JP2002226920A - Sintered ore manufacturing method, and sintered ore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a sintered ore of high reducibility and metallization at low carbon consumption unit and the productivity is high, and to provide the sintered ore. SOLUTION: This sintered ore manufacturing method comprises a primary palletizing step of performing palletizing by mainly mixing flux and carbon in which grain size is regulated to below 3 mm substantially to sintering material, a secondary palletizing step of forming pseudo grains by covering powder- like carbon over the outer side of the palletized stuff obtained in the primary palletizing step, and a step of obtaining sintered ore in which powder iron ore is partially and preliminarily reduced by baking the pseudo particles by an endless moving grate type sintering machine.

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 used as a raw material for a blast furnace and a sintered ore obtained by the method.

[0002]

2. Description of the Related Art Conventionally, as a blast furnace raw material, a sintered ore obtained by mixing fine iron ore, a solvent medium, a fine carbonaceous material, etc., which are sintering raw materials, granulating, and then sintering has been used. I have.

[0003] With respect to such a sintered ore, conventionally, the raw material mixing and the granulation process have been adjusted to improve the air permeability, and to improve the flammability by adhering coke breeze to the surface of the pseudo particle. Various attempts have been made to adjust the structure of the blended raw materials and pseudo particles to increase the fuel efficiency.

[0004] In particular, in view of the improvement of blast furnace operation such as a reduction in the blast furnace fuel ratio, partially reduced sintered ore, which partially requires the function of reducing the blast furnace outside the system, has attracted attention. For example, Japanese Patent Application Laid-Open No.
No. 0432 discloses a two-layer pseudo-particle as an outer layer formed by mixing and granulating fine ore with fine coke and anthracite to form an inner layer, and mixing and coating fine ore, auxiliary materials and fine carbonaceous material and anthracite to form an outer layer. A technique is disclosed in which the pseudo-particles are mixed and granulated as a part of a sintering raw material, and then sintered by a sintering machine to produce a sintered ore. A part of the sinter is reduced by direct reduction of the melt and the solid carbon material in the pulverized carbonaceous material or anthracite in the inner layer.

However, in such a partially reduced ore, it is desirable to efficiently obtain a higher reduction ratio and a higher metallization ratio. However, in the method for producing a semi-reduced ore described in this publication, the outer layer When blending coke and anthracite for fuel into coal, the coke and anthracite of the fuel are blended in a state mixed with fine ore and auxiliary materials, resulting in poor flammability, resulting in high reduction and metallization rates. And productivity is poor.

On the other hand, Japanese Patent Application Laid-Open No. 2000-19215
No. 3 discloses that in pseudo particles having a three-layer structure of a core, an inner layer, and an outermost layer, the fine powder coke as a fuel is blended in the outermost layer to increase the combustion efficiency of the coke breeze, and coarse particles blended as the core. A method for producing a sintered ore, which appropriately determines the quantitative ratio with coke breeze, is shown, whereby the controllability of the ultimate reduction rate is remarkably enhanced, and the reduction rate can be controlled to an arbitrary reduction rate between 20 and 90%. It is stated that it can be done.

However, according to the technology described in this publication, the reduction efficiency of pseudo particles is not sufficient, and in order to obtain a high reduction ratio and a metallization ratio, it is necessary to increase the amount of carbonaceous material such as coke. Therefore, the basic unit of carbon material of the sintering machine is increased. Also, productivity is not enough.

The present invention has been made in view of such circumstances, and it is possible to obtain a sintered ore having a high reduction ratio and a high metallization ratio with a low carbon unit consumption, and to obtain a sintered ore having a high productivity. An object is to provide a production method and a sintered ore.

[0009]

In order to solve the above problems, the present invention provides a method of mixing a sintering raw material mainly with a solvent material and a carbonaceous material whose particle diameter is adjusted to substantially less than 3 mm. A primary granulation step of granulating the particles, a secondary granulation step of coating the granulated material obtained in the primary granulation step on the outside with a powdery carbonaceous material to form pseudo particles, Baking with an endless moving grate type sintering machine to obtain a sinter in which fine iron ore is partially pre-reduced.

A primary granulation step of mixing the sintering raw material mainly with a solvent medium and a carbonaceous material having a particle diameter adjusted to substantially less than 3 mm to form granules; A secondary granulation step of coating the powdered carbonaceous material on the outside of the granulated material obtained in step 2 to form pseudo particles, and firing the pseudo particles with an endless moving grate type sintering machine to partially remove the fine iron ore. Obtaining a pre-reduced sintered ore.

According to the present invention, in the primary granulation step, a sintering material mainly composed of fine iron ore is mainly mixed with a medium solvent and a carbon material such as coke whose particle diameter is adjusted to substantially less than 3 mm. And granulated, coated with pulverized carbonaceous material on the outside to form pseudo-particles of a two-layer structure, mainly reduced by the carbonaceous material in the inner layer,
Sintering is mainly performed using the outer layer carbon material, but the inner layer carbon material mainly used for reduction is finely smaller than 3 mm and is uniformly dispersed in the pseudo particles. , High reduction rate with less carbon unit consumption (preliminary reduction rate)
And a metallization ratio. Further, since the carbonaceous material unit can be reduced in this way, the reaction time of the carbonaceous material is shortened, and the productivity is high.

In the above method for producing a sintered ore, the step of firing the pseudo particles with an endless moving grate type sintering machine is preferably performed by setting the thickness of the bed layer of the pseudo particles to 200 mm or less. By making the layer thickness of the bed layer thinner than before, the air permeability of the bed is improved, and the productivity can be further improved.

It is preferable that the step of firing the pseudo particles with the endless moving grate type sintering machine is performed while circulating the exhaust gas discharged during sintering. By circulating the exhaust gas in this manner, the oxygen partial pressure in the system can be reduced, the reoxidation of the generated reduced structure can be suppressed, and sintering and reduction can be advanced, thereby further improving productivity. it can.

[0014] Further, the step of firing the pseudo particles by the endless moving grate type sintering machine may be such that the average reduction rate of the sinter is 30 or less.
% Is preferably performed. By achieving such a high reduction rate, the fuel ratio in the blast furnace can be substantially reduced, and a part of the reduction of iron ore is performed by a sintering machine with a higher reduction efficiency than the blast furnace, so that the total It is possible to reduce the amount of CO ₂ generated. In addition, the sintering is preferably performed such that the average metallization ratio is 6% or more. Even at the same average reduction rate, when the metallization is partially performed, the fuel ratio is easily reduced in the blast furnace from the viewpoint of reduction equilibrium, and the effect of reducing the fuel ratio is particularly large when the average metallization rate is 6% or more.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. FIG. 1 is a schematic configuration diagram showing an example of equipment for carrying out the method of the present invention. This equipment includes a pseudo particle manufacturing equipment 100 and a downward suction type endless moving sintering machine 200.

The quasi-particle production facility 100 includes a fine iron ore hopper 1 for storing fine iron ore, a fine mine hopper 2 for storing fine mineral ore, a medium solvent hopper 3 for storing medium solvent, and fine coke for inner layer. Is provided with an inner layer powder coke hopper 4, a primary drum mixer 5, a disc pelletizer 6, an outer layer powder coke hopper 7 for storing outer layer powder coke, and a secondary drum mixer 8. The iron ore supplied from the iron ore hopper 1 and the ore supplied from the ore hopper 2 constitute a sintering raw material.

The downward suction type endless moving type sintering machine 200 has an endless moving type moving grate 11, on which the above-mentioned pseudo particles are supplied by the charging system 10 to form a layered bed. 13a is formed.

The moving path of the moving grate 11 includes an ignition furnace 1
2 are provided, and the pseudo particles on the moving grate 11 are ignited when passing through the
Is started, and a sintering bed 13b is formed. An unillustrated crusher is provided on the outlet side of the moving grate 11, and the sinter dropped from the moving grate 11 is crushed by the crusher, supplied to the conveyor 14, and supplied to the blast furnace.

A plurality of wind boxes 15 are arranged directly below the moving grate 11 along the traveling direction of the moving grate 11, and a vertical duct 16 is connected to each wind box 15. These vertical ducts 16 are connected to a horizontally disposed main exhaust gas duct 17, and the exhaust gas is
It is to be discharged through. Main exhaust gas duct 1
The exhaust gas circulation path 18 is provided in the gas supply section 19 above the sintering bed 13b.
The exhaust gas is circulated during sintering. The exhaust gas is passed from the main exhaust duct 17 to the chimney 32 via the electric precipitator 30 by the main blower 31.
Is discharged from.

In the equipment configured as described above, first, a predetermined amount of fine iron ore and ore as a sintering material, a solvent medium and fine coke are cut out from each hopper of the pseudo particle manufacturing equipment 100 and supplied to the primary drum mixer 5. Mix while adding water. Subsequently, the mixed raw material is supplied to the disk pelletizer 6 and granulated while adding water.
At this time, coke breeze having a particle diameter of 3 mm or less is used. Thereby, raw pellets in a state where coke breeze is dispersed in the fine ore are formed. Next, the raw pellets granulated by the disk pelletizer 6 are supplied to the secondary drum mixer 8 and mixed while adding water and coke breeze cut out from the coke hopper 7 for the outer layer. At this time, if the raw pellets have high water content, it is not necessary to add water. As a result, the coke breeze is coated on the surface of the raw pellet, and pseudo particles are produced. When the granulation is sufficiently performed by the primary drum mixer 5 according to the raw material conditions, the granulation step by the disk pelletizer 6 may be omitted.

As shown in FIG. 2, the quasi-particles produced in this way are, as shown in FIG. 2, an inner layer 23 in which powder coke 22 having a particle diameter of 3 mm or less is dispersed in a sintering raw material 21 and an outer layer 24 made of powder coke. And has a particle size of 2
20 mm.

Next, the pseudo particles having such a structure are supplied through the charging system 10 to a downward suction type endless moving type sintering machine 200.
To form a bed 13a of pseudo particles. Then, the surface of the bed 13a is ignited by the ignition furnace 12, and fired while sucking air downward through the wind box 15 to form a sintered bed 13b, which is an aggregate of sintered ore. After sintering in this manner, the ore falls from the moving grate 11 as described above, and the dropped ore is crushed by the outlet-side crusher, supplied to the conveyor 14, and supplied to the blast furnace. You.

At this time, the thickness of the bed 13a is 200 m
m or less. Bed 13a like this
By making the thickness of the thinner than before, it becomes possible to improve the ventilation speed and increase the speed of the great,
Productivity can be improved. Further, it is preferable that the exhaust gas is circulated through the exhaust gas circulation path 18 and the gas supply unit 19 during such a sintering process. By circulating the exhaust gas in this way, the oxygen partial pressure in the system can be reduced, and the sintering and reduction can be advanced while suppressing the combustion of the carbonaceous material, improving the productivity of the highly reduced sinter. Can be done.

Next, the sintering and reduction (preliminary reduction) process of the pseudo particles will be described. Here, the pseudo particle has a two-layer structure of the inner layer 23 in which the coke breeze 22 is dispersed in the sintering raw material 21 and the outer layer 24 made of the coke breeze as described above. Coke breeze 2 dispersed in the sintering raw material 21 of the inner layer 23
2 mainly contributes to the reduction of the sintering raw material, and the coke breeze constituting the outer layer 24 mainly contributes to the sintering. That is, the function is separated between the inner layer coke breeze and the outer layer coke breeze, and reduction and sintering proceed simultaneously.

According to the results of the study by the present inventors, the inner layer 23
The reduction reaction proceeds mainly by a solid-solid reaction rather than a gas-solid reaction. In such a case, the reduction reaction depends on the particle size of the coke breeze 22. Was found to be more likely to occur. Specifically, when coke having a particle size larger than 3 mm is used as coke in the inner layer, the reduction reaction is suppressed, and coke remains in the inner layer 23. Was almost consumed in the reduction reaction.

As described above, the pseudo-particle having a two-layer structure of the inner layer 23 in which the 3 mm under coke powder 22 is dispersed and the outer layer 24 made of the coke powder is used, so that the coke powder 22 is sintered in the inner layer 23. Raw material 21
And a high reduction rate (preliminary reduction rate) and metallization rate can be obtained with a small unit of carbon material. Also,
As described above, since the carbon unit consumption can be reduced, the productivity of the highly reduced sinter is high.

Next, the relationship between the reduction rate of the sintering raw material and the blast furnace operation will be described. FIG. 3 is a diagram showing a gas temperature distribution inside the blast furnace. In FIG. 3, the gas temperature inside the blast furnace is about 150 to 200 ° C. at the top of the furnace, and 2000 to 2000 at the tuyere.
2400 ° C. Further, the shaft portion has a so-called heat preservation zone, which is a constant temperature region of approximately 1000 ° C. In this heat preservation zone, iron oxide is present in the gas composition and reduction stage slightly deviating from the FeO-Fe reduction equilibrium.

The upper part of FIG. 4 shows the relationship between the degree of oxidation of gas in the blast furnace and the degree of oxidation of iron oxide. The horizontal axis represents the degree of oxidation of the gas in the blast furnace (in other words, the ratio of oxygen atoms to carbon atoms, O / C).
The degree of oxidation of the gas is 1 when the gas composition is only CO in the lower part of the blast furnace, and 2 when the gas moves to the upper part while reducing iron oxide and finally becomes the total amount of CO ₂ (+ N ₂ ). It is. The result is basically the same as that of the gas except that H ₂ and H ₂ O are contained in the gas, except that a slight change appears in the reduction equilibrium diagram. On the other hand, the vertical axis indicates the oxygen atom ratio to the iron atom (O / Fe), the oxidation degree of Fe ₂ O ₃ having the highest oxidation degree is 1.5, and 1.33 for Fe ₃ O ₄ ,
In O, it is 1.05.

The lower part of FIG. 4 is an equilibrium diagram of the reduction of iron oxide by CO. The horizontal axis represents the degree of oxidation of the gas as described above, and the vertical axis represents the reduction equilibrium temperature. As shown in FIG.
When the temperature is set to 00 ° C., the degree of gas oxidation (O / C) at the time of Fe—FeO reduction equilibrium at this temperature is obtained from the lower stage of FIG. Since the degree of oxidation of ore (FeO) is 1.05, the point W in the upper part of FIG. 4 can be obtained.

On the other hand, when charged from the furnace top ore oxidation degree 1.5, _(hereinafter referred to as operating line) linearly P _T -P B oxidation degree of oxidation degree and gas ore varies along the. The fuel ratio of the blast furnace is determined by the gradient (C / Fe) of this straight line. When the operation of the blast furnace is ideally performed and the reduction equilibrium has been reached, this straight line is in contact with the point W and the fuel ratio takes the minimum value. shift for operation line without passing through the point W, for example through P ₁ point. Here, the ratio of the length of the straight line P ₀ -W to the length of the straight line P ₀ -P ₁ (P _0-
W) / (P ₀ −P ₁ ) represents the degree of reduction equilibrium of the blast furnace,
It is an index called shaft efficiency. Usually, the shaft efficiency of a blast furnace is about 0.90 to 0.95.

When the partially reduced sinter of the present invention is used as a blast furnace raw material, the oxidation degree of iron oxide at the time of charging the blast furnace is lower than 1.5, so that _{PT ′} is replaced by _{PT ″} in FIG. As a result, the gas composition (degree of oxidation) is also reduced, and as a result, the calorific value of the gas is increased.If the partial reduction ratio of the sinter exceeds 30%, the ordinate of the point W is less than 1.05. low W 'shifts to point. assuming shaft efficiency constant, the operation line shaft efficiency _{(P 0} -P _1' will be passing through the point _{/ P} 0 -W ') P ₁ is _constant', as a result The slope of the operation line becomes smaller and the fuel ratio decreases, but in this case, since the oxidation degree of the gas does not decrease, it is estimated that the calorific value of the gas generated from the blast furnace does not change.

That is, the partial reduction rate is 30% or more (Fe
In the reduction step where O and some metallic iron are present), the fuel ratio of the blast furnace can be reduced according to the preliminary reduction rate. In addition, the sinter can be partially reduced in a sintering machine having a higher reduction efficiency than the blast furnace, and the partially reduced sinter can reduce the fuel ratio in the blast furnace. As a result, the total energy consumption of the blast furnace is reduced, and thus the amount of carbon dioxide generated can be suppressed. At this time, even if the reduction rate is the same on average, the fuel ratio can be reduced as the number of metallized portions increases, that is, as the average metallization rate increases, and the effect is that the average metallization rate is 6%. The above is a larger one. Here, as described above, the particle size of the coke breeze of the inner layer of the pseudo particles was 3 mm.
By making the under powder and fine powder, the reactivity with the sintering raw material is high, and a high reduction rate and a metallization rate can be obtained with a small amount of coke, and the partial reduction rate can be more efficiently increased to 30% or more. Therefore, the amount of coke itself can be reduced, and the total amount of carbon dioxide generated can be further reduced.

Here, SiO _{2 in} the compounding material of the pseudo particles was
It is preferable to adjust the content to 5 mass% or less.
This is because if the blended raw material contains more than 5 mass% of SiO ₂ , a large amount of firelite is generated during the firing process, but this firelite has poor reducibility in lump belts below 1000 ° C in a blast furnace. This causes stagnation of reduction, and also causes a large amount of low-melting slag in the softening / melting zone at 1000 ° C or higher, worsening the burn-through property of the softening / melting zone, and hindering the reduction of the blast furnace fuel ratio. is there.

As the above-mentioned solvent medium, usually quick lime is desirable, but in addition to slaked lime and bentonite, fine powder slag, portland cement and the like may be used. As described above, the coke breeze for the outer layer is for supplying the heat required for sintering, and it is important to form a uniform and strong coating layer on the surface layer of the pseudo-particle. Further, since the change in the amount is directly reflected in the calorific value, the calorific value is excellent. In order to enhance the effect of covering the pseudo particles, the smaller the particle size of the coke breeze for the outer layer, the better. The particle size is preferably 5 mm or less, more preferably 1 mm or less. Although coke breeze was used as the carbonaceous material, anthracite, coal, char, petroleum coke and the like can be substituted.

[0035]

Embodiments of the present invention will be described below. (Example 1) Fine iron ore (-0.125 m
m is 28.96% (average particle size: 2.08 mm) and returned ore (average particle size: 1.4 mm); 92 mass% in total; limestone 4.5 mass% + quick lime 3.5% as a solvent; For the inner layer, a powder coke having a particle diameter of 1 mm was used.
Three types were used: under (3 mm coke), 3 to 5 mm (5 mm coke), and 5 to 8 mm (8 mm coke). First, after mixing and humidifying the sintering raw material, the solvent medium, and the inner layer coke breeze, pellets of 5 to 10 mmφ are produced with a 1.2 m experimental disk pelletizer,
Next, the pellets were coated with a predetermined amount of powdered coke for an outer layer to produce pseudo particles.

Next, the pseudo particles were prepared by simulating the above-mentioned endless moving grate type sintering machine with an inner diameter of 300 mm and a depth of 500 m.
m was filled into a cylindrical pot of a predetermined amount, ignited and sintered. Negative suction pressure at this time 1000Mmaq, a concentration of the suction oxygen blowing _{N 2} from the pot upper sintering latter half portion 15
%. This is to prevent reoxidation of the reduced sinter, and in actual equipment, simulates exhaust gas circulation. At this time, the height of the raw material in the pot corresponding to the bed layer thickness was changed.

After completion of sintering, a series of operating conditions such as sintering time, production rate from product, yield, etc. are evaluated.
The sintered block was dismantled, and the properties of the reduced sinter, such as the pre-reduction ratio and metallization ratio, were evaluated by sampling samples from each part.

FIG. 5 is a graph showing the relationship between the particle size of each inner layer powder coke, with the horizontal axis representing the total amount of carbonaceous material and the vertical axis representing the average preliminary reduction ratio. From this figure, when the powdered coke for the inner layer is 3 mm coke, the total amount of carbon material added is 11 mass% and the preliminary reduction rate is 30% or more, whereas the total amount of carbon material added is 5 mm and 8 mm coke. The preliminary reduction rate is less than 30%,
It can be seen that a larger amount of carbon material is required to obtain a preliminary reduction rate of 30% or more. That is, it was confirmed that the use of 3 mm coke (under 3 mm) as powder coke for the inner layer enables a preliminary carbon reduction ratio of 30% or more to be efficiently obtained with a small amount of carbonaceous material.

FIG. 6 is a diagram showing the relationship between the particle size of each inner layer powder coke, with the horizontal axis representing the total amount of added carbon material and the vertical axis representing the average metallization ratio. From this figure, when the inner layer powdered coke is 3 mm coke, the total amount of carbon material is 11 mass% and the average metallization ratio is 6% or more, while the total amount of carbon material is 5 mass coke in 11 mass%.
Less than 3%, and 13 mass% for 8 mm coke
However, it is less than 1%, indicating that only a low metallization ratio is exhibited. That is, it was confirmed that the use of 3 mm coke (under 3 mm) as the powder coke for the inner layer can efficiently obtain a preliminary reduction ratio of 6% or more with a small amount of carbonaceous material.

FIG. 7 is a diagram showing the relationship between the bed layer thickness on the horizontal axis and the production rate on the vertical axis. As shown in this figure, it was confirmed that as the bed layer thickness became thinner, the production rate increased, and in particular, 200 mm or less was favorable.

[0041]

As described above, according to the present invention,
In the primary granulation process, a sintering raw material mainly composed of iron ore is mixed with a medium solvent and a carbon material such as coke whose particle diameter is adjusted to substantially less than 3 mm to form a two-layer structure. Is formed mainly by reduction with the carbon material in the inner layer, and sintering is mainly performed by the carbon material in the outer layer. Pseudo-particles of less than 3 mm are mainly used as the carbon material in the inner layer mainly used for reduction. Since it is uniformly dispersed in the particles, the reactivity with the sintering raw material is high, and a high reduction rate and a high metallization rate can be obtained with a small unit of carbon material. Further, since the carbonaceous material unit can be reduced in this way, the reaction time of the carbonaceous material is shortened, and the productivity is high.

Further, the step of firing the pseudo particles with an endless moving grate type sintering machine is performed by setting the thickness of the bed layer of the pseudo particles to 200.
When the thickness is set to be equal to or less than mm, the air permeability of the bed is improved, and the productivity can be further improved. further,
By sintering the pseudo particles with an endless moving great type sintering machine while circulating the exhaust gas discharged during sintering, the oxygen partial pressure in the system can be reduced, and the combustion of carbonaceous materials is suppressed. Sintering and reduction can proceed while
Productivity can be further improved.

The fuel ratio in the blast furnace can be substantially reduced by performing the step of firing the pseudo particles with the endless moving grate type sintering machine so that the average reduction ratio of the sinter becomes 30% or more. In addition, since a part of the reduction of the iron ore is performed by a sintering machine having a higher reduction efficiency than that of the blast furnace, the total amount of generated CO ₂ can be reduced. Also,
Even with the same average reduction rate, partial metallization makes it easier to lower the fuel ratio in the blast furnace, and the average metallization rate is 6%
As described above, the effect of lowering the fuel ratio can be particularly increased.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of equipment for performing a method of the present invention.

FIG. 2 is a cross-sectional view showing a pseudo particle having a two-layer structure obtained according to an embodiment of the present invention.

FIG. 3 is a view showing a gas temperature distribution in a blast furnace.

FIG. 4 is a diagram showing the relationship between the degree of oxidation of gas in a blast furnace and the degree of oxidation of iron oxide, and the reduction equilibrium of iron oxide.

FIG. 5 is a graph showing the relationship between the total amount of added carbonaceous material and the average preliminary reduction ratio in the particle size of the powdered coke for each inner layer.

FIG. 6 is a graph showing the relationship between the total amount of carbonaceous materials and the average metallization ratio in the particle size of each inner layer powder coke.

FIG. 7 is a diagram showing a relationship between a bed layer thickness and a production rate.

[Explanation of symbols]

 1 ... iron ore hopper 2 ... returned ore hopper 3 ... solvent hopper 4 ... powder coke hopper for inner layer 5 ... primary drum mixer 6 ... disk pelletizer 7 ... powder coke hopper for outer layer 8 ... 2 Next drum mixer 10 Charging system 11 Moving grate 12 Ignition furnace 13a Bed 13b Sintering bed 18 Exhaust gas circulation path 100 Pseudo-particle manufacturing equipment 200 Downward suction endless moving type Sintering machine

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidetoshi Noda 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Koichi Ichikawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun (72) Inventor Michitaka Sato 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. Nippon Kokan Co., Ltd. F term (reference) 4K001 AA10 BA02 CA18 CA19 CA20 CA21 CA23 CA39 GA12

Claims (8)

[Claims] 1. a primary granulation step of mixing and granulating a sintering raw material mainly with a solvent medium and a carbonaceous material whose particle diameter has been adjusted to substantially less than 3 mm; A secondary granulation step of coating the powdered carbonaceous material on the outside of the granulated material obtained in step 2 and forming pseudo particles, and firing the pseudo particles with an endless moving grate type sintering machine to partially remove the iron ore fines. Obtaining a preliminarily reduced sinter. 2. The step of firing pseudo particles with the endless moving grate type sintering machine, wherein the thickness of the bed layer of pseudo particles is 20
The method for producing a sintered ore according to claim 1, wherein the method is performed at 0 mm or less. 3. The sintering of pseudo particles with the endless moving grate type sintering machine is performed while circulating exhaust gas discharged at the time of sintering. Production method of sintered ore. 4. The step of firing the pseudo particles with the endless moving grate type sintering machine is performed so that the average metallization ratio of the sintered ore is 6% or more. Item 4. The method for producing a sintered ore according to any one of Items 3. 5. The step of firing the pseudo particles with the endless moving grate type sintering machine is performed so that the average reduction ratio of the sintered ore becomes 30% or more. 5. The method for producing a sintered ore according to any one of 4. 6. A primary granulating step of mixing and granulating a sintering raw material mainly with a solvent medium and a carbonaceous material having a particle diameter adjusted to substantially less than 3 mm; A secondary granulation step of coating the powdered carbonaceous material on the outside of the granulated material obtained in step 2 to form pseudo particles, and firing the pseudo particles with an endless moving grate type sintering machine to partially remove the fine iron ore. Obtaining a pre-reduced sintered ore. 7. The sintered ore according to claim 6, wherein the average metallization ratio is 6% or more. 8. The sintered ore according to claim 6, wherein the average reduction ratio is 30% or more.