WO2007052776A1 - Process for producing sintered ore and sintering machine - Google Patents

Abstract

This invention provides a process for producing a sintered ore by feeding various gas fuels from the upper part of a charge layer of a sintering material deposited on a pallet in a sintering machine. In the process for producing a sintered ore, a gas fuel diluted to a lean flammability limit concentration or less is used as the gas fuel fed from the upper part of the charge layer on the pallet, and, in feeding the gas fuel for sintering, at least one of the feed position, charge layer highest attainable temperature, or holding time in a high temperature range is regulated to produce a sintered ore. There is also provided a sintering machine characterized by comprising a gas fuel feed apparatus.

Description

 Specification

^^ and sickle

 The present invention relates to a method for producing ore for a blast furnace raw material using a downward suction type dwythroid (DL), and to tfeM. Background leakage

 Coal ore, which is a material for the blast furnace dredging method, is generally manufactured through the processes shown in Fig. 1. The raw materials are meteorite powder, recovered powder in $! ^ F, shale powder, Cao raw materials such as limestone and dolomite, ¾M such as quicklime, coke and coal. CaO-containing raw materials such as limestone and dolomite are hereinafter referred to as “CaO-based auxiliary materials”. These raw materials are cut out from each hopper 1 ··· at a predetermined rate on the competitor. The cut out raw material is mixed while adding an appropriate amount of water using a drum mixer 2 or the like, and subsequently, a sintered raw material which is a fine particle having an average diameter of 3.0 to 6. O mm is formed. The formed sintered raw material is woven with a rotary kiln 3. The dried thigh raw material is ¾λ from the surge hoppers 4 and 5 arranged on the top to the endless movable let 8 via the drum feeder 6 and the cutting chute 7, and both the bed and the dressing λϋ 9 force S formed. The thickness (height) of the device λϋ is around 400 mm to 800 mm. After that, the carbon material in ¾ ^ 01 is ignited by furnace 10 installed above ¾Λ9. By sucking downward through the wind box 11 located under the pallet 8, the carbonaceous material in ¾Λϋ burns sequentially, and the fuel generated at this time is Burning, leakage, and cake release occur. Thereafter, the obtained cake is crushed and collected as a product composed of a product of 5. O mm or more;

に必要となる «をしている部分もまた、 通気^ tが高くなる。 In the notification process, first, the surface of the charging layer is ignited by the ignition furnace 10. Carbon material in ¾Λ¾ is burned by the action of suction gas drawn from the top of this device Λ to the lower layer. As you do. As the pallet 8 moves, the flocculation gradually advances to the lower layer. At the same time as the combustion progresses, the moisture of the raw material particles in the Λϋ is generated by the combustion of the carbonaceous material. Although it evaporates due to heat, it is absorbed by the bottom of the bow, and still rises and concentrates in the raw material in the wet layer of the lower layer. Since moisture fills the gaps between the raw material particles that are the gas flow paths, the ventilation resistance increases.

The parts that are required for «also have high ventilation.

The production of sintered ore (t Zh r) is generally determined by the sintering production rate (t Zh r · m ² ) X sintering machine area (m ² ). That is, the amount of dredging is the width of the machine, the thickness of the raw material

Λϋthickness), bulk density of raw materials, i mm) time, yield and other factors. This; ^ increasing the amount of ore can be achieved by improving the yield by improving the cold bow of the cake; It is considered a helper.

 Figure 2 is a graph showing the distribution of pressure loss in ¾Λϋ. The ^^ distribution curve in Fig. 2 shows when the combustion (^ flame) front moving in the Λϋ is at a position of about 40 O mm on the pallet in the thickness direction of the Λϋ. The pressure loss distribution at this time is about 60% in the wet zone and about 40% in the combustion melting zone.

Figure 3 shows the ^ ^ distribution within ¾Λϋ of the ore at high and low times. The raw material particles start to melt at a high temperature range above 1 2 0 0 ° C. The time is shown for low production: ^ and for high production where productivity is important, t ₂ . It is necessary to increase the Paretsu bets speed髙production, shorter high temperature zone holding time t ₂ is Te high temperature zone holding time ti and the ratio base at low production. Since the time spent at high temperature is shortened, dredging will be insufficient, leading to a 3 degree cold drop in the ore, resulting in a decrease in yield. Therefore, in order to improve the production of high ores, it is considered effective to maintain and improve the yield by raising the bow of the cake, that is, the ore, cold by any method. In addition, SI (shutter index) and TI (tumbler index) are used for mining cold bow daughters.

Fig. 4 (a) shows the principle of ¾Λϋ on the lett, Fig. 4 (b) shows the distribution (heat pattern) in the Λ 装: about t ^ i, and Fig. 4 (c) shows the step of the cake. Showing the residue distribution Yes. As can be seen from Fig. 4 (b), the upper part of the charging layer ('^ ¾ layer) is less likely to rise in temperature than the lower layer, and the holding time in the high temperature range is shortened. For this reason, the upper part of ^ λϋ has insufficient combustion solution (a reaction), and as shown in Fig. 4 (c): ^ The strength of the cake is lowered, so the yield does not increase and the properties tend to decrease. become.

 Conventionally, a method for imparting high temperature retention to the upper portion of the device Λϋ has been proposed.

 Japanese Patent Application Laid-Open No. Sho 4 8-1 8 10 0 2 discloses blowing a high-concentration combustible gas immediately after the ignition furnace. When the combustible gas was blown, the amount of charcoal material was not reduced, so the temperature inside the layer exceeded 1380 ° C, and it did not enjoy the effects of sufficiently improving cold strength and increasing yield. . In addition, injecting flammable gas immediately after the furnace for 0 to 2 minutes is a technology that has high risk of igniting the flammable gas and causing a large fire, which is not realistic, and has been put into practical use. Naughty.

 In addition, Japanese Patent Laid-Open No. Sho 5 5-1 8 5 8 5 discloses that in order to increase the temperature inside the charging layer of the sintering raw material, a hood is installed on the charging layer. It discloses that a mixed gas with air-cooked furnace gas is blown through the hood at a position immediately after the ignition furnace. The temperature inside the sintered layer becomes higher than 1350 ° C, and the effect of blowing cannot be enjoyed, and the combustible gas mixture is ignited and there is a danger of disaster, so it has been put to practical use. Absent.

 Further, Japanese Patent Laid-Open No. 5-3 1 1 2 5 7 discloses a method in which reversal and charcoal or combustible gas are simultaneously blown at a position immediately after the starting furnace. This method also blows flammable gas with a flame on the surface, so there is a high risk of a large fire, and at the same time the width of the sintered zone becomes sufficiently thick. (About 15 mm or less), I can not fully demonstrate the effect. In addition, because it suffers a lot of low-turn, it causes an iU-like phlegm phenomenon in the ϋ area, closing the pores that are air flow paths. This technique has not been put to practical use until now, because it reduces the productivity by reducing the air permeability.

As described above, none of the conventional technologies proposed so far has been put into practical use, and the search for the blowing conditions that are economically satisfied was eagerly awaited. What is important in ore quality control is the maximum reached during combustion and the retention time in the high temperature range. It is important to determine the quality of baking. In this regard, the method described in Japanese Patent Application Laid-Open No. Sho 4 8-1 8 1 0 2 is a technique for raising the upper part of the first half of the process by burning gaseous fuel on the surface of ^ ^ . However, in this method, the concentration of gaseous fuel is high, so the amount of air (oxygen) that supports combustion is insufficient, and there is a risk of reducing the combustion of the raw carbonaceous material (coke). There is a problem that cannot be completed. In addition, the method described in Japanese Patent Application Laid-Open No. Sho 55-18505 is a method for obtaining a higher temperature by providing a hood and supplying a combustible gas together with a combustion air. However, this method also causes a shortage of heat. In other words, this method also has the problem that the time required for coke combustion slows down because the coke burning in the high temperature zone is consumed by the inflammable gas. is there.

 Furthermore, the method described in Japanese Patent Application Laid-Open No. 5-3 1 1 2 5 7 increases the amount of air (oxygen) and mixes dots and carbonaceous materials. Although the degree of combustion increases, there is a problem that the breathability of the combustion air decreases because the book is blown together. Disclosure of the invention

 The object of the present invention is to produce a high-strength sintered ore at a high yield without impairing the overall air permeability of ^ λ ^, and to carry out this method. It is to make the baking that is used for sadonage.

 In order to achieve the above object, the present invention provides a method for ^^ ore having the following steps.

 Cycle it ^ Pow the powdered ore and charcoal raw material on the moving pallet ^ AIL to form the charcoal ¾ ^ mud λϋ on the pallet

 Point A In the furnace, point A to the carbonaceous material on the surface of ^ λϋ;

Air is sucked through the wind box placed under the pallet, burning the charcoal in ¾λ ^, and generating the cake with the heat of combustion generated. Supply gas fuel below the lower combustion limit concentration from above ¾Λ 、, and burn the llE gas fuel in ^ Λϋ. The self-burning gas combustion process is below the lower combustion limit concentration. Supplied gas fuel from above ¾AS, burns self-assembled gas fuel in ¾Λϋ, and reaches maximum impact in λϋ or high temperature region in ¾Λ (^ time or highest in ¾Λϋ It is preferable that it takes a long time to reach it¾.

 The adjustment of the maximum temperature reached in the t jffiSA layer is preferably carried out in the following manner.

 (A) Supply the gaseous fuel below the lower combustion limit concentration from the top of ¾Λ 最高 and make the maximum arrival a¾ in the device Λϋ.

 (B) The gas fuel diluted below the lower combustion limit concentration is supplied from above ΛΛϋ, and the maximum amount within 焼 結 λϋ is achieved by adjusting the amount of carbonaceous material in the sintered raw material.

 (C) Supply the gaseous fuel below the lower combustion limit concentration from the upper side of ^ Λϋ, adjust the supply amount of the gaseous fuel, and achieve the maximum result.

 (D) A gas fuel having a concentration lower than the lower combustion limit concentration is supplied from above ΛΛ and the amount of carbon in the raw material and the amount of gaseous fuel supplied are tilted to 1).

 In the above (A) to (E), it is desirable to set the lEft high honey ¾t to 1 2 0 5 ~: I 3 5 0 ° 〇. 'It is preferable to adjust the high temperature region holding time in the Λ ^ Λ layer in the following manner.

 (a) Supply gaseous fuel below the lower combustion limit concentration from above ^ Λ ^ and adjust the high temperature region retention time in the ¾Λ layer.

(b) Supply gaseous fuel below the lower combustion limit concentration from above ¾Λϋ, «Adjust the concentration of the gaseous fuel according to the amount of carbon in the raw material, and keep the high temperature region holding time in the charging layer adjust. Further, it is preferable that the self-gas fuel combustion step is to adjust the form of the fuel / eave band with the following sickle. (A) Supply gaseous fuel below the lower combustion limit concentration from above, and adjust the shape of the combustion zone.

 (Ii) Supply gaseous fuel below the lower combustion limit concentration from above Λϋ and adjust the cold bow of the ore ore by extending the high temperature holding time of the combustion zone.

 (C) Combustion of gas fuel, which is employed below the lower limit of combustion, at least partly in the state of combustion, in 供給 ίίΚ¾Λ.Supply from above ^ λ 燃 焼 to ijj and burn. Adjust the form. It is more preferable to obtain the thickness in the height direction of the combustion / melting zone and / or the width in the pallet moving direction. Furthermore, it is preferable that the combustion process be performed in the following manner with respect to the supply position of the gaseous fuel.

 (a) Supply the gaseous fuel below the lower combustion limit concentration from above ΛΛ, burn the gaseous fuel in ^ AS, and determine the supply position of the braided gaseous fuel to ^ λϋ.

 (b) Point Gas fuel that has been reduced to below the lower combustion limit concentration at the position after the furnace is supplied from above ^ λ 、, and SiJfS gaseous fuel is burned in ¾Λϋ.

 (c) Combustion · «; In the region where the thickness of the strip is 15 mm or more, supply the gaseous fuel below the lower limit of fuel coagulation ^ ¾ and burn the ladies' gas fuel at ^ λ ^ 內.

 (d) After the position where the combustion front has reached 1 O O mm below the surface layer, supply the gaseous fuel that is below the lower limit of fuel coagulation, and burn the SiJlB gas fuel within ¾Λϋ. It is more preferable to supply gaseous fuel having a concentration below the lower limit of combustion after the position where the combustion front reaches 200 mm below the surface layer.

 (e) Supply gaseous fuel diluted below the lower combustion limit concentration to both sides of the charging layer on both sides of the charging layer, and burn the self-gas fuel in ¾Λϋ.

 (f) Gas fuel below the lower limit of combustion concentration is supplied in the length direction and supplied from above ¾λϋ. .

The tilt self-gas fuel is preferably a combustible gas diluted to a concentration below 75% of the lower combustion limit and above 2%. More preferred is a combustible gas with a concentration lower than the combustion lower limit of 60% or lower and 2% or higher, and still more preferable is a lower combustion limit concentration of 25% or lower and It is a flammable gas with a concentration of 2% or more.

 Desirable gas fuel is preferably at least one gas selected from blast furnace gas, coke oven gas, blast furnace coke oven mixed gas, propane gas, and a group consisting of natural gas and methane gas. ,. Furthermore, the present invention provides a circulating pallet, a suction windbox disposed below the tB ^ ° let, a raw material for supplying the raw material on the pallet, and a carbonaceous material in the raw material. In a sintering machine equipped with an ignition furnace for igniting, a gas fuel diluted to a concentration equal to or lower than the lower combustion limit concentration from above the charging device AJ1 is injected into the charging layer on the “flow side” of the ignition furnace. Gas burning power ¾ Thoroughly implement a machine that is difficult to lay by itself.

 It is preferable that at least one of the self-fired flame retardant devices is arranged in the machine direction on the downstream side of the ignition furnace.

 It is more preferable that the tillE gas combustion is placed in the position from the stage where the combustion front advances below the surface layer until the completion of the combustion.

In addition, it is desirable that a selfish gas fire retardant is installed near the side warno.

Brief Description of Drawings

 Figure 1 is an illustration of the sintering process.

 Fig. 2 shows the pressure loss and temperature distribution in the sintered layer.

 Figure 3 is a graph of the ^^ distribution at high and low ^ M times.

 Figure 4 is a graph of temperature distribution and yield distribution in the sintering.

 FIG. 5 is an illustration of a gaseous fuel injection process according to the present invention.

 Fig. 6 shows the ¾ | ^ result of the method of the present invention and shows the transition of the internal combustion leakage zone (photo):

 Figure 7 is a comparison graph for the sintering pot test.

 FIG. 8 is a diagram for explaining a method for calculating the combustion limit of gaseous fuel.

 FIG. 9 is an explanatory diagram showing the temperature dependence of combustion.

 FIG. 10 is a diagram showing the influence of the gas type when the gaseous fuel is introduced.

 Figure 11 shows the relationship between blowing gas, shutter bow daughter, yield, ^^ time, and production.

 Figure 12 is a schematic diagram of the sintering reaction.

 Figure 13 is a schematic graph of the ^^ process of skeletal secondary hematite.

 Figure 14 is an observation (photo) of the combustion limit when dilute propane is injected.

 Figure 15 shows the effect of the blowing position.

 Figure 16 shows the effect of the blowing position.

 Fig. 17 is an explanatory diagram of the lamellar temperature distribution during sintering.

 Figure 18 is an explanatory diagram of the results of verifying the effect of the Bfe position.

 FIG. 19 is a graph of changes over time in ¾λ (a), exhaust gas (b), passing air volume (c), and exhaust gas composition (d) during propane blowing.

 Fig. 20 is a graph of changes over time in ¾λϋ (a), (a '), exhaust gas (b), and (b') when ^ propane was injected and when only coke was increased.

 Figure 21 is a graph showing the characteristics! ^ Fruit under various blowing conditions.

Figure 22 is a comparative graph showing changes in the mineral composition ratio under various blowing conditions. Figure 23 is a graph showing the change in apparent specific gravity of the product ore.

 Fig. 24 is a pore size distribution graph of 0.5 mm or less in the product sintered ore.

 Fig. 25 is a schematic diagram of the male behavior of the coke only {^ (a) and Φ¾¾2 ^ · h (b).

 Figure 26 is a schematic diagram of the pore structure when diluting gas is injected.

 Figure 27 is a graph of the ^ 1¾ ^ ¾ result of the limit cox ratio that can maintain the cold strength. FIG. 28 is a diagram (photograph) showing the results of Example 1.

 FIG. 29 is a diagram (photograph) showing the results of Example 2. FIG. Reference numerals in FIGS. 1 to 29 described above are shown below.

 1 raw material hopper, 2 drum mixer, 3 bite tally kiln

4, 5 surge hopper, 6 drum feeder, 7 cut chute

 8 pallets, 9 ^ ΛΜ, 10 points, black furnace, 1 1 window box

 1 2 Gas combustion; Mode for carrying out the invention

 The male ore manufacturing method according to the present invention includes a charging process, an ignition process, a 'serious process and a gaseous fuel combustion process. The 廳 ^ Λ process consists of forming Λ raw materials containing stones and charcoal on a circulating pallet and forming Λϋ containing charcoal on the pallet.廳 Self-fire process consists of igniting carbon material on the surface of ¾Λϋ in a point furnace. The filling process consists of sucking air through the wind box placed under the pallet, burning the carbonaceous material in ^ Λϋ, and generating the female cake with the generated heat of combustion. ΙΕIn the gas fuel conversion process, gas fuel below the lower limit of combustion is supplied from above ^ Λϋ and the self-fuel is burned in ^ λϋ. This gas combustion process is one of the present inventions.

ffl In the gaseous fuel combustion process, it is preferable to use a combustible gas diluted to 75% or less, which is less than the lower combustion limit concentration at room temperature in the atmosphere, as iHE gaseous fuel. As a Silia gas fuel, more preferably, a combustible gas that has been reduced to 60% or less, More preferably, the combustible gas is reduced to 25% or less. There are two reasons why it is preferable to use a combustible gas diluted to 75% or less below the lower combustion limit i ^.

 (a) Ιίί Supply of gaseous fuel to the upper part of ^ AJl may cause explosive combustion, so at least at room temperature, it should not burn even if there is a fire.

 (b); Even if it reaches the A * unit on the downstream side of the burner without coming to complete burning at the top (in the middle of the Λ), it is ¾m below the mm mm unit. In a state where there is no risk of burning at all, that is, under the condition below the lower combustion limit concentration.

 As will be explained later, the concentration of this gaseous fuel does not cause the shortage of air (^) necessary for the coagulation of the total carbonaceous material (solid fuel + gaseous fuel) in the crane material, so that there is no shortage of combustion. In addition, it is necessary to use the ones described in «. The gaseous fuel is preferably a combustible gas diluted to a concentration of 2% or more of the lower combustion limit concentration. If the concentration is 2% or more, the strength and yield of sintered ore will be improved. Further, the concentration of the gaseous fuel is difficult depending on the amount of carbon material (solid fuel). Further, as will be described later, the gaseous fuel can be burned at a predetermined region position in ^ λϋ by performing this operation. In the method for producing the ore according to the present invention, the gas fuel that has been applied to the carbonaceous material in the ^ λϋ is supplied to the ^ Λϋ. Even if gas fuel is supplied at a position immediately after the point, combustion only occurs on the ¾ϋ and does not affect the ¾ layer. After the raw material is fired to form a sintered cake layer, the diluted gaseous fuel is

It is preferable to feed to Λϋ. The supplied gaseous fuel can be supplied at an arbitrary position as long as the cake layer is formed. The reason why the supplied gaseous fuel is supplied after the cake layer is formed is as follows.

 (a) If the cake is still in the upper part of ¾λϋ and this gaseous fuel is supplied in the state, there is a risk of explosive coagulation on ¾1.

(b) For gas fuel supply, ¾ "^ is the part that needs to improve the yield. It ’s the best! ^ Or under conditions where the thickness of the melt zone is at least 15 mm or more, preferably 20 mm or more, more preferably 30 mm or more in order to increase the lasing force in the high temperature range Therefore, it is preferable to supply gas fuel. 1 If less than 5 mm, cooling with the atmosphere (mixed body of atmospheric and gaseous fuel) sucked through ^ m cake) does not increase the thickness of the combustion zone even if gaseous fuel is supplied. Supply effect is insufficient. lSelf-fuel deer · When the thickness of the belt is 15 mm or more, preferably 20 mm or more, more preferably 30 mm or more · The thickness of the belt is greatly expanded, and the time and temperature are increased.

 In addition, the thickness of mm. The thickness of the band can be adjusted, for example, by using a transparent quartz window with a tubular ^! ¾, which helps to determine the gas fuel supply position. .

.下層部、 すなわち、 燃焼前線が ¾ϋから 1 0 0 mm移動した段階 （来燃焼のままそこの領域に到達 するように） で始めて燃焼するように、 «気体燃料を供給する。 その理由は、 1 0 0 m m以上下がった位置であれば、 焼結層を通して吸引される大気による冷却に伴う影響が軽 減され、 燃凝 · 帯の厚み拡大を伴うからである。 より好ましくは 2 0 0 mm以上であ れば、 大気による冷却に伴う影響は解消されて燃鹿 ·賺帯の厚みは 3 0 mm以上に拡大 される。 また、 この供給は、 歩留り低下の著しいサイドウォーノ 傍の幅方向 （パレット 進行方向に直 る方向） 両端部で行うこと力 り好ましい。 In addition, the gaseous fuel tiiIS is lowered below the pre-combustion force ¾ layer, and supplied at a position where the fuel * soot zone is 10 O mm or more, preferably 200 mm or more lower than the surface layer. In other words, it is preferable to provide a gas fuel with the middle / lower layer region as ¾ ^.

Gaseous fuel is supplied so that combustion starts only in the lower layer, that is, when the combustion front moves 100 mm from ¾ km (so that it reaches the region there as it is). The reason is that if the position is lowered by 100 mm or more, the influence due to the cooling by the atmosphere sucked through the sintered layer is reduced, and the thickness of the fuel cohesive zone is increased. More preferably, if the thickness is 200 mm or more, the influence due to the cooling by the atmosphere is eliminated, and the thickness of the fuel degassed belt is expanded to 30 mm or more. In addition, it is preferable that this supply be performed at both ends in the width direction (direction to return to the pallet traveling direction) near the side warn where the yield reduction is remarkable.

Gas fire! ^^ ¾ is different depending on the scale of; for example, gas flame retardance 1, 0 0 0-5, 0 0 O m ³ (standard) Zh, about 150,000 t / day Capability of a machine size of 9 Om, and the ability to place it about 5 m downstream of the point furnace.

In the manufacturing method according to the present invention, the supply position of ttltB «gaseous fuel is in the movement direction of the pallet, on the furnace exit side; after the male cake is formed, the slow combustion front advances below the surface layer. (For example, gas fuel combustion occurs at a depth of 100 mm or more below the surface layer, preferably about 200 mm or less below the surface layer. It is preferable to perform at one or more arbitrary positions until ^ is completed. In other words, this means that the gas fuel supply starts when the combustion front moves below the surface of ^ Λ ^ as ± ^ ^. Since it occurs inside λϋ and then gradually moves to the lower layer, it means that there is no risk of explosion and safe burning is possible.

 In the manufacturing method according to the present invention, the supply of gaseous fuel into the AS is ^^, which means that the cake is reheated. That is, the supply of the gaseous fuel originally has a short holding time in the high temperature region, so that the cold ¾ ^ of the ore is low and the ¾¾ cake is supplied with solid fuel in this part. This is because, by using ^ 1 "high-quality gaseous fuel, it has the significance of regenerating and expanding the combustion 'melting zone and compensating for the heat of combustion that tends to be insufficient.

 Also, according to the present invention, in the ore production method, at least a part of the tilted self-gas fuel supplied from the upper part of ¾λ after the point is sucked (introduced) to the combustion 'melting zone while remaining unburned. It is preferable to burn at the target position. It is considered that it is more effective to spread the gas fuel supply, that is, the effect of blowing into the charged layer not only to the upper part of ¾λϋ but also to the combustion / melting zone which is the central part in the thickness direction. Because. That is, if gaseous fuel is supplied to the upper part of the charging layer, which is prone to heat shortage (insufficient holding time in the high temperature range), it will lead to sufficient fuel consumption, and this part of the quality daughter) This is because it can be improved. And, when the gas combustion; ^ feeding action is spread to the zone below the middle layer, the result is equivalent to the original combustion · reburning · forming a transmining zone above and below this zone. This leads to a widening of the direction, and it is possible to extend the holding time of the high temperature range without increasing the maximum, so that sufficient ^ is achieved without reducing the pallet speed. As a result, the quality of the sintered cake of the whole Λ 装 (improvement of cold strength) is improved, and as a result, the quality of the product; ^ ore (cold bow girl) and productivity are improved.

In the present invention, the supply of the gaseous fuel has the first feature in that the supply position is determined from where the effect of the supply 'effect in the ¾Λ layer is affected. Along with the supply, the maximum ¾¾ and the high temperature range retention time in ^ Λ The second point is how to do it according to the amount of solid fuel below.

 Therefore, in the present invention, when supplying the gaseous fuel into the charging layer, not only the position of the supply but also the form of the fuel conversion 'adjustment zone itself and thus combustion' It is preferable to have a maximum time in the belt and / or high temperature.

 In general, ^ λϋ after ignition is a combustion flame with the movement of the pallet）. The front gradually expands downward and forward (downstream), and the position of the combustion zone is shown in Fig. 4 ( It changes as shown in a). As shown in Fig. 4 (b), the thermal males received in the layers are different in the upper layer, middle layer, and lower layer. As shown in the figure, in the upper layer to the lower layer, the high temperature region holding time (about 1 2 0 0 ° C or more) is very different. As a result, the sintered layer has a yield distribution as shown in Fig. 4 (c). That is, the yield of the surface layer portion (Ctl) is low, and the yield distribution is high in the middle and lower layers. Therefore, when IE gas fuel is supplied according to the method of the present invention, the combustion zone changes in a direction in which the thickness and range in the vertical direction increase, which is reflected in the improvement of the quality of the product sintered ore. It is. In the middle layer and the lower layer, which have a high yield distribution, the retention time in the high temperature region can be further adjusted, so that the yield can be further increased.

 By changing the supply position of the self-gas fuel, the shape of the combustion zone, that is, the thickness in the height direction of this zone and / or the width in the direction of movement of the pallet can be reduced, and the maximum pressure and high temperature range { It will lead to time traps. These adjustments further enhance the effect of the present invention, and by always increasing the vertical thickness width of the combustion / melting zone and adjusting the maximum temperature and holding time of the high temperature range, the product is always sufficiently fired, and the product ^ ¾ Contributes effectively to improving the cold strength of ores.

In the present invention, it can also be said that the supply of the selfish gaseous fuel into ¾λϋ is to increase the cold strength of the entire product sintered ore. In this regard, the purpose of blowing this gaseous fuel was originally to improve the cake, and thus; ¾¾ ore's cold bow daughter, in particular, adjusting the gas fuel supply position, burning difficult materials. By adjusting the holding time in the high temperature range, such as the time to ^ ¾, and adjusting the maximum temperature, the cold strength (shutter index SI) of the sintered ore is 75% to 85% ¾¾, preferably 80% or more, More preferably 90% or more. This level is determined by taking into consideration the amount of charcoal in the raw material (especially under the condition that the input heat amount is constant). It is possible to cheat at a low cost by cheating on the above. On the other hand, the improvement of the mining cold bower may lead to an increase in air venting and a decrease in productivity. However, in the present invention, such problems are best solved ^ and high temperatures ^ ) 'Improve the cold bow daughter of the ore. In addition, the above-mentioned cold bow daughter SI value of ^ ore produced by shows an SI value that is 10% to 15% higher than the pot pot value.

In the manufacturing method of this invention, the adjustment of the supply position of the braided gas fuel in the direction of movement of the pallet can be done in any zone between the cake and the wet zone in the ^ Λϋ: ^ ore cold bow. Let's say what to do with the daughter. For this purpose, in the present invention, the scale (size), number, position (from the furnace), gas concentration of the gas fuel supply device, preferably the gas content in the raw material (solid fuel) Therefore, not only the size of the combustion zone (width in the vertical direction and pallet movement direction), but also high S¾ii¾, high temperature range time, and thus, in ¾λϋ Yes Adjust the bow of the cake. In the above method of the present invention, as the gaseous fuel, it is preferable to use any of blast furnace gas, coke oven gas, blast furnace-coke mixed gas, propane gas, natural gas, methane, or a mixed gas thereof. . Each of these contains a fuel component, which is used as a gaseous fuel having a concentration lower than the combustion lower limit concentration of 75 or less by using air or the like. Note that the gas fuel may be formed by a combination of an inert gas other than air, an inert gas and an inert gas and air, and air. Also, in carrying out the method of producing ore according to the present invention, a suction windbox is arranged under a pallet that circulates on the raw material charging layer, and the raw material is placed on the pallet. In the downward suction type DU ^ ¾ equipped with a point furnace at the downstream side of the pallet traveling direction of this device, the concentration below the lower combustion limit concentration is set on the downstream side of the ΐΕίΐΕ point furnace from above ¾Λϋ. In the present invention, a braided gas fuel burner is used, which is provided with a gas burning device for blowing gaseous fuel into the charging layer. Both pallets It is preferable to be disposed so as to straddle the sidewall. The gaseous fuel supply device is a blowing hood that supplies diluted gaseous fuel, or a gas fuel that is formed by arranging slits or blowing nozzles in a plate shape in the blowing hood. Gaseous fuel supply ^: It is preferable that it is composed of pipes.

Note that one or more lilt self-gas burners are installed at one of the positions in the pallet travel direction during the course of the downstream force combustion zone of the furnace traveling in the λϋ range. It is preferable that the supply of the ftjf gas fuel to the inside is performed at a position after ignition of the carbonaceous material in the charging layer. That is, this device is arranged at one or more positions downstream of the ignition furnace, at any position after the combustion front has traveled below the surface layer. The size, position, and number are entered from the 亂. In addition, this gas flame retardant is to be installed near the side of the side waron ^ 5. »A self-gas fuel is 75% or less of the lower combustion limit concentration and 2%. It is preferable to use a flammable gas having the above concentration, and further to use a flammable gas having a concentration of 60% or less of the lower limit of fuel coagulation and 2% or more. As described above, according to the present invention, as described above, in the operation of the downward suction type air compressor, it is possible to burn at the target position in the device λϋ by using the gas fuel that has been added from above the layer. By adjusting the gas fuel supply position, the maximum temperature reached during combustion, and the holding time in the high temperature range, the combustion strength tends to be insufficient and the cold strength of the sinter is increased. The degree of sinter strength can be increased not only at the upper part of the ¾Λ layer but also at any portion below the middle layer of the charging layer. However, in the present invention, the air permeability of the entire ¾Λϋ is not deteriorated, and particularly in the combustion · Ml band, for example, by adjusting the width in the vertical direction of this band, Since the strength of the cake removed at the location can be increased, it becomes possible for the ore as a whole to produce cold arch girl's high-grade product; And by using; ^ ¾ of the present invention, such ^^ can be performed stably. FIG. 5 shows an embodiment of a sintered ore production apparatus according to the present invention. The present invention is of this exemplary form It is not limited only to the state. Gas fuel supply device (hood) for injecting gaseous fuel such as mixed gas (M gas) of blast furnace gas and coke oven gas (hood) 12 forces Ignition furnace 10 pallet 1 on the upper side of ^ Λϋ which corresponds to the downstream side in the moving direction Only the base is arranged and laid. The gas fuel 12 is composed of a plurality of pipe-like gas blowing nozzles 12a arranged in a self-aligned manner in a leaking direction. The plurality of pipe-shaped gas injection nozzles 12 a are arranged so as to cover ^ Λϋ from above a sidewall (not shown) via the gas fuel separator 12. Μίΐ か ら gas supplied from the gas fuel storage 12 passes through the top of the layer from the top of the λϋ to the deep layer (lower shoulder) of the layer, down to the lower shoulder of the pallet 8 in the wind box 11 under the pallet 8 Suction is absorbed and sucked in. In addition, when the yield shown in Fig. 4 (c) is as low as 60% and the yield of the area is improved, a large amount of gaseous fuel can be supplied to the side of the pallet on both sides. It is preferable to arrange the self nozzle 12a.

 Examples of the gaseous fuel supplied from the gaseous fuel 12 are blast furnace gas (B gas), coke oven gas (C gas), and mixed gas of blast furnace gas and coke oven gas (M gas). ), Propane gas, natural gas (LNG), methane, or a mixture of these is used. These gaseous fuels may be supplied separately from the furnace 10 under a separate piping system. In addition, it is installed in the same pipe as the furnace fuel paste self-pipe, especially with the gas introduction pipe, and the concentration of the gaseous fuel is made to be below the lower limit of flammability. You may comprise so that it may be on an extension of a supply pipe (illustration ¾ "f).

 The following example 3 shows examples of gas concentrations of various gaseous fuels used in the present invention at the lower combustion limit concentration and the upper injection limit (75%, 60%, 25%).

 For example, in propane gas, the lower combustion limit concentration is 2.2 vol%, the upper limit of the blown gas concentration diluted to 75% is 1.7 V o 1%, and the upper limit of the blown gas concentration set to 60% is 1.3. The concentration of blown gas diluted to 1% and 25% is 0.4 V o 1%. The concentration at which this effect begins to appear, ie, the lower limit of the concentration of diluted blown gas, is 0.05%. Accordingly, the preferred range is as follows.

 Preferred range (1): 2. 2 v o l% to 0.05 vol l%

Preferred range (2): 1.7 vol% to 0.05 vol% Preferred range (3): 1.3 V o 1% to 0.05 V o 1% 'preferred, range (4): 0.4 vol l% to 0.05 vol%

 For C gas, the lower limit of combustion is 5.0 V o 1%, the upper limit of blown gas concentration diluted to 75% is 3.8 vol%, and the upper limit of blown gas concentration diluted to 60% is 3. The concentration of the blown gas diluted to 25% is 0.9 V o 1%. The concentration at which this effect begins to peak, that is, the lower limit of the concentration of diluted blown gas is 0.24 vol%. Therefore, the preferred range is as follows.

 Preferred range (1): 5. Ovo l% to 0.24 vo l%

 Preferred range (2): 3.8 vo l% to 0.24 vo l%

 Favorable, range (3): 3. Ov o l% ~ 0.24vo l%

 Preferred range (4): 0.9 vo l% to 0.24 vo l%

 For LNG, the lower limit of combustion is 4.8 V o 1%, and the upper limit of gas concentration is 75%, and the upper limit of gas concentration is 3.6 V ο 1%, the concentration of blown gas diluted to 60%. The upper limit is 2.9 V ο 1%, and the concentration of the injected gas at 25% is 0.9 vol%. The lower limit of the blown gas concentration is 0. l v o l%. Accordingly, the preferred range is as follows.

 Preferred range (1): 4. 8vo l% to 0. l v o l%

 Preferred range (2): 3.6 vo l% to 0. l vo l%

 Preferred range (3): 2.9 V ο 1% to 0 · 1 V ο 1%

 Preferred range (4): 0.9 V ο 1% to 0.1 V ο 1%

 In blast furnace gas, the lower limit of combustion is 40.0 V ο 1%, the upper limit of the concentration of blown gas diluted to 75% is 30.0 V ο 1%, and the upper limit of the concentration of blown gas diluted to 60% is 24 The concentration of the blown gas diluted to 0 ν ol% and 25% is 7.6 vol%. The lower concentration limit of diluted blown gas is 0.24 V ο 1%. Accordingly, the preferred range is as follows.

 Preferred, range (1): 40. 0 V ο 1% to 1.25 V ο 1%

 Preferred, range (2): 30. 0 V ο 1% to 1.25 V ο 1%

 Preferred range (3): 24. Ovo l% to l. 25v o l%

Preferred range (4): 7.6 v ol% to l. 25 v ol% Next, Table 2 shows the contents and amounts of hydrogen, CO, methane, ethane, and propane as C 3, LNG, and B gas. table 1

表 2

Table 2

In the following, according to the present invention «Mine! Explain the weaving that was the key to developing the law. This experiment is based on the actual situation shown in Fig. 6, that is, a sleeper tube (1 50 mm ψ X 40 OmmH) with a window made of transparent quartz, and the gas fuel to be used is a mixture of blast furnace gas and coke oven gas. Using the gas (M gas), the same as that of the applicant's company: factory ¾ raw material, that is, using the raw material shown in Table 3, the lower suction pressure 1 1. 8 Kpa-constant Example It is. Here, the concentration of the OVI gas burnt is an example in which the concentration was changed within the range of 0.5 vo 1% to 15 V o 1% by working with air. The lower limit concentration of M gas used in this experiment is 1 2 V o 1%. Table 3

この図 6はまた、 itsi明石英窓からビデ^ m察した »、 とくに燃焼前線の移動に伴 ぅ下献況を示している。 図 6からわかるように、 1^ ^内原料堆蘭中に、 燃焼下限濃 度 （1 2 V o 1 %) を超える 1 5 V o 1 %の Mガスを含む気体燃料を吹き込んだ場合、 気 体燃料は¾ ^1表面ですぐに燃焼を開始し、 ¾Λϋの下層にまでは届力

This figure 6 also shows the Bidet conjecture from itsi clear quartz window », especially with the movement of the combustion front. As can be seen from Fig. 6, when gaseous fuel containing 1 5 V o 1% M gas exceeding the lower limit of combustion (12 V o 1%) is blown into the 1 ^^ inner raw material lantern, Body fuel starts burning immediately on the ¾ ^ 1 surface and reaches the lower layer of ¾Λϋ

There were few. In contrast, in accordance with the present invention, when gaseous fuel diluted with air to 3 V o 1%, which is 75% or less of 1 2 V o 1%, which is the lower combustion limit concentration of selfish gaseous fuel, is used as a raw material. There was no longer any thighs on the surface of the sedimentary layer, and it went deep inside ^ Λϋ, that is, the combustion 'equivalent zone. As a result, in the atmosphere, the thickness of the combustion zone ■ · «also called« band ”was 7 O mm, whereas in this example the thickness of the combustion zone was 15 O mm, It was possible to expand more than twice. In other words, the expansion of the thickness of the combustion zone is nothing but an extension of the high temperature time.

In this experiment with! ^^, the lowering of the combustion zone (the reciprocal is the male time), which is the progression of the combustion front accompanying the movement of the pallet in the ^^ machine, The same as when coke is increased or hot air is blown Thus, the vertical thickness range of the combustion zone could be expanded. In this way, when appropriately diluted gaseous fuel is injected into the layer of sintered raw material, conventional solid fuel, liquid fuel, and «Shinnana flammable 'gas are used: It was found that the expansion effect of the fuel coagulation was remarkable, and the descent of the combustion front proceeded in the same way as the large ^^.

 Figures 7 (a) to (d) summarize the results of the above-mentioned experiment. According to this result, when appropriately diluted M gas was blown into the raw material charging layer according to the present invention, the yield was slightly improved although the time hardly changed (Fig. 7 (a) ) And „also increased (Fig. 7 (b)). The shutter bow daughter (SI), which is a cold tube am signifi- cantly affected by the blast furnace, is more than 10% (Fig. 7 (c)) has also been improved and reduced powder characteristics (RD

I) improved by 8% (Fig. 7 (d)).

In the present invention, the degree of dilution will be described below the force of using the gas used as the tine gas fuel to be supplied in Λ. Table 4 shows the lower and upper limits for blast furnace gas, coke oven gas and mixed gas (M gas), propane, methane, and natural gas. For example, if a gas with such a combustion limit does not burn in the ¾Λ layer and goes to the exhaust fan, there is a risk of burning in the middle of the power MS ^. Therefore, the inventors decided to use gas fuel with a concentration that does not pose the above danger, that is, a concentration below the lower limit of combustion as a result of the row, and to further increase the ^: 14, In addition, it was possible to use a gaseous fuel with a concentration of 75% or less of the above, but there was no problem in many experiments. For example, as shown in Table 4, the blast furnace gas power S flammability category has a combustion limit of 40 ν ο 1% (ie, it does not burn below 40 ν ο 1%) in the atmosphere, and Its upper combustion limit is 71 V ο 1%. If it exceeds 71 V ο 1%, the blast furnace gas concentration becomes too high. ^ Also means that it will not burn and become a condition. The following explanation is based on the drawings based on the grounds of these figures. Table 4

(vol%)

Figure 8 shows an example of the method used to determine the pre-fire limit of blast furnace gas. The ratio of combustible components (flammable gas) and other (inert: inert gas) contained in the blast furnace gas in the figure is determined by the combination of H ₂ , 0 _{2 and} CO and N ₂ And as follows.

(1) The ratio of (inner gas) Z (combustible gas) for the combination of “H ₂ and C0 ₂ ” is 3.5 / 20. 0 = 5.7.

Therefore, the horizontal axis indicating the ratio of (inert gas) / (combustible gas) in this combustion limit diagram, the partial burn limit where the H ₂ + C0 ₂ curve intersects the axis 5.7, was obtained. The lower limit is 32 V o 1% and the upper limit is 64 vo 1%. That is, the lower limit of the combustion limit of H ₂ + C0 ₂ is 32 V o 1%, and the upper limit is 64 V o 1%. '

(2) On the other hand, the ratio of (Inner gas) / (Flammable gas) in the combination of “CO and N ₂ ” which is the remaining amount of fuel: tj ^ is 53.5 / 23. 0 Since = 2.3, the lower limit: 44 vo 1% and the upper limit: 7 4 V o 1% are obtained from the point where the horizontal axis 2.3 and the curve of CO + N ₂ intersect. Therefore, the lower limit of the combustion limit in this case is 44 V o 1%, and the upper limit is 74 V o 1%.

 Further, the lower limit of combustion of blast furnace gas including both fuels can be obtained by the following equation. Lower combustion limit = 100 / (23. 5/32 + 76.5 / 44) = 40%

 In addition, the upper limit of combustion can be obtained by applying the above formulas (1) and (2). In this way, the lower combustion limit and upper combustion limit of blast furnace gas can be obtained.

In the present invention, another reason for focusing on the lower limit of combustion of gaseous fuel is as follows. Explained. FIG. 9 shows Γ 蕭 between the concentration and the temperature of the gaseous fuel at the normal temperature in the atmosphere. (Reference: Corona «Fashion Manual) Now, although the combustion limit is determined as ζϋ, the combustion limit has a dependency, and as an example, it is under normal temperature combustion! Even if it is approximately 40 V ο 1%, it changes from 26 to 27 V o 1% in the 2 0 0 ° C region, and f in the 1 0 0 0 ° C region. %, It is known that in the 1 2 0 0 ° C region, it will burn even if it is less than 1 vol%.

 From this, the concentration of the gaseous fuel supplied to ^ Λϋ contains fines 4) until it reaches the safety zone that is even lower than the lower limit of combustion at room temperature. As long as the concentration of is sufficient, the degree of freedom in setting up the fuel in the ¾Λϋ thickness distribution) will increase.

 In this way, the combustion of gaseous fuel has such dependency, for example, the fuel spreads as the ambient temperature becomes higher, and burns well in the temperature field near the combustion and melting zone of the furnace. However, it was also found that in a temperature field of about 200 ° C., such as in an electric machine on the downstream side of the machine, it does not burn as shown in the preferred embodiment of the present invention.

 By the way, the self-gas fuel supplied in ^ λϋ of J fiber raw material in the production of sintered ore is sucked by the wind box under the pallet and burns the solid fuel (powder coke) in the charging layer. Combustion formed by burning in the high temperature region of the cocoon belt. Therefore, the supply of gaseous fuel should be adjusted under the condition that ¾λ heat quantity to ^ Λϋ is constant, and adjusting the amount of knitted gas fuel; ) You will be able to In addition, degassing of gaseous fuel means adjusting the gas fuel coagulation to occur at the expected position (Ϊ ^ region) in ^ λϋ.

In this sense, under the conventional technology, the combustion zone in ΛΛϋ is a zone where only solid fuel (powder coke) burns, but in addition to the powder coke of the present invention, it is further a gaseous fuel. Can also be said to be a zone that burns together. Therefore, in the present invention, ig ^ l¾ ^ 4 of the gaseous fuel and other supply conditions are suitable for the TO with the assumption that there is a powdery cous as a part of the fuel. If changed, it will be possible to achieve the desired maximum holding time of ita¾ and / or high temperature range, and improve the bow of the cake ^ S. In the method of the present invention, yet another reason to use the improved gaseous fuel is: * Through the morphing of the cocoon belt; ^ To bow the bow of the cake; It is the role of this «gaseous fuel in doing the ¾ of how; and how long the cake is allowed to reach the high temperature zone (^ burning zone). It works because of power. In other words, the selfish gas fuel means: ^ The raw material has a long high temperature range, which is adjusted to increase to IE¾. Such adjustment is made so that the amount of combustion-supporting gas (air or oxygen) in the combustion atmosphere does not cause excess or deficiency in accordance with the amount of solid fuel in the raw material (powder coke 4). It means that the adjusted gaseous fuel is used. In this regard, in the conventional technology, the amount of combustible gas (oxygen) is insufficient because the amount of combustible gas is blown without adjusting the concentration of the combustible gas, regardless of the amount of solid fuel in the raw material. When the failure of the fuel is caused, the force \ conversely causes a partial overcombustion, resulting in a variation in strength. That is, according to the present invention, such a problem can be avoided by using the gaseous fuel after adjusting the dilution concentration.

 Next, we will show the effect of gaseous fuel supplied for each type of gaseous fuel. FIG. 10 shows the conditions and results of a comparative experiment between the conventional sintering method (without blowing gaseous fuel) and the sintering method of the present invention using gaseous fuel diluted below the lower combustion limit. The conventional method is an example of powdered coke 5 without dilution gas fuel injection. In the example of gas fuel injection according to the present invention, gas fuel equivalent to 0.8% of powder coke is injected. In order to keep the total heat constant, an example is shown in which the powder coke inlet is 4.2 mass%. Sickle gas burning; for example, even if there was a discrepancy, the shutter, product yield, and productivity were improved. In addition, in «Gaseous combustion; iSHiffl example, the reason for the improvement of the shutter and bow yield, product yield, etc. is thought to be due to the expansion of the coagulation zone shown as the combustion status. ^ I understand that the extended result is ¾ίΧ ^

Fig. 11 shows the effect of propane gas and C gas as gaseous fuel: ^ ^ Blowing gas concentration, «Gaseous fuel concentration, shutter), yield (b), time It shows the relationship between (c) and production rate (d). As can be seen in this figure, propane gas, which uses this as «gaseous fuel ^, sha '; Addition of 0. 0 5 vo 1% produces an effect, and the yield is almost the same. A clear effect is obtained from 0.1 V ο 1% for propane gas, preferably 0.2 V ο 1%, and 0.24 V ο 1% for C gas. It has an effect, more than 0.5 V ο 1% for girls or more, and 1. O vol% or more for a clear improvement effect. Therefore, with propane gas, it is at least 0.05 V o 1% or more, preferably 0.1 V o 1% or more, more preferably 0.2 v o 1% or more. On the other hand, in the case of C gas, at least 0.24 Vο 1% or more, preferably 0.5 Vο1% or more, more preferably 1.0 · 0 Vο1% or more, and the upper limit is 7 5% of the lower combustion limit concentration. % Or less. The effect of propane gas: ^, 0.4 V o 1% is almost the same, and the gas concentration at this time corresponds to 25% of the lower combustion limit concentration.

 Next, in accordance with the method of the present invention, it was produced by supplying a fillE gaseous fuel in consideration of the amount of carbon in the raw material; the cold ore reduction 14 (R D I) of ore will be described. "Mineral engineering"

According to (Naki, Ikuhisa Takeuchi, Ryohei Fujiki, 1 9 7 6, 1 75, Asakura Shoten), the schematic diagram of; can be summarized as shown in Figure 12. In addition, Table 5 shows the values of various mineral pullers (the values of coldness and reducibility shown in about ^ Sli. As is clear from Fig. 12, the melting temperature at 1 200 ° C is shown in Fig. 12. The liquid begins to form, and the ¾¾ ore structure produces the most highly arched cocoon ferrule and is relatively highly reducible. 0. Beyond C, cold bow daughter and reducibility will be the lowest, amorphous (calcium silicate) and reduced powder will be transformed into secondary tie. In order to improve the cold bower of the ore and improve the RDI, it is necessary to keep the calcium-ferrite "tir" and keep it stable.

Table 5

また、 上記刊行物 「鉱物工学」 の説明によると、 ； ¾鉱の還元粉化の起点となる二次へ マタイトの析出挙動については、 図 13に示すように説明している。 その説明によると、 鉱物合；*^の結果、 還元粉化の起点となる骸晶状二次へマタイトは、 Ma g. s s + L i q .域まで し冷却したのちに、析出するため、状態図上では、 （ 1 ) «でなく、 （ 2) 繊を介して; ^鉱を § ^することで、還元粉化性を抑制できるとしている。したがって、 低 RD 1；¾鉱と高¾^¾¾鉱を製造するには、 1200°C (カルシウム一フェライトの 固相線 と約 1380°C (転 の範囲内に、 如何にして長時間保持したヒート パターンを装入層内において実現するカゝが重要である。 従って、 添加する炭材量を気体燃 料の供給により^ Sする^ 最高到 ]§¾は 1200°C超え 1380°C未満とするもの であり、 1205〜： 1350°Cの範囲とすることが好ましいことがわかる。

According to the description of the above-mentioned publication “Mineral Engineering”, the precipitation behavior of secondary hematite, which is the starting point of reductive powdering of ¾ ore, is explained as shown in FIG. According to the explanation, as a result of the mineral combination; * ^, skeletal secondary hematite, which is the starting point of reduced powdering, precipitates after cooling to the Mag. Ss + L iq. In the figure, (1) not «, but (2) through the fiber; ^ § ^ ore is able to suppress the reduction powdering property. Thus, to produce low RD 1; ¾ or high ¾ ^ ¾¾ ore, 1200 ° C (calcium-ferrite solidus and about 1380 ° C (in the range of rolling, how long kept The key to realizing the heat pattern in the charging layer is important, so the amount of carbon to be added can be increased by supplying gaseous fuel ^ Supreme] §¾ is over 1200 ° C and below 1380 ° C. It is understood that it is preferable to set the temperature within the range of 1205 to: 1350 ° C.

Next, in order to know the relationship between the width of the fuel excavation zone and the feed gas, the inventors used a tube with a transparent quartz window; and propane gas, which was the exhaust gas of the cooler, from above the pan. ; ^ An experiment was conducted in which the raw material was blown into ¾Λϋ. The raw materials used in this experiment were the general ones used by the applicant company, and the suction pressure was 1200 mmH ₂ O—constant. In this experiment, the concentration of the blown propane gas was diluted to 0.5 v ol% and 2.5 v ol%. In terms of input calorific value, propane gas 5 v o 1% was blown in, and almost equivalent to powdered coke lma ss%.

Figure 14 is a photograph showing the observation results of the combustion zone when propane gas was injected in this experiment. The As shown in this figure, propane gas with a concentration of 2.5 V o 1% expands on the raw material ^ λϋ immediately after injection and gas fuel does not enter ¾λϋ. I got it. On the other hand, if the propane gas is diluted to 0.5 V ο 1% of the air, it will enter the ¾01 without burning at the top of the Λϋ, and ¾Λϋ 內And I burned it. As a result, the vertical width of the combustion zone under atmospheric conditions was 勺 70 mm, whereas when flr ^ propane gas was injected, the width of the coagulation zone (that is, the high temperature region holding time) Equivalent) The force has been expanded to more than double the force up to 150mm.

 Therefore, it was found that the effect of increasing the thickness of the combustion zone was exhibited even at a concentration of 0.5 V o 1%, which is the concentration of 1Z5 at the lower limit concentration of propane of 2.5 V o 1% (theoretical value, anti-air). Conversely, it has also been found that the gas fuel injection technique according to the present invention is difficult to achieve within ¾λ unless it is a gas fuel.

 Furthermore, in this soot, we also examined the descending of the soot (this reciprocal is the holding time in the high temperature range), but as a result, we simply increased the amount of coke. However, the power is much faster compared to the solid fuel example, using the gas fuel, but the drop in the combustion zone is a force with almost no difference in the atmosphere. ^

 Next, the inventors investigated the influence of the injection position of diluted gaseous fuel / ^

Table 6 shows the starvation of this experiment.纖 No. 1 is coke in difficult raw materials: TO base condition with 5 mass% mix, Experiment No. 2 is 1 mass% lowering the proportion of powder coke to 4 mass%, instead Propane gas 0.5 vo 1% constant amount of heat input, Difficult No. 3 is compounded with powdered coke 10 ma ss%, Experiment No. 4 is heat retention (JP-A-60-155626) In order to verify the difference from this, 450 ° C high temperature gas was injected. Table 6

FIG. 15 shows the result, which is an example in which the coke oven gas' (C gas) is used as 2% as the gaseous fuel. This figure shows the results of investigating the injection position and the product sintered ore shutter bow daughter and product yield when gaseous fuel was blown. «Gaseous fuel was blown at 100-200 mm, 200-300 mm, and 300-400 mm from the ¾Λ surface. As can be seen from the results shown in this figure, at the injection position 100 to 200 mm, the brighter (white) combustion 'melting zone shown in the figure moves to the 100 mm position. The gas fuel is supplied to the work zone while it is in the range of 100-200 mm. Similarly, when the combustion / melting zone reaches the 200 mm position, the gas fuel is supplied from above ^^, and the same applies to the 300-400 mm position. In addition, gaseous fuel was supplied from the stage when the m · «belt reached the 300 mm position. For reference, the combustion zone at each position of the fiilE layer when the gas fuel is not blown in the conventional method is also shown.

 Also, the supply of combustion air for trial I flows from the top to the bottom in the same manner as in the operation. When adding gaseous fuel, the gaseous fuel is added to the fuel air so that it has a predetermined concentration. Deceived and supplied.

As shown in Fig. 15, the burning band is bright (white). In the region of 100 to 200 mm, it is only slightly thicker than the conventional method. In the 200 to 300 mm region, the thickness of the excavation and turning belt is clearly increased compared to the conventional method. It can be seen that the mm region also has a clear difference compared to the conventional method.

 From the above, it can be said that «gas combustion; the effect of entrainment is in the region of 20 O mm or less from the surface of ¾Λϋ; that gas fuel is supplied to the 纖 '纖 zone on the pallet It is preferable to reduce the cost of gas fuel H¾ffi. And when the area less than 200 mm from the surface of ^ 01 is not supplied with gaseous fuel, it will be With the power of a significant increase, the product; ^ the overall yield can be improved. .

Fig. 16 schematically shows the state of combustion in the upper layer from the charged layer surface to 20 O mm and in the lower layer of less than 200 mm. The arrow A shown in this figure indicates the direction of sintering (the direction of the material), and Figure 16 (a) shows the powder coke and gas fuel in part J ii (up to <20 O mm). This shows the flame standing. This «band formed by the powdered co-tas fuel is originally narrow in the upper part of the device Λϋ, and the combustion zone of this powdered coatus and the point of conversion of the gaseous fuel exchanged in this combustion zone are close to each other Therefore, the pattern is as shown on the right side of the figure. In this distribution, the combustion area of the powdered coke (solid fuel) is shown as a hatched part, and the area of the gaseous fuel that burns above it is shown as a non-hatched part. As can be seen from this figure, in the upper part of ^ Λϋ, coke and gaseous fuel are burned at the same time (both will be burning close to each other), so it is indicated by the letter T ₂ in the figure. The holding time in the high temperature range (equivalent to about 120 ° C) becomes narrow as shown in the figure. In other words, the distribution of the coke fuel indicated by the noch and the pinching part is increased. This means that the gas fuel supply to ^ λϋ is preferably done after the combustion / melting zone thickness of 15 mm or more is reached. At the same time, the blowing effect of the gaseous fuel is low. On the other hand, in Fig. 16 (b), gaseous fuel was supplied to the middle and lower layers. In the middle and lower layers, the combustion zone increased as ^ λ 汁 increased from the bottom to the bottom, and the combustion zone width Expands and burns at a position higher than in Fig. 16 (a). As a result, the distribution shown on the right side of Fig. 16 (b) is obtained. In other words, the solid fuel (coke) solidification point indicated by hatching is the solidification curve of the gas fuel, so the synthesized ^^ distribution curve has a large bottom distribution. Therefore, solid fuel and gas fuel indicated by Τ ₃ and Τ ₄ The high temperature region based on the fuel excretion can be obtained by increasing the time, and the ore shutter bow daughter is improved.

 In the case of Fig. 16 (b), the ignition of the gaseous fuel ^ for adjusting the high temperature range retention time is 400. C to 800 ° C. is preferable, and the most preferable ignition rate is 500 to 700. The reason for this is that if the ignition is set to less than 400 ° C, it does not lead to the expansion of the high temperature region, but merely the expansion of the low temperature region, while if it exceeds 800 ° C, the high temperature region retention time due to the combustion of solid fuel is limited. This is because the effect of extending the high temperature range holding time is small.

 Next, an example of a method for adjusting the maximum implosion (inside ^^) in the device λϋ by supplying «gaseous fuel 'will be described. Fig. 17 schematically shows the temperature distribution in the layer during sintering. This figure is based on the example of distribution in the conventional method, based on solid fuel (coal powder) 5ms s% inlet! ^ Explains the law. For example, in the sintering operation with the addition of 5 ms s% of coke, the conventional ¾ method is shown by curve a. In general, it is effective to increase the amount of coke breeze in order to extend the holding time in the high temperature range.For example, as shown in the figure, add 3% of the powder coke for 10 ms 3%. As shown, the high-temperature region retention time indicated by the layer thickness extends to (0—A) (0-B), but the maximum rises from about 1300 ° C to about 1370 ° C to 1380 ° C. As a result, it is no longer possible to obtain low RDI I or high bow ore.

In this respect, according to the method of the present invention: In the method, while the amount of powder coatas is suppressed to 4.2 mass%, ¾r ^ C gas is blown in, so that the maximum ¾¾ can be suppressed to 1270 ° C. At the same time, the high temperature holding time is extended to (0—C), so that the low RDI and high bow ^ ^ ore production and production, which could not be achieved by the conventional method, can be sufficiently fulfilled. Become. In short, the conventional: ^ method is an operation method that focuses on one of the adjustments in the high temperature holding time force adjustment level. In this respect, the present invention method adjusts the amount of powdered coke used (for example, 4. Under this condition, the maximum temperature (1205 ~; I 350 ° C) is adjusted while the high temperature range holding time is made difficult by blowing diluted gas fuel. Curve d in Fig. 16 shows an example in which the solid fuel consumption is simply reduced to 4.2 mass%, and the maximum temperature reached is low and the high-temperature region holding time is short. Fig. 18 shows an example of using conventional powder coke 5 mass% as the ¾¾¾ method, and as an example of adapting the present invention, the amount of powdered coke was 4.2 mass% and the concentration was 2. Ovol%. An example of using gas blowing together is shown. As can be seen from the thermovia in this figure, in the conventional method, a combustion state exceeding 1400 ° C occurred in order to maintain the high temperature range retention time. On the other hand, the volume of powder coke was limited to 4.2 mass%, and the same gas ¾¾Δ was measured: t, 1400 ° C range disappeared, and the maximum arrival ^ was below 1350 ° C. At the same time, it became possible to prolong the time in the high temperature range.

 Figure 19 shows the changes over time in the temperature in the charge bed (a), the exhaust gas temperature (b), the passing air volume (c), and the exhaust gas composition (d) due to the injection of diluted propane gas under constant input heat conditions. It is shown. Here, the temperature in the layer is a value measured in the above-mentioned sample by a pair that is λλ at a height of 20 Omm (¾λ thickness: 60 mm) from the great bar. In addition, measurements were taken at two locations 5 mm from the center and the wall in the circumferential direction of ^^. From these figures, it can be seen that the time when the raw material heated to 1205 ° C or higher is leaked by blowing the propane gas (hereinafter referred to as “high temperature range time”) is more than doubled. It was confirmed that the highest ¾¾¾ has not risen. In addition, when propane gas is blown in, the oxygen concentration in the exhaust gas is reduced, and it is estimated that is an efficient contribution to fuel.

Fig. 20 shows ^ λϋ (a), (a ') when diluted propane is injected (0.5 V o 1%) and when only the coke is increased (1 Oma ss%). And the change with time of exhaust gas separation (b) and (b,). From these figures, when the percentage of powder powder is doubled, the retention time at a high temperature range of 1200 ° C or higher is almost the same as when blowing propylene gas diluted to a concentration of 5 V o 1%. The best to it¾ exceeded 1350 ° C. Also, by increasing the amount of coke breeze, the C0 ₂ concentration in the exhaust gas greatly increased from 20 V o 1% to 25 vo 1%, and the CO concentration also increased, and the powder coke power '; I enjoyed the fact that the contribution ratio was decreasing.

Figure 21 summarizes the various features in these. As can be seen from this figure, the propane gas injection increased slightly; ½ ^ time was slightly extended, but the yield was improved as the yield of the shutter bow daughter and the production rate was improved. Also covered It was confirmed that the reducibility was also greatly improved, and by optimizing the injection of industrial gas fuel, in addition to improving the production rate ^^ distilling;

 On the other hand, only if the coke breeze was added to 1 O mass% "^:; not only increased time but also the maximum temperature increased more than necessary. A lot of crystal quality ¾ ^^, and both shutter and yield decreased significantly, and in the case of the 45 ° C. thermal furnace, the improvement effect of shutter bow daughter and yield was small, This is almost the same as the result in the business of,

ことなく、 一方で高温域^時間につ いては、 供給される^ ガスの燃焼によって延長される。 As can be seen from the above description, ^ gas fuel is used: ^, this gas burns in the Λ 装, leading to the expansion of the combustion zone in the layer, and ^^ A wide-band combustion zone is formed by the synergistic action of the combustion heat of the gas and the combustion of the propane gas. as a result,

On the other hand, the high temperature range is extended by the combustion of the supplied gas.

Next, the inventors formed article ^ reducibility of ¾ ore by blowing «gaseous fuel, 'Influence on cold. Bow daughter like, conventional methods _{^{(5 mass 0/0, 1}} O mass% The survey was conducted in comparison with COTAS and thermal JIl injection. Measured items are: product; ^ mineral in mineral ore Wf 恰 (influence on cold bow daughter and reducibility), apparent specific gravity (influence on cold daughter), pores less than 0.5 mm ί ^ cloth (reducible Is an effect on sex).

 First, Fig. 22 shows the result of investigating the MfiJ of the mineral phase in the product ore quantified by powder X-ray diffraction. From this figure, it can be seen that when ί¾λ calorie is constant (coix 4 maa% + propane 0.5 vol%), solid fuel and «propane gas are used together ^ This is thought to have led to an improvement in sex and an increase in cold bow girls.

Fig. 23 shows the measurement result of the apparent specific gravity of the product; ^ ore, and Fig. 23 shows the measurement result of the pore size distribution of 0.5 mm or less using a water-type porosimeter. As shown in Fig. 22, as a result of the dilute propane gas being blown from the outside, the melt is promoted and the porosity (apparent ratio fi) is reduced to 0.5 mm or more. This is thought to be a factor in improving cold strength. Also, from Fig. 24, ¾Λ heat quantity is constant! ^ Propane gas is injected. As a result, the amount of

It is considered that the rice field pores of 500 μm or less became ¾ @ L ^J ^, making it possible to produce highly reduced '14 ^ ores.

 Fig. 25 shows a schematic diagram of the behavior when using only Kotas (a) and when «gas combustion; | ¾H combined use (b). As shown in this figure, while the conventional coke that uses only coke was heated from the inside of the particles by powdered coke combustion, the combined method of coatus + gaseous fuel as in the present invention, gas As the fuel burns, it will be heated from the outside of the soot particles, so it is thought that there are no paddy pores in the ore, RDI is low, and JI SR I can be relatively high. .

 Fig. 26 shows a schematic diagram of the production of ore gas during a gas fire. As shown in this figure, improving ore productivity has an impact on yield and cold bow daughter, promoting coalescence of 0.5-5mm pores, reducing their number, and affecting air permeability. It is ^) to increase the proportion of pores of 5 mm or more that affect the thickness. In addition, it can be seen that, in order to improve the reducibility of the mine, it is desirable to have a pore structure with a large number of rice field pores of 0.5 mm or less in the stone. In this respect, according to the present invention, it is considered that it is possible to approach the ideal ore structure by the gas infiltration.

 Figure 27 shows the limit coke ratio that can maintain the required cold bow daughter (the limit coke ratio is equivalent to 73%, which is the maximum value when propane gas is not added to the shirt tar bow daughter). This shows the result of the grasp of the coke ratio. As shown in this figure, the cox ratio for obtaining the same cold (shutter bow ¾g 73%) by propane gas blowing (concentration 0.5 v o 1%) is shown in Fig. 27 (a). As shown in Fig. 5, it can be reduced from 5 ma ss% to 3 m ass% (about 20 kgZt). In addition, as shown in Figures 27 (b) and (c), it is clear that the cox ratio decreases from 5 ma ss% to 3.5 ma ss% to obtain 73% yield and 1.86 production rate, respectively. It is.

As is clear from the above description, the present invention is a gas fuel that is appropriately adjusted according to the amount of carbonaceous material while the combustion zone shifts from ¾ϋ of ^ Λϋ to the lower layer as the pallet progresses. By selecting the right place and supplying it, the action to expand the function of the ligament in ¾Λϋ It is possible to improve the quality of the mineral and improve the property.

 ■ m

 (1) Example 1: Using coke oven gas (C gas) as the gaseous fuel (1-2, 5 V o 1%) shown in Fig. 6 (Coke) A pot pot with an amount of 5 ma ss% was performed. The other conditions are the same as the actual results of ± Φ (paragraph 0037). The results are shown in FIG. As shown in this figure, when TO gas C according to the method of the present invention is increased, if the c gas is increased, the expansion of the combustion band is remarkable, and the yield and ^ 0 rate are improved. I found that cold bow girl (SI) can also improve.

 (2) Example 2: I ^ was performed under the same conditions as in Example 1. The results are shown in FIG. As shown in this figure, when using propane gas (0.02 to 0.5 vol%) made according to the method of the present invention, if the concentration of the C gas is increased, the expansion of the fuel coagulation is remarkable. Moreover, it was found that the yield and production rate can be improved, and the cold bow degree (SI) can be improved.

 (3) Example 3: In this example, the coke oven gas (C gas) produced by using the ^^ pan shown in Fig. 6 and the cooler exhaust gas in comparison with the example without dilution gas injection was used. This is an example in which the material was blown into the charging layer of the sintering raw material (including 20M ss% return) shown in Table 7 from above.

 In this example, the layer contains 4.8 to 5 mass% («) of powdered coke, and as a conforming example of the present invention, the concentration is 1.0 to 2.0 V o 1% (to air) C gas at a suction pressure of 1200 mmAq (¾E 1000 A q)

In this example, the total thickness is 600 mm, and the difference thickness is 20 Omm of return ore layered on the bottom layer. Note that the position of the knitting ¾¾ ^ is DL; ^ The machine ^ 1 is set to 8 Om. If this is applied to the total height of 600 mm, the blow position of No. 2 is 100 to 20 Omm is 80 (m) XI 00 to 200 Z600. This corresponds to an example in which the sintering machine is operated by installing a gas injection hood 12 having a length of 13.3 m at the position of (mm) = 13.3-36.6 (m). . Therefore, the example of 纖 No. 2 blowing position 200-300 mm is about 13.3 m long ¾r¾ gas blowing at about 26.7-39.7 mm behind the Λ furnace on the reto This is equivalent to installing the hood 12 and injecting gas.

The percentage of tas is an outside number.

Table 8 shows the ¾¾T result of this example (No .:! To No. 7). As can be seen from the results of this ¾¾ 鉱, the cold arch daughter (SI bow daughter) of the ore is compared with No. 1 as a comparative example, and in both No. 2 to No. 7 which shows a conforming example of the invention. In particular, the improvement is remarkable in the cases where the blowing position is in the middle of ¾Λϋ (No. 3, 4, 6, 7). Also, rather than lowering the amount of coke and increasing the concentration of the blown gas, the rate will be higher if the blown gas ¾g is 1 vo 1% under a certain amount of coke (4.8 ma ss%). I understood. In addition, regarding the quality of male ore, the most effective method is to inject both the reduction rate (RI) and the reduction powdering rate (RDI) so as to affect the middle stage of ¾¾λϋ at only 200 to 300 mm. I found out that

Table 8

(4) Example 4: This example describes an example in which the method for producing ore according to the present invention is applied to D with a daily scale of 10,000 tons. The captain of the DL ^ t shelves is <90m from the furnace to the exhaust β. A gas blowing hood with a length (pallet movement direction) of 15 m and covering the entire gage is installed at the position of about 3 Om behind the furnace at ^ ¾, ^ coke oven gas (gas fuel) C gas) was used. In particular, without targeting the ± ϋ part of the raw material of this; AS, the thickness of the layer is 600 Om (excluding | 0 yen 20 Omm). Combustion that progressed to a considerable extent · C gas at a concentration of 2 vo 1% by supplying air at room temperature was supplied to a position corresponding to 30 Omm from the position where the β-band occurred. This blow-in C gas reaches the position of ffJlE through the layer by the negative suction pressure ¾ of the wind box below the let so that it is burned in the combustion zone ^ Large ^ This is Kazuwazuzu ^ :: EJI, l Balanced with the suction negative pressure of my own windbox. The amount of C gas used at this time is 3,000m ³ (standard TO state) Zh.

As a result, as a result, tumbler bow S ^ as a whole is about 3% better than usual, RDI is about 3% better than usual, and RI is better than usual. About 4% improvement. However, the drought rate increased by 0.03 t / hr · m ² .

Claims

The scope of the claims 1. ¾Λ of total raw material including stone and charcoal on the circulated pallet, and form the carbon material ^ Ji on the pallet ¾Λ process;  In the point furnace, the point where the carbon material on the surface of ^ λ  Air is sucked through a wind box placed under the pallet, the charcoal in the bed is burned, and the generated fuel makes the cake ^^  Gas fuel expansion process that supplies gas fuel below the lower combustion limit concentration from above ^ λ ^ and burns the gas fuel within ¾λϋ;  ¾ made of ore with 2. The self-gas fuel combustion process supplies gas fuel below the lower combustion limit concentration from above ¾Λϋ, burns the gas fuel in ¾Λϋ, and reaches the maximum in ^ λϋ, Or a high temperature region in ¾Λϋ, or a high temperature time in ^ Λ 桌 and a high temperature time in ^ Λϋ. 3. The self-gas fuel combustion process supplies the gas fuel, which is used below the fuel lower limit concentration, from above the device Λ 、, combusts the knitted gas fuel in ¾Λϋ, and the highest in ¾Λϋ In claim 2 consisting of difficult to reach m¾ | Ε¾; 4. The self-gas fuel combustion process supplies gas fuel that has been reduced to below the lower fuel limit concentration from the top of λϋ, burns the self-gas fuel within ^ λϋ, and the amount of carbon in the raw material The production of the ^ ¾ ore according to claim 3, comprising adjusting the maximum itag within ^ Λϋ by 5. The ffjE gas fuel expansion process supplies gas fuel below the lower combustion limit concentration from ¾λϋ, burns gas fuel in ^ Λϋ, and reduces the amount of carbon in the raw material. To do According to claim 4, comprising the step of sizing tiilit high arrival a¾ to 1 2 0 5 to 1 3 5 0 ° C. 6. | ΐί | 5 Gas fuel combustion process supplies gas fuel that has been set to below the lower limit of combustion. 4. The ore $ ^ method according to claim 3, comprising adjusting the amount to ΙίίΐΕ * 高 to 1 2 0 5 to 1 3 5 0 ° C. 7. The selfish gas fuel combustion process supplies gas fuel below the lower limit of fuel conversion from ¾Λϋ, burns ilS gas fuel in ¾Λϋ, and charcoal material in ship materials According to claim 3, comprising adjusting the amount of gaseous fuel to 1 2 0 5 to 1 3 5 0 0 C by checking the amount and supply of gaseous fuel: ^ §a ¾¾o of ore 8. Sflt self-gas combustion: ^ Supply the gas fuel below the flammability lower limit from ¾Λϋ, burn the tfrlE gas fuel within ¾λϋ, and maintain the high temperature range in ¾Λϋ According to claim 2, consisting of saving time; ^ ore production ¾ο 9. ttl Gaseous fuel combustion process supplies gaseous fuel below the lower combustion limit concentration from above the AS, burns the knitted gas fuel within ¾λϋ, and reduces the amount of carbon in the fiber In response, the concentration of the gaseous fuel is adjusted and the temperature in the high temperature range is set in the time range. Manufacturing method of sintered ore as described in 8 1 0. Gaseous fuel; ^ When the combustion process supplies gaseous fuel below the lower combustion limit from above ¾Λϋ, the gaseous fuel below the lower combustion limit concentration remains at least partially unburned. 2. The ore 3 ^ method according to claim 1, wherein the method comprises burning in a compilation Β¾Λϋ and igniting it up to the band. 1 1 .fillB gas fuel combustion process supplies gaseous fuel, which is used below the lower combustion limit concentration, from above Λϋ, burns the knitted gas fuel in ¾Λ1, and forms the combustion band shape Claim 1 consisting of

1 2. The method of producing a sintered ore according to claim 11, wherein the shape of the sinter / band is the adjustment of the thickness in the height direction and the width in the Z or pallet movement direction of the band. 1 3. The self-burning gas combustion process supplies gaseous fuel, which is used below the lower combustion limit concentration, from above ¾Λϋ, burns tfrffl gaseous fuel in ^ Λϋ, and burns it. The ore law according to claim a1, which consists of extending the cold bow daughter of the ore. 1 4. Self-gas fuel combustion; 15) Supply a gas fuel with a temperature lower than the lower combustion limit concentration from the top of ^ λϋ, burn the self-gas fuel in ¾Λϋ, and The supply of fuel to ^ Λ 記載. According to claim 1 consisting of positioning; ^ ore i¾½feo 1 5. Fil gas fuel dredging process consists of supplying gaseous fuel below the lower limit concentration at the position after the furnace, supplying from above ^ λ, and burning tine gas fuel in ^ Λϋ Claim 1 to! E¾; ^ Made ¾o  1 6. FiJlE gas fuel combustion process supplies gas fuel that is below the lower limit of fuel excavation until the power is completed after the cake is made at the head of ^ Λϋ, and within ¾λϋ Claim 1 consisting of self-gas fuel coagulation: ^ Made of ore i * ¾o 1 7. The self-gas fuel combustion process supplies gas fuel that is below the lower combustion limit concentration in the region where the thickness of the coagulation / melting zone is 15 mm or more, and burns the tilt self-gas fuel at ¾Λϋ 內The ^^ ore production according to claim 1 consisting of 1 8. The self-gas fuel combustion process supplies gas fuel that is below the lower combustion limit concentration after the point where the combustion theory reaches 100 mm below the surface layer. The method for producing a sintered ore according to claim 1, comprising burning 1 9. The claim wherein the gaseous fuel ^ combustion step comprises supplying gaseous fuel having a concentration lower than the lower combustion limit concentration in the vicinity of both side walls of the charging layer, and burning the gaseous fuel within ¾Λϋ 1 «Mine production ¾ο  2 0. The gas fuel combustion process is performed by supplying gas fuel that has been set to below the lower combustion limit concentration; supplying it from the top of the Λϋ in the length direction, and burning the gas fuel of selfishness in the layer, And the cold of the ore removal is β;  2 1. The method for producing a sintered ore according to claim 1, wherein the ffjfS gaseous fuel is a combustible gas with a combustion lower limit of not more than 75% and not less than 2%. 2. The method for producing a sintered ore according to claim 10, wherein the tilt self-gas fuel is a combustible gas diluted to a concentration of 60% or less and 2% or more of a lower combustion limit concentration. 2 3. The production of ¾ ore according to claim 11, wherein the gaseous fuel is a combustible gas diluted to a concentration lower than the lower combustion limit concentration of 25% or less and 2% or more. 2 4. l The self-fuel is at least one gas from the blast furnace gas, coke oven gas, blast furnace / coke oven mixed gas, propan gas, natural gas and methane gas. The method for producing ore according to claim 1. 2 5. A pallet that circulates, a suction windbox located below the braid, a base for feeding the raw material on the pallet, and a charcoal in the raw material Point to In a furnace equipped with an ignition furnace, a gas for injecting gaseous fuel diluted to a concentration below the lower combustion limit concentration from above the charging layer into the charging layer is formed downstream of the furnace. ^ Suppose that the fuel supply device is installed; M; ^ ¾ 2 6. The firing according to claim 24, characterized in that at least one of the self-gas burn-off is at least one in the longitudinal direction of the point downstream of the furnace. 2 7. From the stage where the self-flame flammability separation is arranged in the direction of travel of the Nott and the combustion front has proceeded downward: Range ¾m as described in 2 4  2 8. ½ i gas flame weaving is arranged near the side warno. Claims 2 4 to ¾ j½ «o  2 9. The lift self-gas fuel supply device supplies a combustible gas diluted to a concentration of 75% or less of the lower combustion limit concentration and 2% or more of the lower combustion limit concentration. ^ m  3 0. Disgusting The gaseous fuel supply device supplies a combustible gas diluted to a concentration of 60% or less and 2% or more of the lower combustion limit concentration. To the word B¾ 3 1. The fir ffjt self-gas fuel supply device supplies a combustible gas diluted to a concentration not more than 25% and not less than 2% of the lower combustion limit concentration. of