in the expansion and contraction direction of the leveling section) was set to 0.4. Also, WB / WA: (distance from the tip of the plate portion 83 to the wall portion 7a facing the plate portion 83) / (distance between wall portions in the expansion and contraction direction of the leveling section 80) was set to 0.3. Further, d / WA: (height from the lower end of the plate portion 83 to the apex of the charged material) / (distance between wall portions in the expansion and contraction direction of the leveling section 80) was 0.10. Moreover, a flat plate made of acrylic with a thickness of 5 m was used for the plate portion of the leveling section. In addition, the speed of the expansion and contraction operation of the plate portion of the leveling section was 1 m / s.

[0045] The charged material consisted of 95% by mass of the molded product and 5% by mass of the powder. Also, the amount of the charged material supplied to the collection box in one supply operation was set to 25 kg. In this example, the charged material with a diameter of 20 mm or more was defined as the "molded product", and the molded product with a diameter of less than 20 mm was defined as the "powder". Also, for the measurement of the particle size, a square sieve with a mesh opening of 20 mm was used. That is, what remained on the sieve was regarded as the molded product, and what fell through the sieve was regarded as the powder.

[0046] (Measurement) After expanding and contracting the leveling part to level the mountain-shaped charged material, the height of each charged material was measured at five points (in the depth direction) of the charged material, and the standard deviation of the height was calculated from the measurement results.

[0047] After that, the second supply operation of the charged material was performed. Furthermore, at the above five locations, sampling was carried out to investigate the powder ratio. The powder ratio was defined as the weight ratio of the sample (powder) that fell through a square sieve with a mesh opening of 20 mm when the sample was sieved. Also, the maximum powder ratio was the maximum value of the powder ratios obtained by comparing the powder ratios at these five points. The results are shown in Fig. 5.

[0048] As shown in Fig. 5, regardless of the direction in which the leveling part was operated, whether it was in the directions of B1, B2, A1, A2, or A3, better results were obtained for the "standard deviation of height" and the "maximum powder ratio" than when the leveling part was not operated (none).

[0049] Also, regardless of the direction in which the leveling part was operated, whether it was in the directions of A1, A2, or A3, better results were obtained for the "standard deviation of height" and the "maximum powder ratio" than when the leveling part was operated in the directions of B1 and B2.

[0050] Furthermore, regardless of the direction in which the leveling part was operated, whether it was in the directions of A1 or A2, better results were obtained for the "standard deviation of height" than when the leveling part was operated in the direction of A3.

[0051] Moreover, when the leveling part was operated in the direction of A2, better results were obtained for the "maximum powder ratio" than when the leveling part was operated in the direction of A1.

[0052] As described above, by horizontally operating the expansion and contraction direction of the leveling part in the depth direction of the device, it was confirmed that the mountain-shaped molded product (charged material) can be effectively leveled. From this, it can be understood that it is possible to suppress the deposition of the powder contained in the molded product supplied for the second time at a biased position.

[0053] Also, by expanding and contracting the leveling part from the wall part where the charging chute is provided toward the opposing wall part, while leveling the mountain-shaped molded product (charged material), the powder staying in the vicinity of the charging chute can be pushed out in its extension direction. As a result, it is possible to suppress the deposition of the powder contained in the molded product at a biased position.

[0054] (Test Example 2: Elongation Rate Test of Leveling Part) Regarding a plurality of examples with different elongation rates of the leveling part, the standard deviation of the height of the charged material and the maximum powder ratio in a test system modeled after a carbonization furnace were confirmed. In this test example, the same device as in Test Example 1 was used. Also, in this test example, the standard deviation of the height of the charged material and the maximum powder ratio were measured in the same manner as in Test Example 1. Furthermore, the expansion and contraction direction of the leveling part was set to the horizontal direction.

[0055] The results are shown in FIG. 6. As shown in FIG. 6, when the value of WB / WA exceeded 0.4, in all cases, the height standard deviation exceeded 60 mm. That is, it was found that when the value of WB / WA exceeds 0.4, it is difficult to sufficiently level the mountain-shaped molded product (charged material). Also, when the value of WB / WA exceeded 0.4, the maximum powder ratio also exceeded 15%, reaching the same level as the case where the leveling part is not operated and the ratio is 1.0. Therefore, it was found that it is difficult to suppress the deposition of the powder contained in the charged material at a biased position at this ratio.

[0056] In addition, when WB / WA is less than 0.2, it was found that the maximum powder ratio becomes 15% or more. This is presumably because the charged material is pinched between the plate part and the wall part, and further pressure is applied, causing the charged material to break and turn into powder. Based on the above, it is desirable that the elongation rate of the leveling part satisfies 0.2 ≦ WB / WA ≦ 0.4.

[0057] (Test Example 3: Resistance Test on the Leveling Part) Regarding a plurality of examples with different heights d from the lower end of the plate part to the apex of the charged material, the standard deviation of the height of the charged material and the maximum powder ratio in a test system modeled after a retort furnace were confirmed. In this test example, the same apparatus as in Test Example 1 was used. Also, in this test example, the standard deviation of the height of the charged material and the maximum powder ratio were measured in the same manner as in Test Example 1. Furthermore, for the leveling part, WB / WA was set to 0.3, and its expansion and contraction direction was set to the horizontal direction.

[0058] The results are shown in Fig. 7. As shown in Fig. 7, when d / WA is less than 0.05, all the results show that the standard deviation of the height exceeds 60 mm. That is, when d / WA is less than 0.05, it was found that it is difficult to sufficiently level the mountain-shaped molded product (charged material).

[0059] Also, when d / WA exceeds 0.15, good results were obtained for the standard deviation of the height and the maximum powder ratio. However, the load on the leveling part was high, and cracks were confirmed in the leveling part after the experiment.

[0060] As described above, it is desirable that the ratio of the height d from the lower end of the plate part to the apex of the charged material to the distance WA between the wall parts in the expansion and contraction direction of the leveling part is in the range of 0.05 ≦ d / WA ≦ 0.15.

Explanation of Symbols

[0061] 1 Charging chute 4 Molded product layer 5 Powder layer 6 Charged material 7 Retort furnace body 7a Wall part 10 Charging chute 11 Vertical retort furnace 12 Raw material manufacturing device for blast furnace 80 Levelling section 81 Fixing section 82 Telescopic section 83 Plate section

Claims

1. In a raw material manufacturing apparatus for a blast furnace having a retort furnace body and a charging chute provided above the retort furnace body for supplying a carbon-containing substance to the retort furnace body, the retort furnace body has a leveling portion including a fixing portion fixed to its wall portion, a telescopic portion having a base end fixed to the fixing portion and formed to be telescopically extendable in a direction away from the wall portion, and a plate portion provided at the tip of the telescopic portion, in the raw material manufacturing apparatus for a blast furnace.

2. The telescopic portion of the raw material manufacturing apparatus for a blast furnace according to claim 1 extends and contracts along the horizontal direction.

3. The retort furnace body has a pair of wall portions arranged to face each other in the depth direction thereof, The telescopic portion of the raw material manufacturing apparatus for a blast furnace according to claim 1 or 2 extends and contracts in the depth direction.

4. The charging chute is provided on one of the pair of wall portions, The telescopic portion of the raw material manufacturing apparatus for a blast furnace according to claim 3 extends and contracts in a direction in which the pair of wall portions face each other from the one wall portion provided with the charging chute.

5. In the raw material manufacturing apparatus for a blast furnace according to claim 4, the relationship between the height from the charging chute to the apex of the charge of the carbon-containing substance supplied to the retort furnace body and the distance between the pair of wall portions satisfies the following formula. D / WA ≤ 0.5 D: Height from the opening end of the charging chute to the apex of the charge WA: Distance between the pair of wall portions

6. In the raw material manufacturing apparatus for a blast furnace according to claim 3, the distance between the pair of wall portions and the distance from the plate portion to the wall portion facing the plate portion when the leveling portion is extended satisfy the following formula. 0.2 ≤ WB / WA ≤ 0.4 WA: Distance between the pair of wall portions WB: Distance from the plate portion to the wall portion facing the plate portion when the leveling portion is extended

7. In the raw material manufacturing apparatus for a blast furnace according to claim 4, the distance between the pair of wall portions and the distance from the plate portion to the wall portion facing the plate portion when the leveling portion is extended satisfy the following formula. 0.2 ≤ WB / WA ≤ 0.4 WA: Distance between the pair of wall portions WB: Distance from the plate portion to the wall portion facing the plate portion when the leveling portion is extended

8. In the raw material manufacturing apparatus for a blast furnace according to claim 5, the distance between the pair of wall portions and the distance from the plate portion to the wall portion facing the plate portion when the leveling portion is extended satisfy the following formula. 0.2 ≤ WB / WA ≤ 0.4 WA: Distance between the pair of wall portions WB: The distance from the plate part to the wall part facing the plate part when the leveling part extends

9. The blast furnace raw material manufacturing apparatus according to claim 3, wherein the distance between the pair of wall parts and the height from the lower end of the plate part to the apex of the charge of the carbon-containing substance supplied to the retort furnace main body satisfy the following formula: 0.05 ≦ d / WA ≦ 0.15 d: The height from the lower end of the plate part to the apex of the charge WA: The distance between the pair of wall parts

10. The blast furnace raw material manufacturing apparatus according to claim 4, wherein the distance between the pair of wall parts and the height from the lower end of the plate part to the apex of the charge of the carbon-containing substance supplied to the retort furnace main body satisfy the following formula: 0.05 ≦ d / WA ≦ 0.15 d: The height from the lower end of the plate part to the apex of the charge WA: The distance between the pair of wall parts

11. The blast furnace raw material manufacturing apparatus according to claim 5, wherein the distance between the pair of wall parts and the height from the lower end of the plate part to the apex of the charge of the carbon-containing substance supplied to the retort furnace main body satisfy the following formula: 0.05 ≦ d / WA ≦ 0.15 d: The height from the lower end of the plate part to the apex of the charge WA: The distance between the pair of wall parts

12. The blast furnace raw material manufacturing apparatus according to claim 6, wherein the distance between the pair of wall parts and the height from the lower end of the plate part to the apex of the charge of the carbon-containing substance supplied to the retort furnace main body satisfy the following formula: 0.05 ≦ d / WA ≦ 0.15 d: The height from the lower end of the plate part to the apex of the charge WA: The distance between the pair of wall parts

13. The blast furnace raw material manufacturing apparatus according to claim 7, wherein the distance between the pair of wall parts and the height from the lower end of the plate part to the apex of the charge of the carbon-containing substance supplied to the retort furnace main body satisfy the following formula: 0.05 ≦ d / WA ≦ 0.15 d: The height from the lower end of the plate part to the apex of the charge WA: The distance between the pair of wall parts

14. The blast furnace raw material manufacturing apparatus according to claim 8, wherein the distance between the pair of wall parts and the height from the lower end of the plate part to the apex of the charge of the carbon-containing substance supplied to the retort furnace main body satisfy the following formula: 0.05 ≦ d / WA ≦ 0.15 d: The height from the lower end of the plate part to the apex of the charge WA: The distance between the pair of wall parts

15. A method for manufacturing a blast furnace raw material, using the blast furnace raw material manufacturing apparatus according to claim 1 or 2 to manufacture a blast furnace raw material.

16. A supply step of supplying the carbon-containing substance to the retort furnace main body, and A leveling step of expanding and contracting the leveling part. The supply step is executed two or more times, The method for producing raw materials for a blast furnace according to claim 15, wherein the leveling step is executed after the supply step is executed and before the next supply step is executed.

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