JP5979114B2 - Method for producing sintered ore - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for producing a sintered ore using a DL (dwightroid) type sintering machine, and more particularly, to a method for producing a sintered ore by blending a cleaning recovered material generated in an ironworks with a compounding raw material for sintering. .

  In the production of sintered ore using a DL-type sintering machine, a raw material for sinter production (hereinafter simply referred to as a “mixed raw material”) containing various raw materials is combusted and condensed. There are a main raw material that is a raw material of the ore itself, and a secondary raw material that adjusts the components of the sintered ore. The main raw materials include fine iron ore (sinter feed), fine ore, and return ore, and auxiliary raw materials include limestone, quicklime, quartzite, dolomite, and serpentine. In addition, there are carbonaceous materials (such as powdered coke and anthracite) as a coagulant necessary for sintering the blended raw materials.

The blended raw material is conveyed to a granulator and granulated into pseudo particles with or without powder coke. The quasi-particles are charged and filled in layers on the pallet of the sintering machine and ignited at the top of the packed bed. Then, coke in the sintering raw material is combusted by sucking air from below the packed bed, and the sintering reaction proceeds from the upper part to the lower part of the packed bed. The lump (so-called sintered cake) sintered to the lower part of the packed bed is roughly crushed in the discharge portion of the sintering machine, and then cooled by a cooler to become sintered ore. As described above, the sinter ore manufacturing method is characterized in that the fuel is burned by heat transfer of the combustion gas that is provided with the fuel inside or outside the raw material and passes through the packed bed of the raw material from the upper part to the lower part.
The combustibility of the agglomerated material greatly affects the quality and productivity of the sintered ore. If there is uneven combustion, the quality of the sintered ore, such as the strength and resistance to reduction dusting, will decrease, and the yield will decrease. Therefore, in the production of sintered ore, it is important to improve the combustion efficiency of the agglomerated material internally and externally provided on the raw material.

On the other hand, in recent years, there is a tendency that the procurement cost of coagulated materials such as powdered coke and anthracite coal increases. Therefore, a new aggregating material that complements these is desired, and the present inventors, as agglomerated material, have collected dust collected in the steelworks, particularly dust containing various carbons (C) (hereinafter referred to as “the agglomerated material”). Attention was paid to cleaning materials that contain “carbon-containing dust”.
Looking at the technology for producing sintered ore by utilizing the collected cleaning material collected in the steelworks, there is a technology described in Patent Document 1. Here, first, a sintered raw material composed of iron ore, a SiO ₂ -containing raw material, a limestone powder raw material and a solid fuel powder raw material is prepared, and these are mixed with a stirring and mixing drum mixer to produce a mixed raw material. The mixed raw material is granulated with a disk pelletizer to generate pseudo particles, and the pseudo particles are supplied to an outer layer forming drum mixer. At the same time, the solid fuel system powder raw material and the high carbon dust prepared at a ratio of 5 to 40% by mass with respect to this, CDQ dust collection powder, dust collection powder during iron powder production and dust collection of the storage tank Techniques using powder have been proposed.

JP 2013-036051 A

However, in the technique of Patent Document 1, among the collected cleaning materials collected in the steelworks, the dust collected in the dry state as the collected material from the dust collector, that is, the CDQ dust collecting powder, the dust collecting powder and the debris at the time of iron powder manufacturing are collected. Since only the dust collected from the tank was used, the recycling rate of the cleaning recovered material was not high when viewed from the total amount of the cleaning recovered material collected in the steelworks containing other dust. For this reason, a technology that can reuse the entire amount of collected cleaning materials has been demanded.
The present invention has been devised in order to solve the above-mentioned unsolved problems, and uses a cleaning recovered material collected in a steelworks as a blending raw material at the time of sinter ore production. It is an object of the present invention to provide a technique capable of reusing the entire amount of the collected cleaning product without reducing the quality and without reducing the productivity of the sintered ore.

  As a result of verifying the above problems, the present inventors have found that the collected cleaning materials collected in the steelworks also contain various carbon (C) and iron, but this is used as a raw material for sintering. As the blending ratio of the cleaning recovered material in the blended raw material increases, the uneven distribution of carbon-containing dust (such as dry dust and recovered coal powder as the recovered material from the dust collector) due to the cleaning recovered material in the blended raw material It has been found that the influence of slag increases and it adversely affects the quality of sintered ore. The reason is shown below.

(Cleaning collection)
First, the carbon-containing dust caused by the collected cleaning material is generally an aggregate of fine particles having a particle size of about 1 mm or less, excluding falling recovered material, and also contains moisture and oil. It becomes higher than the particles of the raw material for sintering. For this reason, the cleaning recovery product (carbon-containing dust) is unevenly distributed in the blended raw material when blended with other raw materials.
FIG. 9 shows a cross section of a pile 14 of the blended raw material in which the cleaning recovered material 1 ′ and various raw materials 2a to 2d blended together with the cleaning recovered material 1 ′ are stacked. When the cleaning collection 1 is stacked from above the stack 14, it does not fall down to the skirt as in the other blended raw materials 2 a to 2 d as shown in the figure. The collected cleaning material 1 is stopped at the middle of the pile 14 or is accumulated on one inclined surface (right side in FIG. 2) of the left and right inclined surfaces. The layer thickness is also uneven. As described above, at the time of forming the pile 14 of the blended raw material, it is difficult to stack the cleaning recovery products 1 so that they are uniformly present in the pile 14 with an equal layer thickness. That is, it is very difficult to suppress the uneven distribution of the cleaning recovered material 1 in the blended raw material 4 during the payout operation.

Therefore, the present inventors conducted a preliminary experiment 1 for confirming to what extent the pore structure formed in the sintered ore during the combustion of the pseudo particles is affected by the cleaning recovery material unevenly distributed in the blended raw material. .
First, the collected cleaning material used in the experiment will be described. The cleaning collection mainly has the following components (α) to (γ), each having a mass ratio of 1/3.
(Α) Wet dust It is a dust-like recovered material containing moisture collected from a gutter inside the steelworks, and mainly contains ore powder and coal powder. It has a high moisture content and is in the form of a slurry, which is carried by a vacuum car or the like. Iron ore and coal powder are scattered, flowed by rainwater, and settled in a gutter that drains in-house.
(Β) Dry dust Dust collected from a dust collector in a dry state and having a high carbon and iron content. For example, there are CDQ dust collection powder, dust collection powder at the time of iron powder production, dust collection powder in a storage tank, and dust collection powder collected by a steelmaking related dust collector.
(Γ) Difficult-to-separate recovered materials These are recovered materials at the time of unloading, and are mixed with ore, coal, secondary raw materials for manufacturing sintered ores, etc. that have fallen at the cargo handling berth. In addition to containing various carbon (C), it also contains iron.
Table 1 shows an example of main component concentrations of the collected cleaning material.

(Preliminary experiment 1)
Next, the preliminary experiment 1 using this cleaning collection thing is demonstrated.
In the preliminary experiment 1, a blended raw material having a base mass of 35 kg other than the powder coke was prepared. As the carbon-containing dust, the blending ratio of the cleaning recovered material in the blended raw material was set to 10% by mass, and 3.37% by mass of powder coke was used as an outer coating for the blended raw material.
Two cylindrical sintering pots having a diameter of 300 mm and a height of 400 mm were prepared. In one sintering pot (1a), the cleaning recovered material in the blended raw material was uniformly dispersed and arranged, and the same amount of the cleaning recovered material was unevenly distributed in the other pot (1b). The sintering pot (1a) of the uniform dispersion arrangement of the preliminary experiment 1 was a granulated powder after stirring and dispersing uniformly for 40 seconds or more when adding the cleaning recovered material to the blended raw material. In addition, the unevenly distributed pan (1b) used was granulated after stirring and mixing for 20 seconds or less when adding the cleaning recovered material to the blended raw material.

  In the sintering pot (1b) in which the carbon-containing dust is unevenly distributed, the carbon-containing dust is subdivided by one third, and each subdivided carbon-containing dust is divided into three layers in the sintering pot divided into three layers. Arranged. At that time, the subdivided carbon-containing dusts were arranged so as not to overlap each other in the height direction in a fan-like state having a central angle of 120 degrees in a plan view. As described above, the carbon-containing dust was unevenly distributed and distributed in three places in the sinter pan (1b) by one third. And the internal combustion state for 360 seconds after ignition to the powder coke of the upper part of each sintering pot was observed using CT scanner. Moreover, after combustion, samples of sintered ore obtained in each sintering pot were taken out from the sintering pot and observed.

  As a result, in the case of the sintering pot (1a) in which the carbon-containing dust was evenly distributed, the combustion proceeded while the inner melting zone was horizontal from the start to the end of the combustion. Moreover, when the obtained sintered ore sample was seen, there was almost no unburned part in the whole compounding raw material, and the carbon containing dust was also almost burning. On the other hand, in the case of the sintering pot (1b) in which carbon-containing dust is unevenly distributed in a three-dispersion arrangement, it has been found that the melting zone is not horizontal and the flow of combustion gas is uneven. Moreover, when the obtained sintered ore sample was seen, the big cavity generate | occur | produced inside and many unburned parts generate | occur | produced in the whole mixing | blending raw material rather than the case of a sintering pot (1a). Moreover, many unburned portions were also generated in the carbon-containing dust.

  Moreover, the pores formed inside each sintered ore were thinned into a branch shape, and the branches obtained from the respective sintering pots were compared. As a result, both in the case of the sintering pot (1a) in which the carbon-containing dust is uniformly distributed and in the case of the sintering pot (1b) in which the carbon-containing dust is unevenly distributed in the three-dispersion arrangement, the final after combustion is completed. The pore area was almost the same. Moreover, when the branch density of each sintering pot is compared, the branch density at the end of combustion is smaller in the sample of the sintering pot (1a) of the uniform dispersion arrangement than in the sample of the sintering pot (1b) of the three dispersion arrangement. Thus, it was found that the sample of the uniformly distributed sintering pot (1a) grew to a larger pore structure.

(Verification of uneven distribution suppression effect by granulator)
Next, in addition to the phenomenon that the carbon-containing dust is unevenly distributed in the blended raw material, the present inventors have dealt with the problem of this uneven distribution, depending on the conventional manufacturing process of sintered ore, We obtained the knowledge that the effect of alleviating the uneven distribution of is weak. For example, a drum mixer is generally used as a granulator at the time of manufacturing a sintered ore, and the cleaning recovered material is charged into the drum mixer together with other raw materials.

Normally, the raw material put into the drum mixer is mixed and stirred in the first half of the drum mixer, and then granulated. The process is the movement of lifting along the inner wall of the drum mixer and the surface of the blended raw material. This is done by repeating the rolling and falling motion in one direction. This unidirectional rolling / falling motion is effective for granulating pseudo particles with a predetermined particle size by repeatedly attaching and peeling the raw material, but disperses the cleaning recovered material in the blended raw material and contains carbon. It is not enough to eliminate the uneven distribution of dust. In addition, since the movement of the raw material does not cause movement of the raw material particles, the carbon-containing dust is not dispersed.
Therefore, when the pseudo particles granulated by this granulator are burned by a sintering machine, a portion that is easy to burn and a portion that is difficult to burn are generated in the sintering pallet, causing partial combustion unevenness and sintering. It is thought to reduce the quality and productivity of the ore.

(Preliminary experiment 2)
Next, the present inventors conducted a preliminary experiment 2 for confirming to what extent the quality of the obtained sintered ore is affected by the degree of uneven distribution of the carbon-containing dust contained in the cleaning recovered material.
The mixing ratio of the raw materials for sintering used in the preliminary experiment 2 was the same as that in the preliminary experiment 1, and the base mass of the mixed raw materials other than coke was 35 kg.
Moreover, three same sintering pots as those in the preliminary experiment 1 were prepared. Two of the three sintering pots are a sintering pot (2a) in which the carbon-containing dust is uniformly distributed as in the preliminary experiment 1, and a sintering pot in which the carbon-containing dust is in the three dispersion arrangement as in the preliminary experiment 1. A pan (2b) was obtained. In the remaining one sintering pot (2c), the carbon-containing dust is subdivided into one third at a time, and the subdivided carbon-containing dust is arranged in each layer divided into three layers in the height direction. did. At that time, the carbon-containing dust of each layer was further divided into five equal parts, and one of the carbon-containing dusts divided into five equal parts was arranged at the center of a circle in plan view of the sintering pot. Further, the remaining four carbon-containing dusts divided into five equal parts were arranged at equal intervals along the inner wall surface of the sintering pot. In this way, the carbon-containing dust was distributed and distributed unevenly at 15 places in the sintering pot (2c) at a ratio of 1/15.

And each compounding raw material is burned using each sintering pot, and the firing time, strength (TI), product yield, product production rate, reduction of each sintered ore sample obtained in the sintering pot An index (RI) and a reduced powder index (RDI) were measured.
As a result, regarding the firing time, strength (TI), reduction index (RI), and reduction powdering index (RDI), the differences between the sintering pots (2a) to (2c) were small and almost the same.
Regarding the yield of the finished product, as shown in FIG. 7, the sintering pot (2b) with 3 dispersions was about 56%, whereas the sintering pot (2c) with 15 dispersions was about 61%. % And rose. Furthermore, the evenly-distributed sintering pot (2a) rose as much as about 69%.

As for the production rate of the product, as shown in FIG. 8, the 3 dispersive sintering pot (2b) was about 1.17 [t / h · m ² ], whereas the 15 dispersive sintering pot was The pan (2c) rose to about 1.24 [t / h · m ² ]. Furthermore, the sintering pot (2a) of the uniform distribution rose greatly to about 1.47 [t / h · m ² ].
As a result of the preliminary experiment 1 described above, based on the verification of the uneven distribution suppression effect by the granulator and the result of the preliminary experiment 2, the present inventors distributed the carbon-containing dust evenly in the blended raw material in the manufacturing process of the sintered ore. As a result, it was found that the amount of carbon-containing dust used can be increased without lowering the quality and production rate of the obtained sintered ore. The present invention has been made based on these findings, and the gist thereof will be described below.

Sintered ore according to one aspect of the present invention, the iron ore in the sinter feedstock and auxiliary materials for adjusting the components of the sintered ore, the mixed material containing a cleaning recovered material recovered in steel works, A mixing raw material stirring step for stirring so that the carbon-containing dust in the cleaning recovered material is uniformly dispersed in the mixing raw material, and a carbon material as a coagulating material is added to the stirred mixing raw material to form pseudo particles. A granulating step of granulating and a sintering step of sintering the granulated pseudo particles to produce a sintered ore.

  Here, stirring is performed so that the carbon-containing dust in the cleaning recovered material is uniformly dispersed in the blended raw material, and the iron ore of the raw material of the sintered ore and the auxiliary raw material for adjusting the components of the sintered ore In addition, the cleaning material collected in the steel mill is mixed, and the blended raw material obtained through the mixing step of obtaining the blended raw material in which these are blended is further added with a stirring step. According to the configuration, after the carbon-containing dust is mixed with the other raw materials for blending and before the blended raw material is charged into the granulator, the carbon-containing dust in the cleaning recovered material is stirred. It becomes evenly dispersed in the blended raw material.

Moreover, it is good also considering the mixture ratio in the said mixing | blending raw material of the said cleaning recovery thing as 2 mass% or more and 10 mass% or less. The reason why it is set to 2% by mass or more is that when it is less than this, the blending ratio of the carbon-containing dust cannot be greatly increased as compared with the conventional case. Further, the reason why it is set to 10% by mass or less is that if it is more than this, the influence of uneven distribution in the raw material of carbon-containing dust begins to appear, and the flammability of the pseudo particles deteriorates.
Moreover, it is good also as having the cleaning collection thing stirring process which stirs the said cleaning collection thing before it is contained in the said mixing | blending raw material .
Moreover, it is good also as having further the grinding | pulverization process which grind | pulverizes the lump in the said cleaning collection | recovery thing, before it is contained in the said mixing | blending raw material .

  Therefore, according to the method for producing sintered ore according to the present invention, the even dispersibility of the carbon-containing dust contained in the cleaning recovered material in the blended raw material before being charged into the granulator is increased. Even if the blending ratio of the cleaning recovered material in the blended raw material is increased, the generation amount of unburned dust is suppressed, and the flammability of the pseudo particles is improved. Therefore, the cleaning recovery material collected in the ironworks is used as a raw material for the production of the sintered ore, the quality of the sintered ore is not deteriorated, and the productivity of the sintered ore is not deteriorated. The entire amount can be reused. Moreover, the usage-amount of the carbon containing dust contained in a cleaning collection | recovery thing can be increased, and the usage-amount of a condensing material can be reduced by the part. Moreover, the iron-containing thing of cleaning collection | recovery material can also be used effectively.

It is a schematic diagram explaining the manufacturing method of the sintered ore which concerns on embodiment of this invention. It is a schematic diagram explaining the manufacturing method of a cleaning collection thing. It is a flowchart explaining the manufacturing method of the sintered ore which concerns on embodiment of this invention. It is a figure explaining the state of the cleaning collection thing in the pile of compound raw materials concerning this embodiment. It is a figure which shows the relationship between the mixture ratio of a cleaning collection | recovery thing, and the intensity | strength of a sintered ore. It is a figure which shows the relationship between the mixing | blending ratio of a cleaning collection | recovery thing, and the production rate of a sintered ore. It is a figure which shows the relationship between the uneven distribution conditions of cleaning collection | recovery, and the yield of a sintered ore. It is a figure which shows the relationship between the uneven distribution conditions of cleaning collection | recovery, and the production rate of a sintered ore. It is a figure explaining the state of the cleaning collection thing in the pile of conventional compounding raw materials.

  In the method for producing sintered ore according to the embodiment of the present invention, the iron ore of the raw material of the sintered ore, and the auxiliary raw material for adjusting the components of the sintered ore are mixed with the cleaning recovered material collected in the ironworks, The blended raw material obtained by mixing is sintered to produce a sintered ore. The configuration will be described below with reference to the drawings. In addition, the shape, size, or ratio of each equipment and each device used in the manufacturing process of the sintered ore shown in the drawing is appropriately simplified and exaggerated.

(Overall configuration of equipment)
First, the main equipment in which the manufacturing method of the sintered ore which concerns on embodiment of this invention is implemented is demonstrated centering on a raw material yard and a sintering machine using FIG.
In the raw material yard, the cleaning recovered material 1, various raw materials for blending 2 and the carbonaceous material 3 as raw materials for the sintered ore are prepared as piles 11, 12, and 13, respectively. As described above, in the cleaning collection 1, various dusts generated in the ironworks are collected into a cleaning collection, and this becomes the pile 11 of the cleaning collection 1 containing carbon. The raw material 2 for mixing | blending is each raw material which comprises main raw materials or auxiliary materials, such as iron ore, and the pile 12 is formed for every raw material. In addition, the carbonaceous material 3 is formed with a pile 13 alone, stored in a storage hopper, or manufactured whenever necessary.

  The raw material yard is provided with a discharging device such as a reclaimer and a stacking device such as a stacker (both not shown). The cleaning collected material 1, the various raw materials 2 for mixing, and the charcoal material 3 are paid out in a predetermined amount by the paying-out device in accordance with the respective mixing ratios. The collected material 1 for cleaning and various raw materials 2 for mixing are sequentially stacked by a loading device at a handling place where these are mixed in an ironworks, and a pile of mixed raw materials 4 in which the respective raw materials are stacked. 14 (see FIG. 2) is formed. Further, after a predetermined amount is dispensed from the pile 14, the blended raw material 4 is loaded on a conveyor (not shown) such as a belt conveyor and conveyed to a granulator 8 such as a drum mixer or pelletizer.

  In addition, as shown in FIG. 1, in the raw material yard, when loading the pile 14, the pulverizer 7 for crushing coarse particles contained in the cleaning collection 1 and the first stirring for stirring the cleaning collection 1 A device 6a is provided. The pulverizing apparatus 7 reduces the size of the particles contained in the cleaning collection 1 so as to be effectively used for sintering. As such particles, dust is agglomerated and agglomerated, and agglomerated material that is recovered from falling or mining coal, falling coal at the time of unloading.

  Further, as the first stirring device 6a, for example, a stirring device having a high-speed stirring blade such as an Eirich mixer (trade name) is used. By agitating the cleaning collection 1 of the pile 11 with the first stirring device 6a, the non-uniformity of water content based on the particle size difference in the cleaning collection 1 is eliminated, and aggregated particles in which fine particles such as dust are gathered Is crushed and enables layered loading on the pile 14. In addition, if the agglomerated particles in which fine particles such as dust are gathered are left unbalanced when the piles 14 are stacked, the agglomerated particles will grow by adhering the surrounding powder, and the uneven distribution will increase. The first stirrer 6a prevents the occurrence of non-uniformity during stacking.

  Further, on the upstream side of the sintering machine 9, in order to stir and pulverize the blended raw material 4 conveyed from the pile 14, a second stirring device 6b which is the same stirring device as the first stirring device 6a described above is provided. It is arranged in front of the granulator 8. Further, on the upstream side of the incinerator 9, a granulating machine 8 for charging the mixed raw material 4 stirred by the second stirring device 6 b and granulating the pseudo particles 5, and the granulated pseudo particles 5 are charged. And a sintering machine 9 for producing sintered ore, and a conveying device (not shown) for conveying the blended raw material 4 or the pseudo particles 5 by connecting these devices.

(Manufacturing method of cleaning collection)
Next, the manufacturing method of the cleaning | collection collection material used by this embodiment is demonstrated using FIG.
The cleaning collection 1 includes the above-described three brands (α) to (γ), each having a mass ratio of 1/3. For example, the wet dust 1a and the dry dust 1b are each 33% by mass, and the hardly separable recovered material 1c is 34% by mass. Since the wet dust 1a has a high moisture content, it must be dried when used as a raw material for sintering. Therefore, the wet dust 1a is once mixed with the dry dust 1b using a shovel car or the like, and the moisture content is adjusted in advance as a mixture 1d. . Thus, since the moisture adjustment is performed by mixing the wet dust 1a and the dry dust 1b, the drying step is not necessary.

Next, the mixture 1d of the wet dust 1a and the dry dust 1b is mixed using a shovel car or the like with a hardly separable recovered material 1c, which is a recovered material of falling or falling coal or falling auxiliary material at the time of unloading. In order to prevent coarse particles (for example, particles having a particle size exceeding 20 mm) that are not suitable as a raw material for sintering from being mixed in the mixed material, those having a sieve size of 20 mm or less are used as the cleaning and recovering material 1 used in the present embodiment. Sift through a sieve and use. The cleaning collection 1 is once stacked as a pile 11 in the raw material yard in FIG.
Thus, the cleaning collection thing concerning this embodiment is manufactured.

(Method for producing sintered ore)
Next, the manufacturing method of the sintered ore which concerns on this embodiment using the above-mentioned cleaning collection thing is demonstrated using the flowchart shown in FIG.1 and FIG.3.
First, a predetermined amount of the cleaning / collecting material 1 is paid out from the pile 11 of the cleaning / collecting material 1 by using a loading device. Next, the lump contained in the discharged and collected cleaning product 1 is pulverized using the pulverizer 7 (pulverization step, S1).
Next, the cleaning recovery product 1 in which the lump is pulverized is stirred using the first stirring device 6a (cleaning recovery product stirring step, S2). By this stirring step, a plurality of dust mixtures mixed in the cleaning / collecting material 1 are made uniform and easily stacked on the stack 14.

Next, the cleaning collection 1 that has been agitated is stacked on the stack 14 of the handling field so as to be stacked together with a plurality of compounding raw materials 2 using a stacking device, as shown in FIG. The cleaning recovered material 1 and the mixing raw material 2 (2a to 2d) are mixed (mixing step, S3). Thereby, the mixing | blending raw material 4 with which the fine iron ore, the auxiliary | assistant raw material, and the cleaning recovery material 1 were mix | blended is obtained. As compared with the case of FIG. 9, the cleaning collection 1 in FIG. 4 suppresses the non-uniformity of the layer thickness, and depending on the location, there are places where it falls down to the bottom of the pile, but the blended raw material 4 still remains. Accumulate in the middle.
Then, the obtained blended raw material 4 is stirred using the second stirring device 6b, and stirred so that the cleaning recovered product 1 is evenly dispersed in the blended raw material 4 (blended raw material stirring step, S4). Thereby, each particle | grains which comprise the cleaning recovery material 1 in the mixing | blending raw material 4 raises the uniform dispersibility of the cleaning recovery thing 1 in the mixing | blending raw material 4 by stirring.

Next, the stirred blended raw material 4 is charged into the granulator 8. At this time, powder coke is added to the granulator 8 as the carbonaceous material 3 and granulated (interior), and the pseudo particles 5 are granulated (granulation step, S5). Alternatively, the blended raw material 4 is charged into the granulator 8 for granulation, and powder coke is added from the discharge side of the granulator 8 to adhere (exterior) the powder coke around the pseudo particles 5. As a result, the coagulant (fuel) is provided inside or outside the pseudo particles 5. Since the pseudo particles 5 are granulated from the blended raw material 4 to which the cleaning / recovery 1 is added, the carbon contained in the cleaning / recovery 1 as well as the powder coke is incorporated as a coagulant (fuel).
Next, the granulated pseudo particles 5 are charged into a sintering pallet (not shown) of the sintering machine 9 and filled, and the packed bed is ignited and burned for a predetermined time to be sintered (sintering process, S6). Then, post-processes such as coarse crushing and cooling are performed on the obtained sintered cake to obtain sintered ore. Thus, the manufacturing method of the sintered ore which concerns on this embodiment is comprised.

(Verification test)
The present inventors conducted a test for demonstrating the quality and productivity of a sintered ore manufactured using the method for manufacturing a sintered ore according to this embodiment. The results will be described with reference to Table 2, FIG. 5 and FIG. The carbon-containing dust used in this test is the above-mentioned cleaning recovery product 1. Moreover, only the powder coke was used as the carbonaceous material 3 of a condensing material.

  In Table 2, the ratio of each raw material in the mixing | blending raw material 4 used by the demonstration tests (1)-(4) and outer-powder coke is shown. Here, the blending ratio of the cleaning recovered material 1 in the blended raw material 4 was set to 4 patterns: test (1) 0%, test (2) 2%, test (3) 5%, test (4) 10%. In any case, the cleaning recovered material 1 was uniformly distributed in the sintering pot, and the blended raw material 4 was burned. As in the case of the sintering pot (1a) in (Preliminary Experiment 1), the sintering pot here was granulated after stirring and evenly dispersing for 40 seconds or more when adding the recovered material to the blended raw material. I used something. FIG. 5 shows the strength (TI) of each sintered ore obtained in the demonstration tests (1) to (4), and FIG. 6 shows the production rate.

  As shown in FIG. 5, each intensity | strength in test (2)-(4) exceeded all slightly with respect to the intensity | strength obtained by the test (1) which is a case where the cleaning collection material 1 is not included at all. . Moreover, as shown in FIG. 6, each production rate in tests (2) to (4) slightly exceeded the production rate in test (1). Therefore, if the manufacturing method of the sintered ore according to the present embodiment is used, the strength of the sintered ore is reduced at 10% by mass or less even when the mixing ratio of the cleaning recovered material 1 in the compounding raw material 4 is 2% by mass or more. It was proved that the productivity of the sintered ore was not lowered while it was not lowered.

  Moreover, as shown in Table 2, the usage-amount of the powder coke was able to be decreased, so that the compounding ratio of the cleaning collection | recovery 1 was increased like tests (1)-(4). Similarly, the amounts of powdered iron ore (one kind of yandy powder and two kinds of carajas powder) and limestone were also reduced. Moreover, when the mixing | blending ratio of the cleaning collection | recovery 1 was 5 mass% and 10 mass%, the usage-amount of the silica stone was able to be reduced rather than the case of a test (1).

(effect)
According to the method for producing a sintered ore according to the present embodiment, even if the blending ratio of the cleaning recovered material that is carbon-containing dust in the blended raw material of the sintered ore is increased, the cleaning dispersion evenly distributed in the blended raw material. Therefore, the generation amount of unburned dust is suppressed, and the flammability of the pseudo particles is improved. Therefore, the cleaning recovery material collected in the ironworks is used as a raw material for the production of the sintered ore, the quality of the sintered ore is not deteriorated, and the productivity of the sintered ore is not deteriorated. The entire amount can be reused. Moreover, the usage-amount of the carbon containing dust contained in a cleaning collection | recovery thing can be increased, and the usage-amount of a condensing material can be reduced by the part. Moreover, the iron-containing thing of cleaning collection | recovery material can also be used effectively. Moreover, the usage-amount of the cleaning collection | recovery at the time of manufacture of a sintered ore can be increased compared with the past, and the usage-amount of a powder coke can be reduced by that much.

  Moreover, according to the manufacturing method of the sintered ore concerning this embodiment, the ratio in the mixing | blending raw material of cleaning collection | recovery shall be 2 mass% or more and 10 mass% or less, and it is 2% or more conventionally in terms of quality and productivity. It is possible to increase the blending ratio of the carbon-containing dust that has been difficult to achieve. The reason why it is set to 2% by mass or more is that when it is less than this, the blending ratio of the carbon-containing dust cannot be greatly increased as compared with the conventional case. Further, the reason why it is set to 10% by mass or less is that when it is more than this, the influence of uneven distribution in the raw material of carbon-containing dust begins to appear, and the flammability of the pseudo particles deteriorates.

Moreover, according to the manufacturing method of the sintered ore which concerns on this embodiment, before mixing a cleaning recovery material with the raw material for a mixing, it stirs beforehand and improves the dispersibility of the some dust inside a cleaning recovery material. Thereby, the uneven distribution in the mixing | blending raw material of a cleaning collection thing can be suppressed.
Moreover, in the manufacturing method of the sintered ore which concerns on this embodiment, a cleaning collection | recovery has a lump. The lump is then pulverized to reduce its particle size. In addition, the cleaning collection containing the crushed lump is then stirred. As described above, the cleaning recovered material easily mixed with other raw materials and the raw material for blending are mixed and used in the blended raw material, so that a lump useful for the production of sintered ore can be effectively utilized.

In addition, if the method for producing sintered ore according to the present embodiment is used, even if it is very difficult to evenly distribute the cleaning recovered material in the pile where the mixing raw materials are stacked, the cleaning recovered material is mixed. It is possible to increase the even dispersibility in the raw material and increase the amount of the collected cleaning material.
Further, according to the method for producing sintered ore according to the present embodiment, since the cleaning component that is carbon-containing dust contains iron (Fe), the use of the cleaning recovery item increases the main amount. The amount of raw iron ore used can be reduced. Thereby, the procurement cost of a fine iron ore can be reduced. Similarly, since the cleaning recovery contains silicic acid (SiO ₂ ) and calcium oxide (CaO), the amount of auxiliary materials (silica and limestone) used can be reduced.

  In addition, the amount of cleaning collected used as carbon-containing dust in the present embodiment is relatively large in the steelworks. Therefore, the amount of the collected cleaning materials increases year by year, and the stock tends to be a factor that presses the space of the raw material yard. Therefore, by increasing the amount of the collected cleaning material used by the method for producing sintered ore according to the present embodiment, the space of the raw material yard can be expanded and the raw material yard can be effectively utilized.

(Other)
In addition, in implementation of the manufacturing method of the sintered ore which concerns on this embodiment, although a cleaning collection thing is stirred using a 1st stirring apparatus and a 2nd stirring apparatus (all are Eirich mixers), implementation of this invention However, the method for evenly distributing the cleaning recovered material is not limited to this form. A stirring device other than the Eirich mixer may be used, or it may be performed manually without using a machine. In short, it is only necessary to increase the uniform dispersibility of the cleaning recovered material in the mixed raw material after mixing the cleaning recovered material with the mixing raw material and before granulating the pseudo particles.

Further, in the method for producing sintered ore according to the present embodiment, each raw material is dispensed from each pile of each compounding raw material and cleaning recovered formed in the raw material yard, and each discharged raw material is handled at the handling ground. The raw materials are mixed by stacking together to form one pile, but the mixing of the raw materials is not limited to this form. For example, each raw material may be accommodated in a dedicated storage facility, taken out from the storage facility each time, and mixed.
Further, in the method for producing sintered ore according to the present embodiment, the pulverization apparatus and the first stirring apparatus that are both provided in the raw material yard are separate apparatuses. However, the present invention is not limited to this form. It may be a single device having one function.

DESCRIPTION OF SYMBOLS 1 Cleaning collection material 2 Raw material for mixing | blending 3 Charcoal material 4 Compounding raw material 5 Pseudo particle 6a 1st stirring apparatus 6b 2nd stirring apparatus 7 Crushing apparatus 8 Granulator 9 Sinter machine

Claims (4)

And iron ore in the sinter feedstock and auxiliary materials for adjusting the components of the sintered ore, the mixed material containing a cleaning recovered material recovered in steel works, carbon-containing dust of the cleaning recovery thereof in said formulation A mixing raw material stirring step of stirring so as to be evenly dispersed in the raw material;
A granulation step of granulating pseudo particles by adding a carbonaceous material that is a coagulant to the stirred blended raw material;
A sintering step of sintering the granulated pseudo particles to manufacture a sintered ore.   2. The method for producing a sintered ore according to claim 1, wherein a blending ratio of the cleaning recovered material in the blended raw material is 2% by mass or more and 10% by mass or less. The manufacturing method of the sintered ore of Claim 1 or 2 which further has the cleaning collection thing stirring process which stirs the said cleaning collection thing before it is contained in the said mixing | blending raw material . The manufacturing method of the sintered ore as described in any one of Claims 1-3 which further has the grinding | pulverization process which grind | pulverizes the lump in the said cleaning collection | recovery thing, before being included in the said mixing | blending raw material .

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