JP4532313B2 - Manufacturing method of carbonized material agglomerates - Google Patents

Description

  The present invention relates to a method for producing an agglomerated carbonaceous material agglomerated material that can be used as a raw material for vertical furnaces such as blast furnaces and cupolas. Regarding the method.

  For the purpose of using as a raw material for vertical furnaces such as blast furnaces and cupolas, the present inventors have formed a conventional carbon material interior by hot forming a mixture of fine ore and a soft and meltable carbon material. We have developed an agglomerate of carbonaceous materials that can provide high strength without adding a binder such as cement, such as cold pellets.

  Such a carbonaceous material agglomerated material can be produced, for example, by a process as shown in FIG. That is, the powdered iron ore B was heated to 400 to 800 ° C. with the rotary kiln 2 and the powdered carbon material A having soft melting property was separately dried with the rotary dryer 1 at a temperature of less than 250 ° C. at which softening and melting did not occur. After that, the powdered carbon material A and the powdered iron ore B are mixed with a biaxial mixer 3 to obtain a mixture C of 250 to 550 ° C., which is a temperature at which the powdered carbon material A is softened and melted. Then, the mixture C is hot-molded by a twin-roll molding machine 4 to form a briquette, the briquette (molded product) D is sieved by a sieve (screen) 8, and the powder F under the sieve is returned to the mixer 3 again. In this way, the mass E on the sieve is recovered as an agglomerated carbonaceous material agglomerated for the purpose of effective utilization as a raw material (see Patent Documents 1 and 2).

  In the above method, the under-sieving powder F after hot forming is returned to the mixer 3 and effectively used as a raw material. However, it has been found that the following problems occur due to the subsequent studies by the inventors.

That is, when the mixture C is hot-formed by the twin roll molding machine 4, in addition to the regular molding D, unmolded powder spilled from the ends of the twin rolls and unsteady starting / stopping of the molding machine 4. Occasionally, a molded product out of specification is generated. In addition, since the regular molded product D itself has so-called burrs, powder derived from the burrs is generated during the conveyance process. These out-of-standard molded products and powders are collectively referred to as “non-standard products” below. This non-standard product can be returned to the mixer 3 again and mixed into the mixture C for effective use, as in the case of the sieve powder F, but has the following problems. That is, the non-standard product has been coarsened as compared with the powdered iron ore B by mixing with the softened carbonaceous material in the mixer 3 or the molding process in the molding machine 4. Therefore, depending on the type, fluidity and mixing amount of the powdered carbonaceous material A, when such a non-standard product is mixed with the mixture C, the adhesion between the powders decreases, resulting in molding. This causes a decrease in strength of the molded product D obtained. When the strength of the molded product D decreases, the amount of powder generated further increases, the recovery yield of the carbonaceous material agglomerated product E as a product decreases, and the strength of the carbonaceous material agglomerated product E itself also decreases. It becomes unsuitable as a charging material for a vertical furnace. Further, in order to compensate for such a decrease in strength of the molded product D, increasing the blending amount of the powdered carbonaceous material A having the softening and melting property into the mixture C increases the cost and increases the carbonaceous material interior lump. The amount of the carbonaceous material in the chemical E is excessive than the amount required for reduction, which is useless.
Japanese Patent No. 3502011 Japanese Patent No. 3502008

  Then, this invention aims at providing the manufacturing method of the carbonaceous material agglomerated material which can ensure the collection | recovery yield and intensity | strength of a lump top mass thing while utilizing effectively the undersieving powder after hot forming. To do.

  The invention according to claim 1 is a carbon material drying and heating step of drying and heating a powdered carbon material having softening and melting properties at 350 ° C. or less, and a raw material heating step of heating the powdered iron-containing material to 400 to 800 ° C. And a mixing step of mixing the dried powdered carbonaceous material and the heated powdered iron ore into a mixture of 250 to 550 ° C, and hot forming the mixture into a molded product A molding step, a sieve process for classifying the molded product into a sieved lump and a sieved powder, and collecting the sieved lump as a carbonaceous material agglomerated product, and the sieved powder. A solid powder circulation step for returning all or part of the solid powder to the raw material heating step, and using the solid powder circulation step as part of the heated fuel for heating the powdered iron-containing raw material. It is a manufacturing method of a chemical compound.

  Invention of Claim 2 is a raw material heating process which heats the powdery iron containing raw material to 400-800 degreeC, and the carbonaceous material drying heating process which dries and heats the powdered carbonaceous material which has soft melting property at 350 degrees C or less And a mixing step of mixing the dried powdered carbonaceous material and the heated powdered iron ore into a mixture of 250 to 550 ° C, and hot forming the mixture into a molded product A molding step, a heat treatment step of maintaining the molded product at a temperature of the hot molding temperature to 800 ° C. to remove volatile components and tars remaining in the molded product, and sieving the molded product to sieve Classifying into lump and under sieve powder, recovering the above lump mass as a carbonaceous material agglomerated material, and all or part of the solid powder consisting of under sieve powder into the raw material heating process The solid powder used as part of the heating fuel for heating the powdered iron-containing raw material. A step, a carbonaceous material decorated agglomerate manufacturing method, characterized by comprising a.

  Invention of Claim 3 is a raw material heating process which heats a powdery iron containing raw material to 400-800 degreeC, and the carbonaceous material drying heating process which dries and heats the powdered carbonaceous material which has soft melting property at 350 degrees C or less And a mixing step of mixing the dried powdered carbonaceous material and the heated powdered iron ore into a mixture of 250 to 550 ° C, and hot forming the mixture into a molded product A molding step, a non-standard product removing step for removing a non-standard product generated in the hot molding step from the molded product, and a molded product after the non-standard product is removed from the hot molding temperature to 800 ° C. A heat treatment step for removing volatile and tar components remaining in the molded product while maintaining the temperature of the molded product, and sieving the molded product to classify it into a sieved lump and a sieved powder, From the sizing process to collect as an agglomerated carbonaceous material agglomerated material, the non-standard product and the under sieve powder A solid powder circulation step for returning all or part of the solid powder to the raw material heating step and using it as part of the heated fuel for heating the powdered iron-containing raw material. It is a manufacturing method of an agglomerated material.

  “Powdered carbon material having soft melting property” means coal, SRC, tire chip, plastic, asphalt, tar, etc. whose log MF (where MF is Giesera maximum fluidity) is 1.0 or more. It is a generic term for powders that contain at least one carbonaceous material having soft melting properties. This “powdered carbonaceous material having softening and melting properties” includes carbon having substantially no softening and melting properties, such as coke, steaming coal, anthracite, and oil coke, in addition to the carbonaceous material having softening and melting properties. It may be a mixture of one or more substances. “Powdered iron-containing raw material” means a raw material mainly containing iron oxide such as iron ore and iron-making dust (blast furnace dust, converter dust, electric furnace dust, mill scale, etc.), or two or more of these raw materials It is a general term for a mixture of powders.

  According to the present invention, the carbon material in the solid powder is combusted by returning the solid powder composed of the carbon material after dry distillation and the iron-containing raw material to the raw material heating step and using it as part of the fuel. Thus, the powdered iron-containing raw material disappears while heating, so that only the remaining iron-containing raw material is added to the new powdered iron-containing raw material heated in the raw material heating step and reused. In addition, even if the carbonaceous material is not completely burned out and remains partially, there is no problem because it can be used as a constituent material of a molded product.

  Therefore, the carbonaceous material content in the solid powder is effectively used as combustion energy, and the effect of reducing the heated fuel is obtained, and the iron-containing raw material content in the solid powder is replaced with a part of the new powdered iron-containing raw material. And effectively used. Furthermore, unlike the above prior art, the carbonaceous material that is light in solid powder and has lost its softening and melting property can be prevented from being mixed into the mixture, and can be molded in a tightly packed state. Strength can be secured.

(Embodiment)
The conceptual diagram of the manufacture flow of the carbonaceous material interior agglomerate which concerns on FIG. 1 at one Embodiment of this invention is shown. In addition, the same code | symbol was used for the apparatus and substance which are common in FIG. 2 demonstrated by the said prior art. Hereinafter, powdered iron ore will be described as a representative example as a powdered iron-containing raw material. Among the carbon materials, a carbon material having soft melting property (for example, caking coal, SRC, etc.) is 1 mm in order to maintain a good mixed state with the powdered iron ore and the carbon material substantially not having soft melting property. It is desirable to grind to the following extent. Moreover, in order to improve the filling property with the above-mentioned softening and melting carbonaceous material, iron ore and a carbonaceous material that does not substantially have softening and melting property (for example, coke powder, general coal, anthracite, oil coke). Etc.) should be crushed and used if necessary. Although the upper limit of the pulverized particle size is a particle size that can be molded, the lower limit is not particularly limited, but it is preferably about the same as that of a carbon material having softening and melting properties.

[Carbon dry drying process]
The powdery carbonaceous material A thus adjusted in particle size is dried and heated at a temperature of 350 ° C. or less at which the carbonaceous material A is not substantially softened and melted in the carbonaceous material drying heating facility (for example, a rotary dryer) 1. Remove adhering moisture. Here, the drying heating temperature of the powdered carbon material was “less than 250 ° C.” in which the carbon material is not softened and melted in the conventional technology (see Patent Documents 1 and 2). It was found that the carbonaceous material was not substantially softened and melted even when the drying heating temperature was increased to “350 ° C. or lower”.

[Raw material heating process]
On the other hand, the powdered iron ore B is preheated to 400 to 800 ° C. with the raw material heating equipment (for example, rotary kiln) 2 so that the target temperature becomes 250 to 550 ° C. when mixed with the powdered carbon material A. As fuel injected from the burner of the rotary kiln 2, pulverized coal that is solid fuel, heavy oil that is liquid fuel, natural gas that is gaseous fuel, COG, or the like can be used. A non-standard product G generated during hot forming, which will be described later, and a briquette underfloor powder F after heat treatment (hereinafter collectively referred to as “solid powder H”) are added to the fuel. Is blown into the rotary kiln 2. In the case where a large particle size such as burrs derived from briquette D is present as it is in the solid powder H, the particle size of the new powdered iron ore B from the viewpoint of improving the combustibility of the carbonaceous material in the solid powder H and protecting the burner It is preferable to use after pulverizing or pulverizing to the same extent. In this way, the solid powder H blown into the rotary kiln 2 together with the fuel burns the carbonaceous material and contributes to the heating of the powdered iron ore B. Only stones are mixed into the new powdered iron ore B.

[Mixing process]
The mixing of the dried powdered carbon material A and the preheated powdered iron ore B is short as a mixing facility in order to suppress unnecessary granulation due to mineralization and / or softening of the carbonaceous material. For example, a bowl-shaped mixing tank 3 that is commonly used in this type of industry that can be mixed with time is used. In addition, this bowl-shaped mixing tank 3 is insulated and / or kept warm in order to ensure the molding temperature. Although solid powder H is mixed in the powdered iron ore B, as described above, the carbonaceous material in the solid powder H is completely or almost burned and disappeared in the rotary kiln 2 (strictly In other words, the ash content of the carbonaceous material can remain in the solid powder H, but the amount thereof is very small and does not substantially cause a problem.) Maintained. As a result, the strength of the carbonaceous material agglomerated material (hereinafter also simply referred to as “agglomerated material”) E after heat treatment, which will be described later, is maintained high.

[Hot forming process]
The mixture C composed of the powdered carbon material A and the powdered iron ore B is pressure-molded by using, for example, a hot-rolling twin-roll molding machine 4 as a molding facility to obtain a molded product D. The pressure molding has a strength sufficient to allow the agglomerate E obtained by heat-treating the molded product D to withstand handling from the molding machine 4 to charging into a vertical furnace (for example, a blast furnace). The molding pressure is set to 10 kN / cm or more so that 5 kN / piece or more is obtained.

  In the molded product D thus molded, the melted softening and melting carbon material A enters the voids of the powdered iron ore B, and this carbon material A acts as a lubricant to form the molded product D. Since the molding pressure applied to the surface of the material extends almost uniformly to the inside of the molded product D, it is prevented that only the vicinity of the surface is consolidated, the porosity distribution in the molded product D is averaged, and during heating, An agglomerate E in which no explosion occurs is obtained.

  In addition, the carbonized material A after solidification firmly connects the particles of the powdered iron ore B and has a large contact area with the powdered iron ore B, and the agglomerates obtained in this way. E has high strength and excellent reducibility.

[Non-standard product removal process]
The non-standard product (non-standard molded product, powder, etc.) G is removed from the molded product D thus formed using, for example, the screen 8 ', and the molded product D is recovered.

[Heat treatment process]
The molded product D was charged into a heat treatment facility (for example, a shaft furnace) 5 adjusted to a temperature of the hot molding temperature (250 to 550 ° C.) or higher and 800 ° C. or lower, and the volatile matter remaining in the molded product D and Remove tar and solidify charcoal. Thereby, when the agglomerated product E obtained by heat-treating the molded product D is charged in the vertical furnace and heated, the carbonaceous material is no longer softened and the strength of the agglomerated product E is maintained. In addition, a large amount of tar is not generated, and trouble such as tar sticking to the exhaust gas system of the vertical furnace can be prevented. The lower limit of the temperature in the shaft furnace 5 is set as the molding temperature because if the temperature is lower than the molding temperature, it is very difficult to remove volatile components and tar components, and the upper limit is set to 800 ° C. This is to prevent the strength of the agglomerated material H from being reduced unnecessarily in the shaft furnace 5. In order to promote the removal of volatile matter and tar, it is one of effective means to control the inside of the shaft furnace 5 to a negative pressure.

  The agglomerate H heat-treated in the shaft furnace 5 may be ignited or burnt if discharged into the atmosphere while being hot. Therefore, the agglomerate H may be cooled to 400 ° C. or lower with an inert gas such as nitrogen gas at the bottom of the shaft furnace 5. It is desirable to discharge from.

  The rotary dryer 1, the vertical mixing tank 3, the molding machine 4 and the shaft furnace 5 have a structure that prevents the entry of air (oxygen) from the outside, and the pyrolytic gas (volatilization) of the carbonaceous material A generated in these facilities. Since the main component is hydrocarbon, the gas is sucked and recovered using an ejector or the like, and the recovered gas is used as a heating fuel for the rotary kiln 2 or the like. In addition, since harmful components such as dust and high boiling point tar are contained in this gas, it is desirable to use it after dust removal and cleaning by an exhaust gas treatment facility (for example, a water-resistant scrubber) 9.

[Sizing process]
The molded product D discharged from the shaft furnace 5 is loaded into a sizing apparatus (for example, a rotating drum) 7 as necessary and rolled for a predetermined time to remove burrs formed during molding. After that, it is discharged from the rotary drum 7 and sieved with a screen 8 and classified into a sieved lump E and a sieved powder F, and the sieved lump E is recovered as the intended high-strength carbonaceous agglomerate. To do.

[Solid powder circulation process]
As described above, the solid powder H (non-standard product G and unsieved powder F) is crushed or pulverized to the same particle size as that of the new powdered iron ore B as necessary, and then the solid powder carrying pipe 10 Then, the carrier gas is used to return to the raw material heating step, and is added to the burner fuel supply pipe of the rotary kiln 2 to be used as fuel.

(Modification)
In the above embodiment, an example in which a rotary dryer is used for the carbonaceous material drying and heating process has been shown, but a fluidized bed dryer, a tube dryer, an externally heated multi-cylinder rotary dryer, an airflow dryer, a fluidized bed dryer, etc. Alternatively, a combination of these may be used.

  Moreover, in the said embodiment, although the example which uses a rotary kiln for the raw material heating process was shown, using a fluidized bed type heating furnace, a tube type heating furnace, an external heating type multi-cylinder kiln, an indirect heating furnace by heating solid, etc. Alternatively, a combination of these may be used.

  Moreover, although the example which uses a vertical mixing tank for a mixing process was shown in the said embodiment, a container rotation type mixing tank, a horizontal type mixing tank, etc. may be used and you may use combining these two or more. In addition to the continuous mixing method, a batch type mixing method in which a hopper is installed upstream of the mixing tank and operated intermittently may be adopted. Also good.

  Moreover, although the example which uses a twin roll type | mold molding machine for the hot forming process was shown in the said embodiment, you may use an extrusion molding machine, a tableting machine, etc.

In the above embodiment, both the non-standard product removal process and the sizing process are provided, and the non-standard product is removed in the non-standard product removal process. However, the non-standard product removal process is omitted. Then, after removing the non-standard product from the heat treatment step in the heat treatment step together with the molded product, it may be removed as a sieve powder in the granulation step.

  Moreover, in the said embodiment, although the example which uses a shaft furnace for the heat treatment process was shown, you may use a rotary kiln, a rotary hearth furnace, an external heating type multi-cylinder kiln, a batch furnace, etc., combining these two or more. It may be used.

  Moreover, although the example which provided the heat processing process was shown in the said embodiment, when the usage-amount of the carbonaceous material agglomerated material in a vertical furnace is small, since the total amount of tar generation in a vertical furnace also decreases. The heat treatment step may be omitted. In addition, the carbonaceous material agglomerate produced by the method of the present invention is gradually heated in the furnace when charged into the vertical furnace, so even if volatile matter remains inside, Volatiles are gradually removed, so there is no risk of the agglomerates exploding. When the heat treatment step is omitted, the nonstandard product removal step in the preceding stage may be omitted, and the nonstandard product may be removed in the granulation step in the subsequent stage of the heat treatment step.

  Moreover, although the example which provided the cooling part in the lower part of the shaft furnace was shown in the said embodiment, you may provide cooling equipment separately from a shaft furnace.

  Moreover, in the said embodiment, although the rotating drum for burr | flash removal and the screen 8 for sieving were shown in the granulation process, the burr removal and sieving were performed simultaneously using only a vibration screen. It may be.

  Moreover, in the said embodiment, although the example which uses solid powder conveyance piping and carrier gas for the solid powder circulation process was shown, for example, when using pulverized coal for the fuel for burners of a rotary kiln, solid powder is pulverized coal by a conveyor etc. It may be transferred to the hopper and charged.

  Moreover, in the said embodiment, although the example which returns solid powder only to a raw material heating process was shown, a part is returned to a mixing process to such an extent that it does not affect the intensity | strength of a molded object (agglomerated material), and the remainder is heated to raw material. You may make it return to a process. Further, instead of or in addition to the raw material heating step, it may be used as a part of heating fuel such as a carbonaceous material drying heating step and a heat treatment step. However, when using it as a part of heating fuel other than a raw material heating process, measures, such as collect | recovering the residual materials which have the ore part after combustion as a main component and returning to a raw material heating process, are required.

[Flammability of solid powder]
For the purpose of investigating the flammability of sieving powder among solid powders (non-standard products and sieving powder), first, the following hot forming experiments and deburring experiments were conducted to prepare the sieving powder. went.

FIG. 3 shows an outline of the hot forming machine used in this hot forming experiment. After preheating the pulverized coal shown in Table 1 and the pulverized iron ore shown in Table 2 at a mass ratio of 22:78 to only 600-700 ° C. in an electric furnace not shown, The mixture was charged in a mixer kept at a temperature of 400 ° C. and mixed to 400 to 550 ° C., and the mixture was supplied hot to a twin roll type molding machine under conditions of a roll rotation speed of 4 to 6 rpm and a molding pressure of 10 to 50 kN / cm. 30 mm × 25 mm × 15 mm (about 6 cm ³ ) egg-shaped briquette (molded product). And a part of this briquette was heat-treated under conditions of 600 to 800 ° C. for several minutes to 1 hour in a nitrogen atmosphere.

  Next, the following burr removal experiment was performed. That is, the briquette before heat treatment and the briquette after heat treatment were each cooled to room temperature, and then 5 kg was subjected to vibration for 60 minutes on a screen having a sieve size of 5 mm, and classified into a lump-like mass and a sieve powder. As a result, regardless of before and after the heat treatment, no burrs were visually left in the obtained mass on the sieve, and a crushing strength of 0.5 to 2 kN / piece was obtained. The mass of the upper lump / total briquette mass [5 kg] × 100%) was 85 to 95%.

  Next, the briquette sieving powder after heat treatment was exposed to a burner flame and burned for 10 minutes. As a result of measuring the mass of the sample before and after combustion, a mass decrease of 20 to 25 mass% was observed. Moreover, as a result of elemental analysis of the samples before and after combustion, the carbon content was 17 to 20% by mass before combustion, but it became 5% by mass or less after combustion, and most of the carbon in the under-sieve powder was combusted. It was done.

  For further confirmation, the flammability evaluation of the sieving powder was performed by differential thermal analysis of the briquette sieving powder after heat treatment and the coke powder as a comparative material.

The differential thermal analysis was performed using a differential thermal analyzer (TG8110, manufactured by Rigaku Corporation) under the conditions of heat pattern: room temperature to 1000 ° C., heating rate: 10 ° C./min, and atmosphere: Air. An example of the measurement result is shown in Table 3. From Table 3, the weight reduction rate (21.8%) of the sieving powder almost coincides with the carbon content in the sieving powder (= fixed carbon + volatile content = 100% −ash content = 21.6%). It has been found that it can burn substantially completely and is much more flammable than coke powder. From the above results, the briquette underpowder powder after the heat treatment has a fine particle size and can be sufficiently combusted by being mixed with the burner fuel.

  The above flammability evaluation test was carried out only for the briquette under-sieving powder after heat treatment and not for the briquette under-sieving powder (non-standard product) before the heat treatment. It is obvious that the product is superior in combustibility because it contains a larger amount of volatile matter than the briquette powder after heat treatment.

  Therefore, there is no problem in combustibility even when solid powder (non-standard product and under-sieving powder) is returned to the raw material heating step and used as fuel.

It is a conceptual diagram of the manufacture flow of the carbonaceous material interior agglomerate which concerns on implementation of this invention. It is a conceptual diagram of the manufacture flow of the carbonaceous material agglomerate by the conventional method. It is a flowchart which shows the outline | summary of the hot forming machine used in the Example.

Explanation of symbols

1: Carbon material drying and heating equipment (rotary dryer)
2: Raw material heating equipment (rotary kiln)
3: Mixing equipment (vertical mixing tank)
4: Molding equipment (twin roll molding machine)
5: Heat treatment equipment (shaft furnace)
7: Sizing equipment (rotating drum)
8, 8 ': Screen 9: Exhaust gas treatment facility (Ansui scrubber)
10: Solid powder transfer piping A: Powdered carbon material (powdered coal)
B: Powdered iron-containing raw material (powdered iron ore)
C: Mixture D: Molded product (briquette)
E: Mass on sieve (carbon material interior agglomerated material)
F: Sieve powder G: Non-standard product H: Solid powder

Claims (3)

A carbonaceous material drying and heating step of drying and heating a powdered carbonaceous material having softening and melting properties at 350 ° C. or lower;
A raw material heating step of heating the powdered iron-containing raw material to 400 to 800 ° C;
A mixing step of mixing the powdered carbonaceous material after drying and the powdered iron ore after heating into a mixture of 250 to 550 ° C;
A hot forming step of hot forming the mixture to form a molded product;
Sieving the molded product and classifying it into a sieving lump and under-sieving powder, and collecting the sieving lump as a carbonaceous material agglomerated product,
A solid powder circulation step in which all or part of the solid powder composed of the under-sieving powder is returned to the raw material heating step, and used as part of the heated fuel for heating the powdered iron-containing raw material,
A method for producing an agglomerated carbonaceous material, comprising: A carbonaceous material drying and heating step of drying and heating a powdered carbonaceous material having softening and melting properties at 350 ° C. or lower;
A raw material heating step of heating the powdered iron-containing raw material to 400 to 800 ° C;
A mixing step of mixing the powdered carbonaceous material after drying and the powdered iron ore after heating into a mixture of 250 to 550 ° C;
A hot forming step of hot forming the mixture to form a molded product;
A heat treatment step of removing the volatile component and tar component remaining in the molded product while maintaining the molded product at a temperature of the hot molding temperature or higher and 800 ° C. or lower;
Sieving the molded product and classifying it into a sieving lump and under-sieving powder, and collecting the sieving lump as a carbonaceous material agglomerated product,
A solid powder circulation step in which all or part of the solid powder made of the under-sieving powder is returned to the raw material heating step and used as a part of the heating fuel for heating the powdered iron-containing raw material,
A method for producing an agglomerated carbonaceous material, comprising: A carbonaceous material drying and heating step of drying and heating a powdered carbonaceous material having softening and melting properties at 350 ° C. or lower;
A raw material heating step of heating the powdered iron-containing raw material to 400 to 800 ° C;
A mixing step of mixing the powdered carbonaceous material after drying and the powdered iron ore after heating into a mixture of 250 to 550 ° C;
A hot forming step of hot forming the mixture to form a molded product;
A non-standard product removal step of removing a non-standard product generated in the hot molding process from the molded product;
A heat treatment step for removing a volatile component and a tar component remaining in the molded product by holding the molded product after removing the non-standard product at a temperature of the hot molding temperature or higher and 800 ° C. or lower;
Sieving the molded product and classifying it into a sieving lump and under-sieving powder, and collecting the sieving lump as a carbonaceous material agglomerated product,
A solid powder circulation step in which all or part of the solid powder composed of the non-standard product and the under sieve powder is returned to the raw material heating step, and used as part of the heated fuel for heating the powdered iron-containing raw material,
A method for producing an agglomerated carbonaceous material, comprising:

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