WO2015151847A1

WO2015151847A1 - Coal blend

Info

Publication number: WO2015151847A1
Application number: PCT/JP2015/058387
Authority: WO
Inventors: 貴洋宍戸; 濱口　眞基; 菊池　直樹
Original assignee: 株式会社神戸製鋼所
Priority date: 2014-03-31
Filing date: 2015-03-19
Publication date: 2015-10-08
Also published as: US20170096603A1; CA2938960A1; KR20160127096A; CN106062138A; AU2015241616B2; JP2015193740A; JP6266409B2; CN106062138B; AU2015241616A1

Abstract

　In order to reduce the cost of coke raw materials, the present invention involves mixing ashless coal, which is a solvent extract of coal, and steam coal in a weight ratio of 1:1 to 1:5 without heating, and producing a coal blend having a Gieseler fluidity of 1.0 (log ddpm) or higher and an average maximum reflectance of 0.75 (%) or higher.

Description

Coal mixture

The present invention relates to a coal mixture formed by mixing ashless coal, which is a solvent extract of coal, and steam coal.

In the production of steel using a blast furnace, coke obtained by heating and carbonizing raw coal is used as a reducing agent. Here, in order to produce high-quality coke, blended coal for coke whose main raw material is highly caking coal with high caking properties is required. However, strong caking coal may become difficult to obtain in the future and the price may rise.

Therefore, it is required to reduce the cost of coke raw materials by using inferior raw materials (non-caking coal, slightly caking coal, steaming coal) as coke raw materials, thereby reducing the amount of strong caking coal used. .

Patent Document 1 discloses that coking coal for coke production is heated by heating a mixed coal composed of inferior coal and ashless coal (hyper coal) substantially free of ash to a softening temperature of ashless coal or higher. A method of manufacturing is disclosed. If this raw coke for coke production is used as a coke raw material, the amount of strongly caking coal used in coke production can be suppressed.

Japanese Unexamined Patent Publication No. 2009-215454

By the way, if an inferior raw material having low caking properties is simply blended with the coal for coke, the caking property of the coal for coke is lowered, and the coke strength is also lowered. Therefore, in normal operation, the negative effects due to the blending of inferior raw materials are adjusted by increasing the distribution of high quality coking coal, and the typical properties (volatile content, average maximum reflectance, Gieseller fluidity) required for coking coal are appropriate. It is managed so that it is within the range. However, in this method, it is necessary to increase the amount of expensive strong caking coal as the amount of inferior raw material used increases, and the cost of the coke raw material cannot be reduced.

In addition, although the petroleum-based caking additive that has been put into practical use has a high caking-compensating effect, the production amount is limited, and the sulfur content is high and remains in the coke. Here, when the sulfur content contained in iron ore or coke increases, the sulfur content remaining in the hot metal also increases, and there is a problem that the load on the desulfurization treatment process increases. In order to avoid this, an upper limit is set for the sulfur content input to the blast furnace. Sulfur is known to deteriorate the properties of iron. For this reason, the amount of petroleum-based caking additive in coke coal is limited to a few percent. As described above, since there is a limit to the caking supplement, it is not easy to increase the amount of the inferior raw material blended in the coke blending coal.

An object of the present invention is to provide a coal mixture capable of reducing the cost of coke raw materials.

The coal mixture in the present invention is a mixture of ashless coal, which is a solvent extract of coal, and general coal, in a weight ratio of 1: 1 to 1: 5, without heating, and mixed after mixing. Charcoal has a Gieseler fluidity of 1.0 (Log ddpm) or more and an average maximum reflectance of 0.75 (%) or more.

¡According to the coal mixture of the present invention, the cost of coke raw materials can be reduced.

It is a schematic diagram of an ashless coal manufacturing facility.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Composition of coal mixture)
The coal mixture according to the embodiment of the present invention is obtained by mixing ashless coal using coal as a raw material and steam coal in a weight ratio of 1: 1 to 1: 5 without heating. Ashless coal is a solvent extract of coal, and is obtained by extracting coal components soluble in a solvent from a slurry obtained by mixing and heating coal and a solvent.

(Steam coal)
The general coals used for the coal mixture of the present embodiment are bituminous coal, subbituminous coal, and lignite, which belong to the C to F2 coal classification in Table 1. That is, the general coal of this embodiment is coal with a calorific value (anhydrous ashless standard) (kcal / kg) of 5800 or more and less than 8400.

Here, the calorific value (anhydrous ashless standard) (kcal / kg) defined by Japanese Industrial Standard (JIS M 1002: 1978) is calculated based on the following equation.
Calorific value (corrected anhydrous ashless base) = calorific value / (100-1.08 x ash-moisture) x 100

The fuel ratio is a value obtained by dividing fixed carbon by volatile matter. Here, when steaming coal is heated to a high temperature in an inert gas such as nitrogen, the side chain portion and / or the bridge portion of the polymer matrix constituting the steaming coal is cut by thermal decomposition, and low molecular weight hydrocarbons or the like are reduced. Boiling components, CO, H _{2 and the} like are generated and released to the outside of the general coal particles in a gas form. These low-boiling components such as low molecular weight hydrocarbons, CO, H _2, etc., released to the outside of the general coal particles in gas form are called volatile matter (VM) of general coal, and are based on dry weight (dry-base) ). Moreover, fixed carbon is a non-volatile component of the carbon contained in steam coal.

Coal coal with calorific value (anhydrous ashless basis) (kcal / kg) of 5800 or more and less than 8400 is coking coal, sub-bituminous coal, and lignite coal, etc. In Table 1, bituminous coal belonging to the B1 and B2 coal categories, that is, cohesive coal and coking coal, which is a coking raw coal, is inferior in caking property. Yes.

(Ashless coal)
The ashless coal used in the coal mixture of this embodiment is obtained by extracting a coal component soluble in a solvent from a slurry obtained by mixing and heating coal and a solvent, and has an ash content of 5 It refers to those not more than wt%, preferably not more than 3 wt%. Here, “ash” means a residual inorganic substance when coal is incinerated by heating at 815 ° C., and the inorganic substance is silicic acid, alumina, iron oxide, lime, magnesia, alkali metal, and the like. Also, ashless coal has no moisture.

Ashless charcoal is excellent in fluidity and expansibility and shows a high effect as a binder. Suitable ashless coal has a maximum fluidity (log MF) of 4.78 (Log ddpm) or higher, which is confirmed by a Gieseler fluidity test by the Gieseler plastometer method specified in JIS M8801. A solidification temperature exceeding 450 ° C. is also suitable as ashless coal.

The coal that is the raw material of ashless coal is not particularly limited, and bituminous coal with a high extraction rate may be used, or cheaper inferior quality coal (subbituminous coal, lignite) may be used. Therefore, in this embodiment, steam coal is used as a raw material for ashless coal. The production of ashless coal using steam coal as a raw material expands the use of steam coal in the manufacture of coal blends. In addition, by using steaming coal as a raw material for ashless coal, ashless coal is produced in the production area of steaming coal, and a coal mixture is produced from this ashless coal and steaming coal. It is possible to perform consistently from production to the production of coal blends.

(Method for producing ashless coal)
Here, the manufacturing method of ashless coal is demonstrated. As shown in FIG. 1, the ashless coal production facility 100 used in the method for producing ashless coal includes, in order from the upstream side of the production process, a coal hopper 1, a solvent tank 2, a slurry preparation tank 3, a transfer pump 4, and a preheating. 5, an extraction tank 6, a gravity sedimentation tank 7, and

solvent separators

8 and 9.

The method for producing ashless coal has an extraction step, a separation step, and an ashless coal acquisition step. Hereinafter, each step will be described. In the present embodiment, steam coal is used as a raw material for ashless coal.

(Extraction process)
The extraction step is a step of heating a slurry obtained by mixing coal and a solvent to extract a coal component soluble in the solvent (dissolving in the solvent). This extraction step is performed in the slurry preparation tank 3, the preheater 5, and the extraction tank 6 in FIG.

Coal which is a raw material is charged into the slurry preparation tank 3 from the coal hopper 1 and a solvent is charged into the slurry preparation tank 3 from the solvent tank 2. The coal and solvent charged into the slurry preparation tank 3 are mixed by the stirrer 3a to become a slurry composed of coal and solvent. The slurry prepared in the slurry preparation tank 3 is supplied to the preheater 5 by the transfer pump 4 and heated to a predetermined temperature, then supplied to the extraction tank 6, and held at the predetermined temperature while being stirred by the stirrer 6a. Extraction is performed. As a solvent for extracting a coal component soluble in the solvent, an aromatic solvent (hydrogen donating or non-hydrogen donating solvent) can be suitably used.

(Separation process)
In the separation step, the slurry obtained in the extraction step is solidified by, for example, gravity precipitation, a solution in which a coal component soluble in a solvent is dissolved, and a coal component (solvent insoluble component such as ash) insoluble in the solvent. This is a step of separating into a concentrated solution (solvent-insoluble component concentrated solution). This separation step is performed in the gravity settling tank 7 in FIG. The slurry obtained in the extraction step is separated into a supernatant liquid as a solution and a solid content concentrated liquid by gravity in the gravity settling tank 7. The supernatant liquid in the upper part of the gravity settling tank 7 is sent to the solvent separator 8, and the solid content liquid settled in the lower part of the gravity settling tank 7 is sent to the solvent separator 9.

(Ashless coal acquisition process)
The ashless coal acquisition step is a step of obtaining ashless coal (HPC) by evaporating and separating the solvent from the solution (supernatant liquid) separated in the separation step. This ashless coal acquisition step is performed by the solvent separator 8 in FIG. The solution separated in the gravity sedimentation tank 7 is supplied to the solvent separator 8, and the solvent is evaporated and separated from the supernatant in the solvent separator 8.

As a method for separating the solvent from the solution (supernatant liquid), a general distillation method, evaporation method or the like can be used. By separating the solvent from the supernatant, ashless charcoal (HPC) substantially free of ash can be obtained.

Ashless coal contains almost no ash, has no moisture, and shows a higher calorific value than raw coal. Furthermore, softening meltability (fluidity), which is a particularly important quality as a raw material for coke for iron making, has been greatly improved, and the obtained ashless coal (HPC) is good even if the raw coal does not have softening meltability Soft meltability.

In the solvent separator 9, by-product charcoal (also referred to as RC or residual charcoal) in which solvent-insoluble components including ash and the like are concentrated by separating the solvent from the solid concentrate separated in the gravity sedimentation tank 7. Can be obtained.

(Coal mixture)
Next, the coal mixed material of this embodiment is demonstrated. The above-mentioned inferior raw materials containing non-caking coal, non-caking coal, slightly caking coal, and steaming coal are inferior in caking property to strong caking coal and quasi-strong caking coal that are coking coal. Therefore, when using an inferior raw material as a coke raw material, by increasing the blending ratio of strong caking coal in the coke blending coal, typical properties required for coke blending coal (volatile matter, average maximum reflectance) , Gieseller fluidity) must be within the proper range. That is, as the amount of the inferior raw material used in the coal for coke is increased, the amount of expensive strong caking coal needs to be increased, so the cost of the coke raw material cannot be reduced.

Further, in coke production, caking properties are compensated by using a petroleum-based caking material that has been put to practical use. However, petroleum-based binders have a high sulfur content and remain in the coke, increasing the sulfur content contained in the coke. On the other hand, the sulfur content input to the blast furnace is limited. Therefore, the blending amount of the petroleum-based binder into the coal for coal coke is limited to a few percent. For this reason, it is not easy to increase the amount of the inferior raw material blended into the coal for coke.

Therefore, the coal mixture of this embodiment is a mixture of ashless coal and steam coal in a weight ratio of 1: 1 to 1: 5, more preferably in a weight ratio of 1: 3 to 1: 5, without heating. Do it. By mixing ashless coal and steam coal without heating at such a weight ratio, the mixed cellar has a Gieseller fluidity of 1.0 (Log ddpm) or more, more preferably 1.5. (Log ddpm) or higher. Moreover, the average maximum reflectance of mixed coal shall be 0.75 (%) or more. The Gieseller fluidity and average maximum reflectance of the mixed coal mean values obtained by weighted averaging of the values of ashless coal and steam coal contained in the mixed coal, respectively. The mixed coal has a Gieseler fluidity of preferably less than 4.0 (Log ddpm), and more preferably less than 3.8 (Log ddpm). Further, the average maximum reflectance of the mixed coal is preferably less than 1.2 (%), and more preferably less than 1.0 (%). As a result, the properties of the resulting coal mixture are equivalent to those of general strong caking coal (general strong viscosity) or semi-strong caking coal belonging to the categories BD in Table 2.

Here, the properties of general strong caking coal (general strong caking) or semi-hard caking coal are volatile matter 20-33 (mass%), average maximum reflectance 0.8-1.3 (% ), And the Gieseller fluidity is 1.5 to 4.0 (Log ddpm). The average maximum reflectance (%) is calculated based on a formula defined by Japanese Industrial Standard (JIS M 8816: 1992).

As described above, ashless coal is excellent in fluidity and expansibility, and exhibits a high effect as a binder. Therefore, by mixing ashless coal and steam coal without heating, it is possible to obtain mixed coal having caking properties similar to those of high-quality strong caking coal. And, by mixing ashless coal and steamed coal in a weight ratio of 1: 1 to 1: 5 without heating, the mixed coal has a Gieseller fluidity of 1.0 (Log ddpm) or more. The average maximum reflectance is 0.75 (%) or more. Thereby, the coal mixed material which has the property equivalent to a general strong caking coal (general strong caking) or a semi-strong caking coal can be obtained. By using this coal mixture as a coke raw material instead of strong caking coal, the amount of strong caking coal in coke production can be reduced, and the amount of steam coal contained in the coke blending coal can be reduced. Can be increased. In addition, since the ashless coal has a sulfur content similar to that of steam coal, the amount of ashless coal added to the coke blended coal is not limited by the sulfur content. Therefore, the quantity of the inferior quality raw material which can be mix | blended with the coal mixture for cokes can be increased by using the coal mixed material formed by mixing ashless coal and steam coal without heating as a coke raw material. Thereby, the cost of a coke raw material can be reduced. Mixing of ashless coal and steam coal is performed without applying heat from the outside by a heating means. Moreover, the coal itself mix | blended may have a heat | fever, and the temperature at the time of mixing can be about less than 100 degreeC, less than 60 degreeC, etc.

In addition, ashless coal and steam coal are coarsely pulverized during or before mixing. Here, the coarse pulverization means pulverization so that the particle diameter becomes 20 mm or less. Ashless coal and steam coal may be mixed in the pulverizer without being heated while being coarsely pulverized, or mixed separately after being separately input into the pulverizer and coarsely pulverized. They may be mixed without being heated by being put into a coal blender so as to have a ratio. In addition, when ashless coal and steaming coal are simultaneously fed into a pulverizer and mixed while coarsely pulverizing, they mix more uniformly, making it easier for ashless coal to adhere to the surroundings of steaming coal particles. . In addition, when verifying the particle size of coal, such as whether the particle size of coal is 20 mm or less, the screening test prescribed | regulated to JISA1102 is used, for example.

Ashless coal tends to be pulverized more easily than steam coal. Generally, finely pulverized coal tends to generate dust. In general, finely pulverized coal easily undergoes low-temperature oxidation, so there is a concern that spontaneous combustion may occur due to oxidation heat generation. Thus, coarsely pulverizing ashless coal and steam coal allows them to mix evenly during mixing, and the ashless coal comes into close contact with the particles of steam coal. Thereby, since dust generation and low-temperature oxidation are suppressed, a coal mixed material can be stably stored or transported. Moreover, since the caking effect by ashless coal is enhanced by the close adhesion of ashless coal with high caking properties around the particles of steaming coal with low caking properties, the caking property of coal mixture is increased. Can do.

Note that when the coal mixture is used as coking coal, the pulverizer associated with the coke oven causes the particle size of the general coke blended coal (particle size of 3 mm or less to occupy the entire proportion). (About 80% by weight).

Also, as described above, coal that is a raw material for ashless coal is steam coal. Since the amount of steam coal contained in the coal for coke is further increased by using as a coke raw material a coal mixture obtained by mixing steam coal without heating ashless coal and steam coal as raw materials, The cost of the coke raw material can be further reduced. Also, from the production of ashless coal to the production of coal blends, such as producing ashless coal in the production area of steam coal and producing a coal blend with this ashless coal and steam coal. As a result, transportation costs and the like can be suppressed, and thus manufacturing costs can be reduced.

In addition, when the production of ashless coal to the production of coal mixture is performed consistently in the production area of steam coal, by-product coal obtained as a by-product in the production of ashless coal is used as fuel for local power plants. It is preferably used as a fuel in the ash coal production process. By effectively using by-product coal, which is a by-product, as a fuel, the production cost of ashless coal, and thus the production cost of a coal mixture can be reduced.

(Mixing ratio evaluation)
Next, from the properties of the coal mixture expected when one of the four typical coals A, B, C, D and ashless coal are mixed without heating, the ashless It evaluated about the mixing ratio (weight ratio) of charcoal and steam coal. The properties of the coal mixture are targeted for the properties of strong caking coal (general strong viscosity) or semi-strong caking coal (characteristics of categories B to D) in Table 2, with a Gieseller fluidity of 1.0 (Log ddpm). As described above, the average maximum reflectance was set to 0.75 (%) or more.

First, the produced ashless coal and steam coal are transported from a coal storage or silo, and simultaneously charged into a pulverizer, and heated at room temperature (25 without coarsely pulverizing so that the particle size is 20 mm or less. The mixture was mixed in the state of about ℃. Alternatively, ashless charcoal and steamed charcoal are charged separately into the pulverizer, coarsely pulverized so that the particle size is 20 mm or less, and then each is charged into the coal pulverizer so as to obtain an appropriate mixing ratio. Mixed without. And it is typical as coking coking coal expected when one of four typical steaming coals A, B, C, D and ashless coal are mixed without heating. By calculating the analysis values (volatile content, average maximum reflectance, Gieseller fluidity), the mixing ratio satisfying the target property was evaluated. Table 3 shows the properties of ashless coal and four types of steaming coals A, B, C, and D, respectively.

First, the mixing ratio (weight ratio) was changed in 6 steps between 1: 1 and 1:20, ashless coal and steaming coal A were mixed without heating, and the properties were evaluated. The results are shown in Table 4.

When the mixing ratio (weight ratio) was 1: 1, the average maximum reflectance and the Gieseller fluidity were within the target range, but the volatile content exceeded the upper limit of 33% of the target range. When the mixing ratio (weight ratio) was 1: 3 to 1: 5, the Gieseller fluidity was within the target range, but the volatile content exceeded the upper limit of 33%, and the average maximum reflectance was the target range. It was below the lower limit of 0.8%. When the mixing ratio (weight ratio) was 1: 8, the volatile component exceeded the upper limit of 33%, which was the upper limit of the target range, and the average maximum reflectance and the Gieseller flow rate were lower than the lower limit of the target range. When the mixing ratio (weight ratio) was 1:10 to 1:20, the volatile content was within the target range, but the average maximum reflectance and the Gieseller flow rate were below the lower limit of the target range. From the above, it was judged that the mixing ratio (weight ratio) of 1: 1 was good.

Next, the mixing ratio (weight ratio) was changed in 6 steps between 1: 1 and 1:20, and ashless coal and steaming coal B were mixed without heating, and the properties were evaluated. The results are shown in Table 5.

When the mixing ratio (weight ratio) was 1: 1, the average maximum reflectance and the Gieseller fluidity were within the target range, but the volatile content exceeded the upper limit of 33% of the target range. When the mixing ratio (weight ratio) was 1: 3, all of the volatile matter, the average maximum reflectance, and the Gieseller fluidity were values within the target range. When the mixing ratio (weight ratio) was 1: 5 to 1:20, the volatile content and the average maximum reflectance were values within the target range, but the Gieseller fluidity was 1.5 (Log), which is the lower limit value of the target range. ddpm). However, when the mixing ratio (weight ratio) was 1: 5, the Gieseller fluidity was 1.0 (Log ddpm) or more. From the above, it was judged that the mixing ratio (weight ratio) of 1: 3 was optimal, and the mixing ratio (weight ratio) of 1: 1 and 1: 5 was good.

Next, the mixing ratio (weight ratio) was changed from 1: 1 to 1:20 in 6 stages, and ashless coal and steaming coal C were mixed without heating, and the properties were evaluated. The results are shown in Table 6.

When the mixing ratio (weight ratio) was 1: 1, the average maximum reflectance and the Gieseller fluidity were within the target range, but the volatile content exceeded the upper limit of 33% of the target range. When the mixing ratio (weight ratio) was 1: 3 to 1:20, the Gieseller fluidity was within the target range, but the volatile content exceeded the upper limit of 33%, and the average maximum reflectance was the target range. It was below the lower limit of 0.8%. However, when the mixing ratio (weight ratio) was 1: 3 and 1: 5, the average maximum reflectance was 0.75 (%) or more. From the above, it was judged that the mixing ratio (weight ratio) of 1: 1 to 1: 5 was good.

Next, the mixing ratio (weight ratio) was changed from 1: 1 to 1:20 in six stages, and ashless coal and steaming coal D were mixed without heating, and the properties were evaluated. The results are shown in Table 7.

When the mixing ratio (weight ratio) was 1: 1, the average maximum reflectance and the Gieseller fluidity were within the target range, but the volatile content exceeded the upper limit of 33% of the target range. When the mixing ratio (weight ratio) was 1: 3 to 1: 5, all of the volatile matter, the average maximum reflectance, and the Gieseller fluidity were within the target range. When the mixing ratio (weight ratio) was 1: 8 to 1:20, the volatile content and the average maximum reflectance were within the target range, but the Gieseller fluidity was 1.5 (Log ddpm), which is the lower limit of the target range. Below. However, when the mixing ratio (weight ratio) was 1: 8 and 1:10, the Gieseller fluidity was 1.0 (Log ddpm) or more. From the above, it was judged that the mixing ratio (weight ratio) of 1: 1 to 1: 5 was optimum, and the mixing ratio (weight ratio) of 1: 8 and 1:10 was good.

From the above, the mixing ratio of ashless coal and general coal having the same properties as general strong caking coal (general strong caking) or semi-strong caking coal is 1: 1 to 1: 5 by weight, More preferably, the weight ratio was from 1: 3 to 1: 5.

In addition, the above evaluation is performed by increasing the weight of steam coal than ashless coal, but when the weight of ashless coal is increased than steam coal, the Gieseller fluidity and volatile matter increase, Since it becomes excessive and greatly deviates from the target property, the effect as a coal mixture cannot be expected.

(effect)
As described above, in this embodiment, ashless coal and steam coal are mixed at a weight ratio of 1: 1 to 1: 5 without heating to obtain a coal mixture. Ashless coal is excellent in fluidity and expansibility, and shows a high effect as a binder. Therefore, by mixing ashless coal and steam coal without heating, it is possible to obtain mixed coal having caking properties similar to those of high-quality strong caking coal. And, by mixing ashless coal and steam coal at a weight ratio of 1: 1 to 1: 5 without heating, the mixed coal coal has a Gieseller fluidity of 1.0 (Log ddpm) or more. The average maximum reflectance is 0.75 (%) or more. Thereby, the coal mixed material which has the property equivalent to a general strong caking coal or a semi-strong caking coal can be obtained. By using this coal mixture as a coke raw material instead of strong caking coal, the amount of strong caking coal in coke production can be reduced, and the amount of steam coal contained in the coke blending coal can be reduced. Can be increased. Specifically, the blending amount of the coal mixture in the coke blending coal is preferably 10% by mass to 50% by mass, and preferably 20% by mass to 30% by mass based on the total coke blending coal. When using ashless coal alone as an additive, it was necessary to adjust the appropriate amount according to the properties of the blended coal, but the coal mixture of the present invention is pre-blended with appropriate amounts of coal and ashless coal. Therefore, an appropriate amount can be easily added and blended with the coal for coke. In addition, since the ashless coal has a sulfur content similar to that of steam coal, the amount of ashless coal added to the coke blended coal is not limited by the sulfur content. Therefore, the quantity of the inferior quality raw material which can be mix | blended with the coal mixture for cokes can be increased by using the coal mixed material formed by mixing ashless coal and steam coal without heating as a coke raw material. Thereby, the cost of a coke raw material can be reduced.

Also, ashless coal and steaming coal are coarsely pulverized. Ashless coal tends to be pulverized more easily than steam coal. Generally, finely pulverized coal tends to generate dust. In general, finely pulverized coal easily undergoes low-temperature oxidation, so there is a concern that spontaneous combustion may occur due to oxidation heat generation. Thus, coarsely pulverizing ashless coal and steam coal allows them to mix evenly during mixing, and the ashless coal comes into close contact with the particles of steam coal. Thereby, since dust generation and low-temperature oxidation are suppressed, a coal mixed material can be stably stored or transported. Moreover, since the caking effect by ashless coal is enhanced by the close adhesion of ashless coal with high caking properties around the particles of steaming coal with low caking properties, the caking property of coal mixture is increased. Can do.

Also, coal, the raw material for ashless coal, is steam coal. Since the amount of steam coal contained in the coal for coke is further increased by using as a coke raw material a coal mixture obtained by mixing steam coal without heating ashless coal and steam coal as raw materials, The cost of the coke raw material can be further reduced. Also, from the production of ashless coal to the production of coal blends, such as producing ashless coal in the production area of steam coal and producing a coal blend with this ashless coal and steam coal. As a result, transportation costs and the like can be suppressed, and thus manufacturing costs can be reduced.

(Modification of this embodiment)
The embodiment of the present invention has been described above, but only specific examples are illustrated, and the present invention is not particularly limited, and the specific configuration and the like can be appropriately changed in design. Further, the actions and effects described in the embodiments of the invention only list the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to what was done.

This application is based on a Japanese patent application filed on March 31, 2014 (Japanese Patent Application No. 2014-072439), the contents of which are incorporated herein by reference.

The coal mixed material of the present invention is useful as a raw coal for producing coke and can be produced at low cost.

1 Coal hopper
2 Solvent tank
3 slurry preparation tank
3a Stirrer
4 Transfer pump
5 Preheater
6 Extraction tank
6a Stirrer
7 Gravity sedimentation tank
8,9 Solvent separator 100 Ashless coal production equipment

Claims

Ashless coal, which is a solvent extract of coal, and steam coal are mixed at a weight ratio of 1: 1 to 1: 5 without heating, and the mixed coal has a Gieseller fluidity of 1. A coal mixture characterized by being 0 (Log ddpm) or more and an average maximum reflectance of 0.75 (%) or more.
The coal mixture according to claim 1, wherein the ashless coal and the steam coal are coarsely pulverized.
The coal mixture according to claim 1 or 2, wherein the coal that is a raw material of the ashless coal is steam coal.