Sintered ore manufacturing method and sintering machine

Abstract

To provide a method for optimizing as needed progress of combustion of a carbonaceous material and melting of a sintering raw material, by measuring the progress of the combustion of the carbonaceous material and melting of the sintering raw material in an inserted layer, when manufacturing a sintered ore.SOLUTION: Provided is a method for producing sintered ore, in which sintering raw materials are charged into a circulating pallet 26 to form a charging layer, and an ignition furnace 20 is used to ignite an upper surface layer of the charging layer, air is sucked below the charged layer, a carbonaceous material contained in the sintering raw material is burnt to form a sintered cake, and then the sintered cake is discharged from the ore discharge section to produce sintered ore, wherein an amount of shrinkage or a shrinkage rate of the charge layer after ignition is measured, and one or more of a supply amount of gaseous fuel to the charge layer upper layer, a supply amount of liquid fuel supplied to the upper surface layer of the charging layer, an amount of blended carbonaceous material in the sintering raw material, a thickness of the charging layer, an amount of air sucked, and a moving speed of the pallet are adjusted so that the amount of shrinkage or the shrinkage rate of the charge layer falls within a predetermined range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing sintered ore, which is a raw material for a blast furnace, and a sintering machine for producing sintered ore. [Background technology]

[0002] Sintered ore, which is a raw material for blast furnaces, is generally produced using iron-containing raw materials such as iron ore powder, powder recovered in steelworks, and sintered ore undersize powder, CaO-containing raw materials such as limestone and dolomite, and carbonaceous materials (solid fuel) such as coke powder and anthracite as sintering raw materials, using a Dwight Lloyd sintering machine (hereinafter referred to as the "sintering machine"), which is an endless moving sintering machine.

[0003] The sintering raw materials are charged into the endless moving pallet of the sintering machine, and a charging layer is formed. The thickness (height) of the charging layer is about 400 to 800 mm. Then, the carbonaceous material in the charging layer is ignited by an ignition furnace installed above the charging layer. The carbonaceous material in the charging layer is burned one by one by sucking air downward through a wind box installed under the pallet. This combustion progresses gradually downward and forward as the pallet moves. The combustion heat generated at this time burns and melts the sintering raw materials, and a sintered cake is produced. The obtained sintered cake is then crushed in the discharge section, cooled in a cooler, and sized to become the finished sintered ore.

[0004] In the above-mentioned sintering machine, from the viewpoint of improving the strength and yield of sintered ore, it is important to grasp and optimize the progress of the combustion of the carbonaceous material and the melting of the sintering raw materials in the charging bed. For example, Patent Document 1 discloses a temperature measuring device that protrudes from the bottom of a pallet and has two or more temperature measuring parts for the purpose of measuring the temperature and sintering speed in the charging bed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-243443 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional techniques have the following problems.

[0007] That is, in Patent Document 1, the temperature in the charging bed is measured by a temperature measuring device, but the temperature in the charging bed decreases regardless of the progress of the combustion of the carbonaceous material and the melting of the sintering raw materials due to disturbance factors such as local voids generated in the charging bed and excessive air intake through the boundary between the charging bed and the pallet. Therefore, the temperature in the charging bed does not necessarily reflect only the progress of the combustion of the carbonaceous material and the melting of the sintering raw materials in the charging bed, and there is a problem that the error is large when used as an indicator of the progress of the combustion of the carbonaceous material and the melting of the sintering raw materials.

[0008] The present invention has been made in consideration of such problems, and its object is to provide a method for producing sintered ore and a sintering machine that can accurately measure the progress of combustion of carbonaceous material and melting of sintering raw materials in a sintering bed when producing sintered ore, and can optimize the progress of combustion of carbonaceous material and melting of sintering raw materials as necessary. [Means for solving the problem]

[0009] The gist of the present invention for solving the above problems is as follows. [1] A method for producing sintered ore, comprising: charging raw materials into a circulating pallet to form a charging layer; igniting the upper surface of the charging layer using an ignition furnace; drawing in air from below the charging layer to combust the carbonaceous material contained in the sintered raw materials to produce a sintered cake; and then discharging the sintered cake from a discharge section to produce sintered ore, A method for producing sintered ore, characterized in that the amount of shrinkage of a sintering bed after ignition is measured, and one or more of the amount of gaseous fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the amount of carbonaceous material mixed in the sintering raw material, the thickness of the sintering bed, the amount of air suction, and the moving speed of the pallet are adjusted so that the amount of shrinkage of the sintering bed is within a predetermined range. [2] A method for producing sintered ore, comprising: charging raw materials into a circulating pallet to form a charging layer; igniting the upper surface of the charging layer using an ignition furnace; drawing in air from below the charging layer to combust the carbonaceous material contained in the sintered raw materials to produce a sintered cake; and then discharging the sintered cake from a discharge section to produce sintered ore, A method for producing sintered ore, comprising: measuring a contraction rate of a sintering bed after ignition; and adjusting one or more of the amount of gaseous fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the amount of carbonaceous material mixed in the sintering raw material, the thickness of the sintering bed, the amount of air suction, and the moving speed of the pallet, so that the contraction rate of the sintering bed after ignition falls within a predetermined range. [3] The method for producing sintered ore described in [1] or [2] above, characterized in that the measurements are taken at two or more locations in the width direction of the pallet, and one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the amount of carbonaceous material in the sintering raw material, the thickness of the sintering bed, and the amount of air suction are adjusted in the width direction of the pallet. [4] The method for producing sintered ore described in [3] above, characterized in that the measurement is performed at two or more locations in the direction of movement of the pallet. [5] The method for producing sintered ore described in [4] above, wherein the measurement comprises measuring the height position of the upper surface of the sintering bed. [6] The method for producing sintered ore according to the above [5], characterized in that the measurement is performed without contacting the sintering bed. [7] A sintering machine having a circulating pallet, a feeding section for feeding sintering raw materials onto the pallet to form a sintering layer, an ignition furnace for igniting the carbonaceous material on the surface of the sintering layer, and a wind box for drawing air from below the sintering layer, the sintering machine sintering the sintering raw materials by the combustion heat of the carbonaceous material contained in the sintering raw materials, A sintering machine having a position measuring device for measuring the amount of shrinkage of the sintering bed after ignition, and having a function of adjusting one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the amount of carbonaceous material mixed in the sintering raw material, the thickness of the sintering bed, the amount of air suction, and the moving speed of the pallet, so that the amount of shrinkage of the sintering bed is within a predetermined range. [8] A sintering machine having a circulating pallet, a feeding section for feeding sintering raw materials onto the pallet to form a sintering layer, an ignition furnace for igniting the carbonaceous material on the surface of the sintering layer, and a wind box for drawing air from below the sintering layer, the sintering machine sintering the sintering raw materials by the combustion heat of the carbonaceous material contained in the sintering raw materials, A sintering machine having a position measuring device for measuring the contraction speed of the sintering bed after ignition, and having a function of adjusting one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the amount of carbonaceous material mixed in the sintering raw material, the thickness of the sintering bed, the amount of air suction, and the moving speed of the pallet, so that the contraction speed of the sintering bed is within a predetermined range. [9] The sintering machine described in [7] or [8] above, characterized in that the position measuring device has the function of measuring two or more locations in the width direction of the pallet and adjusting one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the carbonaceous material content of the sintering raw material, the thickness of the sintering bed, and the amount of air suction in the width direction of the pallet.

[10] The sintering machine described in [9] above, characterized in that the position measuring device measures two or more locations in the direction of pallet movement.

[11] The sintering machine described in

[10] above, characterized in that the position measuring device measures the height position of the upper surface of the charging bed.

[12] The sintering machine described in

[11] above, characterized in that the position measuring device measures without contacting the sintering bed. Effect of the Invention

[0010] According to the present invention, the amount of shrinkage or the shrinkage rate of the sintering raw material loading layer during sintering is measured, so that the progress of the combustion of the carbonaceous material and the melting of the sintering raw material in the loading layer can be measured with high accuracy, and the progress of the combustion of the carbonaceous material and the melting of the sintering raw material can be optimized as necessary. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side schematic view showing an example of a sintering machine used when carrying out a method for producing sintered ore according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective schematic view of the sintering machine shown in FIG. [Diagram 3] FIG. 13 is a diagram showing the results of investigating the amount of shrinkage of the sintering bed during sintering by changing the blending amount of carbonaceous material. [Figure 4] FIG. 13 is a diagram showing the results of investigating the yield and TI strength of sintered ore after sintering by changing the amount of shrinkage of the sintering bed by changing the blending amount of carbonaceous material. [Diagram 5] FIG. 13 is a diagram showing the results of investigating the yield and TI strength of sintered ore after sintering by changing the blending amount of carbonaceous material. [Figure 6] FIG. 13 is a graph showing the results of investigating the amount of shrinkage of the sintering bed during sintering by adding 0.4 volume % of natural gas to the area with little carbonaceous material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a side schematic view showing an example of a sintering machine 10 used when carrying out a method for producing sintered ore according to this embodiment. Fig. 2 is a perspective schematic view of the sintering machine 10 shown in Fig. 1.

[0013] Sintering raw materials, including iron-containing raw materials such as iron ore powder, ironworks recovered powder, sintered ore undersize powder, CaO-containing raw materials such as limestone and dolomite, and carbonaceous materials (solid fuels) such as coke powder and anthracite, are fed from a surge hopper 12 provided in the ore feeding section 40 of the sintering machine 10 by a roll feeder 14 and charged into an endless moving pallet 26 that moves in a circular manner, forming a charging layer of the sintering raw materials inside the pallet 26. At this time, the thickness (height) of the charging layer is controlled by adjusting the opening of a plurality of split gates 16 installed along the width direction of the pallet 26 at the bottom of the surge hopper 12. In this embodiment, the split gate 16 is divided into, for example, eight as shown in FIG. 2, and each split gate 16 is assigned a gate number (1 to 8) corresponding to the order of the position in the width direction of the pallet 26.

[0014] The charging layer formed on the pallet 26 moves toward the downstream side of the sinter machine 10 together with the pallet 26. A level gauge 18 is provided downstream of the dividing gate 16. Eight level gauges 18 are provided, the same number as the number of divisions of the dividing gate 16, and one is provided downstream of each dividing gate 16. Each level gauge 18 is assigned the same number as the dividing gate number, and each level gauge 18 measures the thickness of the charging layer of the dividing gate 16 to which the same number is assigned. In this embodiment, an ultrasonic level gauge is used as the level gauge 18.

[0015] Each level meter 18 measures the thickness of the charging layer and outputs the measured thickness data to the control device 32. The control device 32 controls the opening degree of each dividing gate 16 based on the input thickness data so that the thickness of the charging layer becomes uniform in the width direction of the pallet 26 or becomes a specified thickness.

[0016] The upper surface of the sintering bed is ignited by the ignition furnace 20 installed downstream of the ore feeding section 40. Furthermore, air is sucked in by the blower 24, and the air in the sintering bed is sucked downward through the wind boxes 22 installed in the machine length direction below the pallets 26, and air is introduced into the sintering bed from above, combusting the carbonaceous materials contained in the sintering raw materials. The amount of sucked air can be adjusted by adjusting the rotation speed of the blower 24.

[0017] The sintered raw materials are baked and solidified by the heat of combustion of the carbonaceous material to become sintered cakes, which are lumps of sintered ore. The sintered cakes are discharged from the ore discharge section 42. The sintered cakes discharged from the ore discharge section 42 crack in the width direction of the pallet 26 just before falling from the pallet 26, causing them to break.

[0018] Thereafter, the sintered cake falls from the ore discharge section 42, is crushed, cooled in a cooler (not shown), and sized to become a product sintered ore consisting of agglomerates with a particle size of, for example, more than 5.0 mm.

[0019] The control device 32 has a storage unit 34 and a control unit 36. The control device 32 is, for example, a general-purpose computer such as a workstation or a personal computer. The storage unit 34 is, for example, an updatable flash memory, a built-in hard disk or a hard disk connected via a data communication terminal, an information recording medium such as a memory card, and a read / write device for the information recording medium. The storage unit 34 stores in advance a program required for carrying out the sintered ore manufacturing method according to the present embodiment, data used during execution of the program, and the like. The control unit 36 ​​is, for example, a CPU, and controls the operation of the sintering machine 10 using the program and data stored in the storage unit 34.

[0020] In the sintering machine 10 according to this embodiment, injection nozzles (not shown) for supplying gaseous fuel such as natural gas or liquid fuel such as heavy oil from above onto the upper surface layer of the charging layer of the pallet 26 are installed at multiple locations in the width direction of the pallet 26 and multiple locations in the moving direction of the pallet 26. Moreover, only a specific selected injection nozzle out of the multiple injection nozzles has a function of injecting gaseous fuel or liquid fuel.

[0021] After ignition, the temperature rise and melting of the sintering raw materials due to the combustion of carbonaceous materials progresses from the top surface of the sintering bed to the bottom surface. It is known that the sintering bed shrinks during this sintering process. The shrinkage progresses in all directions, but due to the effect of the weight of the sintering bed, most of the shrinkage is observed as a decrease in the height of the top surface of the sintering bed.

[0022] The present inventors have observed the shrinkage behavior by measuring the height position of the upper surface of the sintering bed while changing the sintering conditions, and have obtained the following findings.

[0023] (1) The shrinkage rate of the sintering bed increases according to the amount of carbonaceous material mixed, and reaches 10-20% at the appropriate carbonaceous material mixture (4.0-4.4% by mass) where the sintering reaction proceeds without excess or deficiency. When the amount of carbonaceous material mixed is increased by 1% by mass near the appropriate amount of carbonaceous material mixed, the increase in the shrinkage rate of the sintering bed is 7% or more, which is more than 7 times the amount of carbonaceous material mixed. From this, it can be seen that the shrinkage of the sintering bed is not greatly influenced by the volume reduction due to the burning of the carbonaceous material itself, but is largely influenced by the melting of the sintered layer and the filling of voids, and that the shrinkage of the sintering bed accurately reflects the progress of sintering.

[0024] In addition, there is a limit to the charging density that can be changed only by adjusting the opening of the split gate, and the correlation between the charging density and the shrinkage rate is weak. In other words, it is difficult to control the shrinkage rate of the charging layer to a target range by adjusting the opening of the split gate. On the other hand, as described above and shown in Figure 3 described later, there is a strong correlation between the amount of carbonaceous material in the raw materials and the shrinkage rate of the charging layer, and the shrinkage rate also varies widely. For this reason, the amount of carbonaceous material can be said to be suitable as a parameter for estimating and controlling the yield and TI strength of the finished sintered ore. The amount of carbonaceous material is adjusted by charging the sintered raw material, the amount of which has been adjusted to a predetermined value, into the surge hopper 12 and then charging the sintered raw material into the pallet 26.

[0025] (2) When the amount of carbonaceous materials is less than the optimum amount, the time from the ignition of the sinter bed to the start of contraction becomes longer. However, the difference in the contraction rate after the start of contraction was small, and the effect of the amount of carbonaceous materials was small.

[0026] Figure 3 shows the results of investigating the amount of shrinkage during sintering when the initial height of the sintering bed was set to 600 mm and the amount of carbonaceous material mixed was changed in the range of 3.2 to 5.0 mass%. When the amount of carbonaceous material mixed was 3.2 mass%, the shrinkage stagnation period (the time from ignition to the start of shrinkage) was about 19 minutes, whereas when the amount of carbonaceous material mixed was 5.0 mass%, the shrinkage stagnation period was about 4 minutes. When the amount of carbonaceous material mixed was the appropriate value of 4.2 mass%, the shrinkage stagnation period was about 7 minutes. Also, from Figure 3, it was found that the difference in the shrinkage speed after the start of shrinkage was very small.

[0027] (3) There was a good correlation between the amount of shrinkage of the sintered ore bed during sintering and the yield and TI strength of the sintered ore.

[0028] Figure 4 shows the results of investigating the yield and TI strength of sintered ore after sintering when the initial height of the sintering bed is set to 600 mm and the amount of carbonaceous material mixed is changed to change the amount of shrinkage of the sintering bed. As shown in Figure 4, a good correlation was found between the amount of shrinkage of the sintering bed during sintering and the yield and TI strength of the sintered ore after sintering. Here, TI strength is the rotational strength index defined in JIS M 8712:2022.

[0029] (4) Figure 5 shows the results of investigating the yield and TI strength of sintered ore after sintering by changing the amount of carbonaceous material mixed with the initial height of the charging bed set at 600 mm. As shown in Figure 5, a clear correlation was found between the carbonaceous material mixing ratio in the sintering raw material and the yield and TI strength of sintered ore after sintering. Therefore, it was found that if it is predicted that the amount of shrinkage of the charging bed during sintering will decrease and the yield and TI strength of the sintered ore after sintering will decrease, the carbonaceous material mixing ratio in the sintering raw material should be increased. Figure 5 is a graph in which the amount of shrinkage on the horizontal axis of Figure 4 is replaced with the amount of carbonaceous material mixed.

[0030] (5) Even when the amount of carbonaceous material is less than the appropriate value and the shrinkage of the sintering bed is small, it was found that the shrinkage of the sintering bed can be increased by supplying gaseous fuel such as natural gas or liquid fuel such as heavy oil from above the sintering bed to promote the progress of the sintering reaction. Therefore, when it is predicted that the shrinkage rate of the sintering bed during sintering will decrease and the yield and TI strength of the sintered ore after sintering will decrease, it was found that it is sufficient to add gaseous fuel such as natural gas or liquid fuel such as heavy oil from above the sintering bed or to increase the amount of addition.

[0031] Figure 6 shows the results of investigating the amount of shrinkage of the sintering bed during sintering when the width of the sintering bed is 800 mm, the initial height of the sintering bed is 400 mm, the amount of carbonaceous material is changed, and 0.4 volume % of natural gas is added to the area with less carbonaceous material. It was found that adding natural gas can eliminate the heat shortage and ensure the amount of shrinkage of the sintering bed.

[0032] Based on the above findings, the sintering machine 10 according to this embodiment is provided with a position measuring device 28 for measuring the amount and speed of shrinkage of the charging bed during sintering. The position measuring device 28 is provided downstream of the ignition furnace 20, and measures the position of the upper surface layer of the charging bed that has come out of the ignition furnace 20, and outputs the measured height position data to the control device 32.

[0033] <Measurement mechanism of the position measuring device 28> The measurement target of the position measuring device 28 is the outer surface of the sintering bed, which is at a lower temperature than the inside of the sintering bed, which reaches 1200°C or higher. Therefore, it is also possible to measure the height position of the upper surface of the sintering bed using a contact-type weight or a roller with an arm as the position measuring device 28. However, from the viewpoint of durability, it is preferable that the position measuring device 28 be of a non-contact type such as an ultrasonic distance meter.

[0034] From the viewpoints of the wideness of the measurement field and the measurement depth, the high position resolution, the number of measurement points, and the high measurement speed, it is more preferable that the position measuring device 28 is a non-contact optical type such as a laser scanner. As a laser scanner, for example, the Leica 3D scanner ScanStation P series can be mentioned, but many of them realize high-speed scanning by minute movements of a galvanometer mirror that reflects a laser, and if they are installed directly above the charging layer and vertically downward measurement is attempted, there may be restrictions such as a decrease in measurement accuracy and speed (there are models that do not have restrictions, but the higher the speed and accuracy of the models, the greater the restrictions tend to be).

[0035] In such a case, it is sufficient to install the laser diagonally above the charging bed and measure diagonally downward, instead of directly above it. The smaller the depression angle (the angle that the line of sight to the object below makes with the horizontal), the fewer the constraints such as a decrease in the accuracy and speed of the measurement. However, if the incident angle of the laser to the top surface of the charging bed is small, a blind spot will be created at the measurement position due to the unevenness of the top surface of the charging bed, and the accuracy of the height measurement will decrease, so it is preferable to set the depression angle to 15 degrees or more.

[0036] When measuring over a wide range in the length direction of the sintering machine 10 (the moving direction of the pallet 26), the depression angle may be insufficient for locations far from the position measuring device 28. In such cases, multiple position measuring devices 28 may be installed.

[0037] <Measurement target position of position measuring device 28> The purpose of the measurement by the position measuring device 28 is to grasp the shrinkage of the charging layer accompanying the sintering reaction, so it is necessary to measure downstream of the ignition furnace 20 where the sintering reaction starts. In particular, if the measurement is performed near the ore discharge part 42 where the sintering reaction is considered to have completed or near its upstream side (for example, within 2 m from the ore discharge part 42), the progress of sintering of the sintered cake after sintering can be grasped.

[0038] By measuring at the ore discharge section 42 or further upstream of its vicinity (for example, within 10-90% of the travel from the ignition furnace 20 to the ore discharge section 42), that is, measuring at two or more locations in the moving direction of the pallet 26, and comparing the measurements with previous or subsequent measurements, it is possible to grasp not only the degree of sintering of the sintered cake after sintering, but also the sintering rate during sintering. Understanding the sintering rate is useful information for preventing the sintering from progressing too quickly, which inhibits the formation of calcium ferrite phase and reduces strength.

[0039] Furthermore, by measuring further upstream than the ore discharge section 42 or its upstream vicinity, the degree of sintering progress can be grasped more quickly than when measuring near the ore discharge section 42 or its upstream vicinity, so operational action can be taken more quickly to optimize the progress of the sintering reaction.

[0040] Furthermore, if the position measuring device 28 measures two or more points in the width direction horizontally perpendicular to the movement direction of the pallet 26, even if a difference in the progress of sintering occurs in the width direction of the pallet 26, the progress of sintering can be optimized by adjusting, for example, the amount of gas fuel or liquid fuel supplied to the surface layer above the sintering bed, which can be adjusted in the width direction of the pallet 26.

[0041] <Measurement frequency of the position measuring device 28> Regarding the measurement frequency of the position measuring device 28, it is effective to perform measurements at a low frequency limited to timing when changes in the progress of the sintering reaction are expected, such as when the raw material composition is changed, but by setting the measurement interval to within the time required for the sintering raw material to pass through the entire length of the sintering machine (e.g., 20 minutes), and more preferably within 2 minutes, which can be considered as virtually continuous measurement, it is possible to respond to unexpected changes in the composition or particle size of the sintering raw material.

[0042] When the control unit 36 ​​acquires height position data of the upper surface of the sintering bed from the position measuring device 28, it calculates the shrinkage amount and shrinkage speed of the sintering bed from the amount of descent of the upper surface of the sintering bed. If the shrinkage amount or shrinkage speed of the sintering bed is not appropriate, it adjusts one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed, the amount of liquid fuel supplied to the upper surface layer of the sintering bed, the amount of carbonaceous material mixed in the sintering raw material, the thickness of the sintering bed of the sintering raw material, the amount of air sucked by the blower 24, and the moving speed of the pallet 26 to control the shrinkage amount or shrinkage speed of the sintering bed within a predetermined range.

[0043] The thickness of the sintering layer before ignition can be calculated from the opening degree of the dividing gate 16, or the measurement data by the level gauge 18 can be used. Furthermore, if a non-contact optical device such as a laser scanner that has a wide measurement field and can measure a large number of measurement points at high speed is used as the position measuring device 28, the thickness of the sintering layer after ignition and the thickness of the sintering layer before ignition can both be measured by the same position measuring device.

[0044] Furthermore, when a non-contact optical device such as a laser scanner is used as the position measuring device 28, the upper surface layer from which the height position data has been acquired can be divided into two or more parts in the width direction of the pallet 26, and the average height position in the divided parts can be calculated. For example, when the upper surface layer is divided into two parts in the width direction of the pallet 26, the average height of the front area and the average height of the back area are calculated, with the center in the width direction as the boundary.

[0045] As described above, according to the present invention, the amount of shrinkage or the shrinkage rate of the sintering raw material charging layer during sintering is measured, so that the progress of the combustion of the carbonaceous material and the melting of the sintering raw material in the charging layer can be measured with high accuracy, and the progress of the combustion of the carbonaceous material and the melting of the sintering raw material can be optimized as necessary. EXAMPLES

[0046] [Example 1] Hereinafter, an embodiment in which sintered ore was produced using the same sintering machine 10 as shown in Figures 1 and 2 will be described. In this embodiment, the amount of natural gas added was adjusted in accordance with the amount of shrinkage of the sintering raw material charging layer in two regions (region 1 and region 2) divided in the width direction of the pallet 26 (Invention Example 1). The results of Inventive Example 1 and Comparative Example 1 in which no natural gas was added are shown in Table 1.

[0047] [Table 1]

[0048] In this way, it was confirmed that the sintering yield and the TI strength of the product can be improved by adjusting the amount of natural gas added for each region divided in the width direction of the sintering machine to reduce the deviation in the amount of shrinkage of the sintering raw material charging layer.

[0049] [Example 2] An example in which sintered ore was produced using the same apparatus as the sintering machine 10 shown in Figures 1 and 2 will be described. In this example, the thickness of the charging layer of the sintering raw material was adjusted in accordance with the amount of shrinkage of the charging layer in four regions (region 1, region 2, region 3, and region 4) divided in the width direction of the pallet 26 (Example 2 of the present invention). The results of Example 2 of the present invention and Comparative Example 2 in which the adjustment of the charging layer thickness was not performed are shown in Table 2.

[0050] [Table 2]

[0051] In this way, it was confirmed that the sintering yield and product TI strength can be improved by adjusting the thickness of the sintering raw material charging layer for each region divided in the width direction of the sintering machine and reducing the deviation in the amount of shrinkage of the sintering raw material charging layer. [Explanation of symbols]

[0052] 10 Sintering machine 12 Surge Hopper 14 Roll Feeder 16 Split Gate 18 Level Gauge 20 Ignition furnace 22 Wind box 24 Blower 26 Palettes 28 Position measuring device 32 Control device 34 Storage area 36 Control Unit 40 Ore supply department 42 Mine Discharge Section

Claims

1. A method for producing sintered ore, comprising the steps of: charging raw materials for sintering onto a circulating moving pallet to form a charging layer; igniting an upper surface layer of the charging layer using an ignition furnace; drawing in air from below the charging layer to combust carbonaceous materials contained in the sintered raw materials to produce a sintered cake; and then discharging the sintered cake from a discharge section to produce sintered ore, A method for producing sintered ore, comprising: measuring an amount of shrinkage of a sintering bed after ignition; and adjusting one or more of an amount of gaseous fuel supplied to an upper surface layer of the sintering bed and an amount of liquid fuel supplied to the upper surface layer of the sintering bed so that the amount of shrinkage of the sintering bed is within a predetermined range.

2. A method for producing sintered ore, comprising the steps of: charging raw materials for sintering onto a circulating moving pallet to form a charging layer; igniting an upper surface layer of the charging layer using an ignition furnace; drawing in air from below the charging layer to combust carbonaceous materials contained in the sintered raw materials to produce a sintered cake; and then discharging the sintered cake from a discharge section to produce sintered ore, A method for producing sintered ore, comprising: measuring a contraction rate of a sintered ore bed after ignition; and adjusting one or more of an amount of gaseous fuel supplied to an upper surface layer of the sintered ore bed and an amount of liquid fuel supplied to the upper surface layer of the sintered ore bed so that the contraction rate of the sintered ore bed is within a predetermined range.

3. 3. The method for producing sintered ore according to claim 1, wherein the measurement is performed at two or more locations in the width direction of the pallet, and one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed and the amount of liquid fuel supplied to the upper surface layer of the sintering bed are adjusted in the width direction of the pallet.

4. The method for producing sintered ore according to claim 3, characterized in that the measurement is performed at two or more locations in the moving direction of the pallet.

5. The method for producing sintered ore according to claim 4, wherein the measurement comprises measuring a height position of an upper surface of the sintering bed.

6. The method for producing sintered ore according to claim 5, wherein the measurement is performed without contacting the sintering bed.

7. A sintering machine comprising: a pallet that moves in a circular manner; a feeder that charges sintering raw materials onto the pallet to form a charging layer; an ignition furnace that ignites carbonaceous material on the surface of the charging layer; and a wind box that draws air from below the charging layer and is installed below the pallet, and sinters the sintering raw materials by the combustion heat of the carbonaceous material contained in the sintering raw materials, A sintering machine comprising: a position measuring device for measuring an amount of shrinkage of the sintering bed after ignition; and a function for adjusting one or more of an amount of gas fuel supplied to an upper surface layer of the sintering bed and an amount of liquid fuel supplied to the upper surface layer of the sintering bed so that the amount of shrinkage of the sintering bed falls within a predetermined range.

8. A sintering machine comprising: a pallet that moves in a circular manner; a feeder that charges sintering raw materials onto the pallet to form a charging layer; an ignition furnace that ignites carbonaceous material on the surface of the charging layer; and a wind box that draws air from below the charging layer and is installed below the pallet, and sinters the sintering raw materials by the combustion heat of the carbonaceous material contained in the sintering raw materials, A sintering machine having a position measuring device for measuring a contraction rate of the sintering bed after ignition, and having a function of adjusting one or more of an amount of gas fuel supplied to an upper surface layer of the sintering bed and an amount of liquid fuel supplied to the upper surface layer of the sintering bed so that the contraction rate of the sintering bed is within a predetermined range.

9. The sintering machine according to claim 7 or claim 8, characterized in that the position measuring device has a function of measuring two or more locations in the width direction of the pallet and adjusting one or more of the amount of gas fuel supplied to the upper surface layer of the sintering bed and the amount of liquid fuel supplied to the upper surface layer of the sintering bed in the width direction of the pallet.

10. 10. The sintering machine according to claim 9, characterized in that the position measuring device measures at two or more locations in the direction of movement of the pallet.

11. The sintering machine according to claim 10, wherein the position measuring device measures the height position of the upper surface of the sintering bed.

12. The sintering machine according to claim 11, characterized in that the position measuring device measures without contacting the sintering bed.

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