JP6835037B2 - How to dry blast furnace raw materials - Google Patents

Description

The present invention relates to a method for drying blast furnace raw materials (sintered ore, iron ore, coke breeze) charged into a blast furnace.

In a blast furnace, blast furnace raw materials such as sintered ore, iron ore, and lump coke are charged into the furnace from the top of the furnace, and high-temperature air is blown into the furnace from the tuyere provided at the bottom of the furnace to burn coke. The heat generated by this combustion and CO gas are used to reduce and melt sintered ore and iron ore to produce blast furnace. The blast furnace raw material charged from the top of the furnace is adjusted to a particle size of several mm to several tens of mm and charged into the furnace. As a result, the combustion gas generated by the combustion of coke in the lower part of the furnace passes through the gaps between the granular blast furnace raw materials filled in the furnace and rises toward the top of the furnace.

Since heat is supplied to the blast furnace raw material in the blast furnace by heat transfer by this combustion gas, the temperature rise of the blast furnace raw material becomes unstable unless the flow of the combustion gas in the furnace is in an appropriate state, and the sinter It will hinder the reduction and melting of iron ore.

Therefore, in order to maintain the gas flow in the furnace in an appropriate state, when the blast furnace raw material is put into the furnace interior at the furnace top, the blast furnace raw material of the appropriate particle size can be charged to the appropriate position in the furnace. And the development of the furnace top charging method is in progress.

However, even if the blast furnace raw material is charged using such a charging device or charging method for the blast furnace raw material, if the powdered blast furnace raw material is mixed with the blast furnace raw material itself, the powdered blast furnace raw material causes the blast furnace in the furnace. The gap between the raw materials is filled and the flow of the combustion gas is obstructed, which makes it difficult to optimize the flow of the combustion gas.

The blast furnace raw material is manufactured in a sintering machine or a coke oven to adjust the grain size, and then directly sent to the blast furnace raw material tank, and is manufactured in a sintering machine or a coke oven to adjust the particle size. After that, there is a blast furnace raw material that is stored in an open-air storage place called a yard and then collected and sent to a blast furnace raw material tank. Of these, the blast furnace raw material that is stored in the yard and then sent to the blast furnace raw material tank inevitably becomes wet with rainwater or the like during storage in the yard, and the water content becomes several mass%, and the water content. May exceed 10% by mass.

In a blast furnace raw material having a high water content, the powdery blast furnace raw material adheres to the granular blast furnace raw material due to water content, so that the powdery blast furnace raw material may not be separated and removed from the granular blast furnace raw material even if the particle size is adjusted by a sieve or the like. .. Further, since the powdery blast furnace raw material containing water easily adheres to the sieve net itself, it may cause clogging of the sieve, and further, it becomes difficult to sieve the blast furnace raw material.

When the granular blast furnace raw material to which the powdered blast furnace raw material that has not been separated and removed by the sieve is transferred to the furnace top and charged into the furnace, it is dried by the heat in the furnace and the powdered blast furnace raw material becomes the granular blast furnace raw material. Depart from the surface. This powdery blast furnace raw material enters the gap between the blast furnace raw materials and obstructs the gas flow in the furnace.

Therefore, it can be said that the technology for removing the powdered blast furnace raw material adhering to the blast furnace raw material is as important as the technology for charging the blast furnace raw material into the blast furnace. In order to remove the powdered blast furnace raw material adhering to the blast furnace raw material, it is conceivable to dry the blast furnace raw material having a large amount of water and then separate and remove the powdered blast furnace raw material from the blast furnace raw material by a sieve or the like.

As a technique for drying the blast furnace raw material, Patent Document 1 discloses a technique for drying the yard sinter stored in the yard by the manifestation heat of the produced high-temperature sinter. According to Patent Document 1, the yard sinter is placed in layers on the high-temperature sinter placed in layers on the trough of the cooler device, and the yard is yarded by hot air heated by the high-temperature sinter. The sinter can be heated and dried.

JP-A-2017-137531

When the yard sintered ore is filled in the hopper, the sintered ore having a small average particle size is deposited on the center side of the hopper, and the sintered ore having a large average particle size is deposited on the side surface of the hopper. Therefore, when the yard sinter is filled in the hopper, the yard sinter is cut out from the hopper and placed in a layer on the layer of the high temperature sinter, as shown in FIGS. 1 (a) and 1 (b). A layer of yard sinter 12 having a small average particle size is formed at the center of the trough 10 in the width direction, and a layer of yard sinter 14 having a large average particle size is formed at both ends of the trough 10 in the width direction. .. The layer of the yard sinter 12 having a small particle size is not sufficiently heated and is not dried due to poor passage of hot air heated by the lower high temperature sinter 16. Therefore, there is a problem that the water content of the entire yard sinter after drying increases.

The present invention has been made in view of the above problems, and an object of the present invention is to efficiently dry the blast furnace raw material by the actual heat of the produced high-temperature sinter, thereby containing the water content of the dried blast furnace raw material. It is to provide a method of drying a blast furnace raw material which can reduce the amount.

The features of the present invention for solving such a problem are as follows.
(1) A cooling step in which a high-temperature sinter produced by a sinter is placed in a layer on a blast furnace of a cooler device to cool the blast furnace, and a layer of the sinter cooled in the cooling step. It has a placement step of placing the blast furnace raw material in layers on the top, and in the above-mentioned placement step, the average particle size of the blast furnace raw material is larger than the average particle size of the entire blast furnace raw material and smaller than the average particle size of the entire blast furnace raw material. The blast furnace raw material having an average particle size is mixed in the traveling direction of the trough so that the length of each in the traveling direction of the trough is less than 1/2 of the dimension of the trough in the width direction intersecting the traveling direction of the trough. A method of drying blast furnace raw materials, which are placed alternately.
(2) The blast furnace raw material is stored in a hopper having a storage portion, and is stored.
In the above-described step, the blast furnace raw material deposited on the center side of the cross section perpendicular to the vertical direction of the housing portion and the blast furnace raw material deposited on the side surface side of the housing portion are alternately discharged from the hopper (1). ). The method for drying the blast furnace raw material.
(3) The method for drying a blast furnace raw material according to (2), wherein the accommodating portion of the hopper has a rectangular cross-sectional shape perpendicular to the vertical direction of the accommodating portion.
(4) The method for drying a blast furnace raw material according to (2) or (3), wherein a wall partitioning the central side and the side surface side is provided below the accommodating portion of the hopper.
(5) Below the accommodating portion of the hopper, a shutter that allows the discharge of the blast furnace raw material deposited on the central side and a shutter that allows the discharge of the blast furnace raw material deposited on the side surface side are provided. The method for drying a blast furnace raw material according to any one of (2) to (4).
(6) A flap that swings left and right about one end side is provided below the accommodating portion of the hopper, and the flap swings left and right to discharge the blast furnace raw material deposited on the center side. The method for drying a blast furnace raw material according to any one of (2) to (4), which switches between the method of discharging the blast furnace raw material deposited on the side surface side and the discharge of the blast furnace raw material.
(7) The method for drying a blast furnace raw material according to any one of (1) to (6), wherein the blast furnace raw material is yard sinter.

By implementing the method for drying the blast furnace raw material according to the present invention, the blast furnace raw material can be efficiently dried by the sensible heat of the high-temperature sintered ore, whereby the water content of the blast furnace raw material after drying can be reduced as compared with the conventional case. it can. In this way, if the water content of the blast furnace raw material can be reduced, more powdery blast furnace raw material can be removed by a sieve. It can contribute to the stable operation of the blast furnace.

It is a figure which shows the state of the yard sinter in the prior art. It is a schematic diagram which shows the pressure loss experimental apparatus 20. It is a schematic diagram which shows the drying experimental apparatus 30. It is a schematic diagram which shows an example of the drying processing line 40 which can carry out the drying method of the blast furnace raw material which concerns on this embodiment. FIG. 5 is a schematic cross-sectional view showing a situation in which a yard sinter 60 is placed on a layer of a high-temperature sinter 16 placed on a trough 10. It is a figure explaining the situation which the yard sinter 60 filled in a hopper 46 is discharged. It is a figure explaining the situation which the yard sinter 60 filled in a hopper 90 is discharged.

First, the background to the present invention will be described. FIG. 2 is a schematic view showing the pressure loss experimental device 20. Using the pressure drop experimental apparatus 20 shown in FIG. 2, the relationship between the layer thickness and the pressure loss in the sinters having different average particle sizes was confirmed. In the experiment, sintered ore having an average particle size of 22.4 mm and an average particle size of 13.0 mm was prepared, and these sintered ores were filled in a sintered container 22 having a diameter of 300 mm with different layer thicknesses, and the layer thickness was different. Samples were prepared respectively. Air was blown at a wind speed of 16 m / s using a fan 24 and a damper 26, and the pressure loss of each of these samples was measured. In FIG. 2, FI is a flow meter, PG is a pressure gauge, and TG is a thermometer. The results of the pressure loss experiment are shown in Table 1 below. Further, in the following description, the average particle size is the arithmetic average particle size, and is Σ (Vi × di) (however, Vi is the abundance ratio of particles in the i-th particle size range, and di is the i-th particle size range. It is a particle size defined by).

As shown in Table 1, the pressure loss of the sinter having an average particle size of 13.0 mm is larger than the pressure loss of the sinter having an average particle size of 22.4 mm, and as the layer thickness increases, The difference has widened. From this result, the sinter with a small average particle size has a large pressure loss, and when the yard sinter is placed in a layer on the lower layer of the high temperature sinter, the air heated by the high temperature sinter in the lower layer. It can be seen that it becomes difficult to pass through the layer of yard sinter having a small average particle size.

FIG. 3 is a schematic view showing the drying experimental device 30. Using the drying experimental apparatus 30 shown in FIG. 3, the relationship between the layer thickness and the heat transfer rate in the sinters having different average particle sizes was confirmed. In the drying experiment, sinters having an average particle size of 45.0 mm and an average particle size of 15.0 mm were prepared, and these sinters were filled in a raw material container 32 having a diameter of 130 mm and a height of 350 mm with different filling amounts. , Samples with different layer thicknesses were prepared respectively. Using the fan 24 and the damper 26, hot air at 250 ° C. was blown to the raw material container 32 so that the wind speed was 0.1 m / s, and the weight change of the sample was measured using the measuring instrument 34. This change in weight is due to the evaporation of water, and the sum of the sensible heat and the latent heat of the water reduced by evaporation was taken as the heat transfer amount, and the heat transfer amount per unit area of each sample was measured. The results of the drying experiment are shown in Table 2 below.

As shown in Table 2, the amount of heat transfer per unit area of the sinter having an average particle size of 15.0 mm was larger than the amount of heat transfer per unit area of the sinter having an average particle size of 45.0 mm. Moreover, as the layer thickness increased, the difference increased. From this result, it can be seen that the heat transfer efficiency of the sinter having a small average particle size is higher than the heat transfer efficiency of the sinter having a large average particle size.

From these results, the inventors, in order to dry the blast furnace raw material having a small average particle size, pass heated air and heat the blast furnace raw material having a large average particle size with the heated air to obtain an average particle size. It was considered preferable to transfer the heat of the large blast furnace raw material to the blast furnace raw material having a small average particle size. Therefore, considering that the heat of the blast furnace raw material having a large average particle size is transferred to the blast furnace raw material having a small average particle size, the layer of the blast furnace raw material having a large average particle size and the layer of the blast furnace raw material having a small average particle size are separated. It can be seen that it is preferable to place the layers alternately so that the length in the traveling direction is shortened.

That is, when the blast furnace raw material is placed in a layer on the layer of the high-temperature sinter, the blast furnace raw material having a large average particle size and the blast furnace raw material having a small average particle size have different lengths in the traveling direction of the trough 10. Place them alternately so that they are shorter. By placing the blast furnace raw material in this way, the air heated by the high-temperature sintered ore 16 in the lower layer easily passes through the gaps between the blast furnace raw materials having a large average particle size, and heats and dries the blast furnace raw material. Then, by transferring the heat of the heated blast furnace raw material having a large average particle size to the adjacent blast furnace raw material having a small average particle size, the blast furnace raw material having a small average particle size, which is difficult for heated air to pass through, is efficiently heated. The present invention was completed by finding that it can be dried. Here, the blast furnace raw material having a small average particle size means a blast furnace raw material having an average particle size smaller than the average particle size of the entire blast furnace raw material, and the blast furnace raw material having a large average particle size is larger than the average particle size of the entire blast furnace raw material. It means a blast furnace raw material having a small average particle size.

In the prior art, as shown in FIG. 1, layers of yard sinter 14 having a large average particle size are formed at both ends of the layer of yard sinter 12 having a small average particle size. Therefore, in the prior art, there are two interfaces between the yard sinter 12 having a small average particle size and the yard sinter 14 having a large average particle size with respect to the width dimension L1 of the trough. It can be said that the larger the number of the interfaces per unit size, the more efficiently the heat of the heated yard sinter 14 having a large average particle size can be transferred to the yard sinter 12 having a small average particle size. Therefore, in the method for drying the blast furnace raw material according to the present embodiment, the length of the layer of the blast furnace raw material having a small average particle size in the traveling direction of the trough and the length of the layer of the blast furnace raw material having a large average particle size are defined as the width dimension of the trough. Make it less than 1/2 of L1. As a result, the number of the interfaces per unit size can be significantly increased as compared with the prior art, and the blast furnace raw material made of yard sintered ore having a small average particle size can be heated and dried more efficiently.

Hereinafter, the present invention will be described through embodiments of the invention. An example is shown in which a yard sintered ore having a high moisture content, which is temporarily stored in a yard and exposed to rainwater or the like, is used as a blast furnace raw material to be dried by the drying method according to the present embodiment. However, the raw material for the blast furnace to be dried is not limited to yard sintered ore, but iron ore or coke breeze having a high water content may be used.

FIG. 4 is a schematic view showing an example of a drying treatment line 40 in which the method for drying the blast furnace raw material according to the present embodiment can be carried out. The drying treatment line 40 includes a sinter 42 for producing sinter and a crusher 44 for adjusting the particle size by crushing the high temperature (for example, 500 to 800 ° C.) sinter produced by the sinter 42. It has a cooler device 50 for cooling the sinter whose grain size has been adjusted by the crusher 44 to a predetermined temperature (for example, 100 to 200 ° C.), and a hopper 46 for charging the yard sinter into the cooler device 50. .. The cooler device 50 is composed of, for example, zones 1 to 4. A # 1 cooler fan 52 is provided in the first zone. Similarly, a # 2 cooler fan 54 is provided in the second zone, a # 3 cooler fan 56 is provided in the third zone, and a # 4 cooler fan 58 is provided in the fourth zone.

Further, the cooler device 50 may be equipped with a boiler 48 that takes in high-temperature air discharged when the high-temperature sinter 16 is cooled and recovers the exhaust heat. In the cooler device 50 of the present embodiment, the boiler 48 is attached to the first zone. Therefore, in the example shown in FIG. 1, the first zone is the exhaust heat recovery zone, and the second to fourth zones are the non-exhaust heat recovery zones.

The high-temperature sinter 16 produced by the sinter 42 is placed in a layer on the trough of the cooler device 50 and cooled by each cooler fan in the first zone, the second zone, the third zone and the fourth zone. Will be done. Cooling the high-temperature sinter by the cooler device 50 is the cooling step in the present embodiment.

The yard sinter 60 is housed in the hopper 46. The yard sinter 60 housed in the hopper 46 is cut out from the hopper 46 and layered on a layer of sinter that is cooled between the second and third zones of the cooler device 50. Placed.

Cooler fans 52 to 58 provided in each zone form an updraft flowing from below to above. Due to this updraft, the hot air heated by the high temperature sinter in the lower layer rises, and the yard sinter placed on the layer of the high temperature sinter is heated and dried. As a result, the yard sinter having a high water content can be dried without using a new heat source.

FIG. 5 is a schematic cross-sectional view showing a situation in which the yard sinter 60 is placed on the layer of the high temperature sinter 16 placed on the trough 10. FIG. 5A is a schematic side sectional view, and FIG. 5B is a top view. The details of the placement step of placing the yard sinter 60 on the layer of the high temperature sinter 16 will be described with reference to FIGS. 5 (a) and 5 (b).

The hopper 46 houses the yard sinter 60. The hopper 46 is surrounded by side surfaces and accommodates a yard sintered ore 60, a partition wall 72 provided in the accommodating portion 70, shutters 73, 74, 75 provided with openings, and discharge. It has a slope 76 and.

When the accommodating portion 70 is filled with the yard sinter 60, if the yard sinter 60 is supplied so that the central portion has a mountain shape, the yard sinter 60 having a large average particle size falls on the slope of the mountain. So, yard sinter with a small average particle size does not fall much on mountain slopes. Therefore, the yard sinter 60 segregates the particle size in the process of falling down the slope of the mountain, and the yard sinter 12 having a small average particle size is deposited on the center side of the accommodating portion 70, and averages on the side surface side of the accommodating portion 70. Yard sinter 14 having a large particle size is deposited.

By sliding the three shutters 73, 74, and 75, the yard sinter 12 deposited on the central side of the accommodating portion 70 and the yard sinter 14 deposited on the side surface side of the accommodating portion 70 are discharged. To switch. In the example shown in FIG. 5A, the openings of the shutters 73 and 74 are located below the accommodating portion 70, whereby the yard sinter 14 deposited on the side surface side of the accommodating portion 70 is discharged. .. The discharge slope 76 is a member that guides the yard sinter 60 onto the high temperature sinter 16.

The partition wall 72 is a plate that regulates the movement of the yard sinter 60 below the accommodating portion 70. By providing the partition wall 72 in the accommodating portion 70 in this way, the yard sinter 12 deposited on the central side of the accommodating portion 70 and the yard sinter 14 deposited on the side surface side of the accommodating portion 70 are moved by the particle size segregation. Is regulated so that the side yard sinter 14 is not discharged when the center yard sinter 12 is discharged, and the center yard sinter 14 is discharged when the side yard sinter 14 is discharged. It is suppressed that 12 is discharged.

By controlling the discharge by the shutters 73, 74, and 75, the yard sinter 14 having a large average particle size and the yard sinter 12 having a small average particle size are alternately discharged from the discharge slope 76 from the hopper 46. .. Further, the length L2 of the yard sinter 12 having a small average particle size in the trough traveling direction and the length L3 of the yard sinter 14 having a large average particle size in the trough traveling direction intersect with each other in the trough traveling direction. The operations of the shutters 73, 74 and 75 are controlled so as to be less than 1/2 of the width dimension L1. The operations (switching time, operating speed, etc.) of the shutters 73, 74 and the shutter 75 can be determined by conducting a discharge experiment using the yard sintered ore 60 and the hopper 46 in advance. If the lengths L2 and L3 in the trough traveling direction are too short with respect to the width dimension L1, the yard sintered ore 12 having a small average particle size and the yard having a large average particle size on the high temperature sinter 16 The sinter 14 may be easily mixed with the sinter 14 due to the vibration of the trough or the like, resulting in insufficient drying. Therefore, it is preferable that the lengths L2 and L3 in the trough traveling direction are 1/10 or more of the width dimension L1.

In addition, a cut gate 78 may be provided to regulate the thickness of the yard sintered ore 60 discharged from the discharge slope 76. By providing the cut gate 78, the variation in the layer thickness of the yard sinter 60 can be reduced.

In the method for drying the blast furnace raw material according to the present embodiment, the length L2 of the yard sinter 12 having a small average particle size in the trough traveling direction and the yard baking having a large average particle size are placed on the layer of the high temperature sinter 16. Each yard sinter is placed so that the length L3 of the blast furnace 14 in the trough traveling direction is less than 1/2 of the width dimension L1 of the trough 10 in the direction intersecting the traveling direction of the trough 10. As described above, since the yard sinter 14 having a large average particle size has a small pressure loss and good air permeability, it can be easily heated and dried by the air heated by the high temperature sinter 16 in the lower layer. Since the yard sinter 12 having a small average particle size has high heat transfer efficiency, it can be efficiently heated and dried by the heat of the yard sinter 14 having a large average particle size. As a result, both the yard sinter 14 having a large average particle size and the yard sinter 12 having a small average particle size are heated and dried, and the moisture content of the entire yard sinter 60 after drying is determined by the conventional drying method. It is lower than the moisture content of the dried yard sinter.

FIG. 6 is a diagram illustrating a situation in which the yard sintered ore 60 filled in the hopper 46 is discharged. FIG. 6A shows a state in which the yard sintered ore 14 having a large average particle size deposited on the side surface side of the accommodating portion 70 is discharged. FIG. 6B shows a state in which the yard sintered ore 12 having a small average particle size deposited on the central side of the accommodating portion 70 is discharged. The arrow direction shown in the upper right of FIG. 6 is defined as the up / down / left / right / front / rear direction of the hopper 46.

The shutter 75 is a plate-shaped member provided with an opening 80, and is provided below the position on the center side of the accommodating portion 70. When the shutter 75 is slid backward from the state of FIG. 6A, the opening 80 moves below the accommodating portion 70 and allows the discharge of the yard sinter 12 deposited on the central side of the accommodating portion 70. ..

The shutters 73 and 74 are plate-shaped members provided with openings 82, and are provided below the positions on the side surface side of the accommodating portion 70, respectively. When the shutters 73 and 74 are slid forward from the state shown in FIG. 6A, the opening 82 moves from below the accommodating portion 70, and the yard sinter 14 deposited on the side surface side of the accommodating portion 70 is discharged. Stop. By alternately sliding the shutters 73 and 74 and the shutter 75, the yard sinter 14 having a large average particle size and the yard sinter 12 having a small average particle size can be alternately discharged. The shutters 73, 74, and 75 discharge the yard sinter 12 deposited on the center side of the cross section perpendicular to the vertical direction of the accommodating portion 70 and the yard sinter 14 deposited on the side surface side. This is an example of a member to be switched.

Further, the cross-sectional shape of the accommodating portion 70 perpendicular to the vertical direction (vertical direction) is preferably a rectangle whose dimensions in the left-right direction are longer than those in the front-rear direction. As described above, the yard sinter 60 segregates the particle size in the process of falling down the slope of the mountain. Therefore, if the cross-sectional shape of the accommodating portion 70 is a rectangle having a long horizontal dimension, the particle size segregation in the left-right direction is larger than the particle size segregation in the front-rear direction, and as a result, the particles are discharged by the shutters 73, 74 and the shutter 75. The particle size difference between the yard sintered ore 14 having a large average particle size and the yard sintered ore 12 having a small average particle size is widened.

FIG. 7 is a diagram showing a situation in which the yard sintered ore 60 filled in the hopper 90 is discharged. FIG. 7A shows a state in which the yard sinter 14 deposited on the side surface side of the accommodating portion 92 is discharged. FIG. 7B shows a state in which the yard sinter 12 deposited on the central side of the accommodating portion 92 is discharged. In FIGS. 7 (a) and 7 (b), the same reference numbers are given to the elements common to those in FIG. 5 (a), and duplicate description will be omitted.

The hopper 90 differs from the hopper 46 (FIG. 5) in that it has two flaps 94 instead of the shutters 73, 74, 75. As shown in FIGS. 7A and 7B, the two flaps 94 provided below the accommodating portion 92 swing to the left and right of the drawing with one end side 93 as the central axis, and the yard is deposited on the central side. The discharge of the sinter 12 and the discharge of the yard sinter 14 deposited on the side surface side are switched. The flap 94 is another example of a member that switches between discharging the yard sinter 12 deposited on the central side of the accommodating portion 70 and discharging the yard sinter 14 deposited on the side surface side of the accommodating portion 70. ..

In this way, even if the hopper 90 is used, by swinging the two flaps 94 left and right around one end side 93, the yard sinter 14 having a large average particle size and the yard baking having a small average particle size are used. The sinter 12 can be discharged alternately. Each operation (switching time, rocking speed, etc.) of the two flaps 94 can be determined by performing a cutting experiment using the yard sintered ore 60 and the hopper 90 in advance.

As described above, in the method for drying the blast furnace raw material according to the present embodiment, the blast furnace raw material having a large average particle size and the blast furnace raw material having a small average particle size are alternately cut out from the hopper and cooled by the cooler device. On the layer of the high-temperature sinter, the troughs are alternately placed in the traveling direction so that the length of each in the traveling direction of the trough is less than 1/2 of the width dimension L1 of the trough. As a result, the blast furnace raw material can be efficiently dried by the sensible heat of the high-temperature sintered ore, and the water content of the dried blast furnace raw material can be reduced as compared with the conventional case.

Next, an example in which the yard sinter is dried using the drying treatment line 40 shown in FIG. 4 will be described. In this embodiment, the sinter of 600 ° C. manufactured by the sinter 42 and whose particle size is adjusted by the crusher 44 is layered on the trough of the cooler device 50 so that the layer thickness is 0.8 m. Placed. Then, using the hopper 46 shown in FIG. 6, the yard sinter deposited on the central side of the accommodating portion 70 and the yard sinter deposited on the side surface side of the accommodating portion 70 on the layer of the high temperature sinter. The ore was discharged alternately, and layers of yard sinter having a large average particle size and layers of yard sinter having a small average particle size were alternately formed in the traveling direction of the trough. In this embodiment, the length L2 of the layer of the yard sinter having a small average particle size is 0.6 m, and the length L3 of the layer of the yard sinter having a large average particle size is 0.6 m. The thickness is 0.2 m. Further, the width dimension L1 of the trough of the cooler device 50 is 2.4 m.

In the comparative example, a conventional hopper that simultaneously discharges the yard sinter deposited on the center side of the hopper and the yard sinter deposited on the side surface is used in the width direction on the layer of the hot sinter. A layer of yard sinter having a small average particle size was formed in the center and a layer of yard sinter having a large average particle size was formed at the end in the width direction and dried. Table 3 below shows the average particle size of the sinter used in Examples and Comparative Examples, the average particle size of the yard sinter, and the moisture content of the yard sinter before and after drying. Further, in this example, the average particle size of the yard sinter having a large average particle size was 25.5 mm, and the average particle size of the yard sinter having a small average particle size was 8.6 mm.

As shown in Table 3, the moisture content after drying in the invention example was lower than the moisture content after drying in the comparative example. As a result, the yard sinter deposited on the center side of the hopper and the yard sinter deposited on the side surface side are alternately discharged, and as shown in FIG. 5 (b), the yard sinter having a large average particle size is discharged. By alternately forming a layer of ore and a layer of yard-sintered ore having a small average particle size in the traveling direction of the trough and drying it, the water content of the blast furnace raw material after drying can be reduced as compared with the conventional case. confirmed.

10 Traf 12 yard sinter 14 yard sinter 16 High temperature sinter 20 Pressure loss experimental equipment 22 Sintering vessel 24 Fan 26 Damper 30 Drying experimental equipment 32 Raw material container 34 Weighing instrument 40 Drying processing line 42 Sintering machine 44 Crusher 46 Hopper 48 Boiler 50 Cooler device 52 Cooler fan 54 Cooler fan 56 Cooler fan 58 Cooler fan 60 yards Sintered ore 70 Containment part 72 Partition wall 73 Shutter 74 Shutter 75 Shutter 76 Discharge slope 78 Cut gate 80 Opening 82 Opening Hopper 92 Housing 93 One end 94 Flap

Claims (7)

A cooling process in which the high-temperature sinter produced by the sinter is placed in layers on the trough of the cooler device and cooled.
It has a mounting step of placing the blast furnace raw material in a layer on the layer of the sinter cooled in the cooling step.
In the above-described step, the blast furnace raw material having an average particle size larger than the average particle size of the entire blast furnace raw material and the blast furnace raw material having an average particle size smaller than the average particle size of the entire blast furnace raw material are each lengthed in the traveling direction of the trough. A method for drying a blast furnace raw material, in which the blast furnace raw materials are alternately placed in the traveling direction of the blast furnace so that is less than 1/2 of the size of the trough in the width direction intersecting the traveling direction of the trough. The blast furnace raw material is housed in a hopper having a housing part, and is stored.
In the above-described step, the blast furnace raw material deposited on the center side of the cross section perpendicular to the vertical direction of the housing portion and the blast furnace raw material deposited on the side surface side of the housing portion are alternately discharged from the hopper. The method for drying a blast furnace raw material according to 1. The method for drying a blast furnace raw material according to claim 2, wherein the accommodating portion of the hopper has a rectangular cross-sectional shape perpendicular to the vertical direction of the accommodating portion. The method for drying a blast furnace raw material according to claim 2 or 3, wherein a wall partitioning the central side and the side surface side is provided below the accommodating portion of the hopper. A shutter that allows the discharge of the blast furnace raw material deposited on the central side and a shutter that allows the discharge of the blast furnace raw material deposited on the side surface side are provided below the accommodating portion of the hopper. The method for drying a blast furnace raw material according to any one of items 2 to 4. A flap that swings left and right around one end is provided below the accommodating portion of the hopper.
Any one of claims 2 to 4, wherein the flap swings left and right to switch between the discharge of the blast furnace raw material deposited on the central side and the discharge of the blast furnace raw material deposited on the side surface side. The method for drying blast furnace raw materials according to the section. The method for drying a blast furnace raw material according to any one of claims 1 to 6, wherein the blast furnace raw material is yard sintered ore.

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