JPWO2013175601A1 - Method for producing granulated raw material for sintering, apparatus for producing the same, and method for producing sintered ore for blast furnace - Google Patents

Abstract

A granulating raw material for sintering having a mixing step of adding water to the mixed raw material and mixing with a drum mixer, and a granulating step of granulating the mixed raw material after mixing with a pan pelletizer into pseudo particles In the manufacturing method, in the granulation step, a method for manufacturing a granulated raw material for sintering, which granulates while pulverizing coarse pseudo particles in the surface layer portion of the blended raw material rolling layer that stays in the pan pelletizer, and therefore A method for producing a sintered ore for blast furnace using the above-mentioned apparatus and the obtained granulation raw material for sintering is proposed. As a result, it is possible to produce a raw material for sintering with good air permeability by adhering the powder coke to the granulated pseudo-particles, while being able to granulate using the hardly granulated fine iron ore. it can. And by manufacturing a sintered ore using such a raw material for sintering, the combustion efficiency and melt production conditions can be improved, and the strength and productivity of the sintered ore can be improved.

Description

  The present invention relates to a method for producing a granulation raw material for sintering used in a Dwytroid type sintering machine, an apparatus for producing the same, and a method for producing a sintered ore.

Conventionally, in the production of sintered ore charged into a blast furnace, a predetermined amount of powdered iron ore and other raw materials are mixed, mixed and granulated in the presence of moisture, and the granulated raw material is used as a sintering machine. Charge and sinter. In the granulation, the blended raw materials are aggregated by moisture and become pseudo particles. By inserting the pseudo particles into the sintering machine, it is possible to ensure ventilation on the sintering machine, and the sintering proceeds smoothly.
In recent years, iron ore for sintering has been prone to lower grades due to depletion of high-quality iron ore, such as an increase in slag components and pulverization. There is concern about the decline. On the other hand, from the viewpoint of reducing hot metal production cost in a blast furnace and reducing CO ₂ generation, sintered ore used in a blast furnace is required to have a low slag ratio, high reducibility, and high strength.

  Under these circumstances surrounding the iron ore for sintering, high-quality sintered ore is produced using the high-grade iron ore for pellets, which is a high-grade iron ore for pellets. Techniques for this have been proposed. For example, one of such conventional techniques is a hybrid pelletized Sinter method (hereinafter referred to as “HPS”). This technology is intended to produce sintered ore with low slag ratio and high reducibility by granulating a raw material containing a large amount of fine iron ore such as pellet feed using a drum mixer and pelletizer. (Patent Literature 1, Patent Literature 2, Patent Literature 3, Patent Literature 4, Patent Literature 5).

Japanese Patent Publication No.2-4658 Japanese Patent Publication No. 6-21297 Japanese Patent Publication No. 6-21298 Japanese Patent Publication No. 6-21299 Japanese Patent Publication No. 6-60358

  However, when a raw material containing a large amount of fine iron ore, which is pellet feed, is granulated, the fine iron ore preferentially absorbs moisture, so that the fine powder aggregates and is coarse with low bond strength and contains a large amount of fine iron ore. There was a problem of generating a pseudo-particle. The reason for this is that fine iron ore such as pellet feed is more likely to absorb moisture and retain more moisture between powders as long as it has the same wettability, as long as the wettability is the same. It has been.

  When coarse pseudo-particles with low bond strength are generated, as shown in FIG. 1 (a), the particle size is uneven and the particle size distribution becomes wide. Becomes larger. In addition, the coarse quasi-particles having such a low bond strength are easily compressed and deformed in the quasi-particle packed layer formed when charged on the pallet of the sintering machine. As a result, the porosity of the sinter decreases, which leads to deterioration of the air permeability and hinders the operation of the sintering machine. In addition, the amount of quick lime, which is a binder used for granulation, must be increased. There was also a problem of increasing the cost.

  It is known that a pre-granulation technique should be adopted for such a problem. For example, when granulating a sintered raw material having a particle size of 0.5 mm or less in Patent No. 2790008 of 30 wt% or more, the raw material is mixed while giving a shearing force without substantially crushing the raw material. In this case, a sintering raw material pretreatment method is disclosed in which the moisture content of the sintering raw material is 6.5 to 10.0%.

  This method using a mixer with a built-in high-speed stirring blade does not crush iron ore powder, but applies shearing force, and promotes homogenization of moisture and exudation of absorbed moisture to the particle surface. This is a technique for making the distribution uniform. However, in the method using a mixer with a built-in high-speed stirring blade, there is a problem that it is necessary to perform this treatment on all the blended raw materials charged in the mixer, resulting in a problem that the equipment scale becomes large. If the residence time is shortened so as to increase the time, there is a problem that it is impossible to secure a sufficient time required for water homogenization. Furthermore, when granulation is performed after mixing while giving shearing force without crushing, fine particles or fine powders may reaggregate to form coarse pseudo particles with low bonding strength, which is the problem described above. The solution was inadequate.

  The present invention prevents fine particles or fine particles from agglomerating into coarse pseudo-particles having a low bond strength and containing a large amount of fine iron ore even when difficult-to-granulate fine iron ore is used during granulation. We propose a technique for granulating pseudo-particles of uniform size centering on core particles.

That is, according to the present invention, as shown in FIG. 1B, pseudo particles having a structure in which powder is attached around core particles and having a relatively uniform particle size distribution and having a narrow particle size distribution are mounted on a pallet of a sintering machine. A method for producing a granulation raw material for sintering and a device for the same that show good air permeability when introduced. Furthermore, the present invention can improve the strength and productivity of sintered ore by improving the combustion efficiency and melt generation conditions by producing sintered ore using such a granulating raw material for sintering. As a result, we propose a technology that can reduce hot metal production costs and CO ₂ generation from the blast furnace.

  The inventors of the present invention have a large particle size distribution in the process of granulating a blended raw material containing difficult-to-granulate fine iron ore powder, resulting in the formation of coarse pseudo particles with a weak bond strength due to aggregation of fine particles and fine powder. The aim was to overcome the problem of worsening the air permeability of the raw material packed bed on the pallet during operation of the sintering machine. As a method for this, in the present invention, by continuing the granulation while selectively pulverizing the pseudo particles having a large particle size, the generation of coarse pseudo particles having a weak bond strength is prevented, and the particle size is compared. We have succeeded in developing a method for producing pseudo-particles with a uniform particle size distribution.

  In the present invention, coarse pseudo-particles with low bond strength generated during granulation are selectively crushed. In other words, in the Pampereizer, the blended raw material rolls and stays in a vortex, and many coarse particles are unevenly distributed near the surface layer of the vortex center.Therefore, a small crusher equipped with stirring blades is installed at this position. The coarse pseudo particles are selectively crushed. The pulverized fine powder is re-granulated in the pan pelletizer as it is, and becomes pseudo particles in a desirable form as a granulation raw material for sintering.

  The present invention includes, firstly, a mixing step of adding water to the blended raw material and mixing with a drum mixer, and a granulating step of forming the blended raw material after mixing with a pan pelletizer into pseudo particles. In the method for producing a granulated raw material for sintering, characterized in that in the granulation step, the coarse pseudo particles in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer are granulated while being crushed. A method for producing a granulating raw material for sintering is proposed.

  Secondly, the present invention is a granulating raw material production apparatus for sintering, comprising a pan pelletizer rotatably held at an inclination angle of 30 to 70 °, and a crusher disposed in the pan pelletizer. The crusher rotates in a direction opposite to the pan pelletizer in a plane substantially parallel to the bread bottom surface of the pan pelletizer and can move up and down in a direction perpendicular to the bread bottom surface, and is parallel to the bread bottom surface. A mechanism for crushing and granulating pseudo particles having a particle diameter of 10 mm or more that are unevenly distributed in the surface layer portion of the blended raw material rolling layer that has crushing blades that can move in any direction and stays in the pan pelletizer An apparatus for producing a granulating raw material for sintering is proposed.

  Thirdly, the present invention includes a mixing step of adding water to the blended raw material and mixing with a drum mixer, a granulation step of granulating the blended raw material with a pan pelletizer into a pseudo particle, In the method for producing a sintered ore for blast furnace, which comprises a sintering process in which a sintering raw material obtained by adhering coke powder is charged and deposited on a pallet of a dwellite sinter machine and firing, in the granulation process, The present invention proposes a method for producing a sintered ore for a blast furnace, characterized in that coarse quasi-particles in the surface layer portion of a blended raw material rolling layer are granulated while being pulverized during granulation by a pan pelletizer.

A more preferable solution of the present invention is as follows:
(1) After the granulation step, providing a step of attaching coke powder to the pseudo particles produced through this step to obtain a granulation raw material for sintering,
(2) The pseudo particles are particles having a particle size of 10 mm or more that are unevenly distributed in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer.
(3) The pseudo particles are particles having a particle size of 8 mm or more unevenly distributed in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer.
(4) The pulverization is performed by a pulverizer that faces the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer and can be moved up and down in a direction perpendicular to the bottom surface of the pan pelletizer. about,
(5) The crushing rotates in a plane substantially parallel to the bottom surface of the pan pelletizer and can be moved up and down in a direction perpendicular to the bottom surface, and the pan pelletizer at the position of the surface layer portion of the blended raw material rolling layer Using a crusher with crushing blades rotating in the opposite direction to the rotation direction of
(6) The said crusher can adjust the space | interval of the position of the rotation surface of a crushing blade, and the bread | pan bottom face of a pan pelletizer,
(7) The pulverization is performed by moving the pulverization blade in parallel with the bread bottom surface of the pan pelletizer due to fluctuations in the particle size, ingredients, blending amount, moisture for granulation, etc. of the blended raw material powder (8) Crushing is performed by crushing coarse pseudo particles by pressing force from the crusher,

(1) According to the present invention, it becomes possible to use a large amount of finely divided iron ore that is high quality such as pellet feed but is difficult to granulate as iron ore for sintering, and has a high slag ratio. A reducible, high-strength sintered ore can be advantageously produced. Therefore, in blast furnace operation, the amount of lump coke charged into the furnace can be reduced. As a result, it is possible to greatly reduce the amount of CO ₂ generated from the blast furnace and improve productivity. In addition, the load on the environment can be reduced by reducing the amount of slag generated in the blast furnace.
(2) Moreover, according to this invention, since the intensity | strength of the product sintered ore manufactured can be raised and a yield can be improved, reduction of the amount of powder coke used is attained. Further, since the amount of coke in the formulation in the raw material is reduced, it is possible to reduce the amount of CO ₂ produced during the sinter production.
Furthermore, according to the present invention, since the amount of quicklime (binder) used at the time of granulating the fine powder raw material can be reduced, the production cost of the sintered ore can be reduced.

It is a schematic diagram of the conventional particle packed bed (a) and the particle packed bed (b) of the present invention. It is a schematic diagram of the structure (a, b) of a pseudo particle and the manufacturing process (c) of the granulation raw material for sintering. It is a schematic diagram which shows an example of the granulation raw material manufacturing process for sintering of this invention. It is a basic diagram of the manufacturing apparatus (crushing granulation apparatus) of the granulation raw material for sintering. It is a basic diagram which shows the other example of the manufacturing apparatus (crushing granulation apparatus) of the granulation raw material for sintering. It is a basic diagram which shows the other example of the manufacturing apparatus (crushing granulation apparatus) of the granulation raw material for sintering. It is a perspective view which shows the structural example of the crushing blade of a crusher. It is a particle size distribution figure of the pseudo particle by the presence or absence of fine powder (PF) combination. It is a comparison photograph of the conventional method (b) and the invention method (c) showing the state of granulation (a) and pulverization in the pelletizer. It is a graph which shows the intensity | strength measurement result when a coarse grain and a fine grain are mix | blended. It is a particle size distribution figure of the granulated particle in the example of various granulation processes. It is a graph which shows the operation result in the sintering test suitable for this invention. It is a comparison graph which shows the operation result in the sintering test with the conventional method and this invention method (at the time of pellet feed 40mass% mixing | blending). It is a comparative graph which shows the operation result in the sintering test with the conventional method and this invention method (at the time of 20 mass% of tailing ores mixing). It is a comparative graph which shows the operation result in the sintering test with the conventional method and this invention method (at the time of pellet feed 40mass% + tailing ore 20mass% compounding). It is a graph which shows the example of a particle size distribution of various iron ores.

  FIG. 2 shows the structure of pseudo particles (a, b) and the flow of a general process for producing a granulated raw material for sintering. As shown in this figure, the iron ore powder and the auxiliary material powder, which are blended raw materials cut out from the blending tank 1, are first mixed by the drum mixer 2. Thereafter, the mixed blended raw material is fed to the pan pelletizer 3 and granulated. In the mixing step and the granulation step, water is added to adjust each to a predetermined granulated moisture, and predetermined pseudo particles are obtained.

FIG. 2 (a) is a diagram of pseudo-particles of coarse pseudo-particles formed by using pellet feed, in which fine or fine particles of iron ore are agglomerated with each other through moisture, and which contain a large amount of fine iron ore and have low bonding strength. An example is shown. In the pan pelletizer 3, the blended raw material rolls and stays in a vortex, and many of the coarse pseudo particles are unevenly distributed near the surface layer of the vortex center. This is due to the phenomenon that fine particles segregate in the lower layer and coarse particles segregate in the upper layer due to the sieving effect (percolation) between the rolling particles.
On the other hand, FIG. 2B is an example of a pseudo particle having a relatively uniform particle size with a structure in which powder is attached around the core particle, and is the object of the present invention. The latter pseudo particles are generally stronger and have a uniform particle size than the former pseudo particles.

  In the present invention, in the granulation step by the pan pelletizer 3, coarse particles, that is, fine particles and / or fine powders in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer have moisture. As for the pseudo particles that are aggregated through the pulverized particles, those having a certain size or more are crushed in the pan pelletizer. For example, a blended raw material rolling layer in which coarse pseudo-particles having a particle size of 10 mm or more, preferably 8 mm or more appearing in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer 3 are accumulated. In the surface layer portion, the material is continuously granulated while being pulverized using a pulverizer (hereinafter sometimes abbreviated as “pulverized granulation”). As a result, the pseudo-particles obtained by agglomerating fine particles or fine particles and coarsening them have a low strength because they do not have core particles, and therefore can be crushed (collapsed) relatively easily.

  In this way, coarse pseudo-particles with a low bond strength containing a large amount of fine iron ore are easily crushed and re-granulated in a pan pelletizer, and have a large particle strength as shown in FIG. Pseudo particles having a small particle size distribution and a uniform particle size can be obtained. The surface of the pseudo particles is further coated with a solid fuel such as coke powder and auxiliary materials used as necessary by another drum mixer 4 to produce a sintered ore structure, which is a raw material for producing sintered ore. A grain raw material is obtained.

  Due to the above-mentioned pulverization and granulation, in the present invention, the above-described pulverization blades described later are provided at the portion of the surface layer portion of the blended raw material rolling layer in the pan pelletizer 3 in which the coarse pseudo particles are generated and unevenly distributed. A crusher is disposed, and the crushing blades are rotated. Preferably, the coarse pseudo particles are further crushed and further granulated to obtain pseudo particles having a suitable particle size. In this case, the blended raw material is granulated while adding moisture for granulation to the pan pelletizer 3 that rotates counterclockwise. At this time, in the pan pelletizer, the coarse pseudo-pulverizer is crushed by the crushing blades of the crusher. As a result of the re-granulation process while the particles are crushed, pseudo particles having a relatively uniform particle size are granulated. The pseudo particles thus generated overflow from the pan pelletizer 3 and are discharged onto the belt conveyor. Thus, in the present invention, coarse pseudo particles are crushed by a pulverizer, and the crushed fine particles and fine powder are eventually attached to the core particles and re-granulated into pseudo particles.

  As described above, coarse pseudo-particles containing a large amount of fine iron ore to be crushed and granulated is a particle having a large particle size formed by agglomeration of fine particles and fine particles of high moisture, It can be easily crushed because its strength is weak. If such coarse quasi-particles with low bonding strength are deposited on the pallet of the sintering machine with a certain layer thickness, the quasi-particles are crushed by applying a load (compressive force) and the porosity is small. It becomes a sintered granulated raw material layer having a packed structure. As a result, the granulated raw material packed layer on the pallet has poor air permeability and becomes an impediment to the operation of the sintering machine.

  In this regard, according to the present invention, coarse pseudo particles having a weak particle strength having a particle size of 8 mm or more that are unevenly distributed in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer 3 are crushed at the position of the surface layer portion. By re-granulating while pulverizing using the blades 4a, it is possible to promote the formation of the original pseudo particles.

  The position of crushing by the crusher in the pan pelletizer is the coarse pseudo-particle uneven distribution part, but this position varies depending on the particle size and ingredients of the blended raw material, the blending amount, and the amount of moisture for granulation. It is preferable to change appropriately. However, when granulating the same blended raw material, the crusher may be operated at a certain position.

  In the following, experiments that have triggered the development of the present invention will be described. The main raw materials of the samples used in this experiment are Australian iron ore 50 mass% and South American iron ore 50 mass%. The blending raw material is based on a basicity of 2.0. For example, when 20 mass% of fine iron ore as pellet feed is blended, the above blending ratio (1: 1) of Australian iron ore and South American iron ore remains unchanged. We corresponded by changing to. In addition, as the fine iron ore, tailing ore can be used, and the behavior as fine powder is the same even if a normal blending raw material is used as it is. Here, the tailing ore represents a residue generated in the process of producing a pellet feed. FIG. 3 is a flow showing an example of a granulated raw material manufacturing process for sintering suitable for the method of the present invention used in this experiment.

  In this experiment, as shown in FIG. 3, the coarse pseudo-particles produced by agglomeration of fine particles and fine powders having no core particles based on the above-described existing HPS process are put in the pan pelletizer 3. The case where it crushes in the position of the surface layer part of the mixing | blending mixing raw material rolling layer was implemented. In the method of crushing in the pan pelletizer 3 according to the method of the present invention, a crusher having crushing blades having a rotation speed of 200 rpm and a blade diameter of 60 mm is coarsely visually observed with a blended raw material rolling layer in the pelletizer 3. It was set at a position where many pseudo particles existed. The rotation direction of the crushing blade 4a was opposite to the rotation direction of the pan pelletizer. The clearance between the rotating surface of the crushing blade 4a and the bottom surface of the pan pelletizer is about 10 mm, preferably about 8 mm in order to efficiently crush coarse particles having a particle size of 10 mm or more, preferably 8 mm or more. As a result, the coarse pseudo particles having a particle diameter of 10 mm or more or 8 mm or more were crushed and re-granulated.

  FIG. 4 is an example of a granulating raw material production apparatus for sintering according to the present invention, which shows equipment for stirring granulation in a pelletizer. That is, this apparatus includes a bread pelletizer 3 that is rotatably held at an inclination angle of 30 to 70 °, and a crusher 4 that is disposed so as to face the surface layer portion of the blended raw material rolling layer in the bread pelletizer 3. And mainly consists of

  As the crusher 4 used in the present invention, a crusher provided with crushing blades 4a having various shapes as shown in FIG. 7 is suitable. The crushing blade 4a rotates in a direction opposite to the main body of the pan pelletizer 3 in a plane substantially parallel to the bread bottom surface, and can be moved up and down in a direction perpendicular to the bread bottom surface and parallel to the bread bottom surface. It is possible to translate in the XY axis direction in the plane.

  Moreover, in FIG. 4, 7 shown in the figure is a blended raw material rolling layer in a bread pelletizer, fine grains and fine powder occupy near the bottom of the bread, and coarse pseudo-particles occupy as the upper layer becomes, In particular, so-called coarse pseudo-particles having a large particle size float on the uppermost layer and are mainly distributed in the center of the spiral.

  Reference numeral 8 denotes a laser displacement meter for monitoring the inclination and position of the pan pelletizer. In the figure, 9 is a CCD camera for monitoring the granulated surface, 10 is a monitoring monitor, 11 is a control panel, and 12 is a crushing blade drive. All of these can use known general-purpose devices.

  Since the distribution position of the coarse pseudo-particles in the pan pelletizer 3 is considered to change depending on the raw material conditions and the operation level, control of the crushing position by external monitoring is effective. In addition, by adjusting the clearance between the crushing blade and the bottom of the pan, it is possible to control the particle size of the coarse pseudoparticles to be crushed. Necessary. Therefore, a thickness measuring instrument such as the laser displacement meter is provided, and the size of the pseudo particles to be crushed can be adjusted by this adjustment, and the size of the final pseudo particles granulated is determined. Is done.

  In the production process of the granulation raw material for sintering in this experiment, the granulation moisture added to the drum mixer 2 was set to 7.6 mass% for the base condition and 8.2 mass% for the pellet feed blending condition. The residence time in the drum mixer 2 and the pan pelletizer 3 was set to the same conditions as in the actual machine, and the rotation speed was set so that the fluid number (inertial force / gravity) was constant. The powder coke exterior time in the drum mixer 5 was 30 seconds. The obtained granulation raw material for sintering was sintered by a test sintering machine to produce a sintered ore.

  Next, FIG. 5 is another example of the granulating raw material manufacturing apparatus for sintering according to the present invention. This device is a type including a stamping device 4s in which the crusher vibrates in the vertical direction. In the case of this crusher, the control panel 11a controls the position and height of vibration, stamping and stamping.

  Even with an apparatus equipped with this type of crusher, the same is true for crushing coarse pseudoparticles that are unevenly distributed in the center of the particles that rotate in the inside of the pan pelletizer, Unlike the crushing blades shown in FIG. 4, coarse pseudo particles are crushed by stamping that reciprocates along the depth direction of the pan pelletizer 3.

  However, since the height of the deposition surface of the raw material that rotates in the interior of the pan pelletizer 3 changes depending on the operation, a stamping device is used by using the control panel 11a so as not to apply an impact to the pan pelletizer 3. It is preferable to adjust the position and amplitude of 4s according to it.

  FIG. 6 shows still another example of the granulating raw material manufacturing apparatus for sintering according to the present invention. This apparatus is a type provided with a roller 4r on which the crusher rotates. In the case of this crusher, the control panel 11b controls the rotation speed of the roller and the position and height of the roller.

  In a crusher of the type equipped with this roller 4r, coarse pseudo particles are crushed by using a roller 4r that rotates in the pan pelletizer 3 and compressing between the pan pelletizer 3 and the roller 4r.

  However, since the height of the deposition surface of the raw material that rotates in the interior of the pan pelletizer 3 varies depending on the operation, the position of the roller can be adjusted so that an excessive load is not applied to the pan pelletizer 3. preferable.

  FIG. 8 shows the particle size distribution (Wet state) of the pseudo particles when the blending amount of the pellet feed having an average particle size of about 0.05 mm is 0 mass% and 40 mass%. The particle sizes are as small as -0.25 mm, +0.25 m, +0.5 mm, +1.0 mm, +1.5 mm, +2.83 mm, +4.75 mm, +8 mm, +10 mm and +15 mm. As can be seen from this figure, when the amount of pellet feed (PF) is 40 mass%, ungranulated fine particles (−0.25 to +0.25) and coarse particles (+8 mm, +10 mm, +15 mm) The ratio of increased.

  Next, a method for producing a granulated raw material for sintering by crushing and granulating the pseudo particles using a pan pelletizer 3 with a crusher will be described. FIG. 9 is an appearance photograph (a) of the pseudo particles during rolling inside the pan pelletizer 3, and is a photograph of the state of the particles being granulated near the surface layer portion of the blended raw material rolling layer with a high-speed camera. is there. (B) and (c) in the figure are comparative photographs of the conventional method (b) and the present method (c). As shown in FIG. 4, with the rotational movement of the pan pelletizer 3, the charged blended raw material is lifted to an upper position in the pan pelletizer, and gradually increases while repeating the movement of dropping downward due to its own weight. Grows into particles. In this movement, the position where the ungranulated powder and pseudo particles start to fall is that the higher the rotation speed of the pan pelletizer, the greater the adhesion of the blended material, and the smaller the inclination angle of the pan pelletizer, It will be higher. The charged raw material falling from the start point of dropping in the pan pelletizer 3 is strengthened in granulation by rolling operation on the bottom surface of the pan pelletizer 3 and repeatedly rises and falls while in contact with other blended raw materials. grow up.

  A good rolling state of the blended raw material charged in the pan pelletizer 3 is that the blended raw material rolling layer 7 moves in a spiral shape, and there are many coarse particles in the spiral center. This is due to the percolation phenomenon. In the present invention, in order to selectively crush coarse pseudo-particles, the crushing blade 4a for crushing by rotating at the high speed is disposed at this position. However, the raw material that rolls in the pan pelletizer 3 shows a steady spiral motion when viewed macroscopically, but it is subject to crushing depending on the rotational speed of the pan pelletizer, the adhesion of the raw material, and the inclination angle of the pan pelletizer. The position of the coarse quasi-particles described above is not necessarily constant.

  In addition, here, the crushing blade 4 a is provided with a certain distance from the bottom surface of the pan pelletizer 3. This is because by setting an interval larger than the particle size (10 mm) of coarse pseudo-particles to be crushed, pseudo-particles that do not need to be crushed are allowed to pass below the pulverization blades a to continue rolling motion. This is to make it possible. Accordingly, the disposition of the crushing blades 4a in the pan pelletizer 3 is important in determining the position of the crushing action point, and is set to a position where the probability that coarse pseudo particles to be crushed exist is the highest. Should. However, it is desirable that the crushing blade 4a itself has particle size selectivity of coarse pseudo particles to be crushed, and a specific example is as shown in FIG.

Here, some preferred examples of the crushing blade 4a are shown in FIG.
FIG. 7A shows an example of a centrifugal radiation type agitating blade, in which saw blades squeeze alternately upward or downward radially.
FIG. 7B is an example of a paddle type stirring blade, and six vertical blades are installed on a disk provided to prevent scattering of a stirring object.
FIG. 7C shows an example of a paddle type stirring blade, in which six blades are vertically arranged radially from the central axis.
FIG. 7D shows an example of a propeller type stirring blade, in which three blades are installed.
FIG. 7E shows an example of a paddle type stirring blade, in which four blades are installed radially at an angle of 45 ° from the central axis.
FIG. 7 (f) shows a stirring blade having four blades, and each blade is installed at an angle of 45 °.

  In the granulating raw material production apparatus for sintering according to the present invention, the rotation direction of the crushing blades 4a of the crusher 4 is also important. This is because the crushing blades 4a have a direction opposite to the rotation direction of the main body of the pan pelletizer 3 so that the crushed particles are well scattered during rolling. This is due to the efficient redistribution of water droplets in the pseudo-particles to the rolling raw material by the pulverization of the pseudo-particles and the re-dispersion of the finely divided fragments after the pulverization. This is because it is effective in achieving uniformity and particle size uniformity. As for the number of rotations, the higher the speed, the higher the crushing efficiency. However, if it is excessive, the crushing effect becomes too great, and the average particle size of the pseudo particles may be significantly reduced.

  FIG. 10 shows the measurement results of the compression behavior of coarse particles (27 mm) and fine particles (9 mm) among the pseudo particles granulated by applying the method of the present invention. It can be seen that the coarse grains are significantly deformed even under a low load. Moreover, even if it compares the maximum value of a load-displacement curve, ie, a maximum load, it turns out that the coarse grain is smaller.

  FIG. 11 shows a comparison of the particle size distribution of the pseudo particles after the conventional method and the invention method (pulverization granulation). Coarse particles often found in the conventional method are reduced in the pulverization granulation method according to the present invention. That is, in the latter method, the ratio of intermediate particles of 1.0 mm to 4.75 mm is increased, and the particle size is made uniform. Further, the average particle diameter was reduced by 0.6 to 0.7 mm, and it was confirmed that the use of the method of the present invention was effective.

  Next, a method for producing sintered ore using the above-described sintering granulation raw material will be described. This sintered ore production process is a method for producing a sintered ore by charging a granulated raw material for sintering composed of the pseudo-particles produced by a method suitable for the present invention into a dwellite type sintering machine. .

  FIG. 12 shows sintering test results using various granulation raw materials for sintering. As shown in this figure, when the particle size distribution of the pseudo particles is narrow except for coarse particles and fine particles as in the present invention, the bulk density charged into the sintering test apparatus is lowered. As a result, in the operation of the sintering machine, the average air volume was increased, the sintering speed was improved, and the production rate was improved. On the other hand, compared with the conventional method, there was no big difference about what used the granulation raw material for sintering with a large average particle diameter which cut only the -2mm fine particle which is a comparative example. From this, it was found that the air permeability when using a blended raw material using a pellet feed during the production of sintered ore is greatly influenced by the particle size distribution.

  FIG. 13 shows the result of a sinter production test applying the pulverization granulation process of the present invention based on the conventional method under the condition that a pellet feed is blended for 40 mass% in iron ore. . As shown in this figure, the sintered ore produced using the granulated raw material for sintering produced according to the method of the present invention is composed of a granulated raw material packed layer for sintering deposited on a pallet of a sintering machine ( It was found that the charging bulk density of the sintered bed was small, and the effect of improving productivity was obtained.

  FIG. 14 shows the result of a sinter ore production test applying the pulverization granulation process of the example of the present invention based on the conventional method on the condition that 20 mass% in iron ore is blended with tailing ore. . As shown in this figure, the sintered ore produced using the granulating raw material for sintering produced based on the method of the present invention by blending tailing ore is similar to the condition of blending the pellet feed of FIG. It turned out that the air permeability improvement and productivity improvement effect of the granulation raw material filling layer (sintering bed) for sintering are acquired.

  FIG. 15 shows the result of a sinter ore production test using the pulverization granulation process of the present invention based on the conventional method under the blending conditions of 40 mass% in iron ore as pellet feed and 20 mass% as tailing ore. Is shown. As shown in this figure, the sintered ore manufactured using the granulation raw material for sintering manufactured based on the method of the present invention is the same as the conditions in which the pellet feed and tailing ore of FIGS. Furthermore, it was found that the air permeability improvement and productivity improvement effects of the granulated raw material packed layer (sinter bed) for sintering can be obtained. FIG. 16 is a graph showing the cumulative particle size distribution of pellet feed, tailing ore and fine iron ore used in the sintering test.

  As described above, when fine powder raw materials such as pellet feed and tailing ore are used, the sintering productivity decreases, but from the above sinter production test results, the present invention is effective in improving the productivity. Became clear.

  And if a sintered ore is manufactured using the granulation raw material for sintering manufactured based on this invention method, the improvement effect of the strength of a sintered ore manufacture yield or a sintered ore can also be anticipated. This is because in the conventional method, powder coke is coated on pseudo particles with non-uniform particle size, so that combustion and heat reception become non-uniform and yield decreases, but it was manufactured by applying the present invention. In the case of a granulated raw material for sintering, since the particle size becomes relatively uniform, the existence state of the powder coke is also optimized. In addition, when not implementing external granulation of powder coke, uniform mixing before granulation is necessary to achieve uniform mixing of powder coke and limestone, but in the case of the present invention, such a burden is reduced. The

  The method (crushing granulation) according to the present invention does not require an additional line for crushing, and has a simple equipment configuration in which a crusher with crushing blades is disposed on an existing pan pelletizer. Become.

  The above-described pan pelletizer with a crusher can be applied not only to the production of a granulation raw material for sintering but also to the production technique of a sintered ore for a blast furnace.

DESCRIPTION OF SYMBOLS 1 Mixing tank 2 Drum mixer 3 Pam pelletizer 4 Crusher 4a Crushing blade 5 Doramix mixer 6 Sintering machine 7 Compounding material rolling layer 8 Laser displacement type 9 CCD camera 10 Monitoring motor 11 Control panel 12 Crushing blade drive machine

The present invention includes, firstly, a mixing step of adding water to the blended raw material and mixing with a drum mixer, and a granulating step of forming the blended raw material after mixing with a pan pelletizer into pseudo particles. In the method for producing a granulated raw material for sintering, the coarse pseudo particles in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer in the granulation step are mixed with the blended raw material roll staying in the pan pelletizer. Proposed is a method for producing a granulated raw material for sintering, characterized by granulating while crushing with a crusher arranged facing the surface layer part of the moving bed .

Thirdly, the present invention includes a mixing step of adding water to the blended raw material and mixing with a drum mixer, a granulation step of granulating the blended raw material with a pan pelletizer into a pseudo particle, In the method for producing a sintered ore for blast furnace, which comprises a sintering process in which a sintering raw material obtained by adhering coke powder is charged and deposited on a pallet of a dwellite sinter machine and firing, in the granulation process, At the time of granulation by the pan pelletizer, coarse pseudo particles in the surface layer portion of the blended raw material rolling layer are crushed by a crusher arranged facing the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer We propose a method for producing sintered ore for blast furnace, characterized by granulating while crushing.

A more preferable solution of the present invention is as follows:
(1) After the granulation step, providing a step of attaching coke powder to the pseudo particles produced through this step to obtain a granulation raw material for sintering,
(2) The pseudo particles are particles having a particle size of 10 mm or more that are unevenly distributed in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer.
(3) The pseudo particles are particles having a particle size of 8 mm or more unevenly distributed in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer.
(4) the crushed, it is carried out in a crusher which is movable up and down in a direction perpendicular to the bottom surface of the pan pelletizer,
(5) The crushing rotates in a plane substantially parallel to the bottom surface of the pan pelletizer and can be moved up and down in a direction perpendicular to the bottom surface, and the pan pelletizer at the position of the surface layer portion of the blended raw material rolling layer Using a crusher with crushing blades rotating in the opposite direction to the rotation direction of
(6) The said crusher can adjust the space | interval of the position of the rotation surface of a crushing blade, and the bread | pan bottom face of a pan pelletizer,
(7) The pulverization is performed by moving the pulverization blade in parallel with the bread bottom surface of the pan pelletizer due to fluctuations in the particle size, ingredients, blending amount, moisture for granulation, etc. of the blended raw material powder (8) Crushing is performed by crushing coarse pseudo particles by pressing force from the crusher,

Claims (21)

A granulating raw material for sintering having a mixing step of adding water to the mixed raw material and mixing with a drum mixer, and a granulating step of granulating the mixed raw material after mixing with a pan pelletizer into pseudo particles In the manufacturing method,
A method for producing a granulated raw material for sintering, characterized in that in the granulation step, coarse pseudo particles in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer are granulated while being crushed.   The method for producing a granulation raw material for sintering according to claim 1, further comprising a step of adhering coke powder to the pseudo particles produced through this step after the granulation step.   3. The granulation for sintering according to claim 1, wherein the coarse pseudo particles are particles having a particle size of 10 mm or more unevenly distributed in a surface layer portion of the blended raw material rolling layer staying in the pan pelletizer. Raw material manufacturing method.   3. The granulation for sintering according to claim 1, wherein the coarse pseudo particles are particles having a particle size of 8 mm or more unevenly distributed in a surface layer portion of the blended raw material rolling layer staying in the pan pelletizer. Raw material manufacturing method.   The pulverization is performed by a pulverizer disposed facing the surface layer portion of the mixed raw material rolling layer staying in the pan pelletizer, and the pulverizer is moved up and down in a direction perpendicular to the bottom surface of the pan pelletizer. The method for producing a granulating raw material for sintering according to claim 1 or 2, wherein the method is possible.   The crushing rotates in a plane substantially parallel to the bottom surface of the pan pelletizer and can be moved up and down in a direction perpendicular to the bottom surface, and the rotation direction of the pan pelletizer at the position of the surface layer portion of the blended raw material rolling layer The method for producing a granulated raw material for sintering according to claim 1, wherein the method is performed using a crusher provided with crushing blades rotating in the opposite direction.   The said crusher can adjust the space | interval of the position of the rotating surface of a crushing blade | wing, and the bread | pan bottom face of a pan pelletizer, The manufacturing method of the granulation raw material for sintering of Claim 6 characterized by the above-mentioned.   The said crushing is performed by moving the said crushing blade in parallel with the bread bottom surface of a pan pelletizer by the fluctuation | variation of the particle size of a mixing | blending raw material, a component, a compounding quantity, the water | moisture content for granulation, etc. Method for granulating raw material for sintering.   6. The method for producing a granulated raw material for sintering according to claim 5, wherein the crushing is performed by crushing coarse pseudo particles by a pressing force from a crusher.   An apparatus for producing a granulated raw material for sintering comprising a pan pelletizer rotatably held at an inclination angle of 30 to 70 ° and a crusher disposed in the pan pelletizer, wherein the crusher is a pan An apparatus for producing a granulating raw material for sintering, which is capable of moving up and down in a direction perpendicular to the bottom surface of the pelletizer.   The crusher rotates in a direction opposite to the pan pelletizer in a plane substantially parallel to the bread bottom surface of the bread pelletizer and can move up and down in a direction perpendicular to the bread bottom surface, and moves in a direction parallel to the bread bottom surface. It has a mechanism to crush and granulate pseudo particles having a particle size of 10 mm or more that are unevenly distributed in the surface layer portion of the blended raw material rolling layer that has crushing blades and stays in the pan pelletizer The apparatus for producing a granulated raw material for sintering according to claim 10, wherein the apparatus is a granulated raw material for sintering.   12. The apparatus for producing a granulated raw material for sintering according to claim 11, wherein the crusher is capable of adjusting a distance between a rotational surface of a crushing blade and a bottom surface of a pan pelletizer. .   12. The apparatus for producing a granulated raw material for sintering according to claim 11, wherein the crusher is capable of moving the crushing blades in parallel with the bottom surface of the pan pelletizer.   11. The apparatus for producing a granulated raw material for sintering according to claim 10, wherein the crushing is performed by crushing coarse pseudo particles by a pressing force from a crusher.   It is obtained by adding moisture to the blended raw material and mixing with a drum mixer, granulating the mixed blended raw material with a pan pelletizer to make pseudo particles, and attaching coke powder to the pseudo particles In the method for producing a sintered ore for blast furnace, which comprises a sintering process in which a sintering raw material is charged and deposited on a pallet of a dwytoid sintering machine and then fired, in the granulation process, blended at the time of granulation by a pan pelletizer A method for producing a sintered ore for a blast furnace, characterized in that coarse pseudo particles in a surface layer portion of a raw material rolling layer are granulated while being crushed.   16. The blast furnace sintering according to claim 15, wherein the coarse pseudo-particles are intended for pseudo-particles having a particle size of 10 mm or more that are unevenly distributed in the surface layer portion of the blended raw material rolling layer staying in the pan pelletizer. Manufacturing method of ore.   The pulverization of the blast furnace sintered ore according to claim 15, wherein the crushing is performed by a crusher disposed facing a surface layer portion of a blended raw material rolling layer staying in a pan pelletizer. Production method.   The crushing rotates in a plane substantially parallel to the bottom surface of the pan pelletizer and can be moved up and down in a direction perpendicular to the bottom surface, and the rotation direction of the pan pelletizer at the position of the surface layer portion of the blended raw material rolling layer The method for producing a sintered ore for a blast furnace according to claim 15, wherein a pulverizer equipped with a crushing blade rotating in the opposite direction is used.   The method for producing a sintered ore for a blast furnace according to claim 18, wherein the crusher can adjust a distance between a position of a rotation surface of the crushing blade and a bottom surface of the pan pelletizer.   19. The crushing is performed by moving the crushing blade in parallel with the bread bottom surface of the pan pelletizer due to fluctuations in the particle size and ingredients of the blended raw material, the blending amount, moisture for granulation, and the like. Method for producing sintered ore for blast furnace. The method for producing sintered ore for blast furnace according to claim 17, wherein the crushing is performed by crushing coarse pseudo particles by a pressing force from a crusher.