WO2015099212A1 - Equipment for manufacturing sintered ore and method for manufacturing sintered ore using same - Google Patents

Abstract

The present invention relates to equipment for manufacturing sintered ore and a method for manufacturing sintered ore using the same. The equipment comprises: a plurality of sintering carts which are movable along a movement path and have raw material layers filled therein; an ignition furnace which is provided at one side of an upper portion of the movement path and injects flames to the raw material layers in the sintering carts; an ore discharge part which is provided at the other side of the movement path and discharges the sintered ore for which sintering has been completed; a wind box provided between the ignition furnace and the ore discharge part on the movement path; and a heat quantity controller which is provided between the ignition furnace and the ore discharge part at the upper portion of the movement path and supplies heat quantity and humidified air to the raw material layers, wherein the heat quantity in the raw material layer is uniformly controlled during the sintering process, thereby improving the quality of the sintered ore and productivity.

Description

Sintered ore manufacturing equipment and sintered ore manufacturing method using the same

The present invention relates to a sintered ore manufacturing equipment and a sintered ore manufacturing method using the same, and more particularly, to a sintered ore manufacturing equipment and a sintered ore production using the same to control the amount of heat in the raw material layer during the sintering process to improve the quality and productivity of the sintered ore It is about a method.

In the sintered ore manufacturing process, sintered fine iron ore is manufactured to a size suitable for blast furnace use. In this sintering process, ferrite ore, secondary raw materials and solid fuels (powder coke, anthracite coal) are put into a drum mixer, mixed and humidified (raw material weight ratio of about 7 to 8%), and the sintered raw materials are pseudo-grained to be fixed on the sintered truck. Sintered ore is manufactured when charging of a sintering raw material advances by charging at high height and forcibly sucking air from below after surface ignition by an ignition furnace. The manufactured sintered ore is cooled in a cooler through a crusher of the light distribution unit, classified into a particle size of 5 to 50 mm that is easy for charging and reaction in the blast furnace, and then transferred to the blast furnace.

1 shows a sintered ore manufacturing facility.

The upper light stored in the upper light hopper 10 and the sintered raw material stored in the surge hopper 20 are charged and transported in the sintered trolley, and the moving sintered trolley 50 passes under the ignition furnace 30. At this time, the flame (ie, flame) sprayed from the ignition furnace 30 is ignited on the upper surface of the sintered raw material accommodated in the sintered trolley 50, that is, the surface layer. The trolley passing through the ignition furnace 30 is transferred to the process progress direction by the transfer device 40, in which the sintered trolley 50 passes through the upper side of the plurality of wind boxes 70 arranged in the process progress direction. do. A suction force is generated in the sintered trolley 50 passing through the upper side of the wind box 70 in the downward direction, and the flame complexed by the sucked outside air is moved downward. When the sintering bogie 50 arrives at the wind box 70 located at the end point of the process, the flame reaches the bottom of the sinter bogie and the sintering is completed, and the operation described above for the plurality of sintering bogie 50 is continuous. Is done.

However, when manufacturing the sintered ore using such a facility, the distribution of calories is generated along the depth direction of the raw material layer. That is, in the upper layer of the raw material layer, the heat amount is insufficient due to the inflow of the outside air by the suction force of the wind box 70, and since the outside air is continuously supplied to the lower layer after the temperature is raised while passing through the combustion zone of the fuel layer, the heat amount is excessive in the lower layer. Phenomenon occurs. Therefore, after completion of the sintering process, the surface area increases in the upper layer, thereby reducing sintering ore of low strength, and in the lower layer, the raw material layer is solidified after melting. There is a problem.

In order to solve the problem of quality deviation of the sintered ore according to the height direction of the sintered bogie, oxygen, gaseous fuel, liquid fuel, etc. are supplied to the upper layer of the raw material layer during the sintering process, and the amount of solid fuel is reduced to reduce the amount of solid fuel in the lower layer. The method of uniformly controlling the amount of heat throughout and forming a uniform combustion zone inside a raw material layer is used. However, in the case of supplying liquid fuel, there is a risk of explosion, and in the case of reducing the amount of solid fuel, the combustion of the raw material layer is not performed properly at the upper part, so that the caloric shortage at the upper part is further intensified, and the caloric shortage at the middle part. There is a problem that causes. In addition, when oxygen or gaseous fuel is supplied to the upper layer of the raw material layer, a method of measuring the exact thickness, depth, etc. of the combustion zone in the raw material layer during the sintering step is not proposed. Accordingly, there is a problem in that the thickness and depth of the combustion zone formed in the raw material layer cannot be accurately controlled because oxygen or gaseous fuel supply regions are not established.

The present invention provides a sintered ore manufacturing equipment and a method for manufacturing a sintered ore using the same to suppress the caloric shortage of the raw material layer and the excessive amount of calories generated during the sintering operation to uniformly control the amount of heat throughout the raw material layer.

The present invention provides a sintered ore manufacturing equipment and a sintered ore manufacturing method using the same that can reduce the production cost by reducing the amount of solid fuel used.

The present invention provides a sintered ore manufacturing equipment and a sintered ore manufacturing method using the same that can improve the quality and productivity of the sintered ore.

Sintered ore manufacturing equipment according to the present invention, a plurality of sintered trolley which is movable along the movement path, the raw material layer is charged therein; An ignition furnace installed on one side of the upper portion of the movement path to inject a flame into the raw material layer in the sintered trolley; A light distribution unit installed at the other side of the movement path to discharge the sintered ore sintered to be completed; A wind box provided between the ignition furnace and the light distribution unit in the movement path; And a calorific controller provided between the ignition furnace and the light distribution unit at an upper portion of the movement path to supply calories and humidified air to the raw material layer.

The calorie regulator is provided with an oxygen supply device for supplying a gas containing oxygen to the raw material layer, a gaseous fuel supply device for supplying a gaseous fuel to the raw material layer, and the gaseous fuel supply is provided on one side of the oxygen supply device It is provided on one side of the device, it may include a humidified air supply supply device for supplying humidified air to the raw material layer.

The oxygen supply device includes an oxygen reservoir for storing oxygen, a first hood provided to surround an upper portion of the sintered bogie on an upper portion of the movement path, and having a hole formed in an upper surface thereof, and oxygen stored in the oxygen reservoir. It may include a first nozzle supplied into the first hood.

The gaseous fuel supply device includes a gaseous fuel reservoir for storing gaseous fuel, a second hood provided to surround an upper portion of the sintered bogie on an upper portion of the movement path, and having a hole formed in an upper surface thereof, and the gaseous fuel storage. It may include a second nozzle for supplying the oxygen stored in the inside of the second hood.

The second hood may be provided spaced apart from the first hood.

The oxygen supply device, the gaseous fuel supply device, and the humidifying air device may be sequentially provided along the moving direction of the sintering cart.

The gaseous fuel supply device is provided in an area within one third of a movement path between the light distribution units in the ignition furnace, and the oxygen supply device is 1/4 to 1/2 of an area in which the gaseous fuel supply device is provided. It may be provided in the area.

The second hood may be formed to separate a plurality of internal spaces of the second hood along the width direction of the sintered trolley, and a second nozzle may be connected to each of the separated spaces of the second hood.

The plurality of second hoods may be disposed along the moving direction of the sintered trolley, and the plurality of second hoods may be spaced apart from each other.

The length of the second hood may be 2 to 4 times longer than the distance between the second hoods.

The humidifying air supply device, a moisture reservoir for storing moisture, a third hood is provided to surround the upper portion of the sintered trolley on the upper portion of the movement path, the through hole is formed in the upper surface, and the moisture stored in the moisture reservoir It may include a third nozzle for supplying the inside of the third hood.

The humidifying air supply device may be provided at the rear of the light distribution unit with respect to the moving direction of the sintered trolley.

The sintered ore manufacturing method according to the present invention includes the steps of preparing a sintered raw material; Charging the sintered raw material into a moving sintered trolley to form a raw material layer; Igniting the raw material layer; Supplying heat to the raw material layer; Supplying humidified air to the sintered ore manufactured by sintering the sintered raw material and cooling it; And distributing the sintered ore.

In the process of preparing the sintered raw material, the content of the solid fuel contained in the sintered raw material may be 3.5 to 4.5 wt% based on the total weight of the sintered raw material.

The supplying of calories may include supplying a gas containing oxygen to the raw material layer, and supplying a gaseous fuel to the raw material layer supplying the gas containing oxygen.

The process of supplying oxygen may be performed after the process of igniting the raw material layer.

In the process of supplying the oxygen, the oxygen may be mixed with the outside air and supplied to the raw material layer at a concentration of 21 to 30%.

The step of supplying oxygen and the step of supplying the gaseous fuel may be performed by measuring the temperature of the exhaust gas generated while the sintered raw material is combusted and the oxygen concentration in the exhaust gas so as to be 2/3 high from the surface of the raw material layer. It can be performed in the section where the combustion proceeds.

The supplying of oxygen may be performed until the temperature of the combustion zone formed inside the raw material layer becomes the minimum combustion temperature of the gaseous fuel.

The gas fuel may be supplied to have a lower combustion limit at the temperature of the combustion zone.

In the process of supplying the gaseous fuel, the gaseous fuel and the outside air may be repeatedly supplied alternately.

In the process of supplying the gaseous fuel, the section for supplying the gaseous fuel may be longer than the section for supplying the outside air.

The gaseous fuel may be at least one of liquefied natural gas (LNG), coke oven gas, and blast furnace gas.

The process of supplying the humidified air may be until immediately after the sintered ore is distributed, after the combustion of the sintered raw material positioned at the bottom of the sintered cart is completed.

The sintered ore manufacturing equipment and the sintered ore manufacturing method using the same according to the present invention can suppress or prevent a caloric nonuniformity occurring in the depth direction of the raw material layer during the sintering operation. That is, the reduction of the strength of the sintered ore due to the heat shortage phenomenon occurring in the upper part of the raw material layer and the reduction of the reducing property of the sintered ore due to the excess calorie occurring in the lower part of the raw material layer are suppressed or prevented, thereby improving the quality of reducing or strength of the sintered ore. Of course, the productivity of sintered ore can be improved. Therefore, the process efficiency and productivity of the operation in which sintered ore is used, such as blast furnace operation, can be improved.

In addition, since the content of the solid fuel in the sintered raw material can be reduced, not only saving resources but also environmental pollution caused by exhaust gas can be suppressed.

1 is a view showing a sintered ore manufacturing equipment according to an embodiment of the present invention.

FIG. 2 is a view illustrating a main configuration of a sintering section in the sintered ore manufacturing facility shown in FIG. 1.

3 is a view schematically showing the structure of a calorific controller installed in the sintering section shown in FIG.

Figure 4 is a view showing the result of measuring the side temperature of the sintered bogie in a typical sintered ore manufacturing equipment.

5 is a graph showing the exhaust gas temperature, the oxygen concentration in the exhaust gas, and the internal temperature distribution of the sinter bogie in the sintering section of a typical sintering ore manufacturing facility.

6 is a graph showing the temperature change of the raw material layer in the sintered trolley in the sintering section of the sintered ore manufacturing equipment according to an embodiment of the present invention.

7 is a graph showing the side temperature change of the sintered trolley according to the oxygen concentration in the sintering section.

8 is a view showing the temperature distribution of the side of the sinter bogie according to the gaseous fuel supply in the sintering section.

9 is a graph showing the temperature change inside the raw material layer in the width direction of the sintering direction in the sintering section of a typical sintering ore manufacturing equipment.

10 is a graph showing the side temperature change of the sintered trolley according to the oxygen concentration in the sintering section of the sintered ore manufacturing equipment according to an embodiment of the present invention.

11 is a view showing the temperature change inside the raw material layer according to the gaseous fuel supply in the sintering section of the sintered ore manufacturing equipment according to an embodiment of the present invention.

12 is a flowchart sequentially showing a process of manufacturing a sintered ore by the sintered ore manufacturing method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention and to those skilled in the art. It is provided for complete information.

1 is a view showing a sintered ore manufacturing equipment according to an embodiment of the present invention, Figure 2 is a view showing the main configuration of the sintering section in the sintered ore manufacturing equipment shown in Figure 1, Figure 3 is a sintering section shown in FIG. Figure is a schematic view showing the structure of the gas fuel supply of the calorimeter installed in.

Referring to FIG. 1, the sintered ore manufacturing equipment is assembled after the upper light hopper 10 storing the upper light charged on the bottom of the sintered trolley and the coke used in the upper portion of the upper light and used as an iron ore raw material and a solid fuel. Surge hopper 20 to store the blended raw material, a plurality of sintered bogie 50, which is provided to accommodate the sintered raw material to move in one direction, the transfer device 40 for transferring a plurality of sintered bogie 50 in the process progress direction , Installed on the side of the surge hopper 20 above the conveying device 40, and installed on the ignition furnace 30 and the sintering bogie 50, which inject the flame to the surface layer of the sintered raw material in the sinter bogie. A plurality of wind boxes 70 for sucking the inside of the sintered trolley 50 are included. In addition, the sintered ore manufacturing equipment may include a calorific regulator 100 for controlling the amount of heat in the sintered raw material in the sintered trolley, that is, the raw material layer. And the sintered ore manufacturing equipment is provided in the wind box 70, the calorific regulator 100 using a detector for measuring the temperature of the exhaust gas and the oxygen concentration in the exhaust gas generated while the raw material layer is burned, and the results detected by the detector It includes a controller for controlling the operation of.

Here, the movement path of the sintered trolley 50 forms a closed loop so that the sintered trolley 50 rotates in an endless track manner, and in the upper side movement path, the sintered raw material inside the sintered trolley 50 is sintered. The lower side movement path is a return section for moving the empty sintered trolley 50 which distributes the sintered ore which completed sintering to the upper side movement path for a sintering process. At this time, the upper light hopper 10, the surge hopper 20, the ignition furnace 30 is provided above the upper side movement path, the wind box 70 is provided below the upper side movement path to The inside of the sintered trolley 50 which moves along is attracted. The sintered ore which has been sintered in the sintered trolley is distributed in the process of sintering trolley 50 moving from the upper side moving path to the lower side moving path, which is called the light distribution part 60, and the light distribution part 60 It is located on the opposite side of the ignition furnace 30 in the upper travel path.

In addition, the sintered raw material refers to the blended raw material provided from the upper light and the surge hopper 20 provided from the upper light hopper 10, and is referred to as a raw material layer after the sintered raw material is charged into the sintered bogie 50.

The upper light hopper 10 is provided on one side of the upper side movement path of the sintered trolley 50, and charges the upper light to prevent the flow of the sintered raw bar formed at the bottom of the sintered trolley 50. . The upper light means that the sintered ore having a particle size of about 8 to 15 mm is selected from the sintered ore.

The surge hopper 20 is provided in front of the upper light hopper 10, that is, in front of the movement path of the sintered bogie, and charges the sintered raw material for producing the sintered ore into the sintered bogie. The surge hopper 20 loads the sintered raw material evenly without particle size segregation in the width direction of the sintered trolley, and segregates and loads the particle size so that the particle size becomes smaller from the lower part to the upper side in the depth direction of the sintered bogie.

The ignition furnace 30 is provided in front of the surge hopper 20 so as to ignite the flame by supplying a flame to the surface layer of the raw material layer formed by charging the sintered raw material into the sinter bogie 50.

The wind box 70 sucks the inside of the sintered trolley 50 which is provided under the moving path of the sintered trolley, more specifically, the upper side of the moving path and moves along the upper side of the moving path. The wind box 70 may be provided between the ignition furnace 30 and the light distribution unit 60. The end of the wind box 70 is connected to the duct 80, the duct 80, a blower 84 is installed at the end of the duct 80 to form a negative pressure inside the wind box 70 to sinter the bogie 50 ) It can be sucked inside. In addition, the duct 80 is provided with a dust collector 82 in front of the blower 84, it is possible to filter the impurities in the exhaust gas sucked through the wind box 70 to discharge through the chimney (86). The wind box 70 sucks outside air to enable ignition of the sintered raw material surface layer and combustion of the sintered raw material, thereby producing sintered ore.

The calorific value controller 100 is located in front of the ignition furnace 30 with respect to the moving direction of the sintered trolley and is disposed in front of the oxygen supply device 110 and oxygen supply device 110 for supplying oxygen to the raw material layer. It is provided in front of the gaseous fuel supply device 120 and the gaseous fuel supply device 120 for supplying gaseous fuel to the sintered raw material in the sintered bogie, humidification air supply device 130 for supplying humidified air to the sintered raw material in the sintered bogie ). Here, the oxygen supply device 110 and the gas fuel supply device 120 are configured to control the heat amount of the upper layer of the raw material layer, and the humidifying air supply device 130 is configured to control the heat amount of the lower layer of the raw material layer. The oxygen supply device 110, the gaseous fuel supply device 120, and the gas air supply device 130 may be sequentially provided along the moving direction of the sintered bogie on the movement path of the sintered bogie.

The oxygen supply device 110 supplies oxygen to the raw material layer in front of the ignition furnace to maintain the complexed heat in the ignition furnace for a predetermined time to increase the temperature of the raw material layer. This facilitates the combustion of the gaseous fuel supplied from the gaseous fuel supply device 120.

The oxygen supply device 110 includes an oxygen reservoir 112 for storing oxygen, a first hood 114 provided to surround an upper portion of the sinter bogie at an upper portion of the movement path, and oxygen stored in the oxygen reservoir 112. It may include a first nozzle 116 for supplying the inside of the first hood (114).

The gaseous fuel supply device 120 supplies gaseous fuel to the raw material layer and supplies heat to a combustion zone formed inside the raw material layer. In this case, at least one of Liquified Natural Gas (hereinafter referred to as "LNG"), coke oven gas, and blast furnace gas may be used as the gaseous fuel. However, in consideration of calories, cost and safety, It is recommended to use LNG that generates high calories and does not emit CO gas.

 The gaseous fuel supply device 120 includes a gaseous fuel reservoir 122 for storing gaseous fuel, a second hood 124 provided to surround an upper portion of the sinter bogie on an upper portion of the movement path, and a gaseous fuel reservoir 122. A second nozzle 126 for supplying the gaseous fuel stored in the inside of the second hood 124 may be included. The gaseous fuel supply device 120 may be provided in a movement path between the light distribution units in the ignition furnace, that is, within an area of 1/3 of the sintering section. In other words, the gaseous fuel supply device 120 may be provided over an area corresponding to one third of the total length of the sinter bogie. In addition, the gaseous fuel supply device 120 may be formed over a region about 2 to 4 times wider than a region where the acid supply device 110 is formed in the sintering section. This is substantially because the gaseous fuel supply device 120 serves to provide heat in the material layer, and the oxygen supply device 110 is 1/4 to 1/2 of the area where the gaseous fuel supply device 120 is installed. It may be provided in the area.

A plurality of second hoods 124 may be disposed along the sintering section. In this case, the second hood 124 adjacent to the first hood 114 of the oxygen supply device 110 may be spaced apart from the first hood 114. This is to secure a time for the solid fuel in the sintered raw material to sufficiently burn due to the oxygen supply. In addition, the reason why the plurality of second hoods 124 are arranged to be spaced apart is to supply oxygen required when the gaseous fuel introduced into the raw material layer through the second hood 124 is combusted. That is, the gaseous fuel is supplied through the second hood 124 and outside air, that is, oxygen is supplied through the space between the second hood 124, so that the gaseous fuel is not burned and is exhausted by the suction force of the wind box. This phenomenon can be suppressed. In this case, the region in which the gaseous fuel is supplied (the length of the second hood 124) may be formed to be 2 to 4 times longer than the region in which the outside air is supplied (the length of the space between the second hood 124). Through such a configuration, the external air and the gaseous fuel can be repeatedly introduced into the raw material layer, thereby enabling the complete combustion of the gaseous fuel, thereby sufficiently securing the amount of heat required to burn the sintered raw material.

In addition, as illustrated in FIG. 3, the second hood 124 may have a partition 125 formed therein along the width direction of the sintered trolley. Accordingly, the inner space of the second hood 124 may be divided into a plurality of spaces along the width direction of the sintered trolley. In addition, the second nozzles 126 may be connected to the separated spaces of the second hood 124 to supply gas fuels having different flow rates for each region. As a result, temperature variations in the raw material layer generated along the width direction and the depth direction of the sintered trolley can be suppressed or prevented. This will be described later.

The humidifying air supply device 130 may be installed in a section in which the sintered ore is cooled until the sintered ore which is completed sintering is distributed to the light distribution unit. The humidifying air supply device 130 includes a moisture reservoir 132 for storing moisture, a third hood 134 provided to surround the upper portion of the sintered trolley at the upper portion of the movement path, and the moisture reservoir 132. It may include a third nozzle 136 for supplying moisture into the third hood 134.

Upper surfaces of the first hood 114, the second hood 124, and the third hood 134 may be formed of a porous plate in which the through hole 123 is formed, as shown in FIG. In the hood, oxygen, gaseous fuel and moisture supplied from each nozzle may be mixed and introduced into the raw material layer. 3 illustrates a case of the second hood, but a through hole may also be formed on the upper surfaces of the first hood and the third hood.

Through such a configuration, the sintering facility can uniformly form a heat distribution of the combustion zone formed in the raw material layer during the sintering process, thereby improving the quality and productivity of the sintered ore.

Hereinafter, a method of determining the installation positions of the calorific controller, that is, the oxygen supply device, the gaseous fuel supply device, and the humidified air supply device will be described.

4 is a view showing a result of measuring the side temperature of the sintered bogie in a typical sintered ore manufacturing equipment, Figure 5 is the exhaust gas temperature of the wind phase and the oxygen concentration in the exhaust gas and the internal temperature distribution of the sintered bogie in the sintering section of the typical sintered ore manufacturing equipment 6 is a graph showing a temperature change of the raw material layer in the sintered trolley in the sintering section of the sintered ore manufacturing equipment according to an embodiment of the present invention. Here, the raw material layer in the sintered trolley can be divided into upper, middle and lower layers, where the top layer is one-third down from the surface of the raw material layer, and the middle layer is up to 2/3, and the middle of the raw material layer. The bottom surface can be defined as the lower layer.

Referring to FIG. 4, when a surface layer of a raw material layer is ignited through an ignition furnace in a general sintered ore manufacturing facility, a high temperature is maintained at an upper layer portion of the raw material layer by the ignition heat of the ignition furnace in front of the sintering direction with respect to the sintering direction. However, there is a relatively low temperature transient region up to the section where the combustion of solid fuel occurs normally to maintain a high temperature. This transient region mainly occurs in the upper portion of the fuel layer and acts as a factor for degrading the quality of the sintered ore produced in the upper portion. As mentioned in the problems of the prior art, the upper layer portion of the raw material layer is easily cooled by the outside air introduced into the sintered trolley due to the suction force of the wind box, so that the amount of heat is insufficient in the upper layer portion of the raw material layer. Therefore, since the sintering raw material is not sintered properly, the sintered ore produced in the upper portion of the raw material layer has low strength and low productivity.

Referring to FIG. 5, it can be seen that the exhaust gas temperature change in the wind box and the temperature change inside the sinter bogie in the sintering section in the conventional sintering equipment. Here, the temperature change inside the sinter bogie was derived based on the change in the exhaust gas temperature in the wind box and the change in the oxygen concentration contained in the exhaust gas.

First, the exhaust gas temperature curve (hereinafter referred to as WTC: Waste gas temperature curve) is measured by measuring the temperature of the exhaust gas and the oxygen concentration in the exhaust gas in the sintering section using a detector installed in the wind box, that is, a temperature measuring instrument and an oxygen concentration measuring instrument. Deduce the oxygen concentration curve.

Since the combustion of solid fuel takes place until the combustion zone reaches the bottom of the sinter bogie after ignition in the ignition furnace, oxygen is exhausted and the oxygen concentration in the exhaust gas is kept constant. Then, when combustion is completed to the bottom of the sinter bogie, the oxygen concentration in the exhaust gas is rapidly increased to be equal to the oxygen concentration in the outside air introduced by the suction force of the wind box.

In addition, the temperature of the exhaust gas is measured at a low temperature of 100 ° C. or lower since the combustion zone supplies heat to the drying and wetting of the wet zone below the combustion zone until the combustion zone reaches the bottom of the sinter bogie after ignition. After the combustion is completed to the bottom of the sinter bogie, after the combustion, the sensible heat is moved downward by the suction force of the wind box, and the temperature of the exhaust gas is also rapidly increased, and the temperature is maintained by the inflow of outside air in the cooling section immediately before the light distribution unit. It will descend again.

As described above, since the temperature of the exhaust gas and the oxygen concentration in the exhaust gas change and have a predetermined pattern in the sintering section, the temperature distribution inside the sintered trolley can be predicted using this characteristic.

That is, the point where combustion is completed from the ignition furnace to the bottom of the sinter bogie after burning (Burn Contact Poin, hereinafter referred to as "BCP") corresponds to the point where the oxygen concentration in the exhaust gas and the temperature of the exhaust gas start to rise sharply. do. The point where the combustion of the raw material layer is physically completed after the BCP (Burn Infection Point, hereinafter referred to as "BIP") is a point where the oxygen concentration in the exhaust gas is the same as the oxygen concentration in the outside air to be sucked, and the temperature of the exhaust gas is changed. Corresponds to the inflection point on the curve (WTC). After the combustion of the raw material layer is completed, after the BIP, the exhaust gas temperature increases due to the sensible heat after combustion, and the point where the exhaust gas temperature reaches the highest point (Burn Through Point, hereinafter referred to as "BTP") appears. The BTP position is a section for cooling the sintered ore by outside air from the BTP to the light distribution unit by controlling the speed of the sintered cart so as to be formed just before the light distribution unit.

The temperature of the inside of the sintered trolley can be predicted using the temperature change and the oxygen concentration change of the exhaust gas thus measured to define the range of the combustion zone to a certain temperature, for example, 1200 ° C. or more. That is, in the fuel layer inside the sintered trolley, the line where the combustion of coke, which is a solid fuel, starts after ignition (Frame Front Line, hereinafter referred to as "FFL"), and the line where the combustion of the coke, which is a solid fuel, is completed and starts to cool ( Frame Back Line (hereinafter referred to as "FBL") may be used to define a combustion zone in which coke, a solid fuel, is combusted to produce a sintered ore.

FFL corresponds to a straight line connected from the starting point P1 of the raw material layer to the position P2 of the BCP. FBL corresponds to a straight line connected to the height of h0 of the red light in the sintered cake cross section at the BIP and the light distribution unit at the starting point of ignition P1. A combustion zone is formed over the region between the upper side of the FFL and the lower side of the FBL, in which a sintering reaction occurs in which ore in the sintered raw material is melted and coagulated by combustion of coke. As shown in FIG. 5, the combustion zone moves downward along the advancing direction of the sintered trolley, and it can be seen that its width is expanded.

Referring to FIG. 5, when the height of the raw material layer (from the bottom of the sintered bogie to the surface layer of the raw material layer) in the sintered bogie is H, the quality and productivity of the sintered ore are well burned in the middle layer having a depth of 2 / 3H to 1 / 3H. Based on the width of the stage, it can be seen that the upper portion having a depth of H to 2 / 3H has a relatively narrow width of the combustion zone, and the lower portion having a depth of 1 / 3H to 0H has a relatively large width of the combustion zone. This is due to the direct inflow of outside air at room temperature, the amount of heat required for the formation of sintered ore is insufficient, heat is continuously introduced from the upper layer and the middle layer, the excess heat occurs, the upper layer and the lower layer of the raw material layer The quality and productivity of the sintered ore produced are reduced. In general, when the sintered ore is manufactured, the combustion zone formed inside the raw material layer must be maintained for about 150 seconds to obtain a high quality sintered ore, and this position corresponds to a position of about 2 / 3H from the surface of the raw material layer.

Therefore, the embodiment of the present invention is characterized in that the amount of heat inside the raw material layer is controlled so that the combustion zone formed inside the raw material layer can maintain about 150 seconds in the entire sintering period. Therefore, the heating time of the combustion zone is increased by providing heat to the upper layer of the raw material layer in which the transient area is generated, and the maintenance time of the combustion table can be controlled uniformly throughout the sintering period by shortening the holding time of the combustion table in the lower layer of the raw material layer. have. Provision of heat to the upper portion of the raw material layer may be performed by supplying oxygen and gaseous fuel to the raw material layer. In addition, when the combustion is completed to the lower portion of the sintered trolley, by supplying humidified air to the inside of the sintered trolley, it is possible to shorten the duration of excess heat of the lower layer by promoting cooling of the produced sintered ore. That is, oxygen and gaseous fuel are supplied to the raw material layer at the initial stage of sintering in which the combustion of the upper part is performed so that the combustion of the raw material layer is sufficiently performed in the upper part. In addition, in the section in which the sintered ore is cooled after the sintering is completed, supplying humidified air to the sintered ore to reduce the amount of heat can suppress the excess amount of heat in the lower layer portion.

In the present invention, as shown in FIG. 6, the combustion zone is enlarged in the section in which the combustion zone is formed in the upper layer of the raw material layer so as to uniformly form the holding time of the combustion zone over the entire sintering section, and the combustion zone is formed in the lower layer of the raw material layer. In the formed section, by reducing the combustion zone, it is possible to uniformly control the holding time of the combustion zone throughout the sintering section.

In the section where the combustion zone is formed in the upper layer of the raw material layer, oxygen and gaseous fuel is supplied to enlarge the combustion zone. In the section where the combustion zone is formed in the lower layer of the raw material layer, humidifying air is supplied to cool the sintered ore in the red state. Reduce it. At this time, the combustion zone can be uniformly formed throughout the sintering period by changing the FBL corresponding to the line where the combustion of the coke, which is the solid fuel, is completed and starts to cool.

Here, the section extending the combustion zone is a high temperature section between FFL and FBL, that is, a section of 1200 ° C or more, from the surface layer (H) of the short raw material layer to 2 / 3H, that is, at the point (E2) at which the combustion of the central part begins. Corresponding. This position is called the Heat Interchange Point (hereinafter referred to as "HIP"), and is a position where the combustion zone is increased by the supply of calories, and the combustion zone begins to decrease by the reduction of the solid fuel. In other words, HIP corresponds to the point that can supply the most appropriate amount of heat to manufacture the sintered ore in the sintered trolley.

 In the section in which the combustion zone is formed in the upper portion of the raw material layer, the combustion zone can be expanded by supplying oxygen and gaseous fuel to supply heat to the upper portion of the raw material to delay the point at which the combustion of the solid fuel coke is completed and cooled. At this time, since there is a risk of ignition of the gaseous fuel due to the flame in the ignition furnace, it is preferable to perform the time of supplying oxygen at a portion spaced from the ignition furnace by a predetermined distance.

When the surface layer of the raw material layer is ignited, oxygen is then supplied to the raw material layer inside the sintered trolley, and then gaseous fuel is supplied to the raw material layer. The reason for supplying the gaseous fuel after supplying the oxygen is to supply the oxygen to the ignited raw material layer to facilitate the combustion of the solid fuel contained in the raw material layer, thereby facilitating the combustion of the supplied gas fuel. That is, the gaseous fuel is supplied to the raw material layer in a state diluted to the outside air and the lower limit of the combustion limit. At this time, if the gaseous fuel is not heated up to the minimum temperature required for combustion, the gaseous fuel may be exhausted to the unburned state by the suction force of the wind box. Therefore, the process of raising the temperature inside the raw material layer to the minimum temperature at which gaseous fuel can be burned by supplying oxygen to the raw material layer to promote and delay combustion of the solid raw material. Oxygen may be supplied to the point E1 at which the fuel layer becomes the minimum temperature (lowest combustion temperature) at which the gaseous fuel can be combusted, and then the gaseous fuel may be supplied to supply heat to the upper layer of the raw material layer.

In FIG. 6, when the fuel layer connects the HIP and the point E1 at which the minimum temperature at which the gaseous fuel can be burned is formed, an ideal cooling start line (hereinafter referred to as “IFBL”) may be formed. Comparing the combustion zone formed by the existing FBL and IFBL according to the present invention, the region S1 formed on the upper side of the HIP in the region formed by the FBL and IFBL means a portion to which heat is supplied, and the lower portion of the HIP is supplied. The region S2 formed in the region means a portion where the amount of heat is reduced.

When heat is supplied to the upper layer of the raw material layer, an excessive amount of calories may occur in the middle layer of the raw material layer during the sintering process, and a problem of further exacerbation of the caloric excess in the lower layer may occur. Therefore, it is preferable to reduce the amount of heat by reducing the content of solid raw material, that is, coke, in the sintered raw material charged into the sintered trolley. At this time, the amount of the solid raw material to be reduced is preferably similar or equal to the amount of heat supplied to the upper layer portion of the raw material layer. When the content of the solid raw material in the raw material layer is reduced, the heat amount is reduced from the above-described HIP.

Derived the WTC line through the temperature measurement result of the exhaust gas to determine the position of BCP, BIP and BTP, and measure the h0, the height of the red zone of the sintered ore in the sinter bogie at the light distribution unit, and supply the gas fuel section and the humidification air supply section. Can be derived through Equations 1 to 4. Equation 1 is an equation for deriving the temperature curve (WTC) of the exhaust gas, Equation 2 is an equation for deriving the FFL in the raw material layer, Equation 3 is an equation for deriving the FBL in the raw material layer, 4 is an equation for deriving IFBL in the raw material layer.

Equation 1

Equation 2

Equation 3

Equation 4

In Equations 1 to 4, P, n, S, and C are operation fluctuation indexes determined by the sintering machine structure and operating conditions, and the exhaust gas temperature distribution (T (x)) along the longitudinal direction (x) of the sintering machine. Constant that can be formulated as P has a value of 15000 to 1800 as a BTP temperature determination coefficient, n has a value of 3.5 to 5 as a BIP positioning coefficient, S has a value of 38 to 45 as a BIP positioning coefficient, and C is 1 It means the exhaust gas temperature (degreeC) of a wind box.

When the installation position of the oxygen supply device 110, the gaseous fuel supply device 120 and the humidifying air supply device 130 is determined by the method as described above, the oxygen supply device 110, gaseous fuel supply device on the sintered trolley 120 and a gas air supply device are respectively installed and sintering operation is performed while supplying oxygen, gaseous fuel, and humidified air according to the process conditions.

Hereinafter, look at the effect obtained by adjusting the amount of heat in the raw material layer during the sintering operation.

7 is a graph showing the change in the side temperature of the sinter bogie according to the oxygen concentration in the sintering section, Figure 8 is a view showing the temperature distribution of the side of the sinter bogie according to the gas fuel supply in the sintering section, Figure 9 is a typical sintered ore manufacturing equipment Is a graph showing the temperature change inside the raw material layer in the width direction of the sintering direction in the sintering section of, Figure 10 is a side temperature change of the sintering bogie according to the oxygen concentration in the sintering section of the sintering ore manufacturing equipment according to an embodiment of the present invention 11 is a graph showing a change in temperature of a raw material layer according to a gaseous fuel supply in a sintering section of a sintered ore manufacturing facility according to an embodiment of the present invention.

First, in FIG. 7, in order to confirm the effect obtained by supplying oxygen to the raw material layer during the sintering process, only the outside air is sucked in a general sintering facility, and when oxygen is supplied to the raw material layer according to the embodiment of the present invention, The results of measuring flue zone temperature are shown. At this time, since about 21% of oxygen is contained in the outside air, that is, the atmosphere, the oxygen concentration of the outside air is described as 21%. And when the oxygen concentration was increased to 30%, the combustion zone temperature change in the raw material layer was measured.

According to FIG. 7, it can be seen that the maximum temperature is 1200 ° C. or less when only the outside air is sucked, but the temperature of the combustion zone in the raw material layer is increased to 1200 ° C. or more when the oxygen concentration is increased to 30%. In addition, it can be also seen that the point of time when the temperature of the combustion zone rises also rises faster than when only the outside air is sucked up. When oxygen is supplied to the raw material layer during the sintering process, the combustion of the solid fuel in the sintered raw material is accelerated, and it can be seen that the temperature of the combustion zone can be elevated to a high temperature, that is, a temperature at which the sintered ore is smoothly manufactured. Therefore, during the sintering process, oxygen may be supplied to the upper layer portion having a low temperature and low temperature of the combustion zone, in particular, immediately after the ignition furnace to enlarge the combustion zone, thereby smoothly burning the gas fuel supplied thereafter.

Next, in order to examine the effect obtained by supplying gaseous fuel, the sintering process was performed by simply sucking outside air, and the sintering process was performed while supplying gaseous fuel. The results of measuring the temperature change are shown in FIGS. 8 to 11.

FIG. 8 shows the lateral temperature distribution of the sintered trolley, and FIGS. 9A and 9B show the temperature distribution of the raw material layer in the sintering direction in the width directions 1/2 and 1/4 of the sintered trolley.

Referring to FIG. 8, the temperature between the surface layer at which combustion starts by ignition before the gas fuel injection and the middle layer portion where normal combustion occurs is measured at a low temperature in a transient state.

9 (a) and 9 (b), the temperature of the raw material layer measured at the center portion of the widthwise half point of the sintered trolley and the side portion of the widthwise quarter of the sintered trolley is measured at the same position. Temperature measurement of the depth of 150 mm and 200 mm from the surface layer of the layer shows that the temperature of the side portion is low, and particularly, the position at which the peak reaches at the depth of 150 mm is also formed at the rear end. That is, it can be seen that the internal temperature of the sintered trolley is severely varied in the width direction and the advancing direction of the sintered trolley. The temperature variation in the width direction of the sintered trolley is because the suction force of the wind box is different from each other at the center and the side of the sintered trolley. Does not adversely affect the combustion of solid fuel.

On the other hand, as shown in FIG. 10, when the gaseous fuel is supplied, the temperature of the side surface of the sintered trolley is increased compared to that of FIG. 8 after the surface layer is ignited in the ignition furnace. In addition, it can be confirmed that the temperature of the surface layer of the raw material layer complexed in the ignition furnace is also expanded in the advancing direction of the sintered trolley and the lower direction of the sintered trolley.

FIG. 11 shows the temperature distribution of the upper layer of the raw material layer according to the flow rate of the gaseous fuel, FIG. 11A shows a case where a high flow rate of gaseous fuel is supplied, and FIG. 11B shows a low flow rate gaseous fuel. The case of supply is shown.

Comparing FIG. 8 and FIG. 11, it can be seen that when gaseous fuel is supplied, the time for maintaining a high temperature region of 1200 ° C. or more is increased. In addition, comparing (a) and (b) of Figure 11, as the flow rate of the gas fuel supplied increases the time to maintain a high temperature region of more than 1200 ℃, it can be seen that the upper layer temperature of the raw material layer is continuously maintained have.

Through this, the quality and productivity of the sintered ore produced in the upper layer may be improved by expanding the area of the combustion zone where the sintering reaction is normally performed in the upper layer of the raw material layer by supplying the gaseous fuel. In addition, the temperature variation of the raw material layer generated in the advancing direction and the downward direction of the sintered trolley can be reduced by adjusting the flow rate of the gaseous fuel. Therefore, by supplying oxygen and gaseous fuel during the sintering process, heat can be provided to the upper layer of the initial sintering raw material layer to smoothly sinter the sintered raw material from the upper layer, and by adjusting the flow rate of the gas fuel supplied in the width direction of the sintering bogie. The temperature variation of the raw material layer occurring in the width direction of the trolley can be controlled.

In addition, although not shown in the drawings, a phenomenon in which the quality of the sintered ore deteriorates due to excess calories can be suppressed by accelerating cooling of the sintered ore by supplying humidified air to the sintered ore before the sintered ore is distributed through the light distribution unit.

Hereinafter, a sintered ore manufacturing method according to an embodiment of the present invention will be described.

12 is a flowchart sequentially showing a process of manufacturing a sintered ore by the sintered ore manufacturing method according to an embodiment of the present invention.

Sintered ore manufacturing method according to an embodiment of the present invention, the step of preparing a raw material layer (S110), the step of loading the sintered raw material into the sintered trolley (S112) and the process of igniting the surface layer of the raw material layer (S114), supplying oxygen to the raw material layer (S116), supplying gaseous fuel to the raw material layer (S118), and when the sintered bogie moves along the sintering section to produce a sintered ore, humidified air is supplied to the sintered ore. It includes the step of supplying (S120) and the step of distributing the sintered ore (S122).

The upper light is prepared and supplied to the upper light hopper 10, the sintered raw material including iron ore and the solid raw material is prepared and supplied to the surge hopper 20 to prepare a raw material for manufacturing the sintered ore. At this time, the content of the solid raw material when preparing the sintered raw material can be reduced by about 50 to 60% by weight compared to the content of the existing solid raw material. In general, when the content of the solid raw material is about 9% by weight of the total weight of the sintered raw material, it can be reduced to occupy about 3.5 to 4.5% by weight, thereby increasing the content of iron ore. As such, by reducing the content of the solid raw material, it is possible to suppress the excessive amount of heat in the middle and lower portions of the raw material layer, which may be caused by supplying oxygen and gaseous fuel to the raw material layer during the sintering process. In addition, by reducing the emission of pollutants such as carbon monoxide, it is possible to reduce the occurrence of environmental pollution.

Thereafter, the plurality of sintered trolleys 50 is sequentially passed below the upper light hopper 10 and the surge hopper 20 to charge the upper light and the sintered raw material to each of the plurality of sintered trolleys 50 to form a raw material layer. Each of the plurality of sintered trolleys 50 passes through the lower side of the ignition furnace 30 in order to ignite the flame on the surface layer of the raw material layer, and each sintered trolley 50 is moved toward the light distribution part 60 by the transfer device 40. In this case, each of the sintered trolleys 50 passes sequentially through the upper side of the plurality of wind boxes 70 arranged in the sintering section.

When the flame is complexed to the surface layer of the raw material layer, oxygen is supplied to the raw material layer through the oxygen supply device 110. At this time, the oxygen is preferably controlled to have a concentration of about 21 to 30% by mixing with the outside air in the first hood 114 of the oxygen supply device 110, if the oxygen concentration is lower than the suggested range the desired raw material layer It cannot be raised to temperature, and even if the oxygen concentration is higher than the range presented, there is a limit to raising the temperature of the raw material layer. When oxygen is supplied to the raw material layer, the flame of the surface layer moves to the lower side of the sintered trolley 50 by the suction force of the wind box 70 to burn the solid fuel in the raw material layer. As a result, the temperature inside the raw material layer is raised to the lowest combustion temperature of the gaseous fuel which is subsequently supplied.

After that, the oxygen supply to the raw material layer is stopped and gaseous fuel is supplied. At this time, the gaseous fuel is not supplied after the interruption of the oxygen supply, it is good to ensure a time that the solid fuel can be sufficiently combusted by the oxygen supply. In addition, the gaseous fuel is supplied with a high concentration of gaseous fuel to the second hood 124 through the second nozzle 126 and mixed with the outside air introduced into the through hole 123 formed on the upper surface of the second hood 124. It may be supplied to the raw material layer in a diluted state below the lower combustion limit of about 3%. Accordingly, the gaseous fuel may be moved into the raw material layer by the suction force of the wind box to reach a combustion zone formed in the raw material layer and then burned.

The gas fuel may be intermittently supplied through the second hood 124 spaced apart from each other in the sintering section. Since the gaseous fuel and the outside air can be repeatedly supplied, it is possible to suppress the oxygen shortage that may occur due to the combustion of the solid fuel together with the combustion of the gaseous fuel to prevent the gaseous fuel from being discharged through the wind box without being burned. Can be.

In addition, by adjusting the flow rate of the gaseous fuel in each space through the second hood 124 space-divided in the width direction of the sintered trolley at the time of gas fuel supply, it is possible to suppress the temperature variation occurring in the width direction of the sintered trolley.

Next, the supply of gaseous fuel is stopped and the raw material layer inside the sintered bogie 50 is sintered while the sintered bogie 50 is transferred to the light distribution unit 60 to manufacture the sintered ore.

When the sintered ore is manufactured, humidified air is supplied to the sintered ore through the humidifying air supply device 130 immediately before the light distribution unit 60 to cool the sintered ore. At this time, since the lower layer of the sintered ore continues to be in a red state, the sintered ore of the lower layer may be over sintered, thereby supplying humidified air to promote cooling of the sintered ore in the red state.

The supply of the humidified air may be performed from the bottom of the sinter bogie until after the combustion of the solid raw material is completed, just before the light distribution unit.

Although the invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the invention is not limited thereto, but is defined by the claims that follow. Accordingly, one of ordinary skill in the art may variously modify and modify the present invention without departing from the spirit of the following claims.

The sintered ore manufacturing equipment and the sintered ore manufacturing method using the same according to the embodiment of the present invention can improve the quality and productivity of the sintered ore by uniformly controlling the amount of heat in the raw material layer during the sintering process, and thus an operation such as blast furnace Can improve the process efficiency and productivity of the operation.

Claims (24)

A plurality of sintered trolleys which are movable along a movement path and in which a raw material layer is charged; An ignition furnace installed on one side of the upper portion of the movement path to inject a flame into the raw material layer in the sintered trolley; A light distribution unit installed at the other side of the movement path to discharge the sintered ore sintered to be completed; A wind box provided between the ignition furnace and the light distribution unit in the movement path; And A calorific controller provided between the ignition furnace and the light distribution unit at an upper portion of the movement path, and supplying calories and humidified air to the raw material layer; Sintered ore manufacturing equipment comprising a. The method according to claim 1, The calorie controller, An oxygen supply device for supplying a gas containing oxygen to the raw material layer; A gaseous fuel supply device provided at one side of the oxygen supply device and supplying a gaseous fuel to the raw material layer; Sintered ore manufacturing equipment provided on one side of the gas fuel supply device, comprising a humidified air supply supply device for supplying humidified air to the raw material layer. The method according to claim 2, The oxygen supply device, An oxygen reservoir to store oxygen, A first hood provided at an upper portion of the movement path to surround an upper portion of the sintered trolley and having a through hole formed at an upper surface thereof; And a first nozzle for supplying oxygen stored in the oxygen reservoir into the first hood. The method according to claim 3, The gaseous fuel supply device, A gaseous fuel reservoir for storing gaseous fuel, A second hood provided on an upper portion of the movement path to surround an upper portion of the sintered trolley and having a through hole formed in an upper surface thereof; And a second nozzle for supplying oxygen stored in the gaseous fuel reservoir into the second hood. The method according to claim 4, The second hood is a sintered ore manufacturing equipment is provided spaced apart from the first hood. The method according to claim 4 or 5, The oxygen supply device, the gaseous fuel supply device and the humidifying air device is sequentially provided along the moving direction of the sintered bogie. The method according to claim 6, The gaseous fuel supply device is provided in an area within one third of a movement path between the light distribution units in the ignition furnace, and the oxygen supply device is 1/4 to 1/2 of an area in which the gaseous fuel supply device is provided. Sintered ore manufacturing equipment provided in the area. The method according to claim 4, The second hood is formed to separate a plurality of internal spaces of the second hood along the width direction of the sintered trolley, Sintered ore manufacturing equipment that the second nozzle is connected to each of the separated space of the second hood. The method according to claim 8, A plurality of the second hood is disposed along the moving direction of the sintered cart, The sintered ore manufacturing equipment provided with the plurality of second hoods are spaced apart from each other. The method according to claim 9, And a length of the second hood is 2 to 4 times longer than a distance between the second hoods. The method according to claim 2, The humidifying air supply device, A water reservoir for storing moisture, A third hood provided at an upper portion of the movement path to surround an upper portion of the sintered trolley and having a through hole formed at an upper surface thereof; Sintered ore manufacturing equipment comprising a third nozzle for supplying the water stored in the moisture reservoir into the third hood. The method according to claim 11, The humidification air supply device is a sintered ore manufacturing equipment provided in the rear of the light distribution portion with respect to the moving direction of the sintered trolley. Preparing a sintered raw material; Charging the sintered raw material into a moving sintered trolley to form a raw material layer; Igniting the raw material layer; Supplying heat to the raw material layer; Supplying humidified air to the sintered ore manufactured by sintering the sintered raw material and cooling it; And Sintering ore manufacturing method comprising; distributing the sintered ore. The method according to claim 13, In the process of preparing the sintered raw material, The content of the solid fuel contained in the sintered raw material is 3.5 to 4.5% by weight relative to the total weight of the sintered raw material manufacturing method. The method according to claim 13, The process of supplying the calories, Supplying a gas containing oxygen to the raw material layer; Sintered ore manufacturing method comprising the step of supplying a gaseous fuel to the raw material layer supplied with the gas containing oxygen. The method according to claim 15, The process of supplying oxygen, Sintered ore manufacturing method performed after the process of igniting the raw material layer. The method according to claim 16, In the process of supplying the oxygen, The oxygen is mixed with the outside air and the sintered ore manufacturing method for supplying to the raw material layer in a concentration of 21 to 30%. The method according to claim 17, The process of supplying the oxygen and the process of supplying the gaseous fuel, And measuring the temperature of the exhaust gas generated while the sintered raw material is burned and the oxygen concentration in the exhaust gas, and performing the combustion in a section where the combustion progresses to a height of 2/3 from the surface of the raw material layer. The method according to claim 18, And supplying the oxygen until the temperature of a combustion zone formed inside the raw material layer reaches a minimum combustion temperature of the gaseous fuel. The method according to claim 19, The step of supplying the gaseous fuel is a method of manufacturing a sintered ore to supply so that the lower limit of combustion at the temperature of the combustion zone. The method of claim 20, The step of supplying the gaseous fuel is a method of producing a sintered ore that is repeatedly supplied to the gaseous fuel and the outside air alternately. The method according to claim 21, And a section for supplying the gaseous fuel in the process of supplying the gaseous fuel longer than a section for supplying the outside air. The method according to any one of claims 13 to 22, And the gaseous fuel is at least one of liquefied natural gas (LNG), coke oven gas, and blast furnace gas. The method according to claim 23, The step of supplying the humidified air is a sintered ore manufacturing method until after the combustion of the sintered raw material located at the bottom of the sintered trolley is completed just before the light distribution of the sintered ore.

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