JPH09279262A - Production of sintered ore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method of sintered ore, wherein the productivity of a sintering machine can drastically be improved by increasing the layer thickness of blended raw material and the shifting speed of a sintering pallet. SOLUTION: The blended raw materials containing raw material powdery ore, flux and fuel are charged on the sintering pallets 2 arranged as a caterpillar-state and the lowermost layer filling 10-100mm thickness is formed and ignition is executed to the fuel contained on the surface layer thereof from the upper part. The whole filling layer 3 is completed by further charging the blended raw material on the lowermost filling layer. The fuel in the blended raw material filling layer 3 is burnt by press-blasting upward from the lower part of the sintering pallet 2 while horizontally shifting the sintering pallet 2 in order, and the raw material powdery ore is sintered from the lower layer toward the upper layer of the filling layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sintered ore which is a raw material for a blast furnace iron making method.

[0002]

2. Description of the Related Art For sintering iron ore, a Dwightroid type sintering machine is widely used. This is because the raw material powdered ore is mixed with a solvent such as limestone or silica stone, fuel such as powder coke and water, and mixed and granulated, and the mixed raw material is filled on a sintering pallet arranged in a caterpillar to form a packed layer. After forming and moving the sintering pallet sequentially horizontally, igniting the surface of the packed bed in the ignition furnace, and then sucking from below, the raw material powder ore is generated by the heat generated by burning the fuel in the blended raw material. The combustion zone to be melted and solidified is sequentially transferred from the surface layer portion to the lower layer portion for sintering, and the entire sintering process is completed in about 20 to 30 minutes.

The Dwightroid type sintering machine is a continuous type and is widely used because it is more suitable for mass production than other batch type sintering machines such as a Greenwald type sintering machine. . The current Dwightroid-type sintering machine has become large in size, with a width of 5 m and a length of 100 m, and the productivity is about 34 to 43 t / d / m ² , but further improvement in productivity is pursued. ing. Further, it is said that sinter ore production should be operated so as to maintain the quality of the product sinter and maximize the productivity and minimize the fuel consumption rate and ignition fuel consumption rate.

In Japanese Examined Patent Publication No. 54-24682, hot air is blown to the upper surface of the raw material mixture on the sintering pallet to raise only the upper layer portion of the raw material to a high temperature, and then the upper layer portion of the raw material is ignited, whereby thermal shock at the time of ignition is mitigated. It is described that while the drop strength is constant, the productivity is improved and the coke unit consumption is reduced, but the product yield is slightly lowered.

In Japanese Examined Patent Publication No. 57-45296, hot air is blown onto the upper surface of the mixed raw material on the sintering pallet and sucked from below to dry only the upper layer portion of the raw material, and then the upper layer portion of the raw material is ignited and blown with hot air. Sintering while sucking from below brings about improvements in productivity, reduction of coke consumption, improvement of sinter quality, and suppression of NOx generation.
It is stated that the product yield does not improve much.

In Japanese Patent Laid-Open Publication No. 57-79130, when the burner heating in the ignition furnace and the gas for fuel are supplemented with oxygen so that the oxygen content becomes 16% or more, the sintering bed surface layer is burned. The binding strength is improved, the amount of powdered and returned ore is reduced during sizing of the sintered ore, and productivity is improved,
It is stated that the fuel consumption rate will decrease.

In Japanese Patent Publication No. 61-31165, the amount of powder coke in the sintering raw material passing per unit time is detected, the required air amount is calculated and set, and the amount of air flowing into the furnace is controlled to control the temperature. It is described that productivity and quality of sinter can be improved by eliminating variations and homogenizing the sintering reaction in the sintered surface layer.

In Japanese Patent Publication No. Sho 62-19493, a strip-shaped flame burner capable of raising and lowering and tilting is provided, and the temperature distribution of the raw material layer surface and the holding time of the raw material layer surface average maximum temperature are analyzed.
It is described that the temperature distribution can be made uniform and the fuel consumption rate can be reduced by comparing the analysis result with each set reference value and adjusting the height and / or angle of the strip flame burner based on the comparison result. ing.

In Japanese Examined Patent Publication No. 30800/1990, a burner for pulverized coal fuel is provided in an ignition furnace, and fine coke and fine coal are mixed and supplied and burned to adjust the mixing ratio of fine coal and fine coke. It is described that when the flame is heated to a high temperature away from the burner port, the ignitability is improved and the sintering strength of the surface layer of the sintered ore can be increased.

In Japanese Unexamined Patent Publication No. 7-173546, it is possible to stabilize the sinterability and increase the strength of the sintered ore by blending return ore in a specific depth region from the surface of the raw material packed layer. Has been described.

[0011]

In any of the above-mentioned conventional techniques, the compounded raw materials are layered on a sintering pallet with a layer thickness of 400 to 600.
It is premised on the current operating conditions in which the fuel in the blended raw material is ignited in an ignition furnace after being filled with about mm. However, when pursuing a revolutionary improvement in productivity as a next-generation sintering technology, it is said that the productivity will be improved by increasing the current layer thickness of the compounded raw material filling layer and the moving speed of the sintering pallet. Directions should also be considered.

[0012] At this time, what becomes a problem is the homogenization and the transfer speed of the combustion zone in the packed bed in the width direction of the sintered strand. If the sintering reaction in the combustion zone is non-uniform in the width direction and the rate of transition from the surface layer to the lower layer is the same, sintering is completed when the layer thickness of the packed bed and the moving speed of the sintering pallet are increased. This is because it only increases the length of the sintering machine required for the above, and does not improve the productivity.

In the combustion zone, fuel such as coke burns to sinter the raw material powder ore. Therefore, in order to make the sintering reaction in the combustion zone uniform in the width direction of the sintered strand, the fuel in the blended raw material must be In order to ignite simultaneously and uniformly in the width direction and increase the transfer rate, it is necessary to increase the fuel burning rate in the blended raw material.

In order to uniformly ignite the fuel in the blended raw material, the burner should be improved to an oxygen-enriched burner or a pulverized coal burner, and combustion control should be performed based on the chemical reaction amount and physical amount related to fuel combustion. Can be considered. But,
All of these are due to the performance of the burner in the ignition furnace, and there is a limit to simultaneously and uniformly igniting the fuel in the powdered raw material mixture in the width direction of the sintered strand. Further, since the installation of the ignition furnace shortens the length of the sintered strand effective for firing, it is the current situation that the sintering productivity is reduced accordingly.

In order to increase the supply amount of oxygen, it is conceivable to increase the air blowing speed, perform pressurized air blowing, enrich oxygen, and blow. However, the negative pressure of the suction blower has a limit of 2000 to 2500 mmH ₂ O, and if suction is performed from below, gravity and blast pressure may overlap and the packed bed may be compressed, impairing air permeability. A suction type Dwightroid sinter machine cannot significantly increase the air flow rate or pressurize air, and oxygen enrichment may be possible only partially, but it depends entirely on oxygen enrichment. There is a problem that the cost increases when the burning speed is increased by
Neither can actually be adopted.

Therefore, in the present invention, the fuel in the blended raw material is ignited simultaneously and uniformly in the width direction of the sintered strand to increase the layer thickness of the blended raw material and the moving speed of the sintering pallet to improve the productivity of the sintering machine. It is an object of the present invention to provide a method for producing a sintered ore that can be dramatically improved.

[0017]

The method for producing a sintered ore according to the present invention is as follows.

When charging a raw material powder ore, a raw material mixture containing a solvent and a fuel to form a packed bed on a sintering pallet arranged in a caterpillar shape, first, the raw material mixture is charged to a thickness of 10 to 10. After forming the lowermost layer of the packed layer of 100 mm and igniting the fuel contained in the surface layer from above, further, the compounded raw materials are charged on the lowermost layer of the packed layer to complete the entire packed layer and sinter. While moving the pallet sequentially horizontally, pressurizing air is blown upward from below the sintering pallet to burn the fuel in the mixed raw material packed bed, and to sinter the raw material powder ore from the lower layer to the upper layer of the packed bed. A method for producing a sintered sinter, which is characterized.

When charging a raw material powder ore, a mixed raw material containing a solvent and a fuel to form a packed bed on a sintering pallet arranged in a caterpillar shape, first, a packed material heated to 900 ° C. or higher is charged. After forming the lowermost layer of the packed bed having a thickness of 10 to 100 mm, the compounding raw materials are charged on the lowermost layer of the packed bed to complete the entire packed bed, and the sintering pallet is sequentially moved horizontally while sintering. Pressured air is blown upward from below the pallet to ignite and burn the fuel in the blended raw material packed bed by heat transfer from the heated packing, and the raw material powder ore is sintered from the lower layer to the upper layer of the packed bed. A method for producing a sintered ore, comprising:

The method for producing a sintered ore as described above, wherein the heated filling is a solid body having a particle size of 5 mm or more.

The method for producing a sintered ore according to any one of the above 1 to 3, wherein the compounded raw materials are charged on the lowermost layer of the packed bed, and then a solid body is further charged thereon to complete the entire packed bed.

The method for producing a sinter according to the above or the above, wherein the solid body is return or lump ore.

In the present invention, unlike the conventional dwightroid type sintering machine, it is decided to blow air under pressure from below. In this case, the blast pressure is 3000 to 4000 mmH
It is possible to set it to ₂ O, and it is possible to blow the air more than twice as much as the conventional one. Further, since the blast pressure is upward, there is no problem that the packed bed is compressed by overlapping with gravity. Since the combustion zone moves in the blowing direction, in the present invention, when the lowermost layer of the packed bed is formed from the blended raw material, the fuel in the blended raw material is ignited from above, and the lowermost layer of the packed bed is heated to 900 ° C.
When formed with the filler heated above, by igniting the fuel in the blended raw material by heat transfer from the filler,
Start sintering. In the non-ferrous field, the updraft type sintering machine is used to avoid troubles in the grate and the wind box due to molten Pb in the sintering of lead sulfide concentrate. Not used for sintering.

In the method of the present invention, the packed bed may be fluidized when the blast pressure is made considerably high. Therefore, in such a case, first, the surface layer of the packed bed is irradiated with microwaves to be sintered, or a solid body such as return or lump ore is charged so as to have a thickness of 10 to 100 mm, and fluidized. It is sufficient to form a shell of a solid body for preventing oxidization from the surface layer and then blow air under pressure from below the sintering pallet. The microwave can heat the object from the inside by using the object to be heated itself as a heating element, has high thermal efficiency, and can heat in a short time. 2450M as an INS band
Either Hz or 915 MHz is allowed, so either can be used. In addition, when a solid body is charged to prevent fluidization, the solid body is not particularly limited as long as it has a size of 3 mm or more, and of course, a return body of about 10 mm used in a downward suction type sintering machine. The ore can be used as it is.

In the present invention, rather than depending on the heat of combustion of the burner provided in the conventional ignition furnace, the filler having a high temperature is laid in the lowermost layer, the compounded raw materials are charged on the lowermost layer, and the mixture is charged from below. By blowing air upward, the amount of heat of the heating filling can be transferred to the fuel in the blended raw material to ignite. For this purpose, the temperature of the filling material may be 900 ° C. or higher. Further, by cutting out from the hopper, since the filler can be uniformly charged in the width direction of the sintering pallet, if ignition is performed by heat transfer from the heated filler,
It is possible to ignite the mixed raw material uniformly in the width direction, and the amount of heat is efficiently transferred to the mixed raw material. Since the air is blown upward from below, the filling does not stick to the sintering pallet. Regarding the heating method of the filler charged in the bottom layer, a fluidized bed type heating device is installed in front of the hopper to heat blast furnace gas, coke oven gas, etc. as fuel, and to heat the filler to a specified temperature. There is no particular limitation as long as it can be used, and the hopper can have a heating structure.

In the present invention, since the supply amount of oxygen can be increased, the burning rate of the fuel in the blended raw material can be increased. Therefore, the sintering rate is increased, and the layer thickness of the filling layer can be even 700 to 1200 mm, which is more than double the conventional value, and thereby, the productivity of the sintering machine is remarkably improved, and 70 t / d It is possible to realize productivity twice as ^high as the conventional one, such as / m ² . Further, the moving speed of the sintering pallet can be increased while keeping the layer thickness of the filling layer as it is, and the productivity of the sintering machine can be greatly improved also by this.

[0027]

1 and 2 show an example of a sintering apparatus for carrying out the present invention.

The apparatus shown in FIG. 1 is conventional in that the compounded raw materials are packed on a sintering pallet 2 arranged in a caterpillar shape to form a packing layer 3, and the sintering pallet 2 is sequentially horizontally moved and sintered. It is the same as the Dwightroid type sintering machine. The difference is that a high-pressure blower 7 is provided below the sinter and air is blown upward from the bottom of the sinter, and the bottom layer of the ignition furnace 4 is ignited to fuel the bottom layer of the packed bed 3. The point after the raw material charging device 1 and before the upper layer raw material charging device 5 and the packed bed 3
A surface layer solid body charging device 6 for charging a solid body such as returned ore is provided on the surface of the. Further, in this apparatus, the raw material mixture can be filled with a layer thickness of 700 to 1200 mm thicker than before.

A raw material powder ore to which a solvent such as limestone or silica stone and a fuel such as powder coke is added and mixed and granulated is
The lower layer raw material charging device 1 and the upper layer raw material charging device 5 are separately stored, and solid bodies such as returned ore are charged into the surface layer solid body charging device 6
Is stored in The compounded raw material continuously supplied from the lowermost layer raw material charging device 1 onto the sintering pallet 2 forms the lowermost layer of the packed bed 3, and the ignition furnace 4 ignites the fuel in the raw material.
The remaining blended raw material is continuously supplied from the upper raw material charging device 5 onto the lowermost raw material after ignition, and further, solid bodies such as return ore are continuously supplied to the surface layer from the surface solid solid charging device 6. Then, the filling layer 3 having a layer thickness of 700 to 1200 mm is formed.
Then, the blow pressure from the high pressure blower 7 is 3000 to 400.
The compressed air of 0 mmH ₂ O is blown, and the exhaust gas passing through the packed bed 3 is collected by the hood 8 and discarded.

Also, in the apparatus shown in FIG. 2, the raw materials are filled on the sintering pallet 2 arranged in a caterpillar shape to form the filling layer 3, and the sintering pallet 2 is sequentially horizontally moved and sintered. Is the same as the conventional Dwightroid sintering machine. The difference is that a high-pressure blower 7 is provided below the sinter, and pressure is blown upward from the bottom of the sinter, and the heating filler 11 heated to a high temperature can be charged in the lowermost layer of the packed bed 3. The lower layer heating and charging material charging device 9 is in front of the upper layer raw material charging device 5, and the heating and charging material 1 is provided before the lowermost layer heating and charging material charging device 9.
The point is that a heating device 10 capable of heating 1 is provided. In addition, in this device, the raw material mixture is formed to have a layer thickness of 700 to 1200 m.
m, which is thicker than the conventional one. Further, this apparatus is also provided with a microwave irradiation device 12 for forming a sintered shell for preventing fluidization in the surface layer portion of the packed bed 3 of the mixed raw material. Microwave irradiation device 1
Instead of 2, a surface layer charging device 13 that can charge a solid body such as return mine on the packed bed 3 may be provided.

A raw material powder ore to which a solvent such as limestone or silica stone and a fuel such as coke powder is mixed and granulated is stored in an upper layer raw material charging device 5 and heated and charged into the lowermost layer. After being heated to 900 ° C. or higher by the heating device 10, or 11 has already been heated to 900 ° C. or higher, 11 is stored in the lowermost layer heating filling material charging device 9 as it is. The heated filling 11 continuously supplied onto the sintering pallet 2 from the lowermost layer heating filling device 9 forms the lowermost layer of the filling layer 3. On top of the bottom layer formed from the heat filling 11,
Blended raw materials are continuously supplied from the upper layer raw material charging device 5,
The filling layer 3 having a layer thickness of 700 to 1200 mm is formed. The surface layer portion of the packed bed 3 is irradiated with microwaves or filled with a solid body to form a sintered shell for preventing fluidization, and then a high-pressure blower 7 blows air with a blowing pressure of 3000 to 4000 mmH ₂ O under pressure. The exhaust gas that has passed through the packed bed 3 is collected by the hood 8 to be disposed of.

[0032]

[Examples] Table 1 shows the blending ratio of the blended raw materials used in this experiment. The raw materials for the upper layer are various iron ores and various raw materials such as limestone, quicklime, serpentine, and S in sintered ore.
It was adjusted so that iO ₂ and Al ₂ O ₃ were 5.8% and 1.8%, respectively, and the basicity was 1.7. 3. The return ore mixing ratio is constant at 15% based on 100 new raw materials, and the coke mixing ratio is based on 100 new raw materials.
It was fixed at 0%. The same composition was used for both the comparative example and the example.

[0033]

[Table 1]

In Examples 1 and 2, after blending return ore and powder coke into the new raw material to be blended, water was added and mixed with a mixer,
Granulate and layer in a 50kg test pan 500-1000mm thick
The sintering test was performed. In each of Examples 1 and 2, 50 mm of compounded raw material was charged to form the lowermost layer, which was ignited from above and sucked downward from above to ignite the fuel in the lowermost layer. Next, the compounded raw material was charged from above to form a predetermined packed bed thickness, and air was blown upward from below to sinter the raw material powder ore.

In Examples 3 and 4, after adding return ore and powder coke to the new raw material to be blended, water was added and mixed with a mixer,
Granulated. 11 with burner using coke oven gas as fuel
A mass of ore heated to 00 ° C is placed in a 50 kg test pot with a layer thickness of 30 m.
Then, the mixed raw material was charged so that the total layer thickness would be 500 to 1000 mm, and a sintering test was conducted.

As shown in Table 2, in Examples 1 and 3, the packing layer was made thicker than in the conventional case and air was blown upward from below. In Example 2, the packing layer was made thicker than in the conventional case. Thicken,
After filling the surface layer of the packed bed with 20 mm of sintered ore as return ore, pressure was blown upward from below. In Example 4, the layer thickness of the packed bed was made thicker than before, and the surface layer of the packed bed was microwaved. After forming the sintered shell, pressure was blown upward from below. On the other hand, in the comparative example, as in the prior art, after uniformly filling and igniting the surface layer portion of the filling layer, air was sucked downward from above and sintered.

[0037]

[Table 2]

FIG. 3 shows the production rates and the product yields of the pot tests obtained in Comparative Example and Examples 1 to 4. As can be seen from FIG. 3, in Examples 1 to 4, the production rate was improved as compared with the comparative example. Further, conventionally, the product yield tended to decrease as the production rate increased, but the present invention resulted in a significant improvement in the product yield.

[0039]

EFFECTS OF THE INVENTION According to the present invention, it becomes possible to sinter by a large amount of pressurized air and to ignite a fuel in a blended raw material uniformly, which has been impossible in the past. Therefore, it is possible to increase the layer thickness of the compounded raw material filling layer, increase the pallet moving speed, and obtain uniform sinter quality, and it is possible to significantly improve the productivity of the sintering machine.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a sintering apparatus for carrying out the present invention.

FIG. 2 is a diagram showing an example of a sintering apparatus for carrying out the present invention.

FIG. 3 is a diagram showing a production rate and a product yield in a pan test.

[Explanation of symbols]

 1 Lowermost layer raw material charging device 2 Sintered pallet 3 Packed bed 4 Ignition furnace 5 Upper layer raw material charging device 6 Surface solid material charging device 7 High pressure blower 8 Hood 9 Lowermost layer heating and charging device 10 Heating device 11 Heating and filling Material 12 Microwave irradiation device 13 Surface material charging device

Claims (5)

[Claims] 1. When forming a packed bed by charging a raw material powder ore, a solvent, and a mixed raw material on a sintering pallet arranged in a caterpillar shape, first, the mixed raw material is charged to a thickness. After forming the lowermost layer of the packed layer of 10 to 100 mm and igniting the fuel contained in the surface layer from above,
The raw material mixture is charged on the lowermost layer of the packed bed to complete the whole packed bed, and while moving the sintering pallet sequentially horizontally, pressure is blown upward from below the sintered pallet to blow the mixed raw material into the packed bed. A method for producing a sintered ore, comprising burning a fuel to sinter the raw material powder ore from the lower layer to the upper layer of the packed bed. 2. When forming a packed bed by charging a raw material powder ore, a blended raw material containing a solvent and a fuel, onto a sintering pallet arranged in a caterpillar shape, first, a filler heated to 900 ° C. or higher is charged. After charging to form a packed bed bottom layer having a thickness of 10 to 100 mm, the compounding raw materials are charged on the packed bed bottom layer to complete the packed bed, and while sequentially moving the sintering pallet horizontally, The fuel in the blended raw material packed bed is ignited by the heat transfer from the heating packing to ignite and burn the fuel powder ore from the lower layer to the upper layer of the packed bed. A method for producing a sintered ore characterized by binding. 3. The method for producing a sintered ore according to claim 2, wherein the heating filler is a solid body having a particle size of 5 mm or more. 4. The sintering according to claim 1, wherein the compounded raw materials are charged on the lowermost layer of the packed bed and then a solid body is further charged thereon to complete the entire packed bed. Method of producing ore. 5. The method for producing a sinter according to claim 3, wherein the solid body is return ore or lump ore.