JPWO2010114152A1 - Binder addition method, binder addition apparatus, kneader and kneading method - Google Patents

Abstract

The present invention provides a binder addition method and an addition device that can uniformly add a binder to an iron ore raw material and can control the concentration and amount of the binder with high accuracy and speed in granulation of the iron ore raw material. With the goal. In the binder addition method of the present invention, a mixing nozzle 70 for mixing the binder and water separately supplied by the binder supply pipe 63 and the water supply pipe 66 is installed in the vicinity of the raw material charging section 55 of the kneader 50, and the mixing nozzle 70 The binder aqueous solution in which the binder and water are mixed is sprayed on the iron ore raw material charged in the raw material charging unit 55 of the kneader 50.

Description

  The present invention relates to a binder addition method, a binder addition apparatus, a kneader, and a kneading method that can uniformly add a binder to an iron ore raw material and that can control the concentration and amount of the binder with high accuracy and speed.

  In the granulation of the iron ore raw material, a binder stock solution (also referred to as a granulating agent) and water for adjusting moisture (hereinafter referred to as additive water) are added to the iron ore raw material and kneaded and granulated. In the granulation step, the amount of the binder and the amount of added water, that is, the concentration and amount of the aqueous binder solution are controlled quickly and accurately, and the aqueous binder solution is uniformly added to the iron ore raw material. It is important for improving quality.

  For example, in Patent Document 1, in the granulation of a sintered raw material containing iron ore, water is uniformly dispersed throughout the raw material by spraying a binder and water with separate watering means in a granulator such as a drum mixer. There is a proposed method.

  When granulating in a state where iron ore raw materials including coarse particles having a particle size of several millimeters to fine particles of 250 μm or less are mixed, fine particles in the raw materials are suitably dispersed by a binder functioning as a dispersing agent, and core particles It is important that fine powder adhere to the surface of the coarse particles that become. Therefore, in order to improve the quality of the granulated material when granulating the iron ore raw material mainly composed of such fine powder, a kneader for kneading the iron ore raw material as a pre-stage for producing the granulated material with a granulator It is necessary to add the binder aqueous solution adjusted to a predetermined concentration uniformly to the iron ore raw material and knead sufficiently in the kneader.

  In Patent Document 2, an iron ore raw material containing 60% by mass or more of particles having a particle size of 250 μm or less is first obtained in a kneader in order to obtain a target particle size distribution when granulating an iron ore material mainly composed of fine powder. Kneading to produce a kneaded product having an average particle size of 3 mm to 7 mm, and thereafter granulating the kneaded product with a drum mixer (granulator) to produce a granulated product having a particle size of 3 mm to 10 mm. A method has been proposed.

Usually, when adding a binder aqueous solution in a kneader, for example, as described in Patent Document 2, a binder and water are supplied from the body of a blade-rotating kneader and the binder aqueous solution is added in the kneader. The method to do is adopted.
Further, in Patent Document 3, in order to uniformly mix the granulating agent into the iron ore raw material in the granulator, the granulating agent and the added water are mixed in advance, and the mixture is sprayed into the granulator. A method of mixing with iron ore raw materials has been proposed.

JP 2007-113087 A JP 2007-247020 A JP 2004-137595 A Special table 2003-515440 gazette

  However, in the binder addition method described in Patent Document 2, as shown in FIG. 1, there is a gap between the inner peripheral surface of the barrel portion 2 of the blade rotating kneader 1 and the stirring blade 3. The material adheres to the inner peripheral surface of the material, and the fixing layer 4 (that is, the cell flying layer of the material) is formed. For this reason, since the binder aqueous solution 7 sprayed from the addition nozzle 6 through the pipe 5 connected to the body 2 is obstructed by the fixing layer 4, the body part is not directly sprayed on the raw material being kneaded. 2 flows down along the inner peripheral surface of 2, enters through the break of the fixed layer 4, and is locally added to the raw material. In this case, it is difficult to uniformly add the binder aqueous solution 7 within a predetermined time during which the raw material stays in the kneading machine 1, and the binder is unevenly distributed in the raw material, resulting in a concentration of the binder. A kneaded material suitable for the grain conditions cannot be obtained.

  In addition, the residence time of the raw material in the kneading machine is determined by the input amount and the raw material accumulation amount in the kneading machine, but due to the size of the apparatus, it is difficult to make the residence time extremely long and is usually long. In many cases, the time is about 3 minutes. For this reason, since it is necessary to uniformly mix the binder aqueous solution with a uniform concentration in the whole raw material in such a short time, when adding the binder aqueous solution in the kneader, the binder aqueous solution is controlled to a prescribed concentration. It is necessary.

As a method for ensuring the specified binder concentration from such a viewpoint, for example, the configuration of the granulating agent addition apparatus to the granulator described in Patent Document 3 is applied to the addition of the aqueous binder solution to the kneader. As shown in FIG. 2, the binder stock solution and the added water are mixed by a static mixer 10 disposed at a position away from the position of the addition nozzle 6 of the kneader 1 (hereinafter referred to as the addition position), and the binder aqueous solution is mixed. A method of conveying to the addition position of the kneader 1 by one pipe 5 can be considered.
In this method, the flow rate of the binder stock solution flowing through the pipe 13 is controlled using the flow rate adjusting valve 11 and the electromagnetic flow meter 12, and the additive water flowing through the pipe 16 is controlled using the flow rate adjusting valve 14 and the electromagnetic flow meter 15. By controlling the flow rate, both can be mixed by the static mixer 10 to generate a binder aqueous solution having a specified concentration, and the binder aqueous solution can be supplied to the kneader 1 through one pipe 5.

  However, iron ore raw materials are often stored outdoors, and the moisture contained in the iron ore raw materials (hereinafter referred to as raw material moisture) changes frequently due to the influence of the weather. Moreover, there are many cases where the blending ratio of a plurality of types of iron ore raw materials is changed, and the raw material moisture changes depending on the blending ratio. Due to these causes, the moisture of the iron ore raw material charged into the kneading machine 1 fluctuates frequently and is not stable. For this reason, even if a binder aqueous solution having a specified concentration is generated by the static mixer 10 and added in the kneader 1, the binder concentration actually acting on the raw material varies depending on the raw material moisture. Therefore, it is always required to control the binder concentration and the added amount of the aqueous binder solution with high accuracy in accordance with the moisture content of the raw material. That is, the concentration and addition amount of the aqueous binder solution are adjusted according to changes in the moisture content of the raw material, both the mass of solid content in the binder stock solution and the moisture mass consisting of the sum of the mass of moisture in the binder stock solution and the mass of added water. It is necessary to control with high accuracy.

  However, in the method using the static mixer 10 of FIG. 2 described above, since the aqueous binder solution mixed by the static mixer 10 before the change of the raw material moisture remains in the pipe 5, the pipe 13, Even when the flow rate of 16 was controlled, it was difficult to control the concentration and amount of the binder added to the raw material with high accuracy.

  For example, as will be described later, when the raw material moisture charged into the kneading machine 1 is reduced, the concentration of the aqueous binder solution remaining in the pipe 5 becomes higher than the optimum condition for the reduced raw material moisture. Yes. That is, when the raw material moisture is reduced, it is necessary to relatively increase the amount of added water. Therefore, it is necessary to lower the concentration of the aqueous binder solution itself before the reduction of the raw material moisture, but the binder remaining in the pipe 5 The aqueous solution cannot be adjusted and the binder concentration remains high. Therefore, when the remaining aqueous binder solution is added to the raw material, the binder concentration becomes too high during kneading by the kneader 1, and the kneaded product becomes a solid clay and cannot be granulated (hereinafter referred to as a slurry state). ). On the other hand, when the raw material moisture increases, the concentration of the aqueous binder solution remaining in the pipe 5 is lower than the optimum condition for the raw material moisture after the increase. For this reason, a binder density | concentration becomes low too much at the time of kneading | mixing, and sufficient granulation particle size and intensity | strength will no longer be obtained.

  In particular, when the kneaded product is in a slurry state because the binder concentration is too high, the conveyance from the kneader to the granulator itself may be impossible, which causes a serious trouble of stopping the production line. . In the case that the inventor has experienced, even when the raw material moisture value is reduced by only 0.5% by mass, the raw material unloaded from the kneader 1 is in a slurry state, and subsequent conveyance is not possible. There have been several cases where the raw materials have been stopped and the raw materials have to be manually discharged. Thus, the control delay of the binder concentration caused by the aqueous binder solution remaining in the pipe 5 on the downstream side of the static mixer 10 becomes an important problem.

  In order to cope with such a problem, as shown in FIG. 3, a method of conveying the binder stock solution and the added water through separate pipes 13 and 16 and bringing the static mixer close to the addition position of the kneader 1 can be considered. However, even in the method of FIG. 3, when trying to change the amount of the binder stock solution and the amount of added water mixed by the static mixer 10, the binder stock solution and the added water that have been conveyed at a predetermined pressure in the pipes 13 and 16, respectively, Since they interfere with each other in the static mixer 10 and the pressure balance between the two is lost, there is a problem that it takes time until the pressure becomes steady. Therefore, with the method using the static mixer 10 shown in FIGS. 2 and 3, the flow rate cannot be adjusted instantaneously even when the raw material moisture changes by only 0.5% by mass, and the control flow rate is stable. There is a possibility that the above-mentioned serious trouble may occur because a time delay occurs until the operation is completed. As described above, in the method using the static mixer 10 considered to be indispensable for obtaining a binder aqueous solution having a specified concentration, the responsiveness to the change in the binder concentration according to the fluctuation of the raw material moisture is poor, so it is added to the raw material. It was very difficult to control the concentration and amount of the binder to be quickly with high accuracy.

  From the circumstances described above, conventionally, in order to improve the granulation property in the granulation step, in the kneading step of previously kneading the iron ore raw material mainly composed of fine powder, the binder can be uniformly added to the raw material, and There has been a demand for a method that can quickly and accurately control the concentration and amount of the added binder in accordance with the amount of raw material transport and the amount of raw material moisture that change from moment to moment.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to uniformly add a binder to an iron ore raw material, and to accurately adjust the concentration and amount of the binder. It is an object of the present invention to provide a new and improved binder addition method, binder addition device, kneader and kneading method that can be quickly controlled.

In order to solve the above problems, the inventors have intensively studied, and as a result, the binder and the added water are mixed by a mixing nozzle that is opened on the outlet side, and sprayed on the raw material charged into the raw material charging portion of the kneader. Thus, the present inventors have found that the addition amount and the binder concentration can be quickly controlled and uniformly mixed with the iron-making raw material with respect to the moisture change of the iron ore raw material without damaging the pressure balance of the binder stock solution and the added water.
Moreover, in order to mix a binder with high viscosity and additional water uniformly, it discovered that the binder aqueous solution mixed uniformly can be obtained by making the sprayed additional water collide and contact with a binder.

The present invention has been made by comprehensively considering these findings, and the gist thereof is as follows.
According to one aspect of the present invention, in the granulation of iron ore raw material, a mixing nozzle that mixes the binder and water separately supplied by the binder supply pipe and the water supply pipe and is released from the outlet side is provided. The binder aqueous solution in which the binder and the water are mixed is sprayed from the mixing nozzle to the iron ore raw material charged into the raw material charging portion of the kneader. There is provided a method for adding a binder.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, in the granulation of an iron ore raw material, the binder supply piping which supplies a binder, and the water supply piping which supplies water are iron ore raw materials. A mixing nozzle that is installed in the vicinity of a raw material charging portion of the kneader and mixes the binder and the water separately supplied by the binder supply pipe and the water supply pipe and has an outlet side open, and The mixing nozzle sprays an aqueous binder solution formed by mixing the binder and the water onto the iron ore raw material charged into the raw material charging unit of the kneader, and provides a binder addition device. Is done.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, the kneading machine provided with the said binder addition apparatus is provided.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, sprinkling binder aqueous solution with respect to the iron ore raw material thrown into the raw material input part of a kneader using the said binder addition apparatus. There is provided a kneading method characterized by kneading the iron ore raw material in the kneader.

  The mixing nozzle has a double structure including an outer nozzle and an inner nozzle arranged in the outer nozzle, and the binder supply pipe is connected to one of the outer nozzle or the inner nozzle, The water supply pipe is connected to the other of the outer nozzle or the inner nozzle, and the water supplied by the water supply pipe to the binder supplied into the outer nozzle by the binder supply pipe. The binder and the water are mixed in the outer nozzle to produce the binder aqueous solution, and the binder aqueous solution is sprayed from the nozzle port of the outer nozzle to the iron ore raw material. May be.

  Further, the binder supply pipe is connected to an inflow port penetratingly formed on a side surface of the outer nozzle, and the water supply pipe is connected to communicate with the inner nozzle, from the inflow port of the outer nozzle. The binder aqueous solution may be generated by spraying the water from the nozzle port of the inner nozzle to the binder discharged into the outer nozzle to mix the water with the binder.

  Further, the water supply pipe is connected to an opening formed through a side surface of the outer nozzle, and the binder supply pipe is connected to communicate with the inner nozzle, and is connected to the outer nozzle from the nozzle port of the inner nozzle. The binder aqueous solution may be generated by spraying the water from the opening of the outer nozzle to the binder discharged into the nozzle to mix the water with the binder.

  The binder may be a polyacrylic acid-based dispersant. In addition, it is preferable that the viscosity of a binder undiluted | stock solution is 5000 mPa * s or less.

  The flow rate of at least one of the binder supply pipe and the water supply pipe may be controlled according to the water content of the iron ore raw material or the input amount of the iron ore raw material to the kneader. Good.

  The iron ore raw material includes fine powder and core particles that are kneaded by the granulator and then granulated by the granulator, and the binder is a dispersant that disperses the fine powder in the iron ore raw material. You may do it.

  According to the above configuration, the mixing nozzle is installed in the vicinity of the raw material charging portion of the kneader, and the binder and water are conveyed to the mixing nozzle in the addition position (near the raw material charging portion) through separate pipes. Can be controlled with high accuracy. In addition, the mixing nozzle mixes the binder and water separately supplied by the binder supply pipe and the water supply pipe to generate a binder aqueous solution, and the binder aqueous solution is used as an iron ore raw material to be input to the raw material input portion of the kneader. Spray against. Thereby, before an iron ore raw material is thrown into a kneading machine, the binder aqueous solution of a uniform density | concentration can be uniformly added with respect to the said iron ore raw material. Furthermore, since the mixing nozzle mixes the binder and water under an open pressure, the concentration of the aqueous binder solution can be quickly changed, and by providing the mixing nozzle near the raw material charging portion, Concentrated aqueous binder solution can be immediately added to the iron ore raw material. Therefore, according to the fluctuation | variation of the moisture content of an iron ore raw material and raw material input amount, the density | concentration and addition amount of binder aqueous solution can be changed to an appropriate value rapidly with high precision, respectively, and it can add to an iron ore raw material.

  As described above, according to the present invention, the binder can be uniformly added to the iron ore raw material, and the concentration and amount of the binder can be quickly controlled with high accuracy.

FIG. 1 is an explanatory view showing a fixing layer adhering to the inner peripheral surface of a body portion of a conventional blade rotating kneader.
FIG. 2 is a schematic diagram showing a binder addition method using a static mixer.
FIG. 3 is a schematic diagram showing a modified example of the binder addition method using a static mixer.
FIG. 4 is a schematic diagram showing a sintering facility equipped with a kneader according to the first embodiment of the present invention.
FIG. 5 is a schematic view showing a kneader equipped with a binder addition apparatus according to the embodiment.
FIG. 6 is a schematic view showing a mixing nozzle of the binder adding apparatus according to the embodiment.
FIG. 7 is a schematic diagram illustrating a mixing nozzle of a binder addition device according to a modified example of the embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[1. Overall configuration of sintering equipment]
First, with reference to FIG. 4, the whole structure of the sintering equipment to which the kneading machine provided with the binder addition apparatus which concerns on the 1st Embodiment of this invention was applied is demonstrated. FIG. 4 is a schematic diagram showing the overall configuration of a sintering facility to which a kneader equipped with a binder addition apparatus according to this embodiment is applied.

  As shown in FIG. 4, the sintering facility according to this embodiment mainly includes a pseudo granulation line 20, a pellet granulation line 30, and a sintering machine 40. The pellet granulation line 30 is a production line for producing a granulated product (hereinafter referred to as “sintered raw material pellet”) obtained by granulating an iron ore raw material mainly composed of fine powder. On the other hand, the pseudo granulation line 20 granulates an iron ore raw material containing fine powder and coarse particles, and a granulated product in which the fine powder is adhered to the coarse particles serving as core particles (hereinafter referred to as “pseudo granulated product”). It is a manufacturing line for manufacturing.

  Here, the iron ore raw material for manufacturing the said sintered raw material pellet and pseudo granulated material is demonstrated first. The iron ore raw material is used as a sintering raw material for producing the sintered ore with the sintering machine 40. This sintering raw material is, for example, iron ore raw material, which is the main raw material, and ironmaking dust (blast furnace dust collection dust, converter dust, etc.), pellet feed, limestone, dolomite, silica, olivine, coke powder, The mixed raw material which added 1 type, or 2 or more types, such as anthracite, can be used. The iron ore raw material is not limited as long as it is an iron ore used as a normal sintering raw material. For example, iron ore containing a large amount of crystal water in addition to hematite or magnetite (for example, goethite, limonite (pisolite ore) Etc.), and may be porous (for example, maramamba ore, high phosphorus block man ore, etc.).

Since the iron ore raw material contains a large amount of fine powder, the granulation property is poor, the strength of the granulated product is weakened, and the granulated product in the conveying process up to the sintering machine 40 or the sintering process in the sintering machine 40 Collapses. For this reason, when an iron ore raw material containing a large amount of such fine powder is directly introduced into the sintering machine 40, the air permeability is greatly deteriorated and the productivity of the sintered ore is hindered. Therefore, the iron ore raw material is subjected to a granulation treatment to increase the strength of the granulated product.
That is, the iron ore raw materials as described above are classified according to the ore type and particle size, and granulated (pseudo-particleized or pelletized) in two types of granulation lines, the pseudo-granulation line 20 and the pellet granulation line 30 respectively. To produce sintered raw material pellets and pseudo-granulated products. Each granulation line is described in detail below.

  First, the pseudo granulation line 20 will be described in detail. The pseudo-granulation line 20 is a line for manufacturing a pseudo-granulated product in which fine particles (for example, a particle size of 250 μm or less) are adhered to coarse particles (for example, a particle size of 3 mm or more) of an iron ore raw material serving as core particles. As shown in FIG. 4, the pseudo granulation line 20 includes a raw material tank 21 for storing a sintering raw material including coarse particles and fine powder, a sieve sorter 22, and a kneading for kneading the sintering raw material with a water-soluble binder or the like. And a granulator 24 that granulates the kneaded sintered raw material to produce a pseudo-granulated product.

  The raw material tank 21 stores, for example, iron ore containing coarse particles and fine powder (for example, pisolite ore), iron ore raw material containing powdered coke, limestone, and the like. It is sorted into coarse particles having a predetermined particle size or more (for example, 3 mm or more) and fine particles having a particle size smaller than that. Of these, the coarse particles can be used as core particles as they are, and are therefore conveyed to the granulator 24.

  On the other hand, the fine powder is charged into a kneader 23 composed of, for example, a Redige mixer and kneaded together with a binder to produce a kneaded product. As the kneading machine 23, a blade rotation type kneading machine such as a pro shear mixer or an Eirich mixer can be used. The binder added to the kneader includes, for example, a polyacrylic acid-based dispersant (for promoting solid crosslinking, and includes an aqueous solution and a colloid to which the dispersant is added from the viewpoint of enhancing granulation properties. ), At least one of quicklime and lignin can be used. As the binder to be added to the kneader in the granulation process using the sintering facility according to this embodiment, it is preferable to use a polyacrylic acid-based dispersant.

  The kneaded product obtained by the kneader 23 and the coarse particles from the sieve sorter 22 are charged into a granulator 24 comprising a drum mixer or the like. For example, a drum mixer, a pan pelletizer, or the like can be used as the granulator 24, and the kneaded material of the iron ore raw material is granulated (pseudo-particles) by the granulator 24 to become a pseudo-granulated product. Specifically, fine particles (for example, a particle size of 250 μm or less) contained in the powder coke, other iron ore, and binder are adhered around the core particles that are coarse particles by the granulation treatment by the granulator 24. A pseudo granulated product (for example, a particle size of 1 to 10 mm) is produced.

  Next, the pellet granulation line 30 will be described in detail. The pellet granulation line 30 is a line for producing sintered raw material pellets, which are granulated products obtained by granulating an iron ore raw material mainly composed of fine powder having a predetermined particle size or less. The iron ore raw material mainly composed of fine powder is, for example, an iron ore raw material containing 60% by mass or more of particles having a particle size of 250 μm or less. The sintered raw material pellet is, for example, a granulated product having a particle size of 1 to 10 mm and an average particle size of 5 mm. In this embodiment, the sintered raw material pellet is a granulated product containing 70% by mass or more of particles having a particle size of 3 mm or more.

  As shown in FIG. 4, the pellet granulation line 30 includes a raw material tank 31 for storing iron ore raw materials mainly composed of fine powder, a sieve sorter 32, a pulverizer 33 for pulverizing the iron ore raw materials, and pulverization. A granulated machine 34 for kneading the later sintered raw material and a binder, a granulator 35 for granulating the kneaded sintered raw material to produce a sintered raw material pellet, a sieve sorter 36, and granulated A dryer 37 for drying the sintered raw material pellets. Among these, the kneading machine 34 is an example of a kneading machine provided with the binder addition apparatus of the present invention, and the detailed description thereof will be described later.

  In the raw material tank 31 of the pellet granulation line 30, various iron ore raw materials (for example, maramamba ore, high phosphorus block man ore, etc.) containing a large amount of fine powder, fine powder raw materials such as the above iron making dust, pellet feed, limestone, etc. A sintering raw material containing a binder such as is stored. As this iron ore, coarse particles having a predetermined particle diameter or more are selected and removed in advance by a sieve sorter (not shown) or the like to obtain a fine powder (for example, particle diameter of 3 mm or less). It is preferable from the viewpoint of facilitating and developing the strength of the granulated product.

  The iron ore raw material supplied from the raw material tank 31 is first sieved by a sieve sorter 32, and fine powder having a predetermined particle size (for example, 3 mm) or less is supplied to a pulverizer 33. On the other hand, the particles having a predetermined particle diameter or more are supplied to the granulator 24 of the pseudo-granulation line 20 to be used as the core particles of the above-described pseudo-granulated product. The pulverizer 33 is composed of, for example, a roller press compressor, a ball mill, or the like, and pulverizes the iron ore material that has been charged into a predetermined particle size distribution. Thus, the subsequent granulation process can be facilitated by pulverizing and finely pulverizing and sizing the iron ore raw material.

  Next, in the kneader 34, the binder and water are added to adjust the water content, and then the fine iron ore raw material is kneaded. In the present embodiment, as the kneading machine 34, for example, a blade rotation type kneading machine such as a Redige mixer or a Proshear mixer is used. Thus, in this embodiment, it is set as the structure which improved the kneading | mixing capability of an iron ore raw material and a binder by installing the kneading machine 34 in the front | former stage of the granulator 35. FIG. The binder added to the kneader includes, for example, a polyacrylic acid-based dispersant (for promoting solid crosslinking, and includes an aqueous solution and a colloid to which the dispersant is added from the viewpoint of enhancing granulation properties. ), At least one of quicklime and lignin can be used. As the binder to be added to the kneader in the granulation process using the sintering facility according to this embodiment, it is preferable to use a polyacrylic acid-based dispersant.

  The sintered raw material after being kneaded by the kneader 34 is charged into the granulator 35 and granulated. As the granulator 35, for example, a drum mixer or a pan pelletizer can be used. By the granulation by the granulator 35, for example, sintered raw material pellets which are substantially spherical granules having a particle diameter of 1 to 10 mm, preferably 3 to 6 mm (for example, an average particle diameter of 5 mm) are manufactured. . As for the particle size distribution of the sintered raw material pellets, for example, a particle size of 3 mm or more may be 70% by mass.

  The sintered raw material pellets thus produced are dried by a dryer 37 after a granulated material having a predetermined particle size or more is sorted by a sieve sorter 36. As the dryer 37, a fluidized bed dryer, a packed bed dryer, a drum dryer or the like can be used.

  As described above, the pseudo-granulated product granulated in the pseudo-granulation line 20 and the sintered raw material pellets granulated in the pellet granulation line 30 are blended at a predetermined blending ratio, and the sintering machine 40. The sintering machine 40 sinters the two kinds of sintered raw material granules to produce a sintered ore. The sintered ore is supplied to the blast furnace after being crushed by a crusher (not shown) and cooled by a sintered cooler (not shown).

  The overall configuration of the sintering facility according to the present embodiment has been described above. In the present embodiment, in the pseudo granulation line and the pellet granulation line 30, kneaders 23 and 34 are provided in the preceding stages in order to improve the granulation performance in the granulators 24 and 35, respectively. , 34, after adding a binder to the iron ore raw material and kneading, the obtained kneaded material is provided to the granulators 24 and 35 for granulation. The present embodiment has a feature in a binder addition method at the time of kneading by the kneaders 23 and 34, and the kneaders 23 and 34 have a characteristic structure for realizing the binder addition method. It has. A kneader 50 shown in FIG. 5 described later can be suitably applied to the kneaders 23 and 34 of the sintering equipment shown in FIG. The binder addition apparatus and the binder addition method of the kneader 50, which are features according to this embodiment, will be described later (see FIGS. 5 to 7).

[2. Verification result of necessity of binder concentration control]
Next, prior to detailed description of the binder addition method according to the present embodiment, the necessity of controlling the binder concentration with high accuracy and speed when adding the binder to the kneader is shown in FIG. 2 and FIG. The result verified using the example of an addition method is demonstrated.

  As described above, in the binder addition method of FIGS. 2 and 3, in order to add a uniform aqueous binder solution to the iron ore raw material, the binder stock solution and water for adjusting water (added water) are mixed using the static mixer 10. Thus, a binder aqueous solution having a predetermined concentration was generated, and this binder aqueous solution was supplied to the kneading machine 1 through one pipe 5 and added to the iron ore raw material from the trunk portion 2 of the kneading machine 1. Moreover, since the moisture (raw material moisture) contained in the iron ore raw material charged into the kneading machine 1 varies, the appropriate value of the binder concentration added to the raw material also changes every moment. If the binder concentration added to the iron ore raw material in the kneading machine 1 is not an appropriate value, the granulation property in the subsequent granulation step is lowered. Therefore, when the raw material moisture changes, it is necessary to change the binder concentration to a concentration suitable for the changed raw material moisture as quickly as possible.

  However, since the binder addition method shown in FIGS. 2 and 3 is an apparatus configuration for supplying the binder aqueous solution through one pipe 5 from the static mixer 10 to the kneader 1, the flow rate is adjusted immediately when the raw material moisture changes. Even if the flow rate of the binder stock solution and additive water supplied to the static mixer 10 by the valves 11 and 14 is adjusted to control the binder concentration suitable for the raw material moisture after the change, the binder remaining in the pipe 5 remains. An aqueous solution (a binder aqueous solution having a concentration suitable for the raw material moisture before the change) is inevitably supplied to the kneader 1 and added to the raw material. As described above, in the binder addition method shown in FIGS. 2 and 3, the change in the binder concentration is delayed by the amount of the binder aqueous solution remaining in the pipe 5. .

Therefore, the inventors of the present invention, in the binder addition method of FIG. 2 and FIG. 3 described above, when the raw material moisture is changed, the binder aqueous solution remaining in the pipe 5 is the binder concentration of the kneaded material suitable for granulation. It was verified how badly it adversely affected.
Tables 1 and 2 show the results. Table 1 shows that in the binder addition method, when the ratio of moisture in the iron ore raw material charged into the kneading machine 1 (raw material water ratio) is decreased from 8.5% by mass to 8.0% by mass, The result of having verified the shift | offset | difference from the appropriate value of binder solid content in it is represented. Table 2 shows the result of verifying the deviation from the appropriate value of the binder solid content in the raw material when the raw material moisture ratio increases from 8.0% by mass to 8.5% by mass. In this verification, a pipe 50A having a length of 20 m was used as the pipe 5 in the binder addition method of FIG.

  Here, various terms used in Tables 1 and 2 are defined. In addition, binder aqueous solution is the aqueous solution which mixed the binder stock solution and water (addition water), and raw material water | moisture content is the water | moisture content which an iron ore raw material contains.

Mass of moisture in binder stock solution: WB (ton)
Mass of solid in binder stock solution: SB (ton)
Mass of added water: WW (ton)
Mass of raw material moisture before being put into kneading machine: WF (ton)
Mass of iron ore raw material before being put into kneading machine: SF (dry-ton)

The binder concentration CB is the concentration (mass%) of the aqueous binder solution added to the iron ore raw material and is represented by the following formula.
CB = {SB / (SB + WB + WW)} × 100
The binder aqueous solution addition amount T is the mass of the binder aqueous solution added to the iron ore raw material, and is represented by the following formula.
T = SB + WB + WW
The binder solid content ratio RS is a ratio (mass%) of the solid mass SB in the binder stock solution to the mass SF of the iron ore raw material, and is represented by the following formula.
RS = {SB / SF} × 100
The raw material water ratio RW0 is the ratio (mass%) of the raw material water mass WF to the total mass (SF + WF) of the iron ore raw material and raw material water, and is represented by the following formula.
RW0 = {WF / (SF + WF)} × 100
The raw material moisture ratio RW1 after mixing is the ratio (mass%) of the mass of the total moisture to the total mass after the binder aqueous solution and the iron ore raw material are mixed, and is represented by the following formula.
RW1 = {(WF + WB + WW) / (SF + SB + WF + WB + WW)} × 100

Next, the verification results of Table 1 and Table 2 will be described.
In the binder addition method shown in FIG. 2, as shown in Table 1, when the raw material moisture ratio RW0 decreases from 8.5% by mass to 8.0% by mass, the binder aqueous solution binder remaining in the pipe 5 is used. The concentration CB (14.1% by mass) is higher than the optimum concentration CB (7.7% by mass) with respect to the raw material water ratio after reduction (8.0% by mass). For this reason, in the period A in which the high-concentration binder aqueous solution remaining in the pipe 5 is added to the raw material, the solid content SB ′ in the binder that is about 1.9 times the optimum value SB is the iron ore in the kneader 1. Since it is supplied to the raw material, the binder concentration becomes too high in the kneading. As a result, the binder is excessively supplied and the kneaded material is slurried, which causes a serious influence such as a decrease in granulation property of the kneaded material or a failure to convey the kneaded material.

  On the other hand, as shown in Table 2, when the raw material water ratio RW0 increased from 8.0% by mass to 8.5% by mass, the binder concentration CB (7.7% by mass) of the aqueous binder solution remaining in the pipe 5 was obtained. ) Is lower than the optimum concentration CB (14.1% by mass) with respect to the raw material water ratio after the increase (8.5% by mass). For this reason, at the time A when the low-concentration aqueous binder solution remaining in the pipe 5 is added to the raw material, only about 0.52 times the solid content SB ′ in the binder of the optimum value SB, the iron ore in the kneader 1 Since it is not supplied to the raw material, the binder concentration becomes too low during kneading. As a result, the supply of the binder becomes insufficient and the granulated product has a serious influence such as a small particle size.

  As described above, as can be seen from the verification results in Tables 1 and 2, even if the water content of the iron ore raw material charged into the kneading machine 1 is changed by only about 0.5% by mass, the binder addition method in FIG. There is a problem that graininess is greatly reduced. In addition, although the above problem is somewhat improved even in the binder addition method of FIG. 3, the responsiveness of the static mixer 10 when the binder concentration is changed in accordance with the change in the raw material moisture is low, so the pressure in the static mixer 10 There is a problem that a binder aqueous solution deviated from an appropriate concentration is added until the balance becomes steady. As described above, the binder addition method shown in FIGS. 2 and 3 has an advantage that a binder aqueous solution having a uniform concentration can be generated by using the static mixer 10, but a rapid and appropriate concentration can be obtained when the raw material moisture changes. There was a technical problem that the aqueous binder solution could not be supplied.

  Furthermore, in the binder addition method of FIG. 2 and FIG. 3, since the binder aqueous solution is sprayed from the addition nozzle 6 connected to the body portion 2 of the blade rotating kneader 1, as shown in FIG. If the fixing layer 4 is formed on the inner peripheral surface of the body portion 2, there is a technical problem that the aqueous binder solution cannot be uniformly sprayed on the raw material in the kneader 1.

  Therefore, in order to solve all of these technical problems, the binder addition method according to the present embodiment is a state in which the flow rate of the binder stock solution and the added water is controlled with high accuracy by separate pipes, as described in detail below. The iron ore raw material is fed to the raw material charging part of the kneading machine and mixed with a mixing nozzle arranged in the vicinity of the raw material charging part to form a binder aqueous solution, and the binder aqueous solution is fed from the mixing nozzle to the kneading machine. It is characterized by adding to.

[3. Binder addition device and addition method]
Next, with reference to FIG. 5, the binder addition apparatus which concerns on one Embodiment of this invention, and the binder addition method using this are demonstrated. FIG. 5 is a schematic diagram showing a kneader equipped with a binder addition apparatus according to this embodiment. The kneader 50 shown in FIG. 5 is applicable to the kneaders 23 and 34 provided in the pseudo granulation line 20 and the pellet granulation line 30 of the sintering equipment shown in FIG.

  As shown in FIG. 5, the kneader 50 according to the present embodiment is a kneading machine having a blade rotation structure, and includes, for example, a Redige mixer, a Proshear mixer, and the like. The kneading machine 50 includes a cylindrical body 52 that accommodates an object to be kneaded (for example, iron ore raw material 57), a plurality of stirring blades 53 that are rotated by a rotating shaft 54, and a drive unit that rotates the rotating shaft 54 (see FIG. (Not shown), a raw material charging unit 55 including a reverse cone-shaped raw material charging hopper, and a transporting unit 56 such as a belt conveyor for transporting the iron ore raw material 57.

  In the kneader 50 having such a structure, the iron ore raw material 57 transported by the transport unit 56 falls from the end of the transport unit 56 and is fed from the raw material charging unit 55 into the body 52 of the kneader 50. The When this raw material is charged, a binder aqueous solution is added to the iron ore raw material 57 from a mixing nozzle 70 described later. The iron ore raw material 57 thrown into the body 52 advances in the body 52 in a predetermined direction (for example, the left direction in FIG. 5) while being stirred by the stirring blade 53 that rotates about the rotation shaft 54. Thereby, the iron ore raw material 57 and the binder aqueous solution are kneaded, and a kneaded product (for example, a particle size of several hundred μm to several mm) having a predetermined particle size suitable for granulation in the subsequent granulation step is generated. This kneaded material is discharged from a discharge port (not shown) of the body portion 52 and conveyed to a granulator. In the present embodiment, the kneader 50 is characterized by the structure and addition method of a binder addition device that adds a binder to the iron ore raw material 57.

  First, the binder will be described. The binder is a granulating agent used for granulating an iron ore raw material containing fine iron ore. For this binder, it is preferable to use a polyacrylic acid-based dispersant for keeping the dispersibility of the fine particles of the iron ore raw material high in order to improve the granulation property in the subsequent granulation step of the kneading step.

  As such a binder, for example, a granulating agent (polyacrylic acid-based dispersant) described in JP-A No. 2003-155524 can be suitably used. This granulation treatment agent contains a water-soluble polymer compound having a clay dispersibility of 0.5 or more. The polymer compound contains a carboxyl group and / or a salt thereof, has a number average molecular weight in the range of 500 or more and 20000 or less, and a polydispersity expressed by weight average molecular weight / number average molecular weight is 1. .2 or more and 12.0 or less. More specifically, the polymer compound is selected from the group consisting of, for example, (a) polyacrylic acid, (b) part or all of the carboxyl groups contained in polyacrylic acid are sodium, potassium, calcium, and ammonia. It may be at least one compound selected from the group consisting of at least one neutralized polyacrylate.

  By adding such a polyacrylic acid-based dispersant to the iron ore raw material containing iron ore fine powder as a binder, the fine powder can be evenly dispersed within the raw material, so that the fine powders are solidified together. Instead, the dispersed fine powder can be attached around the core particles (coarse particles). Therefore, when the iron ore raw material containing fine powder is granulated (pseudo-particle or pelletized), the dispersibility of the fine powder in the raw material is kept high, and the dispersed fine powder is attached around the core particles. The effect can be enhanced. Therefore, the iron ore raw material can be suitably granulated (pseudo-particle or pelletized), and the granulation property can be improved.

  Next, with reference to FIG. 5, the binder addition apparatus and the addition method in the kneader 50 according to this embodiment will be described. As shown in FIG. 5, the binder addition apparatus includes a binder supply pipe 63 for supplying a binder stock solution, a water supply pipe 66 for supplying water for adjusting water (added water), the binder supply pipe 63 and water. A mixing nozzle 70 connected to the tip of the supply pipe 66 and a control device (not shown) for controlling the flow rates of the binder supply pipe 63 and the water supply pipe 66 are provided.

  The binder supply pipe 63 is a pipe for supplying the binder stock solution from a binder supply source (for example, a binder stock solution tank, not shown) to the mixing nozzle 70. A flow rate adjusting valve 61 and an electromagnetic flow meter 62 are provided in the middle of the binder supply pipe 63. The electromagnetic flow meter 62 measures the flow rate of the binder stock solution flowing in the binder supply pipe 63, and the flow rate adjustment valve 61 is based on the measurement result of the electromagnetic flow meter 62 and information such as the raw material moisture content or the raw material input amount. The flow rate of the binder stock solution in the binder supply pipe 63 is controlled to a set predetermined flow rate. The binder supply pipe 63 according to the present embodiment supplies the binder stock solution as the binder of the present invention. However, the present invention is not limited to this example. For example, the binder aqueous solution in which the binder stock solution is previously diluted to a predetermined concentration. May be supplied.

  The water supply pipe 66 is a pipe for supplying additive water for adjusting the concentration of the binder aqueous solution from a water supply source (for example, a water tank, not shown) to the mixing nozzle 70. A flow rate adjusting valve 64 and an electromagnetic flow meter 65 are provided in the middle of the water supply pipe 66. The electromagnetic flow meter 65 measures the flow rate of the additive water flowing in the water supply pipe 66, and the flow rate adjustment valve 64 is based on the measurement result of the electromagnetic flow meter 65 and information such as the raw material moisture ratio or the raw material input amount. The flow rate of the added water in the water supply pipe 66 is controlled to a set predetermined flow rate.

  The binder addition device includes a control device (not shown), and data obtained by measuring the raw material moisture and the input amount of the iron ore raw material 57 input to the kneader 50 is input to the control device. . Based on the input data, the control device obtains information such as the raw material moisture content or the raw material input amount, calculates the control amount of the flow rate adjustment valve 61 or the flow rate adjustment valve 64, and sets the opening degree of each adjustment valve. Instruct.

As described above, the raw material moisture constantly varies depending on the storage state of the iron ore raw material, the weather, the raw material mixing ratio, and the like. The control device of the binder addition device according to the present embodiment controls the flow rate adjustment valve 61 or the flow rate adjustment valve 64 in accordance with the fluctuation of the raw material moisture, and determines the amount of the binder stock solution and the amount of added water supplied to the mixing nozzle 70. Control accurately. As for the amount of raw material input, the amount of iron ore raw material is basically supplied quantitatively by setting the amount cut out from the raw material tank.
Therefore, before charging into the kneader 50, for example, the amount of raw material input by the transport unit 56 (belt conveyor or the like) is measured by a measuring means such as a belt scale, and the amount of the binder stock solution and the amount of added water are adjusted according to the measured values. It is also possible to control with high accuracy.

  With the binder supply pipe 63, the water supply pipe 66 and the flow rate control mechanism as described above, the flow rates of the binder stock solution and the added water supplied to the mixing nozzle 70 can be controlled with high accuracy. Therefore, the concentration and amount of the binder aqueous solution added to the iron ore raw material 57 from the mixing nozzle 70 can be controlled with high accuracy in accordance with the raw material moisture of the iron ore raw material 57 and the raw material input amount.

  Next, the function of the mixing nozzle 70 which is a feature according to the present embodiment will be described. The structure of the mixing nozzle 70 will be described later. The mixing nozzle 70 puts the binder stock solution and water separately supplied through the binder supply pipe 63 and the water supply pipe 66, respectively, and the aqueous binder solution obtained by the mixing into the kneader 50. It has a function of spraying on the iron ore raw material 57. Also, since the mixing nozzle 70 is open on the outlet side, unlike the static mixer, the binder stock solution and the added water do not interfere with each other in the static mixer and the pressure balance between the two is not lost. Even if the supply amount is changed, the flow rate is stabilized without any control delay. By using the mixing nozzle 70, the binder addition method according to the present embodiment can be suitably executed.

  The mixing nozzle 70 is provided in the vicinity of the raw material charging unit 55 of the kneader 50 and sprays the binder aqueous solution directly onto the iron ore raw material 57 charged into the raw material charging unit 55. Here, the vicinity of the raw material charging portion 55 where the mixing nozzle is disposed is an arbitrary position where the binder aqueous solution can be directly sprayed from the mixing nozzle 70 to the iron ore raw material 57 charged into the kneader 50. is there. For example, as shown in the drawing, the mixing nozzle 70 may be disposed in the vicinity of the raw material charging unit 55 (a position where the mixing nozzle 70 is separated from the raw material charging unit 55). You may install in the arbitrary locations (for example, hopper side surface) of the raw material injection | throwing-in part 55. FIG.

  Thus, by arranging the mixing nozzle 70 in the vicinity of the raw material charging portion 55 of the kneader 50, the aqueous binder solution mixed by the mixing nozzle 70 is supplied to the iron ore raw material 57 charged into the raw material charging portion 55. Can be sprayed and added directly. Thereby, the binder addition apparatus which concerns on this embodiment increases the responsiveness with respect to the fluctuation | variation of the raw material water | moisture content of the iron ore raw material 57, and can respond quickly to the change of binder density | concentration and addition amount.

  That is, as described above, in the addition method using the static mixer 10 shown in FIG. 2 and FIG. 3, when the raw material moisture fluctuates, the flow rate of the pipes 13 and 16 is changed immediately, and the static mixer 10 An attempt was made to change the amount of binder stock solution added and the amount of added water. However, due to the nature of the piping system, there is a first problem that an aqueous binder solution having an inappropriate concentration remaining in the piping 5 on the downstream side of the static mixer 10 is inevitably added to the iron ore raw material. Furthermore, if the flow rate (pressure) of the binder stock solution and the added water flowing in the pipes 13 and 16 is changed, both interfere with each other in the static mixer 10 and the pressure balance between the two is lost. There was a second problem that it took time until the aqueous binder solution was stabilized. Due to these problems, a binder aqueous solution having a concentration suitable for the raw material moisture after the fluctuation cannot be immediately added, and the responsiveness to the fluctuation of the raw material moisture is poor.

  On the other hand, in the binder addition method according to the present embodiment, the binder stock solution and the addition water are accurately used by using separate pipes 63 and 66 up to the vicinity of the raw material charging portion 55 of the kneader 50 (in the vicinity of the binder addition position). It conveys in the state by which flow control was carried out, it mixes with the mixing nozzle 70, and is directly added to the iron ore raw material 57. FIG. For example, when the raw material moisture rises, the flow rate adjusting valve 64 reduces the flow rate of the added water in the water supply pipe 66 by an appropriate amount. Further, when the raw material moisture decreases, the flow rate adjusting valve 64 increases the flow rate of the added water in the water supply pipe 66 by an appropriate amount. Thereby, the mixing nozzle 70 mixes the binder stock solution and the added water after the flow rate is individually adjusted with high accuracy by the binder supply pipe 63 and the water supply pipe 66, so that the concentration is suitable for the raw material moisture after the fluctuation. A binder aqueous solution is generated with high accuracy and speed and added.

  In the above description, the method of controlling the amount of added water in the water supply pipe 66 by adjusting the flow rate of the additive water in the water supply pipe 66 by the flow rate adjusting valve 64 with respect to the increase or decrease of the raw material moisture has been described. It is also possible to control the amount of binder input by adjusting the flow rate of the binder stock solution in the binder supply pipe 63 by the adjusting valve 61. However, in this case, since the net amount of the binder fed into the kneading machine 50 is changed, and the addition ratio of the binder to the raw material is changed, the flow rate adjusting valve 64 described above causes the water supply pipe 66 to be inside. It is preferable to use a method of adjusting the flow rate of the added water.

  As described above, the binder addition method according to the present embodiment does not need to use the static mixer 10 having poor responsiveness to the change in the binder concentration according to the fluctuation of the raw material moisture, and uses the mixing nozzle 70 as the mixing means. Thus, the binder concentration can be changed immediately in response to the fluctuation of the raw material moisture, and the response of the binder concentration control is excellent. Therefore, the binder concentration can be controlled with high accuracy, and the aqueous binder solution having the optimum concentration to the raw material moisture after the fluctuation can be quickly added.

  Further, in the mixing nozzle 70, the binder stock solution and the added water are mixed in advance before the addition to generate a uniform concentration binder aqueous solution, and the binder aqueous solution is directly sprayed from the mixing nozzle 70 to the iron ore raw material 57 to be charged. To do. Thereby, there is an effect that a binder aqueous solution having a uniform concentration can be uniformly added to the iron ore raw material 57.

  In addition, the binder aqueous solution is not added from the trunk portion 52 of the kneader 50, but the binder aqueous solution is added to the iron ore raw material 57 at a position before being put into the kneader 50. For this reason, the fixing layer 4 formed on the inner peripheral surface of the body portion 2 of the kneading machine 1 as shown in FIG. 1 prevents the addition of the aqueous binder solution and can prevent the problem of non-uniform addition. . That is, in this embodiment, the binder aqueous solution is not added from the barrel portion 52, and the binder aqueous solution is added to the iron ore raw material 57 before being fed into the barrel portion 52 from the mixing nozzle 70 disposed in the vicinity of the raw material throwing portion 55. Is added. For this reason, even if the fixing layer 4 is formed on the inner peripheral surface of the body portion 52 of the kneader 50, the uniform addition of the binder is not inhibited by the fixing layer 4, and the binder is uniformly applied to the iron ore raw material 57. Can be added.

[4. Specific configuration of mixing nozzle]
Next, a specific configuration of the mixing nozzle 70 for suitably realizing the binder addition method according to the present embodiment will be described in detail with reference to FIG. FIG. 6 is a longitudinal sectional view showing a configuration example of the mixing nozzle 70 of the binder addition apparatus according to the present embodiment.

  As shown in FIG. 6, the mixing nozzle 70 has a double cylindrical structure including an outer nozzle 71 and an inner nozzle 72. The outer nozzle 71 is a cylindrical member having a relatively large diameter, and the inner nozzle 72 is a cylindrical member having a smaller diameter than the outer nozzle 71. The inner nozzle 72 is disposed inside the outer nozzle 71 so that the cross section is concentric. In the example of the mixing nozzle 70, the mixing nozzle has a double cylindrical structure, but is not limited to a cylindrical structure, and may have a polygonal cylindrical structure.

  The tip of the binder supply pipe 63 is connected to an inlet 74 that is formed through the side surface of the outer nozzle 71. In FIG. 6, the binder supply pipe 63 is connected perpendicularly to the side surface of the outer nozzle 71, but this connection angle is not particularly limited. In the example of FIG. 6, one binder supply pipe 63 is connected to the outer nozzle 71 at one location. However, the present invention is not limited to this example. For example, a plurality of binder supply pipes 63 are connected to the outer nozzle 71. You may connect to the multiple places of the circumferential direction. Thereby, the binder can be supplied into the outer nozzle 71 more uniformly.

  Further, when the viscosity of the binder stock solution is relatively high, the binder stock solution B is simply dropped from the binder supply pipe 63 and supplied into the outer nozzle 71 as in the example of FIG. However, when the viscosity of the binder stock solution B is relatively low (for example, when a predetermined amount of added water is mixed in advance), the binder stock solution B is sprayed using a spray nozzle in the same manner as the spraying of the added water W. Can be sprayed into the outer nozzle 71 and supplied.

  On the other hand, the tip of the water supply pipe 66 is connected to communicate with the inner nozzle 72. In the example of FIG. 6, a socket 73 for reducing the pipe diameter is connected to the distal end portion of the water supply pipe 66, and an inner nozzle 72 that is a spray nozzle for added water is further connected to the distal end portion of the socket 73. Is connected. With this configuration, the added water W supplied by the water supply pipe 66 can be sprayed into the outer nozzle 72 from the nozzle port 75 at the tip of the inner nozzle 72. It should be noted that the present invention is not limited to an example in which a nozzle member is separately attached to the tip of the water supply pipe 66 and configured as the inner nozzle 72 as shown in the figure. For example, the tip of the water supply pipe 66 and the inner nozzle 72 are configured integrally. Thus, the tip of the water supply pipe 66 itself may function as the inner nozzle 72.

The tip of the water supply pipe 66 and the inner nozzle 72 are disposed in the outer nozzle 71 in the same direction as the axial direction of the outer nozzle 71, and the added water W is diffused to the tip of the inner nozzle 72. A nozzle port 75 having a structure to be sprayed is provided. The position of the nozzle port 75 at the tip of the inner nozzle 72 is downstream (downward) from the inlet 74 of the outer nozzle 71 to which the binder supply pipe 63 is connected, and the nozzle port at the tip of the outer nozzle 71. It is arranged inside the nozzle (upper side) than 76.
With this arrangement, the additive water W is diffused and sprayed from the nozzle port 75 of the inner nozzle 72 downward to the inside of the outer nozzle 71 and collides with the binder stock solution B that hangs down along the inner surface of the outer nozzle 71. It is supposed to be mixed. By causing the sprayed additive water W to collide and mix with the binder, the binder can be uniformly mixed in the additive water. Thereby, the binder can be supplied into the outer nozzle 71 more uniformly.

  Next, the operation of the mixing nozzle 70 of FIG. 6 having the above configuration will be described. The binder stock solution B supplied via the binder supply pipe 63 is discharged (inflowed) into the outer nozzle 71 from the inlet 74 of the outer nozzle 71 and hangs down along the inner peripheral surface of the outer nozzle 71. On the other hand, the added water W supplied via the water supply pipe 66 is diffused and sprayed into the outer nozzle 71 from the nozzle port 75 of the inner nozzle 72. As a result, the diffused / sprayed additive water W and the binder stock solution B collide and mix on the inner lower side of the outer nozzle 71 to generate a binder aqueous solution M having a predetermined concentration. The binder aqueous solution M is sprayed toward the iron ore raw material 57 from the nozzle port 76 at the tip of the outer nozzle 71 by the spray pressure of the added water W. Thereby, the mixing nozzle 70 can produce | generate the binder aqueous solution M of a uniform density | concentration at the addition position (near the raw material injection | throwing-in part 55) of a binder, and can spray it on the iron ore raw material 57. FIG.

  Next, another configuration of the mixing nozzle 70 for suitably realizing the binder addition method according to the present embodiment will be described with reference to FIG. FIG. 7 is a longitudinal sectional view showing the configuration of the mixing nozzle 70 of the binder addition apparatus according to the modified example of the present embodiment.

  As shown in FIG. 7, the mixing nozzle 70 according to the modified example also has a double cylindrical structure including an outer nozzle 81 and an inner nozzle 82, similarly to the mixing nozzle 70 of FIG. 6. The outer nozzle 81 is a relatively large diameter cylindrical member, and the inner nozzle 82 is a smaller diameter cylindrical member than the outer nozzle 81. The inner nozzle 82 is disposed inside the outer nozzle 81 so that the cross section is concentric.

  In the example of FIG. 7, the distal end portion of the binder supply pipe 63 is configured integrally with the inner nozzle 82. That is, the inner diameter and the outer diameter of the binder supply pipe 63 and the inner nozzle 82 are the same, the tip of the binder supply pipe 63 functions as the inner nozzle 82, and the port of the binder supply pipe 63 is the nozzle port 85. Function as. Such a configuration is useful, for example, when the viscosity of the binder stock solution B is relatively high, and the binder stock solution B supplied by the binder supply pipe 63 is discharged from the nozzle port 85 of the inner nozzle 82 at the tip of the binder stock solution B. Hangs down. The nozzle port 82 here means a discharge port for discharging a liquid, and is not limited to a small hole for spraying the liquid.

  In addition, the structure of the front-end | tip part of the binder supply piping 63 and the inner nozzle 82 is not limited to the structure of the said FIG. For example, a nozzle member for discharging a binder stock solution may be separately attached to the tip of the binder supply pipe 63 so as to function as the inner nozzle 82. For example, when the viscosity of the binder stock solution B is relatively low (for example, when a predetermined amount of added water is mixed in advance), a spray nozzle (inner nozzle 82) is provided at the tip of the binder supply pipe 63. (Not shown) may be mounted and the binder stock solution B may be sprayed into the outer nozzle 81 from the nozzle port 85 of the spray nozzle.

  On the other hand, the tip of the water supply pipe 66 is connected to an opening 84 formed through the side surface of the outer nozzle 81. Specifically, a connecting pipe 87 having a diameter larger than that of the water supply pipe 66 is connected to a peripheral portion of the opening 84 of the outer nozzle 81. The water supply pipe 66 is attached to the connection pipe 87 via the flange 88 in a state where the tip end portion is disposed inside the connection pipe 86. At this time, the distal end portion of the water supply pipe 66 is arranged in a direction perpendicular to the extending direction of the outer nozzle 81 and is connected perpendicularly to the side surface of the outer nozzle 81, but is not limited to this connection direction. As long as the water W can be sprayed onto the binder stock solution B, the connecting direction may be arbitrary. In this way, the distal end portion of the water supply pipe 66 is connected to the periphery of the opening 84 of the outer nozzle 81 via the connection pipe 87 and the flange 88.

  Further, a spray nozzle 90 for spraying the added water W into the outer nozzle 81 is attached to the tip of the water supply pipe 66. Specifically, a socket 89 for reducing the diameter of the pipe is connected to the tip of the water supply pipe 66, and a spray nozzle 90 for added water is connected to the tip of the socket 89. The spray nozzle 90 is disposed near the opening 84 of the outer nozzle 81. With this configuration, the added water W supplied by the water supply pipe 66 can be sprayed into the outer nozzle 81 from the nozzle port 91 at the tip of the spray nozzle 90 at the opening 84 of the outer nozzle 81.

  The tip of the binder supply pipe 63 and the inner nozzle 82 are arranged inside the outer nozzle 81 in the same direction as the axial direction (for example, the vertical direction) of the outer nozzle 81. The position of the nozzle port 85 at the distal end of the inner nozzle 82 is on the inner side (upper side) of the nozzle port 86 at the distal end of the outer nozzle 81, and further, the opening of the outer nozzle 81 to which the water supply pipe 66 is connected. It is arranged on the upstream side (upper side) of 84. With this arrangement, the added water W is sprayed in the horizontal direction from the spray nozzle 90 disposed in the opening 84 of the outer nozzle 81, and the sprayed added water W is diffused and sprayed inside the outer nozzle 81. It collides and is mixed with the binder stock solution B that hangs down from the nozzle opening 85 of the nozzle 82.

  In the example of FIG. 7, one water supply pipe 66 is connected to the outer nozzle 81 at one location, but the present invention is not limited to this example. For example, a plurality of water supply pipes 66 are connected to the outer nozzle 81. You may connect to the multiple places of the circumferential direction. Thereby, the additional water W can be supplied into the outer nozzle 81 more uniformly.

  Next, the operation of the mixing nozzle 70 of FIG. 7 configured as described above will be described. The binder stock solution B supplied through the binder supply pipe 63 is discharged (inflowed) from the nozzle port 85 of the inner nozzle 82 into the outer nozzle 81 and drips downward. On the other hand, the added water W supplied through the water supply pipe 66 passes from the nozzle port 91 of the spray nozzle 90 disposed in the opening 84 of the outer nozzle 81 toward the binder stock solution B that hangs down in the outer nozzle 81. Diffused and sprayed on. As a result, the diffused / sprayed additive water W and the binder stock solution B collide and mix on the inner lower side of the outer nozzle 81 to produce a binder aqueous solution M having a predetermined concentration. The aqueous binder solution M is sprayed toward the iron ore raw material 57 from the nozzle port 86 at the tip of the outer nozzle 81 by the spray pressure of the added water W. Thereby, the mixing nozzle 70 can produce | generate the binder aqueous solution M of a uniform density | concentration at the addition position (near the raw material injection | throwing-in part 55) of a binder, and can spray it on the iron ore raw material 57. FIG.

  The specific structure of the mixing nozzle 70 according to the present embodiment has been described above with reference to FIGS. 6 and 7. According to the mixing nozzle 70 according to the present embodiment, the binder aqueous solution M having a uniform concentration can be generated in the vicinity of the raw material charging portion 55 of the kneader 50 and can be uniformly sprayed on the iron ore raw material 57. Moreover, when changing a binder density | concentration according to the fluctuation | variation of a raw material water | moisture content, the responsiveness with respect to the change of the said binder density | concentration is also high, and the binder aqueous solution of uniform density | concentration can be controlled with high precision.

  Specifically, the binder addition method of FIGS. 2 and 3 described above is a method in which the binder stock solution and the added water are mixed in the sealed static mixer 10. For this reason, when the pressure balance of the binder raw solution and the added water in the static mixer 10 is lost due to the change in the flow rate of the binder raw solution or the added water, there is a problem that it takes time to become steady. On the other hand, in the present embodiment, the binder stock solution B and the added water W are mixed in the mixing nozzle 70 opened to the atmosphere. Therefore, no pressure is applied to the binder stock solution B and the added water W in the mixing nozzle 70, and the binder stock solution B and the added water W can be mixed in an open pressure. Therefore, it is possible to respond quickly to changes in the binder concentration in accordance with fluctuations in the raw material moisture, and the concentration of the aqueous binder solution that is generated and dispersed is uniform.

[5. effect]
Heretofore, the binder addition apparatus and the binder addition method applied to the kneader 50 according to the present embodiment have been described in detail. According to this embodiment, the mixing nozzle 70 is disposed near the raw material charging portion 55 (binder addition position) of the kneader 50, and the flow rate of each of the binder stock solution and the added water is set using the separate pipes 63 and 66. It supplies to the mixing nozzle 70 in the state controlled with high precision. Then, the binder nozzle solution and the added water are mixed by the mixing nozzle 70 to generate a binder aqueous solution, and the binder aqueous solution is directly added to the iron ore raw material 57 charged into the kneader 50.

  The mixing nozzle 70 has a double cylindrical structure in order to uniformly mix the binder stock solution and the added water in advance before the addition. As a result, the mixing nozzle 70 sprays the added water W onto the binder stock solution B inside the outer nozzles 71 and 81, thereby causing the binder stock solution B and the added water W to collide and mix to form a binder having a uniform concentration. The aqueous solution M can be generated and sprayed on the iron ore raw material 57.

  With the configuration described above, the binder addition method according to the present embodiment can uniformly add a binder aqueous solution having a uniform concentration to the iron ore raw material, and add it to the raw material according to the raw material input amount or the fluctuation of the raw material moisture. The concentration and amount of the binder can be quickly controlled with high accuracy.

  That is, as described above, the raw material moisture constantly varies depending on the storage state of the iron ore raw material, the weather, the raw material mixing ratio, and the like. According to this embodiment, the amount of the binder stock solution and the amount of added water can be controlled with high accuracy in accordance with the fluctuation of the raw material moisture. In addition, regarding the raw material input amount, for example, the raw material input amount of the iron ore raw material conveyed by the conveying unit 56 is measured before being introduced into the kneader 50, and the binder stock solution amount and the added water amount are adjusted according to the measured values. It can be controlled with high accuracy. As described above, in this embodiment, the binder aqueous solution amount and the added water amount can be accurately adjusted in accordance with the raw material input amount and raw material moisture, which are the fluctuation factors, and the binder aqueous solution having the optimum concentration can be added.

  Specifically, since the binder stock solution and the added water are conveyed by separate pipes to the mixing nozzle 70 disposed immediately before the addition position, fluctuations in the raw material moisture and the input amount of the iron ore raw material 57 charged into the kneader 50 are changed. Thus, a binder aqueous solution having a concentration suitable for the changed raw material moisture and the input amount of raw material can be quickly and accurately generated and added to the iron ore raw material 57. Therefore, as in the addition method shown in FIGS. 2 and 3, it is possible to prevent the binder aqueous solution having an inappropriate concentration remaining in the pipe 5 from being added to the raw material when the binder concentration is changed, and the binder concentration Even without using the static mixer 10 having low responsiveness to the change, the aqueous binder solution having a uniform concentration can be quickly generated using the mixing nozzle 70 having high responsiveness. Therefore, in this embodiment, when changing the concentration of the aqueous binder solution added to the raw material in accordance with the fluctuations in the raw material moisture and the raw material input amount, the concentration of the aqueous binder solution can be controlled quickly and with high accuracy. There is no time lag as in the method of FIG.

  Therefore, the kneading machine 50 according to the present embodiment responds immediately to the raw material conveyance amount and raw material moisture that change from moment to moment, and the concentration and addition amount of the binder aqueous solution added to the iron ore raw material with high accuracy. The iron ore raw material and the binder aqueous solution can be kneaded while adjusting. Thereby, the kneaded material manufactured by the kneading machine 50 can ensure proper granulation conditions without becoming a slurry due to excessive binder and without reducing granulation due to insufficient binder. Therefore, the granulation property in the granulation process by the subsequent granulators 24 and 35 can be improved, and the granulation quality can be kept uniform. As described above, according to this embodiment, the kneading and granulation process can be continued in a state where appropriate granulation conditions are maintained regardless of fluctuations in the raw material transport amount and raw material moisture, which causes equipment stop troubles and the like. Therefore, it is possible to accurately handle changes in raw material moisture and changes in raw material throughput. As a result, it is possible to stably produce a high-quality granulated product, and to stabilize the sintering production process in the sintering machine 40.

  Further, according to the present embodiment, the aqueous binder solution is directly sprayed from the mixing nozzle 70 to the iron ore raw material 57 before being put into the kneading machine 50, not from the body 52 of the kneading machine 50. . Therefore, even if the fixing layer 4 (see FIG. 1) is formed on the inner peripheral surface of the body portion 52 of the kneader 50, the fixing layer 4 can prevent the binder from being hindered, and before the charging, Since a binder aqueous solution having a uniform concentration can be uniformly added to the iron ore raw material 57, uniform kneading in the kneader 50 is possible.

  In addition, the residence time of the iron ore raw material in the kneader 50 is usually a short time of about 3 minutes at the longest, and a uniform aqueous binder solution is uniformly mixed in the entire iron ore raw material in this short time. It is necessary to let In this embodiment, when adding the binder aqueous solution in the kneader 50, the binder aqueous solution having a uniform concentration is mixed by the mixing nozzle 70 while being uniformly sprayed over the entire iron ore raw material to be charged. Even within the above short time, the binder aqueous solution and the iron ore raw material can be sufficiently mixed.

  Also, when granulating iron ore raw material mainly composed of fine powder, it is necessary to knead the binder and iron ore raw material in advance with a kneader before granulation, and then add the kneaded product to the granulator. There is. In the binder addition method of Patent Document 1, the binder and the added water are separately sprayed in the granulator (drum mixer), but when the binder and the added water are sprayed separately, a uniform concentration binder is used as a raw material. It cannot be added uniformly. In this respect, the binder addition method according to the present embodiment can be suitably applied to the kneader 50 for sufficiently kneading the iron ore raw material mainly composed of fine powder as the previous stage of the granulation step.

  Further, the binder used in the present embodiment uses a polyacrylic acid-based dispersant capable of maintaining high dispersibility of fine powder (fine particles) in the iron ore raw material in order to improve granulation. The binder addition method according to the present embodiment can be suitably applied to a binder (granulating agent) containing such a polyacrylic acid-based dispersant. That is, since a binder having a uniform concentration can be uniformly added to the raw material, the effect of dispersing fine powder of the iron ore raw material with the binder and adhering the fine powder around the core particles (coarse particles) can be enhanced. Therefore, the iron ore raw material containing fine powder can be suitably granulated (pseudo-particle or pelletized), and a granulated product having an appropriate particle size (for example, a particle size of about several mm to 10 mm) can be preferably produced.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above-described embodiment, the binder addition apparatus and the addition method of the present invention are applied to the kneaders 23 and 34 provided in the pseudo granulation line 20 and the pellet granulation line 30 of the sintering facility shown in FIG. However, the present invention is not limited to such an example. The binder addition apparatus and addition method of the present invention can be applied to any kneading machine for kneading iron making raw materials such as iron ore raw materials, in addition to the kneading machines 23 and 34.

  In the above embodiment, the binder stock solution and the added water are mixed by the mixing nozzle 70 to generate a binder aqueous solution having a desired concentration. For example, the binder solution diluted in advance to a predetermined concentration and water are mixed. A binder aqueous solution having a desired concentration may be produced.

  Moreover, the structure of the mixing nozzle 70 is not limited to the example shown in FIG.6 and FIG.7, A design change is possible for arbitrary structures, if a binder and addition water can be mixed uniformly.

Example 1
As shown in FIG. 5, the Example using the kneading machine provided with the binder addition apparatus and using the mixing nozzle shown in FIG. 6 is shown below. Granulation was performed using an average of 200 dry-ton / h of the iron ore raw material charged into the pellet granulation line, an average of 8% of the raw material water ratio, and a polyacrylic acid-based dispersant as a binder. (Here, the iron ore raw material and the raw material moisture ratio are shown as average values, as described above, although the iron ore raw material is quantitatively cut out from the raw material tank, there is actually a slight amount of fluctuation. This is because the moisture content of the raw material varies depending on storage conditions, weather conditions, raw material mixing ratio, etc.)
As a result of granulation under this condition, the control delay of the binder concentration caused by the aqueous binder solution remaining in the pipe, which has occurred in the existing equipment shown in FIG. Therefore, even when the binder solid content ratio Rs is as high as 0.2%, the operation can be continued stably, and a granulated product having an appropriate particle size and strength can be produced.

(Example 2)
Except for using the mixing nozzle shown in FIG. 7 in the present invention, even when tested under the same conditions as in Example 1, similarly, even when the binder solid content ratio Rs is a high concentration of 0.2%, the slurry The operation could be continued stably, and the granulated product with an appropriate particle size and strength could be produced.

(Comparative example)
In the existing equipment shown in FIG. 3, as in Example 1, the iron ore raw material charged into the pellet granulation line has an average of 200 dry-ton / h, the raw material moisture ratio of 8% on average, and a polyacrylic acid-based dispersion as a binder. Granulation was performed using an agent. In this case, even when the binder solid content ratio Rs is 0.1%, there are many serious troubles due to the generation of slurry, and the delay in controlling the binder concentration due to the aqueous binder solution remaining in the pipe is an important problem.

  The fact that the present invention can be used in the granulation process of the iron ore raw material in the steel manufacturing process can be understood from the fact that the above detailed description is explained by taking the granulation of the iron ore raw material as an example. Furthermore, the present invention is not limited to the granulation of iron ore raw materials, but can be applied to the granulation of other materials.

DESCRIPTION OF SYMBOLS 4 Adhesive layer 23, 34, 50 Kneading machine 52 Body part 53 Stirring blade 54 Rotating shaft 55 Raw material input part 56 Conveying part 57 Iron ore raw material 61 Flow control valve 62 Electromagnetic flow meter 63 Binder supply piping 64 Flow control valve 65 Electromagnetic flow meter 66 Water supply pipe 70 Mixing nozzle 71, 81 Outer nozzle 72, 82 Inner nozzle 74 Inlet 75, 85 Nozzle port 76, 86 Nozzle port 84 Open 87 Connection pipe 88 Flange 90 Spray nozzle B Binder stock solution W Additive water M Binder aqueous solution

Claims (14)

  In the granulation of iron ore raw material, a mixing nozzle that mixes the binder and water separately supplied by the binder supply pipe and the water supply pipe and is opened at the outlet side is located near the raw material input part of the iron ore raw material kneader. The binder addition method is characterized in that the binder aqueous solution in which the binder and the water are mixed is sprayed from the mixing nozzle to the iron ore raw material charged in the raw material charging portion of the kneader. .   The mixing nozzle has a double structure including an outer nozzle and an inner nozzle disposed in the outer nozzle, and the binder supply pipe is connected to one of the outer nozzle or the inner nozzle, and the other nozzle The outer nozzle is connected to the nozzle by spraying the water supplied by the water supply pipe onto the binder supplied into the outer nozzle by the binder supply pipe. The binder and the water are mixed together to form the binder aqueous solution, and the binder aqueous solution is sprayed on the iron ore raw material from a nozzle port of the outer nozzle. Binder addition method.   The binder supply pipe is connected to an inflow port formed in a side surface of the outer nozzle, and the water supply pipe is connected to communicate with the inner nozzle, and is connected to the outer nozzle from the inflow port. 3. The binder aqueous solution is generated by mixing the water with the binder by spraying the water from the nozzle opening of the inner nozzle to the binder discharged into the nozzle. The binder addition method as described in 4. above.   The water supply pipe is connected to an opening penetratingly formed on a side surface of the outer nozzle, and the binder supply pipe is connected to communicate with the inner nozzle, from the nozzle port of the inner nozzle to the inside of the outer nozzle. 3. The binder aqueous solution is produced by mixing the water with the binder by spraying the water from the opening of the outer nozzle with respect to the binder discharged into the binder. Binder addition method.   The method for adding a binder according to any one of claims 1 to 4, wherein the binder is a polyacrylic acid-based dispersant.   According to the moisture contained in the iron ore raw material or the input amount of the iron ore raw material to the kneader, the flow rate of at least one of the binder supply pipe or the water supply pipe is controlled, The binder addition method of any one of Claims 1-5.   In an iron ore raw material granulator, a binder supply pipe for supplying a binder and a water supply pipe for supplying water are installed in the vicinity of a raw material charging part of an iron ore raw material kneader, and the binder supply pipe and the water A mixing nozzle that mixes the binder and the water that are individually supplied by a supply pipe and that is open on the outlet side, and the mixing nozzle generates a binder aqueous solution that is generated by mixing the binder and the water. The binder adding device is characterized in that it is sprayed on the iron ore raw material charged in the raw material charging portion of the kneader.   The mixing nozzle has a double structure including an outer nozzle and an inner nozzle disposed in the outer nozzle, and the binder supply pipe is connected to one of the outer nozzle or the inner nozzle, and the other nozzle The outer nozzle is connected to the nozzle by spraying the water supplied by the water supply pipe onto the binder supplied into the outer nozzle by the binder supply pipe. The binder aqueous solution is produced by mixing the binder and the water in the inside, and the aqueous binder solution is sprayed on the iron ore raw material from the nozzle opening of the outer nozzle. Binder addition device.   The binder supply pipe is connected to an inflow port formed in a side surface of the outer nozzle, and the water supply pipe is connected to communicate with the inner nozzle, and is connected to the outer nozzle from the inflow port. 9. The aqueous binder solution is produced by mixing the water with the binder by spraying the water from the nozzle opening of the inner nozzle to the binder discharged into the nozzle. The binder addition apparatus described in 1.   The water supply pipe is connected to an opening penetratingly formed on a side surface of the outer nozzle, and the binder supply pipe is connected to communicate with the inner nozzle, from the nozzle port of the inner nozzle to the inside of the outer nozzle. 9. The binder aqueous solution is produced by mixing the water with the binder by spraying the water from the opening of the outer nozzle with respect to the binder discharged into the binder. Binder addition device.   The binder addition apparatus according to any one of claims 7 to 10, wherein the binder is a polyacrylic acid-based dispersant.   The apparatus further includes a control unit that controls the flow rate of at least one of the binder supply pipe and the water supply pipe according to the water content of the iron ore raw material or the input amount of the iron ore raw material to the kneader. The binder addition apparatus according to any one of claims 7 to 11, characterized in that:   A kneader comprising the binder addition device according to any one of claims 7 to 12.   Using the binder addition apparatus according to any one of claims 7 to 12, the iron ore is sprinkled in the kneader while sprinkling an aqueous binder solution on the iron ore raw material charged into the raw material charging portion of the kneader. A kneading method comprising kneading raw materials.

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