JP5928708B2 - Ferro-coke manufacturing equipment and ferro-coke manufacturing method - Google Patents

Description

  The present invention relates to a production facility suitable for producing ferrocoke using an iron source material such as coal and iron ore as a main material, and a method for producing ferrocourse.

  Coke used in the blast furnace ironmaking method is a raw material that plays three roles of a reducing material of iron ore, a heat source, and a breathability maintaining material, and normally, furnace coke is used.

  By the way, in recent years, for example, a method as disclosed in Patent Document 1 has been developed which uses ferro-coke which has a characteristic of higher gasification reactivity than the above-mentioned chamber furnace coke.

  Here, ferro-coke is produced by mixing iron ore with coal and subjecting the mixture to dry distillation treatment. By using this as a raw material for blast furnace, iron ore reduction reaction is generated at a lower temperature. It is expected to reduce energy consumption in the blast furnace.

  Ferro-coke is manufactured by mixing iron ore and coal to produce a lump-shaped molding, and charging the lump-shaped molding into a vertical shaft furnace to dry-distill the molding. It can be broadly divided into two steps of the dry distillation step.

  The mass of the molded product obtained in the molding step is, as its quality, the handling strength when transported to the dry distillation furnace and the pressure due to the load of the molded product when temporarily stored in the hopper prior to transport to the dry distillation furnace. The ferro-coke after dry distillation is required to have a strength that can withstand wear during transportation to the blast furnace or during descent in the blast furnace.

  As a conventional technique for improving the strength of a molded product in the above molding process, a high softening point binder having a softening point of 150 ° C. or higher and a low softening point binder having a softening point of 150 ° C. or lower with respect to iron ore and coal as raw materials. For example, a method disclosed in Patent Document 2 is known, in which the mixture is stirred while heating in the range of 120 to 240 ° C. and then molded.

  Also, a cooling and drying method disclosed in Patent Document 3 is known in which soft coal immediately after molding is placed on a net conveyor, and forcedly ventilated and cooled from above to ensure the strength of the coal char. Yes.

JP 2005-15700 A JP 2007-277489 A Japanese Examined Patent Publication No. 62-45915

  By the way, in the method of adding a binder in the molding process as in the above documents 1 and 2, the strength of the molded product can be improved, but conversely, the crushing strength of the molded product immediately after molding is reduced. There is.

  This is because the temperature of the molded product immediately after molding is almost the same as the temperature during heating, and the binder contained in the molded product, especially the binder with a low softening point is softened, so the molded product receives external force. This is because it easily deforms.

  If the molded product is deformed due to a decrease in crushing strength, cracks are likely to be generated from the deformed portion during dry distillation, which causes a decrease in the strength of ferrocoke after dry distillation. In particular, when the molded product is temporarily stored in a hopper or the like, the molded product located on the lower side is deformed by the pressure of the molded product itself, so a large amount of ferro-coke with reduced strength is produced by the deformation. Will be.

  In addition, it is possible to reduce the chance of deformation of the molded product by directly charging the molded product immediately after molding into the dry distillation furnace without going through a hopper, etc., but the dry distillation furnace that is a vertical shaft furnace is stable. It is important to continuously supply the molded product for efficient operation, so that the molded product is normally supplied to some extent so that the supply of the molded product to the dry distillation furnace will not be interrupted due to operational troubles in the molding process. It is necessary to temporarily store the same amount. Therefore, in order to ensure the crushing strength of the molded product after molding, it is important to prepare a cooling facility for cooling the molded product after molding.

  Moreover, according to the said literature 3, cooling by a net conveyor is efficient at the point which can convey a molding simultaneously. However, when the molding enters the dry distillation furnace with the burrs formed on the outer surface of the molding remaining in the molding process (the material has hardened by protruding from the mold part), the molding descends in the dry distillation furnace. During the process, the burrs are pulverized due to wear between the molded products, the air permeability of the dry distillation furnace is deteriorated, and the heating efficiency of the molded products in the dry distillation furnace is lowered. . In order to remove the burrs, it is necessary to add a dedicated process such as a vibration sieve, and there is a problem that an increase in equipment cost cannot be avoided.

  An object of the present invention is to propose a production facility and a production method for efficiently producing high-strength ferro-coke by enabling removal of burrs simultaneously with cooling of a molded product.

  The present invention includes a stirrer that heats and mixes a raw material containing coal and an iron source material, a molding machine that molds the mixture stirred by the stirrer into a massive molded product, and a molded product molded by the molding machine. In a ferro-coke manufacturing facility equipped with a carbonization furnace for performing carbonization, a molded product molded by the molding machine by suctioning outside air between the molding machine and the carbonization furnace. A ferro-coke manufacturing facility comprising a cooling / deburring device that cools the mold and induces a collision between the molded articles to remove burrs formed on the outer surface of the molded article when molding. is there.

In the ferro-coke manufacturing facility configured as described above,
1) As a cooling and deburring device, a cylindrical body having a laterally inclined posture and supported rotatably around its axis, and having a sieve mesh on the peripheral wall, and surrounding the cylindrical body, A case that has a wall that houses the cylindrical body and has an outside air inlet formed in the bottom wall, a duct that forms a path leading to the top wall of the case, and an outside air inlet that sucks in outside air through the case and the duct. Applying a suction blower for forced ventilation,
2) Applying a cylindrical body that has a plurality of fins arranged radially on the inner side surface of the peripheral wall so as to project substantially parallel to the axis thereof;
3) Arranging a conveyor that rotates in the longitudinal direction of the cylindrical body at the bottom of the cylindrical body;
Is preferable as a means for solving the problems of the present invention.

  The present invention has been made to solve the conventional problems as described above. That is, the present invention relates to a method for producing ferro-coke by heating and mixing coal and a raw material containing an iron source material to form a lump-shaped molded product, and subjecting the lump-shaped molded product to dry distillation treatment, Immediately after molding the massive molded product, the molded product is cooled by forced aeration by the sucked outside air, and at the same time, the collision between the molded products is induced to remove burrs formed on the outer surface when molding the molded product. This is a method for producing ferro-coke.

  According to the ferro-coke manufacturing facility according to the present invention, the outside air is sucked between the molding machine and the carbonization furnace, and the outside air is brought into contact with the molding by forced ventilation to be cooled, and at the same time, the moldings collide with each other. Since a cooling / deburring device for removing burrs formed on the outer surface of the molded product when it is molded is provided, high-strength ferro-coke can be efficiently manufactured.

  Further, according to the ferro-coke manufacturing facility having the above-described configuration according to the present invention, the cooling / deburring device is supported in a laterally inclined posture so as to be rotatable around its axis, and has a sieve mesh on the peripheral wall. And a case having a wall portion surrounding the cylindrical body and accommodating the cylindrical body in the inner space thereof, and a path connected to the top surface wall of the case, and a case in which an outside air inlet is formed in the lower surface wall. Since the duct and the suction blower that sucks the outside air from the outside air inlet through the case and the duct are configured, it is possible to remove the burrs simultaneously with the cooling of the molded product without extending the manufacturing equipment.

  Further, according to the ferro-coke manufacturing facility according to the present invention, the inner surface of the peripheral wall of the cylindrical body is provided with a plurality of fins that project substantially parallel to the axial center and are radially arranged. Collisions between each other can be induced efficiently.

  Furthermore, according to the ferro-coke manufacturing facility according to the present invention, a conveyor that rotates in the longitudinal direction of the cylindrical body is arranged in the lower portion of the cylindrical body, and thus the ferro-coke is removed by the collision between the molded products. The burr is dropped on the conveyor, and the burr can be efficiently collected.

  According to the manufacturing method of the ferrocourse according to the present invention, immediately after being formed into a lump-shaped molded product, the molded product is cooled by forced ventilation by the sucked outside air, and at the same time, the collision between the molded products is induced. While the crushing strength of the molded product is improved, pulverization of burrs in the dry distillation furnace can be prevented, and the ferrocoke strength after dry distillation can be maintained high.

It is the figure which showed typically embodiment of the manufacturing apparatus of the ferro-coke according to this invention. It is the figure which showed the structure of the cooling and deburring apparatus. It is the figure which expanded and showed the principal part of the apparatus shown in FIG. It is the graph which showed the relationship between cooling time and cooling wind speed.

Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 1 is a diagram schematically showing an embodiment of a production facility suitable for use in the production of ferro-coke according to the present invention.

  The code | symbol 1 in a figure is a stirrer which heats and stirs the raw material containing coal and an iron source raw material. Coal and iron source material (steel ore) are pulverized in advance to a predetermined particle size by a pulverizer and charged into the agitator 1 at a predetermined mixing ratio. At this time, a high softening point binder having a softening point of 150 ° C. or higher and a low softening binder having a softening point of 150 ° C. or lower are also added to the stirrer 1.

Further, 2 is a double roll molding machine that sandwiches the agitated material stirred by the stirrer 1 and molds it into a predetermined shape. 3 is a forced cooling of the molded product molded by the double roll molding machine 2 and its outer surface. 4 is a hopper that temporarily stores the molded product that has passed through the cooling and deburring device 3, and 5 is a ferro-coke by dry distillation treatment of the molded product that is stored in the hopper 4. It is a dry distillation furnace

As shown in FIG. 2, the cooling / deburring device 3 is a cylindrical body (rotary body) having a laterally inclined posture and rotatably supported around its axis L and having a sieve mesh on the peripheral wall. and cleans) 3a, has a wall portion to accommodate the cylindrical body 3a in its inner space M surrounds the cylindrical body 3a, the outside air introduction port h connected to the inner space M in the lower wall is formed A case 3b and a duct 3c that forms a path connected to the wall (top wall) of the case 3b, and sucks outside air from the outside air inlet h through the inner space M of the case 3b and the path of the duct 3c. What consists of the suction blower 3d which performs forced ventilation, and the diffusion tower 3e which diffuses the external air attracted | sucked by this suction blower 3d is applied.

  The duct 3c can be provided at a plurality of locations along the longitudinal direction of the cylindrical body 3, whereby efficient cooling can be performed. The outside air inlet h is provided on the lower wall of the case 3b, and the duct 3c is provided on the top wall of the case 3b. However, the outside air inlet h and the duct 3c are provided on the side wall of the case 3b. It is also possible to provide (similar effects can be expected), and this point can be changed as appropriate.

  In the cooling / deburring apparatus having the above-described configuration, the cylindrical body 3a has a molded product conveyance path inside thereof, and is inserted from one end (molded product entry side) of the cylindrical body 3a. The molded product moves in the transport path in accordance with the rotation of the cylindrical body 3 and is discharged from the other end (molded product exit side).

  While the molded product is being conveyed by the cylindrical body 3, the molded product is cooled by forced ventilation by the outside air sucked by the suction blower 3d, and the molded products are rotated, rolled, and dropped. The burrs formed on the outer surface by the impact are destroyed and removed.

  As shown in FIG. 2, a conveyor 6 that extends along the longitudinal direction of the cylindrical body 3a and can be rotated can be arranged at the lower part of the cylindrical body 3a. Efficient recovery of the generated burrs becomes possible.

  Further, on the inner side surface of the peripheral wall of the cylindrical body 3a, as shown in FIG. 3, an enlarged portion thereof is protruded substantially parallel to the axis L and radially arranged. One fin 7 can be provided.

  By providing the fins 7 on the inner side surface of the peripheral wall of the cylindrical body 3a, the molded product is lifted by the fins 7 and dropped, and the contact area with the sucked outside air can be expanded. At the same time, it is possible to apply an appropriate impact for removing burrs.

  In addition, if the scraped height of the molded product is too high, there is a concern that the molded product itself may crack due to an impact at the time of dropping, and the strength may be reduced. Therefore, the height t of the fin 7 is at least a height close to the thickness of the molded product, for example, when the molded product has an elliptical shape, the height t should be 10 to be close to the dimension of the minor axis. It is desirable to be about 30 mm.

  The diameter, length, and rotation speed of the cylindrical body 3 are determined so that the outside air can be efficiently ventilated and a sufficient impact can be applied to the molded product to remove burrs. That's fine.

  For example, with respect to burrs, it is only necessary to give a rotation that provides a sufficient impact to remove the burrs. It is desirable that the molded product inserted therein during the rotation of the cylindrical body 3 is always rollable, and the diameter and rotational speed of the cylindrical body 3 are examined and determined in advance.

  The diameter of the cylindrical body 3 is determined in consideration of the processing amount of the molded product and the layer thickness of the molded product (thickness when the molded product is inserted into the cylindrical body 3). The layer thickness that allows the molded product to always roll in accordance with the rotation of the cylindrical body 3 means that when the molded product is inserted, the molded product cylindrical body 3 is spread one by one. A state in which about 5 pieces are overlapped with each other.

  Further, in order to determine the size (diameter, length) of the cylindrical body 3 and the amount of air sucked into the suction blower 3d, it is necessary to obtain the relationship between the cooling air speed and the cooling time of the molded product.

  The cooling air speed represents the cross-sectional passing air speed at the outside air inlet h of the case 3b, the layer thickness of the molded product is 45 mm, and the cooling air speed and the molded product are cooled when the molded product is cooled from 140 ° C to 100 ° C. FIG. 4 shows a simple relationship between the cooling times obtained by experiments.

  The amount of air sucked into the suction blower 3d is calculated from the relationship between the cooling air speed and the cooling time of the molded product, the conveyance speed of the molded product, the length of the case 3b (length in the conveyance direction of the molded product), and the width of the case 3b. It becomes possible.

Here, the conveying speed of the molded product, the molded product was charged to the tubular body 3 is a speed when moving from charging hole until the outlet, the conveying speed, the cylinder of the target It can be estimated by determining the diameter of the body 3, the layer thickness of the molded product, and the processing amount.

  In addition, since the inclination angle of the cylindrical body 3 also affects the conveyance speed of the molded article, it is necessary to appropriately examine the conveyance speed of the molded article by adjusting the inclination angle of the cylindrical body 3.

It is desirable that the sieve mesh formed on the peripheral wall of the cylindrical body 3 has such a size that the molded product to be conveyed does not fall and the burr can be dropped toward the conveyor 6, and the molding is about 6 cm ^3. For objects, the size of the mesh is preferably about 10 to 14 mm.

In FIG. 4, the data when the cooling target temperature of the molded product is cooled at 100 ° C. is shown . The reason is, for example, that the bottom portion has a conical portion having a diameter of 2.2 m and a height of 1.5 m. And when storing a molding with the storage hopper which consists of a 1 m high cylindrical part on it, the deformation | transformation of the molding at the time of storage can be suppressed by cooling this molding to 100 degrees C or less. Because it became clear.

  When a molded product is stored in a hopper with a higher height, the load applied to the molded product becomes large, but it is considered that the deformation of the molded product can be reduced if it is cooled to approximately 100 ° C. or less. The cooling target temperature is desirably 100 ° C. or lower. In addition, when the magnitude | size and shape of a storage hopper differ remarkably, it is necessary to cool by making cooling target temperature lower.

  When the processing amount of the molded product is large, a method of spraying mist can be combined to increase the cooling rate.

  In this case, the peripheral wall of the front stage of the cylindrical body 3 has no mesh, and mist is sprayed from the inside toward the molded product. If the amount of mist sprayed is 3% or more of the mass of the molded product, the adhering moisture cannot be evaporated, and when the molded product reaches the screen part, the screen may clog. At the same time, there is a concern that the cooling rate of the molded product will be too high, causing cracks in the molded product and reducing the strength. Therefore, the amount of mist sprayed is at most about 2% of the mass of the molded product. Is desirable.

  By spraying a mist of about 2% of the mass of the molded product while the molded product is being conveyed by the cylindrical body 3, cooling can be performed at 20 to 30 ° C. by the evaporation heat of the mist. Cooling time can be shortened.

  A cooling / deburring device (cylindrical body: length 5 m, diameter 1 m, sieve mesh 10 mm, height of fins 10 to 30 mm, number 8) arranged as shown in FIG. 2 is arranged. In order to manufacture ferro-coke using the equipment configured as shown in FIG. 1, the strength of the molded product on the outlet side of the cooling / deburring device was investigated.

  The strength of the molded product is a yield in which 200 g of the molded product is put in an I-type drum tester (cylindrical shape having an inner diameter of 130 mm and a length of 700 mm) and a size of 16 mm or more remains when rotated 30 times per minute. .

As raw materials for producing ferro-coke, coal adjusted to a particle size of 3 mm or less (100%) and iron ore adjusted to a particle size of 0.5 mm or less (100%) are blended, and asphalt pitch (high softening point) Binder, softening point 190 ° C) was added and heated and stirred, and soft pitch (low softening point binder, softening point 55 ° C) was added just before discharging the stirred product from the stirrer, and the stirred product at 160 ° C The molded product was molded by a double roll molding machine equipped with a cup having a size of 6 cm ³ .

  Further, the blending ratios of coal, iron ore, asphalt pitch, and soft pitch were 66.5%, 28.5%, 2%, and 3%, respectively.

The layer thickness of the molded product in the cooling / deburring device is such that about 3 molded products are overlapped, that is, the thickness is about 45 mm (target layer thickness). The rotational speed and the inclination angle of were adjusted appropriately and set to 2.2 m / min. Further, since the molded product immediately after molding had a temperature of about 140 ° C., 0.8 m / s based on the relationship shown in FIG. 4 was used to cool the molded product from 140 ° C. to 100 ° C. The cooling is performed at the cooling air speed for 137 seconds. The blower cooling air volume was 360 Nm ³ / min.

  The results are shown in Table 1 together with the results of the molded product (comparative example) obtained by cooling the molded product immediately after molding to room temperature by natural cooling of the molded product discharged through a vibrating screen having a 10 mm sieve mesh.

  The comparative example in Table 1 required a time of 10 minutes or more until the molded product became 100 ° C. or lower, and its strength was 88.3.

  On the other hand, in Examples 1 to 3 of the present invention, the temperature (actual measurement) of the molded product immediately after molding was 140 ° C., whereas on the outlet side of the cooling / deburring apparatus, it was about 98 ° C. It was confirmed that it was possible to cool to a target cooling temperature of 100 ° C. or lower. Moreover, even if the strength of the molded product is low, it is 88.9, which is improved compared to the comparative example, and it is clear that burrs formed on the outer surface of the molded product are also removed neatly. became.

  In particular, when the cooling and deburring of the molded product is set to 30 mm for the cylindrical body of the cooling / deburring device, the strength of the molded product is the highest. The value (90.4) was shown.

  According to the present invention, it is possible to provide a method and production equipment capable of efficiently producing ferrocoke by enabling removal of burrs simultaneously with cooling of a molded product.

1 Stirrer 2 Molding Machine 3 Cooling / Deburring Device 3a Tubular Body (Rotary Screen)
3b Case 3c Duct 3d Suction blower 3e Dissipation tower 4 Hopper 5 Dry distillation furnace 6 Conveyor 7 Fin L Shaft center M Inner space h Outside air inlet

Claims (5)

Molded by this double roll molding machine, a stirrer that heats and stirs the coal and the raw material containing the iron source material, a double roll molding machine that sandwiches the stirrer stirred by this stirrer and molds it into a massive molded product In a ferro-coke manufacturing facility equipped with a carbonization furnace for subjecting molded products to carbonization treatment,
Between the double roll molding machine and the carbonization furnace, outside air is sucked and the molded product molded by the double roll molding machine is cooled by forced ventilation, and at the same time, the moldings are caused to collide with each other. A ferro-coke manufacturing facility provided with a cooling / deburring device for removing burrs formed on the outer surface of an object during molding.   The cooling and deburring device is supported in a laterally inclined posture so as to be rotatable around its axis, and has a cylindrical body having a sieve mesh on a peripheral wall, and surrounds the cylindrical body in the inner space thereof. A case having a wall portion for accommodating the body, and a lower surface wall formed with an outside air introduction port connected to the inside space, a duct forming a path connected to the top wall of the case, and the case from the outside air introduction port to the case The ferro-coke manufacturing facility according to claim 1, further comprising a suction blower that sucks outside air through the duct and performs forced ventilation.   3. The ferro-coke manufacturing facility according to claim 2, wherein the cylindrical body has a plurality of fins arranged on the inner side surface of the peripheral wall so as to protrude substantially parallel to the axial center and arranged radially. .   The ferro-coke manufacturing facility according to claim 2 or 3, further comprising a conveyor that rotates in a longitudinal direction of the cylindrical body at a lower portion of the cylindrical body. Ferrous coke is obtained by heating and stirring the coal and the raw material containing the iron source raw material, sandwiching the resulting mixture with a double roll molding machine and forming it into a massive molded product, and subjecting the massive molded product to a dry distillation treatment. In the method of manufacturing
Immediately after molding the massive molded product, the molded product is cooled by forced aeration by the sucked outside air, and at the same time, a collision between the molded products is induced, and a burr formed on the outer surface of the molded product is molded. A method for producing ferro-coke, comprising removing the ferro-coke.

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