JP5390977B2 - Iron ore-containing coke and method for producing the iron ore-containing coke - Google Patents

Description

  The present invention relates to iron ore-containing coke and a method for producing the iron ore-containing coke.

  One of the uses of coke is the manufacture of pig iron using coke. Such pig iron was produced at this time by, specifically, charging a coke layer and an iron ore layer in a blast furnace so as to overlap each other and then blowing high-temperature air from the tuyere to burn the coke. It is performed by reducing iron oxide in iron ore with reducing gas.

  In recent years, techniques for producing pig iron by blending iron ore-containing coke (sometimes referred to as ferro-coke) with iron ore interior in an iron ore layer have been developed. By adding iron ore-containing coke to the iron ore layer, reduction of iron oxide in the iron ore layer is promoted by the reducing gas generated by burning the iron ore-containing coke (acting as a reducing agent), It is considered that the production efficiency of pig iron is improved (acts as a heat source) by the catalytic action of iron components in iron ore-containing coke.

  As a method for producing iron ore-containing coke, a vertical shaft furnace is used in which a carbonized-chamber (coal) and iron ore are molded in a briquette shape in advance using a vertical shaft furnace whose carbonization chamber is made of chamotte brick. There is a continuous coke manufacturing method in which charging is performed from the top of the furnace, the molded product is then carbonized, and then extracted from the lower part.

  However, the production method using a vertical shaft furnace has a problem in terms of stable operation of coke production because a load is applied to the compact during the dry distillation process. That is, in the production of general iron ore-containing coke, raw coal (coking coal that can be used as a raw material for coke production) is used as a carbonaceous material, and this raw coal is softened and melted at 300 to 500 ° C. Therefore, the molded product may be deformed and adhered by heating during the dry distillation process, and the furnace may be closed.

  Therefore, in order to prevent the molding from blocking the furnace, there is a method using coal that does not soften and melt instead of the raw coal, but in this case, iron ore and coke are easily separated (iron ore with sufficient strength). Another problem arises that it becomes difficult to obtain stone-containing coke. This is because the iron ore and coke have a low affinity, and the iron ore is partially reduced and shrinks during the carbonization process of the molded product, so the interface between the iron ore and coke that originally had a weaker affinity is more fragile. There is a tendency to become. And if coal which does not soften and melt in the dry distillation process is used, there will be insufficient elements to increase the affinity (adhesiveness) between iron ore and coke. The iron ore-containing coke has a sufficient strength because it is expected to have a role as a spacer for improving ventilation in the blast furnace in addition to the role as the reducing agent and the heat source. And coke are difficult to separate).

  Therefore, in order to obtain iron ore-containing coke having sufficient strength while preventing furnace blockage, semi-anthracite and anthracite, which are coals that do not soften and melt, have been used as charcoal materials, and the affinity between iron ore and coke has been improved. In order to improve the property (adhesiveness), a method of using a softening and melting coal (such as caking coal) or a binder together has been disclosed. For example, Patent Document 1 discloses a method for producing iron ore-containing coke using semi-anthracite or anthracite and blended coal of softened and melted coal and iron ore. Patent Documents 2 and 3 disclose a method for producing iron ore-containing coke using ordinary coal such as semi-anthracite or anthracite, iron ore, and a binder having a predetermined softening point.

  However, both the anthracite and semi-anthracite used here are expensive, and there is a problem that the production cost is increased. Moreover, even if a binder is used, iron ore-containing coke having sufficient strength may not be obtained.

JP 2008-56791 A JP 2008-56777 A JP 2008-56778 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to produce iron ore-containing coke having sufficient strength at a lower cost.

  The iron ore-containing coke of the present invention that has solved the above problems is characterized by being obtained by dry distillation of a mixture containing lignite, iron ore, and a solvent extract of coal.

  Since the lignite used in the present invention is difficult to soften and melt, even if dry distillation is performed using a shaft furnace, it is difficult to block the furnace. Moreover, since the solvent extract of coal is used together, the affinity between lignite-derived coke and iron ore can be increased. Furthermore, since lignite has abundant resource reserves and is inexpensive, the solvent extract of coal can also be obtained using low-grade coal such as lignite, so that the production cost can be reduced.

  Coal is generally classified into anthracite, bituminous coal (strongly caking coal, adhesive coal, weakly caking coal, non-caking coal), lignite, etc., but the definition is not necessarily clear. Therefore, in the present specification, these are classified by the carbon content (daf). The carbon content (daf = dry ash free) refers to the carbon content (% by mass) relative to the organic matter (C, H, N, S, O) excluding moisture and ash content of coal, It can be measured according to JIS M8819.

  According to this classification, anthracite coal has a carbon content (daf) of over 91%, bituminous coal has a carbon content (daf) of 78% to 91%, and brown coal Corresponds to coal with a carbon content (daf) of less than 78%.

  In this invention, it is preferable that the compounding quantity of the said solvent extract with respect to 100 mass parts of said lignite is 10-100 mass parts. In the present invention, the mixture may further contain bituminous coal.

  Furthermore, it is a preferred embodiment that the solvent extract has a Gieseler maximum fluidity (log MF) of 2 or less.

  It is considered that the strength of iron ore-containing coke can be sufficiently increased by adjusting the softening start temperature, fluidity, and volatile content of the solvent extract of coal.

  In the present invention, at least lignite, iron ore, and a solvent extract of coal are mixed and formed, and a step of obtaining a formed product and a step of dry distillation of the formed product are included. A method for producing coke is also included.

  In the production method of the present invention, it is preferable that the carbonization step is performed using a shaft furnace.

  According to the iron ore-containing coke of the present invention, since lignite is used as the carbon material, the iron ore-containing coke can be produced at a low cost. Moreover, since a coal solvent extract (more preferably, a coal solvent extract with a softening start temperature and fluidity adjusted) is used in combination, iron ore-containing coke having sufficient strength can be obtained.

  The iron ore-containing coke of the present invention is obtained by dry-distilling a mixture containing lignite, iron ore, and a solvent extract of coal.

  The present applicant has previously disclosed a solvent extract of coal (Japanese Patent No. 4284314, Japanese Patent Laid-Open No. 2009-144130). And this time, when this solvent extract was used as a binder, it discovered that the iron ore containing coke which has sufficient intensity | strength could be obtained from cheap brown coal with abundant resource reserves, and completed this invention.

  Hereinafter, the iron ore-containing coke of the present invention will be described in detail.

(brown coal)
As described above, the lignite used as a carbon material in the present invention is a coal having a carbon content (daf) of less than 78%, and examples thereof include Victoria coal, North Dakota coal, and Belga coal. Moreover, you may use the modified lignite (Japanese Unexamined Patent Publication No. 7-233383) which the present applicant has already disclosed. Such modified lignite has a low water content and can reduce transportation costs, and since the lignite surface is covered with an oil film, it is difficult to spontaneously ignite and has excellent handling properties. These lignites may be used alone or in combination of two or more. By using lignite as the carbon material, the production cost of iron ore-containing coke can be reduced. In addition, since it is difficult to soften and melt, even if carbonized using a shaft furnace, the carbonaceous material is deformed and adhered, and the furnace is hardly blocked.

(Other charcoal materials)
The iron ore-containing coke of the present invention is preferably produced using only lignite as the carbon material from the viewpoint of reducing the production cost, but other carbon materials may be used in combination. Examples of other carbon materials include bituminous coal having a carbon content (daf) of 78% to 91%. These carbon materials can be obtained relatively inexpensively. Further, if a carbon material that is appropriately softened and melted during the dry distillation process when producing iron ore-containing coke is selected, iron ore-containing coke having a sufficient strength can be produced.

  The blending amount of other carbon materials is preferably 200 parts by mass or less (more preferably 170 parts by mass or less, and even more preferably 150 parts by mass or less) with respect to 100 parts by mass of lignite. It is because the manufacturing cost of iron ore containing coke will rise when the compounding quantity of another carbon material exceeds 200 mass parts.

  The particle size of the carbonaceous material (brown coal and other carbonaceous materials) used in the present invention is preferably 70% by mass or more (more preferably 80% by mass or more, more preferably 90% by mass or more) of 3 mm or less. . This is because the strength of the iron ore-containing coke obtained is often lowered when the carbonaceous material having a particle size exceeding 3 mm exceeds 30% by mass.

  The particle size of the carbon material was measured by a sieving method. Specifically, the charcoal material was sieved using a sieve having an opening of 3 mm, and the amount was determined from the ratio of the remaining amount on the sieve (oversize) or the total passage under the sieve (undersize).

(Iron ore)
The type of iron ore used in the present invention is not particularly limited. For example, hematite (hematite; Fe ₂ O ₃ ), magnetite (magnetite; Fe ₃ O ₄ ), limonite (Fe ₂ O ₃ · nH). ₂ O) and the like. Further, iron oxyhydroxide (FeOOH) may be used. In this case, it is preferable to use dehydrated iron oxide in advance. These may be used alone or in combination of two or more.

  The particle size of the iron ore is preferably 200 μm or less (more preferably 170 μm or less, more preferably 150 μm or less) when the particle size of the carbonaceous material (brown coal and other carbonaceous materials) is in the above range. When the particle size of the iron ore exceeds 200 μm, the stress acting on the interface of the iron ore becomes large, so that the strength of the obtained iron ore-containing coke may be lowered. In addition, the lower limit of the particle size of the iron ore is not particularly limited, and the smaller the better, but for example, it is preferably 30 μm (more preferably 50 μm, still more preferably 70 μm). This is because it takes time and effort to obtain an iron ore having a particle size of less than 30 μm, and the manufacturing cost increases.

  About the compounding quantity of an iron ore, although it does not specifically limit, 10 mass parts or more (more preferably 20 mass parts or more, More preferably 30 mass parts or more) are preferable with respect to 100 mass parts of carbonaceous materials, 100 It is preferably no greater than part by mass (more preferably no greater than 80 parts by mass, and even more preferably no greater than 70 parts by mass).

(Coal solvent extract)
The solvent extract of coal used in the present invention is suitable for improving the adhesion between lignite-derived coke and iron ore. For this reason, the iron ore containing coke of this invention manufactured using this solvent extract can have sufficient intensity | strength, even if it uses the brown coal which is hard to soften and melt as a carbon material. The reason why the solvent extract of coal is suitable for improving the adhesion between coke derived from lignite and iron ore is not clear, but the solvent extract is substantially free of ash and has an appropriate softening start temperature and fluidity. This is considered to be because of having a volatile content.

  In addition, the tar, pitch, and molasses that have been generally used as binders until now cannot enhance the adhesion between lignite-derived coke and iron ore. This is because these known binders have a low carbonization yield and are easily pyrolyzed, so that strength after dry distillation cannot be expected.

  The blending amount of the solvent extract is preferably 5 parts by mass or more (more preferably 15 parts by mass or more) with respect to 100 parts by mass of carbonaceous material (single amount of lignite or the total amount of lignite and other carbonaceous materials). 100 parts by mass or less (more preferably 70 parts by mass or less) is preferable. When the compounding quantity of a solvent extract is less than 5 mass parts, the intensity | strength of the iron ore containing coke obtained may not fully be improved. When the compounding quantity of a solvent extract exceeds 100 mass parts, the manufacturing cost of iron ore containing coke may go up.

  In particular, when only lignite is used as the carbon material, the amount of the solvent extract is preferably 25 parts by mass or more (more preferably 30 parts by mass or more) with respect to 100 parts by mass of the carbon material (brown coal), and 60 masses. Part or less (more preferably 50 parts by weight or less) is preferable. Moreover, when using other carbon materials (bituminous coal) in addition to lignite as a carbon material, the blending amount of the solvent extract is 100 parts by mass of the carbon material (total amount of lignite and other carbon materials). 5 parts by mass or more (more preferably 10 parts by mass or more) is preferable, and 30 parts by mass or less (more preferably 20 parts by mass or less) is preferable.

  In addition, the solvent extract of coal used by this invention can be manufactured through an extraction process, a solid-liquid separation process, and a solvent removal process. Moreover, you may perform heating operation after a solvent removal process. Hereinafter, the manufacturing method of a solvent extract is demonstrated in detail.

<Extraction process>
In the extraction step, coal and a solvent are brought into contact with each other, and a solvent-soluble component contained in the coal is eluted in the solvent and extracted.

  As a solvent used for extraction of a soluble component, a polar solvent or an aromatic solvent can be used. Examples of the polar solvent include N-methylpyrrolidone and pyridine. Aromatic solvents include monocyclic aromatic compounds such as benzene, toluene and xylene, bicyclic aromatic compounds such as naphthalene, methylnaphthalene, dimethylnaphthalene, trimethylnaphthalene and tetrahydronaphthalene (tetralin), and three or more rings such as anthracene. Aromatic compounds and the like. Bicyclic aromatic compounds include other naphthalenes having an aliphatic side chain, and biphenyl and alkylbenzene having a long-chain aliphatic side chain.

  In the present invention, it is preferable to use a hydrogen non-donating solvent among the polar solvents and aromatic solvents. Such a hydrogen non-donating solvent is a coal derivative mainly composed of a bicyclic aromatic compound purified mainly from a coal carbonization product, and examples thereof include naphthalene, methylnaphthalene, and tar light oil. Since the hydrogen non-donating solvent is stable even in a heated state and has excellent affinity with coal, the proportion of soluble components extracted into the solvent can be increased. Moreover, since it can collect | recover easily by methods, such as distillation, after use, it can be recycled in the manufacturing process of a solvent extract, and can aim at the improvement of economical efficiency.

  The above solvents may be used alone or in combination of two or more.

  Especially, the solvent used for extraction of a soluble component has a preferable boiling point of 180-330 degreeC (especially 200-250 degreeC). If the boiling point is too low, the extraction rate of soluble components in the extraction process may decrease. Moreover, the required pressure in an extraction process and the solid-liquid separation process mentioned later may become high. Furthermore, when recovering the solvent, loss due to volatilization increases, and the solvent recovery rate may decrease. On the other hand, if the boiling point is too high, it will be difficult to remove the solvent from the liquid component separated in the solid-liquid separation step described later, or to remove the solvent adhering to the undissolved coal after extracting the soluble components. The solvent recovery rate may be reduced.

  Although the kind of coal used for extraction of a soluble component is not specifically limited, It is preferable that it is cheap coal. Thereby, since a solvent extract can be manufactured cheaply, the improvement of economical efficiency can be aimed at. Of course, high-grade coal such as bituminous coal may be used.

  Examples of such an inexpensive coal include non-caking coal and weak caking coal having almost no softening and melting properties, as well as general coal and low-grade coal. Here, the low-grade coal is coal that normally contains 20% by mass or more of water and is desired to be dehydrated. Such low-grade coal includes, for example, lignite, lignite, and sub-bituminous coal. Brown coal has the above-mentioned types, and sub-bituminous coal includes, for example, West Bango coal, Binungan coal, Samarangau coal, and the like. The low-grade coal is not limited to those exemplified above, and any coal containing a large amount of water and desired to be dehydrated is included in the low-grade coal referred to in the present invention.

  In the extraction step, it is preferable to pulverize the coal to, for example, a diameter of about 5 mm or less in order to facilitate extraction of soluble components from the coal.

  In the extraction step, in order to increase the extraction rate of soluble components from coal, it is preferable to mix coal and a solvent in a slurry state, and it is more preferable to heat the slurry while stirring the mixture.

  For example, the extraction temperature is preferably set to about 300 to 420 ° C. (particularly 350 to 400 ° C.). If the extraction temperature is too low, the easy gasification component contained in the coal cannot be removed from the coal, and further, it becomes insufficient to weaken the intermolecular bonding force of the component constituting the coal, so that the soluble component contained in the coal The extraction rate may be low. On the other hand, if the extraction temperature is too high, recombination of radicals generated by thermal decomposition of coal occurs, so the extraction rate when extracting soluble components from coal may be low.

  In addition, it is preferable to perform an extraction process by pressurizing so that a solvent may not boil, and what is necessary is just to adjust to the range of about 0.8-2.5 MPa (especially 1.5-2 MPa) normally.

  The extraction time may be about 10 to 60 minutes, for example. When the extraction time is too long, the thermal decomposition reaction of the extracted soluble component proceeds, and the radical polymerization reaction proceeds, so the extraction rate of the soluble component may decrease.

  In the case where the extraction step is performed by heating the slurry, for example, it is preferably performed in the presence of an inert gas (for example, nitrogen). If the solvent comes into contact with oxygen during heat extraction, there is a risk of ignition.

<Solid-liquid separation process>
In the solid-liquid separation step, soluble components are extracted from coal in the extraction step, and then undissolved coal (coal remaining after extraction of components soluble in the solvent) is separated to recover the liquid component. This liquid component is composed of a soluble component extracted from coal and a solvent used for extraction.

  The method for solid-liquid separation is not particularly limited, and a known method may be employed, and examples thereof include various filtration methods, centrifugal separation methods, and gravity sedimentation methods. In the filtration method, since the filtration amount of the filtration filter is limited, a large amount of undissolved coal may not be separated. In the centrifugal separation method, clogging with undissolved coal is likely to occur, and it may be difficult to implement industrially. On the other hand, according to the gravity settling method, liquid content can be obtained from the upper part of the gravity settling tank, and undissolved coal can be obtained from the lower part. Therefore, it is preferable.

  In addition, it is preferable to set the temperature of the solvent in a solid-liquid separation process, and the pressure at the time of solid-liquid separation to the same range as the temperature and pressure which were set at the said extraction process. This is to prevent reprecipitation of the solute eluted from the raw material coal.

<Solvent removal step>
In the solvent removal step, the solvent is separated from the liquid obtained in the solid-liquid separation step. Thereby, the solvent extract with little concentration of ash can be obtained. The ash content refers to residual inorganic substances (silicic acid, alumina, iron oxide, lime, magnesia, alkali metal, etc.) when the solvent extract is incinerated at 815 ° C. In the present invention, the solvent extract may contain about several percent of ash within a range that does not affect the performance of the obtained iron ore-containing coke, but the ash content is 5000 ppm or less (more preferably 2000 ppm or less). (Mass basis, the same applies hereinafter) is preferable.

  As a method for separating the solvent, a general distillation method or evaporation method (spray drying method or the like) can be used. In the present invention, it is preferable to reuse the separated and recovered solvent as a part of the solvent used in the extraction step.

<Heating process>
In the present invention, iron ore-containing coke may be produced using the solvent extract obtained through the solvent removal step, but this solvent extract may be further heated. Thereby, the softening start temperature and fluidity | liquidity of a solvent extract can be adjusted. In addition, the amount of volatile components can be adjusted.

  By adjusting the softening start temperature and fluidity of the solvent extract of coal, it is considered that the affinity between lignite and iron ore increases and the adhesion between coke and iron ore is further improved. In addition, by adjusting the amount of volatile matter contained in the solvent extract of coal, defects such as blisters and cracks occur in the iron ore containing coke due to the volatile matter, and the strength of the iron ore containing coke is reduced. Can be prevented.

  In the heating step, the obtained solvent extract is preferably heated to adjust the softening start temperature of the solvent extract to 180 ° C. or higher (more preferably 200 ° C. or higher, more preferably 250 ° C. or higher). Moreover, it is preferable to adjust the Gieseler maximum fluidity (logMF) to 2.0 or less (more preferably 1.9 or less, and still more preferably 1.8 or less). When the softening start temperature is less than 180 ° C. or when the Gieseler maximum fluidity (log MF) exceeds 2.0, the possibility that the molded body is deformed or cracked during dry distillation increases.

  Furthermore, it is preferable to adjust a volatile matter to 24 mass%-35 mass% (preferably 25 mass%-32 mass%). This is because by adjusting the volatile content of the solvent extract to such a range, it is possible to prevent the iron ore-containing coke from being swollen or cracked due to the volatile content. Such volatile matter can be measured by the method defined in JIS M8812.

  The method for heating is not particularly limited, and examples thereof include a method of increasing the molecular weight of the solvent extract by heat or polymerization, removing a component having a relatively low molecular weight by distillation, or both. The heat treatment may be performed in an inert atmosphere or under reduced pressure.

  The heat treatment conditions may be appropriately set so that the softening start temperature and fluidity of the solvent extract to be obtained are in the above ranges, for example, 100 to 200 ° C. (more preferably 130 to 200 ° C.) in atmospheric pressure air. 170 degreeC), and the aspect performed by heating for 5 to 15 minutes is mentioned.

(Method for producing iron ore-containing coke)
The iron ore-containing coke of the present invention is produced through a step of obtaining a molded product by mixing and molding a carbonaceous material such as the above lignite, an iron ore, and a solvent extract of coal, and a step of carbonizing the molded product. can do. Hereinafter, the manufacturing method of the iron ore containing coke of this invention is demonstrated in detail.

<Mixing process>
In the present invention, first, a carbon material, iron ore, and a solvent extract of coal are mixed. This is to obtain a uniform mixture.

  The mixing method of the carbonaceous material, iron ore, and solvent extract is not particularly limited. In addition to the method of simultaneously mixing the carbonaceous material, iron ore, and solvent extract, the mixture of carbonaceous material and iron ore A method of adding and mixing a solvent extract, a method of adding and mixing iron ore to a mixture of a carbon material and a solvent extract, or a method of adding carbon material to a mixture of an iron ore and a solvent extract And a method of mixing them.

  The means for mixing the carbonaceous material, the iron ore, and the solvent extract is not particularly limited, and examples thereof include a mixer, a kneader, or a biaxial or uniaxial mixer.

<Molding process>
In the molding step, the mixture is molded into a molded product having a predetermined strength. When the iron ore-containing coke of the present invention is produced by dry distillation using a vertical shaft furnace, the mixture is introduced from the top of the shaft furnace, so that the carbonaceous material and iron ore are difficult to separate (predetermined This is because it is required to have strength.

  Forming means is not particularly limited. For example, in addition to a double roll (double roll type molding machine) using a flat roll, a double roll type molding machine having an almond type pocket, a single axis press or a roller type molding machine, An extrusion molding machine is mentioned.

  It is preferable that the mixture is molded under conditions where the solvent extract is softened and melted. This is because the carbonaceous material and the iron ore are bonded via the softened melt of the solvent extract.

  Specifically, for example, a method of heat and pressure molding at 200 to 400 ° C. (more preferably 250 to 350 ° C.) using a double roll type molding machine can be mentioned.

  The molded product obtained in the molding step preferably has a crushing load of 98.1 N (10 kgf) or more (more preferably 196.1 N (20 kgf) or more).

<Dry distillation process>
The shaped product is made into iron ore-containing coke by a carbonization process. The dry distillation is preferably performed in an inert gas atmosphere such as nitrogen, for example, in order to set the temperature to about 600 to 1100 ° C. (more preferably 700 to 1000 ° C.) and prevent oxidative deterioration of the carbonaceous material. The residence time in the dry distillation process is preferably about 1 to 24 hours.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.

  First, the evaluation method used in the examples will be described below.

(Molded product strength and iron ore-containing coke strength)
The strength of the molded product and iron ore-containing coke was evaluated by a crushing load measured according to ISO 4700. Specifically, the crushing strength was measured by applying a load to the center of the molding surface in contact with the twin rolls.

(Softening start temperature and Gieseller fluidity test)
The softening start temperature and the Gieseler maximum fluidity (log MF) were measured by the Gieseler plastometer method defined in JIS M8801.

(Production Examples 1-6)
<Manufacture of solvent extract of coal>
A solvent extract of coal was produced according to the method described above (extraction step, solid-liquid separation step, solvent removal step). At this time, general coal was used as the raw material coal, and anthracene oil was used as the solvent. The obtained solvent extract had a softening start temperature of 160 ° C. and a Gieseler maximum fluidity (log MF) of 4.7 or more (above the upper limit of measurement).

  Next, the obtained solvent extract was pulverized to 200 μm or less and then held in air at 150 ° C. for 10 minutes to adjust the softening start temperature and fluidity of the coal solvent extract (hereinafter referred to as “adjusted solvent”). Sometimes referred to as “extract”. The resulting adjusted solvent extract had a softening start temperature of 280 ° C. and a Gieseler maximum fluidity (log MF) of 1.8.

<Molding process>
Coal having the composition shown in Table 1, iron ore having the composition shown in Table 2, and the adjusted solvent extract are mixed well in the ratio shown in Table 3, and a double roll type having an almond type pocket with a capacity of 5 ml. Using a molding machine, molding was performed while heating to 300 ° C. to obtain a molded body.

  In addition, as for the coal as a raw material of a molded object, all used what was grind | pulverized so that a particle size: 3 mm or less might be 90 mass% or more. The iron ore used was pulverized to a particle size of 100 μm or less.

<Dry distillation process>
The obtained molded body was heated to 850 ° C. in a nitrogen atmosphere at a rate of 3 ° C./min, then held at this temperature for 10 minutes and dry-distilled to obtain iron ore-containing coke.

<Characteristic>
The appearance and strength of the obtained molded body and iron ore-containing coke were measured. The results are shown in Table 3.

  In the table, regarding the appearance evaluation, A was given when it was good, B was given when it was slightly deformed and expanded, C was given when it was deformed and expanded, and D was given when the deformation and expansion were severe. As for the strength, “−” represents a case where measurement was impossible.

  From Production Examples 1 and 2, it was found that iron ore-containing coke having sufficient strength can be obtained by using a coal solvent extract even when lignite is used as the carbonaceous material. In particular, it was found that iron ore-containing coke having sufficient strength can be obtained even when the content of lignite in the carbon material is 50% by mass or more.

  From Production Example 3, it was found that when only bituminous coal was used as the carbonaceous material, it expanded too much during dry distillation, and the strength of iron ore-containing coke decreased.

  From Production Examples 4 to 5, it was found that iron ore-containing coke having sufficient strength cannot be obtained when the solvent extract of coal is not used.

  The present invention can provide iron ore-containing coke having sufficient strength at a low cost.

Claims (7)

An iron ore-containing coke obtained by dry distillation of a mixture containing lignite, iron ore, and a solvent extract of coal , wherein the solvent extract has a Gieseler maximum fluidity (log MF) of 2 or less .   2. The iron ore-containing coke according to claim 1, wherein a blending amount of the solvent extract with respect to 100 parts by mass of the lignite is 10 to 100 parts by mass.   The iron ore-containing coke according to claim 1 or 2, wherein the mixture further contains bituminous coal. Mixing at least lignite, iron ore, and solvent extract of coal, and molding to obtain a molded product;
The saw including a step of dry distillation of moldings, the production method of the iron ore containing coke, wherein the Gisera maximum fluidity degree of the solvent extract (logMF) is 2 or less. The manufacturing method of the iron ore containing coke of Claim 4 whose compounding quantity of the said solvent extract with respect to 100 mass parts of said lignite is 10-100 mass parts. The method for producing iron ore-containing coke according to claim 4 or 5 , wherein the step of obtaining the molding is performed by further mixing bituminous coal. The method for producing iron ore-containing coke according to any one of claims 4 to 6 , wherein the carbonization step is performed using a shaft furnace.