JP2002256348A - Method for manufacturing sintered ore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing sintered ore in high yield by preventing the mixing-in of coarse grains into drawn-out coke fines and forming grain size into proper values in a sintered-ore-manufacturing method on a so-called carbonaceous material top charging system where operations are performed while regulating the blending amount of coke fines in a packed bed of raw materials for sintering placed on a pallet so that it is larger in the upper-layer part than in the lower-layer part by adding coke fines drawn out of the side-wall part of a carbonaceous-material hopper to the lower part of the raw materials for sintering flowing down on a sloping chute. SOLUTION: A grizzly 5 having a vibrator is provided to an opening 3 formed in the side wall 2 of the carbonaceous-material hopper 1, and a baffle plate 6 is attached to the inner surface of the side wall 2 at a position above the opening 3. By this method, the mixing-in of the coarse grains into the drawn-out coke fines can be prevented while preventing the clogging of the grizzly 5 due to the coarse grains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving a method for producing a sintered ore, and more particularly, to improving the productivity by uniformly increasing the strength of the sintered ore and improving the yield. The present invention relates to a method for producing a sintered ore.

[0002]

2. Description of the Related Art Sinter ore is mainly composed of iron oxide raw materials such as fine ore or iron-containing raw materials (mill scale, blast furnace dust, converter dust, etc.) generated in an ironworks, and powdered limestone or It is generally manufactured by blending silica stone or the like as an auxiliary material and further igniting and sintering a mixture of coke powder, anthracite powder and the like as a carbon material.

FIG. 3 is a schematic explanatory view showing an outline of a typical Dwyroid (DL) type sintering machine as a sintering machine, in which 21 is a moving pallet, 22 is a drum mixer,
Reference numeral 23 denotes an ignition furnace, 24 denotes a blower, 25a denotes a main raw material (fine ore) hopper, 25b denotes an auxiliary raw material hopper, and 1 denotes a carbon material hopper. In producing sinter by this sintering machine, 10 to 20 m
The mixture of the main raw material, the auxiliary raw material, and the carbonaceous material as described above is placed on a moving pallet 21 on which a m-grain size bed is placed as a floor and 20 to 30 mm is placed. More specifically, hopper 2
5a, 25b, and 1 said main raw materials respectively stored in;
The auxiliary raw material and the carbonaceous material are taken out, water is further added, and the sintering raw material mixed and granulated by the drum mixer 22 and quasi-particled is charged from the supply hopper 26 by the drum feeder 27 into a charging chute (sloping chute). The layers 16 are spread on the movable pallet 21 through the layer 16 to a thickness of 300 to 600 mm. Then, the ignition furnace 23 installed immediately after the raw material charging position ignites the carbon material (usually, coke breeze) present in the upper layer of the raw material layer.
Air flows through the raw material layer spread in layers by air suction from above to below by the blower 24,
As a result, the combustion position gradually burns from the upper portion to the carbon material in the lower portion. Due to the heat generated by combustion of the carbonaceous material, a part of the raw material filling is melted, and then cooled, whereby the raw material particles are sintered and bonded to each other, and then crushed by a crusher (not shown) to about 50 mm or less, and sieved. It is divided and adjusted to a particle size that is easy to use in the blast furnace in the next step.

[0004] Incidentally, the yield of the product sintered ore is affected by various factors such as the amount of heat supplied, the amount of combined slag and its strength and porosity. Among the factors, the effect of the embrittlement layer existing in the upper layer portion of the sintering raw material filling layer is the largest, and the yield of the product sintered ore is particularly low. This embrittlement layer is assumed to be present in the upper part of the depth portion from the outermost layer of the sintering raw material filling layer to 30 to 50 mm, and the amount of molten slag required for bonding of the sintered ore is higher than in other parts. The packing layer is extremely small and brittle. The reason why the embrittlement layer is formed is considered as follows. That is, in the sintering process, air at room temperature is inevitably sucked from above. Therefore, before the ore is heated to a high temperature necessary for melting the slag-making component in the upper part of the sintering material packed bed, the combustion of the coke breeze in the sintering material packed bed (bed) is started. It ends. As a result, in the upper part of the sintering material-filled layer, the amount of molten slag required for bonding the sintered ore tends to be insufficient, and the portion where the amount of molten slag is insufficient is the embrittlement layer. Becomes

[0005] In order to eliminate such an embrittlement layer and improve the yield of sintered ore, the carbon material such as the above-mentioned coke breeze is segregated in the upper layer of the sintering raw material filling layer.
It is known that it is effective to increase the carbon material concentration in the upper layer (for example, “materials and processes”, vo
l. 13, 1990, p. 964), but various proposals have been made as specific methods thereof, but they have not been applicable to the actual method of producing sintered ore (for example, Japanese Patent Application Laid-Open No. 61-12 / 1986).
No. 7827, Japanese Utility Model Application Laid-Open No. 1-66599, and Japanese Patent Application Laid-Open No. 5-98358).

Accordingly, the present applicant has further researched and developed a specific method that can be used for actual production of sintered ore, and as a result, completed the invention disclosed in Japanese Patent Application Laid-Open No. 10-330854. An attempt was made to apply the invention to an actual sintering machine. The outline of the invention disclosed in JP-A-10-330854 is as follows.

[0007] That is, in FIG.
When the sintering raw material R is placed on the moving pallet 21 by the charging chute 16 (16a) installed in the direction opposite to the moving direction of the moving pallet 21 from the supply hopper 26, the sintering raw material R is placed on the charging chute 16 (16a). On the way to fall,
The carbon material P is added to the lower part of the sintering raw material R,
The operation is carried out by increasing the amount of the carbon material present in the upper layer of the sintering raw material packed layer S placed on the upper side than in the lower layer (the charging chute upper stage 16a is described later). This is the configuration of the embodiment of the present invention). Further, as described later in Example 1, the particle size of the carbon material present in the upper layer portion of the sintering raw material packed layer S is most preferably 1 to 3 mm, and then preferably 3 to 5 mm ( See Table 1 below). If the particle size of the carbon material is less than 1 mm,
The heat transfer to the air takes precedence over the heat transfer to the solid ores, so the temperature of the ores does not rise sufficiently, the fusion bonding force between the ore particles is not obtained, and the strength Is likely to decrease. On the other hand, the particle size of the carbon material is 5 mm
If the temperature exceeds the range, the time until the carbon material is ignited by the ignition burner becomes longer, which may cause a reduction in the production speed.

However, in applying the above invention to an actual sintering machine, the following problems remain.

That is, as a carbon material added in advance as a sintering raw material (hereinafter referred to as “a sintering raw material carbon material”),
Usually, a sieve that has been sieved with a screen having an opening of 5 mm square is used. On the other hand, the particle size of the newly added carbon material (hereinafter referred to as “added carbon material”) is most preferably 1 to 3 mm, and preferably 3 to 5 mm as described above. In order to obtain by screen sieving, it is necessary to add a new 1 mm, 3 mm opening screen, which increases the equipment cost. In addition, such a fine opening screen is easily clogged, and the sieving efficiency is reduced. It is not practical because it is significantly reduced. It is also necessary to separately install a hopper for storing the sieved additive carbon material.

On the other hand, when the carbon material for the sintering raw material is gravity-charged from above the hopper in order to temporarily store it in the existing carbon material hopper, it is usually dropped near the center axis of the hopper. Fine particles tend to collect near the center of the hopper, and coarse particles tend to collect on the side wall of the hopper. The present inventors considered that the above problem could be solved by utilizing this segregation phenomenon, and devised the following equipment configuration.

That is, by providing an opening in the side wall of the carbon material hopper and extracting the carbon material from the opening, the ratio of fine particles less than 1 mm is reduced, and the ratio of the added carbon material having a high ratio of particles of 1 to 5 mm is high. Can be selectively taken out. Thus, there is no need to add a new screen, and there is no need to separately provide a hopper for temporarily storing the added carbon material.

[0012]

However, the opening is 5 m.
It is inevitable that particles (coarse particles) having a particle size exceeding 5 mm are mixed in the under-sieved powder sieved with an m-square screen. For example, when the openings become large due to abrasion or breakage of the openings of the screen and coarse particles exceeding 5 mm pass through the screen, or when a plurality of particles arranged in series to transport the carbon material from the screen to the carbon material hopper are provided. Not only for conveying the undersize powder of 5 mm or less, but also for conveying the coarse-grained carbonaceous material on the screen of more than 5 mm for use in other factories. When used alternately and alternately according to the transport destination, it is assumed that coarse particles remaining on the belt conveyor at the time of switching may be mixed under the sieve. Conventionally, even if such coarse particles are mixed in the carbon material for sintering raw material, the mixing ratio is not so high, so that when mixed in the sintering raw material, there is almost no effect and there is no problem. .

However, the coarser the particles, the more they tend to collect on the side wall when charged into the hopper, and the particles extracted from the side wall of the carbon material hopper contain a very high proportion of coarse particles of more than 5 mm. In order to perform the above,
It has been found that the effect of the invention disclosed in Japanese Patent Publication No. 4 cannot be sufficiently obtained.

Accordingly, the present invention provides a method for manufacturing a sintered ore that improves the yield of the sintered ore by preventing such coarse particles from being mixed by simple means and optimizing the particle size of the added carbon material. The aim is to provide a method.

[0015]

According to the first aspect of the present invention, an iron oxide raw material as a main raw material, an auxiliary raw material, and a carbon material cut out from the bottom of a carbon material hopper are mixed in advance to form a sintering raw material. When the sintering raw material is placed in a layer on the moving pallet by a charging chute installed in a direction opposite to the moving direction of the moving pallet, a lower portion of the sintering raw material flowing down on the charging chute is placed on the moving pallet. By adding a new carbon material, the amount of the carbon material present in the upper layer portion of the sintering material packed layer placed on the moving pallet is present in the packed layer portion below the upper layer portion. In the method for producing a sintered ore in which the amount of the carbonaceous material is larger than the amount of the carbonaceous material, the newly charged carbonaceous material is provided on a side wall portion of the carbonaceous material hopper, and includes coarse particle mixing prevention means. Of sintered ore characterized by being cut out from the opening It is a production method.

According to the present invention, since the opening provided with the coarse particle mixing preventing means is provided on the side wall of the hopper, coarse particles are mixed into the newly mixed carbon material (added carbon material). The carbonaceous material having a small proportion of fine grains can be extracted while preventing the carbonaceous material from being added, and the particle size range of the added carbonaceous material can be adjusted appropriately. As a result, the yield of sintered ore can be improved.

According to a second aspect of the present invention, the coarse particle mixing preventing means includes a carbon material extraction leg for extracting the carbon material from the entire surface of the opening or the carbon material from the opening in a direction in which the carbon material is extracted from the opening. The method for producing a sintered ore according to claim 1, wherein a grizzly is provided over the entire cross section.

According to the present invention, the mixing of coarse particles can be prevented by a simple means called grizzly.

According to a third aspect of the present invention, the coarse particle mixing preventing means further comprises a baffle plate provided above the opening and on the inner surface of the side wall of the carbon material hopper. Or a method for producing a sintered ore according to 2.

According to the present invention, the baffle plate prevents or alleviates the inflow of coarse particles directly into the opening, and prevents the space above the grizzly from being densely filled with the particles. Clogging of coarse particles is reduced, and carbon materials can be cut out more smoothly.

According to a fourth aspect of the present invention, the length of the baffle plate extending in the horizontal direction is set to 5 to 5 times the diameter of the horizontal section or the cross length of the carbon material hopper at the height where the baffle plate is installed. The method for producing a sintered ore according to claim 3, wherein the content is set to 20%.

According to this invention, the function and effect of the invention of claim 3 can be reliably obtained by setting the length of the baffle plate extending in the horizontal direction to be not less than the lower limit (5%). By setting the upper limit value (20%) or less, it is possible to secure the amount of particles flowing into the openings in the appropriate particle size range.

According to a fifth aspect of the present invention, the means for preventing coarse particles from entering further comprises a carbon material discharge chute having an opening for extracting a carbon material at a middle portion between a central portion and a side wall portion of the carbon material hopper. The method for producing a sintered ore according to claim 2, wherein the sintered ore is connected to a part.

According to the present invention, since the carbon material is extracted between the central portion and the side wall of the hopper, the mixing ratio of fine and coarse particles to the extracted carbon material (added carbon material) is small, and the grizzly Can reduce the clogging with coarse particles and enable smooth cutting of the carbon material, and can extract the added carbon material having an appropriate particle size.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a carbon material hopper according to an embodiment of the sinter ore production method of the present invention, and FIG. 2 is a sectional view of a sintering machine according to the embodiment of the sinter ore production method of the present invention. FIG. 3 is a schematic explanatory view of an ore supplying section, FIG. 3 is an overall flow diagram of a sintering facility according to an embodiment of a sinter ore production method of the present invention, and FIG. FIG. 4 is a schematic flow chart of a facility for supplying a newly added carbon material (added carbon material) according to the embodiment.

That is, in FIG. 3, the raw material tank comprises a fine ore hopper, an auxiliary raw material hopper, and a carbonaceous material hopper. Is added in a drum mixer, mixed and granulated to obtain a sintering raw material. Note that the carbon material for the sintering raw material is cut out from the bottom of the hopper as in the past. The sintering raw material granulated by the drum mixer is temporarily stored in a feed hopper provided above the entrance of the sintering machine by a bucket elevator or the like, and then is quantitatively thrown from the feed hopper to a drum feeder by a drum feeder ( Into the sintering chute), placed on the moving pallet of the sintering machine,
A sintering raw material filling layer is formed.

The steps up to this point are common to the conventional method for producing a sintered ore that does not use the added carbon material. Hereinafter, features of the present invention will be described.

As shown in FIGS. 1 (a) and 1 (b), an additional carbon material extraction leg 4 is connected to an opening 3 provided in a side wall portion 2 of a carbon material hopper 1, and the rear portion of the opening (addition). The grizzly 5 is installed on the entire surface of the opening 3 or the entire cross section of the upper part of the leg 4 on the side of the carbon material extracting direction). The slit width of the grizzly 5 may be about 5 mm so that coarse particles exceeding 5 mm are not mixed into the leg 4.
Is set so that the coarse particles return to the inside of the hopper 1 without accumulating on the grizzly bar 5a.
5 °) or more is desirable. On the other hand, if it is too close to vertical, even particles of an appropriate particle size are rebounded by the grizzly bar 5a, and it becomes difficult to extract a sufficient amount to the leg 4, so that it is about 60 ° or less. Is preferred. Further, it is preferable that the grizzly bar 5a is installed not along the horizontal direction but along the inclination direction of the grizzly 5 so that the coarse particles hardly accumulate on the grizzly bar 5a. Further, it is preferable that the slit width is set to slightly widen downward and the grizzly 5 can be vibrated continuously or intermittently. Thereby, even if coarse particles are caught in the slits, they easily come off due to vibration, slide down on the slits, and return to the hopper 1. Even if the coarse particles returned to the hopper 1 are cut out from the bottom 7 and mixed with the sintering raw material as the sintering raw material carbon material Q, as described above, the coarse particles are mixed into the sintering raw material. There is no problem because the ratio is small.

As shown in FIGS. 1A and 1B,
It is preferable that a baffle plate 6 be provided on the inner surface of the side wall 2 of the hopper 1 above the opening 3. As mentioned above, hopper 1
The coarse particles tend to collect on the side wall portion 2 due to the percolation phenomenon when the carbon material is charged into the side wall portion.
It is prevented or mitigated that the coarse particles gathered at the opening directly flow into the opening 3 and the space above the grizzly 5 is
The particles are prevented from being densely packed, and the grizzly 5 is less likely to be clogged with coarse particles. Note that the overhang length Wa of the baffle plate 6 is determined by the hopper 1 at the installation height of the baffle plate 6.
Is preferably 5 to 20% of the diameter or the passing length Wb. When Wa becomes 5% or more of Wb, the opening 3
The flow of coarse particles into the grizzly 5 is remarkably reduced, and the space above the grizzly 5 is sufficiently loosely packed, so that the clogging of the grizzly 5 is hardly recognized.
If it is 0% or less, a sufficient amount of particles having an appropriate particle size range to flow into the opening 3 can be secured, and the required amount can be smoothly extracted. In order to prevent coarse particles from flowing into the opening 3 from the side and the tip of the baffle plate 6, the mounting width of the baffle plate 6 is made wider than the width of the opening. It is more preferable to attach the plate 8 in the orientation. Further, the baffle plate 6 may be installed upward from the mounting portion toward the center of the hopper 1. This is because the coarse particles stay on the baffle plate 6 and do not easily flow into the opening 3. The upward angle is preferably 40 to 60 degrees with respect to the horizontal.

Alternatively, instead of the baffle plate 6, a carbon material extraction chute having an opening for extracting the carbon material is provided at the center of the carbon material hopper 1 and at an intermediate portion between the side walls, and this is connected to the opening 3. You may. For the position and height of the opening of the carbon material extraction chute, for example, by appropriately changing the position and height of the opening, the particle size distribution of the extracted carbon material (added carbon material) in each case is measured, and the appropriate particle size distribution is determined. What is necessary is just to determine by selecting the position and height of the opening at the time of being obtained.

As shown in FIG. 4, the added carbonaceous material P extracted from the legs 4 is transferred to the belt conveyor 11 as shown in FIG.
For example, it is sent to the added carbon material pumping device 12. Then, the added carbon material P is pneumatically transported by, for example, high-pressure air by the pressure feeding device 12 and temporarily stored in the added carbon material hopper 14 provided above the inlet of the sintering machine 13. Since the added carbonaceous material P is not mixed with coarse particles exceeding 5 mm, clogging does not occur in the pipe 15 or the like in the middle even by air flow transportation.
Note that, instead of the pressure feeding device 12, a belt conveyor, a bucket elevator, or the like is used, and the hopper 1 above the sintering machine 13 is used.
4 can be transported. In such a case, the problem of clogging in the pipe or the like does not originally occur, but there is a problem that the equipment cost is higher than that of the pressure feeding device 12.

Next, as shown in FIG. 2, for example, the added carbon material P is quantitatively cut out from the added carbon material hopper 14, and the added carbon material spraying device 17 provided above the sloping chute 16 provides a wide sloping chute 16 with a large width. It is supplied so as to uniformly enter the lower part of the sintering raw material R flowing down in the width direction. Here, the added carbonaceous material dispersing device 17 is a device in which an elongated triangular dispersing plate is horizontally installed over the width of the sloping chute 16 and the dispersing plate is horizontally vibrated in the width direction of the sloping chute. The additive carbon material P is placed on the side, and the additive carbon material P is moved in the direction of the apex of the triangle so that the additive carbon material P is uniformly dispersed in the width direction of the sloping chute 16. 2000-178661). As a means for supplying the added carbon material P to a wide area, the added carbon material spraying device 17 is preferable because the installation area is small and the equipment cost is low, but the present invention is not limited to this. A feeder or the like may be used. As a method of supplying the added carbon material P so as to enter the lower part of the sintering raw material R,
For example, as shown in FIG.
Is partially divided into two stages, and a method of charging a sintering raw material into the upper stage 16a and charging an additional carbon material P into the lower stage 16b is used. It is preferable because it surely enters the lower part of the frame.

[0034]

Embodiment 1 In the first embodiment, an appropriate particle size range of the added carbon material was confirmed by a sinter ore production experiment using a sinter pot. In the second embodiment, the present invention was applied to an actual sintering machine. Then, the effect was confirmed. (Example 1) Using the apparatus shown in FIG. 2 (however, the charging chute upper stage 6a was not provided), only the particle size of the added carbon material was changed, the sintering raw material was stacked, the inner diameter was 105 mm, and the height was 370.
An experiment for producing a sintered ore was conducted using a cylindrical sintering pot having a diameter of 2 mm. The conditions for the sintering raw material are as follows: low-cost iron ore such as high-crystal water ore is used as an iron oxide raw material, and 13.8 parts by mass of limestone, 2.5 parts by mass of quicklime, and 1. 8
Parts by mass, 5.3 parts by mass of coke powder, and an appropriate amount of water were added to form a pseudo-particle with a small drum mixer. In order to compensate for the loss, the blending amount of the actual sintering raw material [5.1 parts by mass] is used), and the added carbonaceous material is a sedimentation breathe having an average particle size of 0.5 mm and a coke powder is sieved. -1mm, 1-3m
m, coke powder having a particle size of 3 to 5 mm and +5 mm was used. In addition, as a charging condition of the added carbon material, the charging amount of the sintering raw material was set to 360 kg / time,
0.72kg / min of added carbon material to sintering raw material
The total amount of the carbon material in the sintering raw material after the addition was 5.5 parts by mass with respect to 100 parts by mass of the iron oxide raw material. The angle of the sloping chute is 50 °, the opening of the slide gate is 50 mm, the rotation speed of the drum feeder is 45 rpm, the height of the cut-off gate is 350 mm, the moving speed of the pallet truck is 2.0 m / min. 300m
m. Further, the sintering conditions were as follows: the sintering raw material charged on the pallet was charged into the cylindrical sintering pot, air was sucked by a fan from the lower portion of the pot, and the packed layer surface layer was ignited by a propane burner. . At this time, the suction pressure of the fan was adjusted to be constant at 3530 Pa until sintering was completed.

The sintered ore was sintered under these conditions, and the drop strength of the sintered ore was measured. Drop strength is 2 cakes after sintering.
From the height of m, crush it by dropping it on an iron plate four times, 5 mm
Evaluation was made based on the mass ratio on the above sieve.

Table 1 shows the relationship between the particle size of the added carbon material and the drop strength of the sintered ore. As is clear from Table 1, the drop strength of the sintered ore was determined by the particle size of the added carbon material being 1 to 3 mm and 3 to 5 mm.
mm shows a high value of 72% by mass or more (Experiment N
o. 3, 4), when the particle size is smaller than 1 mm or larger than 5 mm, the particle size is reduced to 69% by mass or less (Experiment No. 3).
1, 2, 5).

From the above results, the particle size of the added carbon material is 1 to
It was confirmed that 5 mm was desirable.

[0038]

[Table 1]

(Example 2) Granulation capacity of drum mixer 1
The effect was confirmed by applying the present invention to an actual sintering machine having a firing area of 390 t / h and a firing area of 330 m ² .

First, equipment was modified so that the supply capacity of the added carbon material was 2 t / h with respect to the actual sintering machine (see FIG. 3) which had been performing the conventional operation method using no added carbon material. went. That is, the carbon material hopper 1 is provided with only the opening 3 for extracting the additional carbon material in the side wall portion 2 (the grizzly 5 and the baffle plate 6 are not provided), the additional carbon material pumping device 12, the additional carbon material hopper 14, and the additional carbon material hopper 14. A carbon material spraying device 17 was newly installed (see FIG. 4), and a modification was made to make the sloping chute 16 two-stage. Using the equipment after this remodeling, under the same raw material blending and sintering conditions as in the sintering pot experiment of Example 1 described above (however, the amount of coke powder blended was smaller than in the sintering pot experiment,
The amount of added carbon material was reduced accordingly), and a sintering material-packed layer was placed on a moving pallet, and sintering was performed (Comparative Example).

Next, a grizzly 5 having a vibrating device (not shown) is installed on the carbon material extraction leg 4 connected to the opening 3 and a hopper is provided above the opening 3 with respect to the above facilities. A plate (a so-called "baffle plate") 6 having an overhang length Wa of about 11% of the horizontal length Wb of the horizontal cross section of the hopper 1 is attached to the inner surface of the side wall 2 at an upward angle of about 60 ° from the attachment portion to the center of the hopper 1; Further, a plate 8 is provided to cover the upper side of the opening 3 downward from the side and the tip of the baffle plate 6 (see FIG. 1). Then, using the equipment after the remodeling, the sintering raw material packed layer S was placed on the moving pallet 21 under the same raw material mixing and sintering conditions as in the comparative example, and sintering was performed (Example of the present invention). ).

In order to confirm the effect of removing coarse particles from the added carbon material by the application of the present invention, the carbon material was cut out from the added carbon material hopper 14 before and after the application of the present invention, that is, in each of the comparative example and the present invention example. Collect additional carbon material P,
The particle size distribution was measured. FIG. 5 shows the measurement results.
As is clear from FIG. 5, before application of the present invention (comparative example), the ratio of fine particles of -1 mm was as low as 6% by mass, and coarse particles were segregated due to being pulled out from the side wall 2 of the carbon material hopper 1. Although an effect utilizing the phenomenon is observed, 28% by mass of +5 mm coarse particles are mixed, and the ratio of 1 to 5 mm, which is a desirable particle size range, is 68% by mass (1 to 3 mm is 40% by mass and 3 to 5 mm is 28% by mass). On the other hand, after application of the present invention (Example of the present invention), coarse particles of +5 mm were not mixed at all, and the proportion of 1 to 5 mm was 92 mass% (1 to 3 mm was 54 mass%, and 3 to 5 mm was 38% by mass). Note that -1
Although the ratio of fine particles of 5 mm is slightly higher than that of the comparative example (6% by mass) (8% by mass), the mixing of coarse particles of +5 mm is prevented, and the ratio of each particle size range of 5 mm or less increases. And the proportion of fines of -1 mm is kept sufficiently low.

FIG. 6 shows changes in the drop strength (yield) of the sintered ore before and after the application of the present invention. As is clear from FIG. 6, the drop strength (yield) before application of the present invention (comparative example) was about 70%, but the drop strength (yield) after application of the present invention (example of the present invention). ) Increased to about 71% by about 1%, confirming the effect of the present invention.

[0044]

As is apparent from the above description,
According to the first aspect of the invention, since the opening provided with the coarse particle mixing preventing means is provided on the side wall of the hopper, the ratio of fine particles is reduced while preventing the coarse particles from being mixed into the added carbon material. A small amount of carbon material can be extracted, and the particle size range of the added carbon material can be made appropriate, and as a result, the yield of sintered ore can be improved.

According to the second aspect of the present invention, the coarse particles can be prevented from being mixed by a simple means such as grizzly, so that an increase in equipment cost can be minimized.

According to the third aspect of the present invention, the provision of the baffle plate prevents or alleviates the direct flow of coarse particles into the opening, and the space above the grizzly is densely filled with particles. Is prevented, grizzly is prevented from being clogged with coarse particles, and the added carbon material can be cut out more smoothly.

According to the fourth aspect of the present invention, the operation and effect of the third aspect of the present invention can be reliably obtained by setting the length of the baffle plate extending in the horizontal direction to a predetermined lower limit or more. By setting the overhang length to a predetermined upper limit value or less, it is possible to secure an inflow amount of particles in an appropriate particle size range into the opening portion, and it is possible to smoothly remove a necessary additive carbon material.

According to the fifth aspect of the invention, since the added carbon material is extracted between the central portion and the side wall portion of the hopper, the fine and coarse particles mixed into the extracted carbon material (added carbon material) It is possible to extract the added carbonaceous material having an appropriate particle size while reducing the clogging of the grizzly with coarse grains and enabling smooth cutting of the carbonaceous material.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a carbon material hopper according to a sinter production method of the present invention.

FIG. 2 is a schematic explanatory view of an ore supplying section of a sintering machine according to the sinter ore production method of the present invention.

FIG. 3 is an overall flow diagram of a sintering facility according to the sinter production method of the present invention.

FIG. 4 is a schematic flow chart of equipment for supplying a newly added carbon material (added carbon material) according to the sinter production method of the present invention.

FIG. 5 is a diagram showing the particle size distribution of the added carbon material in each of the comparative example and the present invention example.

FIG. 6 is a transition diagram showing a change in drop strength before and after application of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Carbon material hopper, 2 ... Side wall (side wall part), 3 ... Opening (opening), 4 ... Added carbon material extraction leg, 5 ... Grizzly,
5a: Grizzly bar, 6: Baffle plate, 7: Bottom, 8 ...
Plate, 11: Belt conveyor, 12: Added carbon material pumping device,
13 ... Sintering machine, 14 ... Additional carbon material hopper, 15 ... Piping,
16 ... Charging chute (sloping chute), 16a
… Upper loading chute, 16b… lower loading chute, 17
... added carbon material spraying device, 21 ... moving pallet, 23 ... ignition furnace, 24 ... suction fan, 25a ... fine ore hopper, 25
b: auxiliary material hopper, 26: supply hopper, 27: drum feeder, P: added carbon material, Q: carbon material for sintering raw material, R
... Sintering raw material, S ... Sintering raw material packed layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Katsuhiko Shibuda, Kanazawa-cho, Kakogawa-shi, Hyogo Kobe Steel, Ltd. Kakogawa Works (72) Inventor Takayoshi Miyamoto 1-Kanazawacho, Kakogawa-shi, Hyogo Inside Steel Works Kakogawa Works (72) Inventor Akira Iwasaki 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Steel Works Kakogawa Works F Term (Reference) 4K001 AA10 BA02 CA34 CA36 CA39 CA41 GA10 GB01

Claims (5)

[Claims] An iron oxide raw material as a main raw material, an auxiliary raw material,
The carbon material cut from the bottom of the carbon material hopper is preliminarily mixed with the carbon material to form a sintering material, and the sintering material is placed on the moving pallet by a charging chute installed in a direction opposite to the moving direction of the moving pallet. At the time of placing in a layered manner, a new carbon material is added to a lower portion of the sintering material flowing down on the charging chute, so that it is present in an upper layer portion of the sintering material packed layer placed on the moving pallet. The amount of carbonaceous material to be added is greater than the amount of carbonaceous material present in the packed bed portion below the upper layer portion. Is cut out from an opening provided on a side wall of the carbonaceous material hopper and provided with means for preventing coarse particles from mixing. 2. The method according to claim 1, wherein said coarse-grained mixing preventing means is provided on the entire surface of the opening or on the entire surface of the cross section of the carbon material extraction leg for extracting the carbon material from the opening toward the side of the carbon material extracting direction from the opening. The method for producing a sintered ore according to claim 1, wherein: 3. The apparatus according to claim 1, wherein the coarse particle mixing preventing means further comprises a baffle plate provided above the opening and on an inner surface of a side wall of the carbon material hopper.
3. The method for producing a sintered ore according to item 1. 4. The length of the baffle plate extending in the horizontal direction toward the center in the hopper is set to 5 to 5 times the diameter or horizontal length of the horizontal section of the carbon material hopper at the height where the baffle plate is installed. The method for producing a sintered ore according to claim 3, wherein the content is 20%. 5. A carbon material discharging chute having an opening for discharging a carbon material in a middle portion between a center portion and a side wall portion of the carbon material hopper, wherein the coarse material mixing preventing means is connected to the opening portion. The method for producing a sintered ore according to claim 2, wherein