JP6618866B2 - Method for producing coking coal for coke production, device for producing coking coal for coke production, and method for producing coke for blast furnace - Google Patents

Description

  The present invention relates to a method for producing coking coal for producing coke, a device for producing coking coal for producing coke, and a method for producing coke for blast furnace.

  Coke used in ironmaking in a blast furnace has a function as a reducing agent for iron ore (iron oxide), a function as a heat source (fuel), and a breathability in the furnace that can withstand the load between the coke itself and iron ore. Three functions are expected for the function as a filler for ensuring the resistance. In order to fulfill these functions, the coke is required to have a certain strength and reactivity (reducibility and combustibility).

  In general, coke is produced by forming coal and then steaming it at a high temperature of 1000 ° C. or higher (hereinafter sometimes referred to as “dry distillation”). When obtaining coke with high strength, coking coal, which is highly caking, is used, but such coking coal is relatively expensive. Therefore, for the purpose of reducing the production cost of coke, it is desirable to use inexpensive inferior coal with low caking properties. However, when inferior coal is used, the strength of coke decreases due to its low caking property, so the amount of inferior coal that can be blended is limited.

  On the other hand, as one of the measures to increase the strength of coke while reducing the production cost of coke, a method of using ashless coal obtained by solvent extraction treatment of coal as a caking filler is known. (See JP 2009-215454 A). In this method, ashless coal is mixed with inferior coal and heated to the melting point of ashless coal or higher to fix the ashless coal on the coal surface. In this conventional method for producing coke, while reducing the production cost by using inferior coal, the ashless coal has a particle size of 0.5 mm or less, thereby improving the mixed state with ashless coal, and coke. The strength of is increased. However, because the mixture of ashless and inferior coal is solid, the strength of coke is reduced due to insufficient contact between ashless and inferior coal and the uneven distribution of ashless coal that serves as a binder. There is a risk that it will not rise sufficiently.

JP 2009-215454 A

  The present invention has been made based on the circumstances as described above, and an object of the present invention is to provide a method for producing raw coke for producing coke, which can improve the strength of coke, while reducing the production cost of coke, and for producing coke. An object is to provide a raw coal production apparatus and a blast furnace coke production method.

  The invention made in order to solve the above problems includes a step of mixing the first coal and the solvent, a step of eluting a coal component soluble in the solvent from the first coal in the slurry obtained in the mixing step, A step of separating from the slurry a solution in which the coal component obtained in the elution step is dissolved in a solvent, a step of evaporating the solvent from the solution separated in the separation step, and a liquid state obtained in the solvent evaporation step. It is a manufacturing method of the raw coal for coke manufacture provided with the process of mix | blending ashless coal with 2nd coal.

  The coke production raw coal production method includes a step of blending the liquid ashless coal obtained in the solvent evaporation step with the second coal. That is, since the produced ashless coal is blended with the second coal in a liquid state without cooling, the ashless coal adheres to the surface of the second coal, and a part thereof is impregnated in the coal pores. . For this reason, compared with the case where ashless coal is mixed as a solid, a coke production raw material that can obtain a stronger bond and a uniform dispersion of ashless coal between ashless coal and second coal and improve coke strength. Charcoal is obtained. Moreover, since the said ashless coal is liquid, it is easy to contact with 2nd coal, and is high temperature. For this reason, the heat exchange efficiency of ashless coal and 2nd coal is high, and a part of calorie | heat amount required in order to dry raw material coal for coke manufacture can be supplemented. Therefore, the production cost of coke can be reduced by using the method for producing coking coal for coke production.

  As temperature of the liquid ashless coal of the said compounding process, 200 to 300 degreeC is preferable. In this way, by setting the temperature of the liquid ashless coal within the above range, the liquid ashless coal can be mixed while suppressing the melting of the second coal, so the bond between the ashless coal and the second coal. Is further increased.

  The total expansion rate of the second coal is preferably 0% or more and 10% or less. In the method for producing coking coal for coke production, by combining liquid ashless coal, a strong bond and a uniform dispersion of ashless coal can be obtained between the ashless coal and the second coal. As the two coals, inferior coal having a low total expansion rate can be used. Therefore, the manufacturing cost of coke can be reduced.

  Another invention made in order to solve the above-mentioned problem is to elute a solvent component soluble in the solvent from the first coal in the slurry obtained by the mixing unit for mixing the first coal and the solvent and the mixing unit. An elution part, a separation part for separating the solution obtained by dissolving the coal component obtained in the elution part in the solvent from the slurry, a solvent evaporation part for evaporating the solvent from the solution separated in the separation part, and the solvent evaporation It is the manufacturing apparatus of the raw coal for coke manufacture provided with the mixing | blending part which mix | blends the liquid ashless coal obtained by the part with the 2nd coal.

  The coke production raw coal production apparatus blends liquid ashless coal obtained in the solvent evaporation section with the second coal in the blending section. That is, since the produced ashless coal is blended with the second coal in a liquid state without cooling, the ashless coal adheres to the surface of the second coal, and a part thereof is impregnated in the coal pores. . For this reason, coke that can obtain stronger bond between ashless coal and coal and uniform dispersion of ashless coal in the coke tank and improve coke strength than when mixing ashless coal in solid form Coking coal for production is obtained. Moreover, since the said ashless coal is liquid, it is easy to contact with 2nd coal, and is high temperature. For this reason, the heat exchange efficiency of ashless coal and 2nd coal is high, and a part of calorie | heat amount required in order to dry raw material coal for coke manufacture can be supplemented. Therefore, the production cost of coke can be reduced by using the apparatus for producing raw coal for producing coke.

  Still another invention made in order to solve the above-mentioned problem is a method for producing coke for blast furnace, comprising a step of dry-distilling coking coal for producing coke produced by the method for producing coking coal for producing coke.

  The blast furnace coke production method uses coke production raw coal produced by the coke production raw coal production method. Since the ashless coal adheres to the coal surface in the coke production raw coal, a strong bond between the ashless coal and the coal is obtained during dry distillation, and the ashless coal is unevenly distributed in the coke tank. Can be prevented. Furthermore, since the 2nd coal is preheated when adhering to the coal surface and solidifying, a part of calorie | heat amount required for coal drying at the time of coke manufacture is supplemented, and the manufacturing cost of blast furnace coke is reduced.

  Here, ashless coal (Hypercoal, HPC) is a type of modified coal obtained by reforming coal, and a modified coal that removes ash and insoluble components from coal as much as possible using a solvent. It is. However, the ashless coal may contain ash as long as the fluidity and expansibility of the ashless coal are not significantly impaired. In general, coal contains ash content of 7% by mass or more and 20% by mass or less, but ashless coal may contain ash content of about 2% by mass, and in some cases about 5% by mass. The “ash” means a value measured according to JIS-M8812: 2006.

  The “total expansion coefficient of coal” is a value measured in accordance with the dilatometer method of JIS-M8801: 2008.

  As described above, by using the coke production raw coal production method, the coke production raw coal production apparatus, and the blast furnace coke production method, while reducing the coke production cost, Strength can be improved.

It is the schematic which shows the manufacturing apparatus of the raw coal for coke manufacture of 1st embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a coke production raw coal production apparatus, a coke production raw coal production method, and a blast furnace coke production method according to the present invention will be described in detail.

[Coking coal production equipment for coke production]
The coke production raw coal production apparatus of FIG. 1 includes a first coal supply unit 1, a solvent supply unit 2, a mixing unit 3, a pump 4, a heating unit 5, an elution unit 6, and a separation unit 7. The 1st solvent evaporation part 8, the 2nd solvent evaporation part 9, the 2nd coal supply part 10, and the compounding part 11 are mainly provided.

<First coal supply department>
The first coal supply unit 1 supplies the first coal to the mixing unit 3. As the 1st coal supply part 1, well-known coal hoppers, such as a normal pressure hopper used in a normal pressure state, a pressure hopper used in a normal pressure state and a pressurization state, can be used.

  The 1st coal supplied from the 1st coal supply part 1 is coal used as the raw material of ashless coal. As the first coal, various quality coals can be used. For example, bituminous coal with a high extraction rate of ashless coal or cheaper inferior quality coal (subbituminous coal or lignite) is preferably used. Further, when coal is classified by particle size, finely pulverized coal is preferably used. Here, “finely pulverized coal” means, for example, coal in which the mass ratio of coal having a particle size of less than 1 mm to the mass of the entire coal is 80% or more. Moreover, lump coal can also be used as the coal supplied from the first coal supply unit 1. Here, “coal” means, for example, coal in which the mass ratio of coal having a particle size of 5 mm or more to the mass of the entire coal is 50% or more. Since the lump coal has a larger coal particle size than finely pulverized coal, the separation in the separation unit 7 described later can be made efficient. Here, “particle size (particle size)” refers to a value measured in accordance with JIS-Z8815: 1994 general screening test rules. In addition, the metal net sieve prescribed | regulated to JIS-Z8801-1: 2006 can be used for the classification by the particle size of coal, for example.

  The lower limit of the carbon content of the inferior coal is preferably 70% by mass. On the other hand, the upper limit of the carbon content of the inferior coal is preferably 85% by mass, and more preferably 82% by mass. There exists a possibility that the elution rate of a solvent soluble component may fall that the carbon content rate of the said inferior coal is less than the said minimum. Conversely, if the carbon content of the inferior coal exceeds the upper limit, the cost of the supplied coal may increase.

  In addition, as a 1st coal supplied to the mixing part 3 from the 1st coal supply part 1, you may use the coal which mixed a small amount of solvent and made it slurry. By supplying the 1st coal slurried from the 1st coal supply part 1 to the mixing part 3, the 1st coal becomes easy to mix with a solvent in the mixing part 3, and a 1st coal can be dissolved earlier. However, if the amount of the solvent to be mixed at the time of forming the slurry is large, the amount of heat for raising the temperature of the slurry to the elution temperature in the heating unit 5 becomes unnecessarily large, which may increase the manufacturing cost.

<Solvent supply unit>
The solvent supply unit 2 supplies the solvent to the mixing unit 3. The solvent supply unit 2 includes a solvent tank that stores a solvent, and supplies the solvent from the solvent tank to the mixing unit 3.

  Although the solvent mixed with the first coal is not particularly limited as long as it dissolves the first coal, for example, a bicyclic aromatic compound derived from coal is preferably used. Since this bicyclic aromatic compound has a basic structure similar to the structural molecule of coal, it has a high affinity with coal and can obtain a relatively high extraction rate. Examples of the bicyclic aromatic compound derived from coal include methyl naphthalene oil and naphthalene oil, which are distilled oils of by-products when carbon is distilled to produce coke.

  The boiling point of the solvent is not particularly limited. For example, the lower limit of the boiling point of the solvent is preferably 180 ° C, more preferably 230 ° C. On the other hand, the upper limit of the boiling point of the solvent is preferably 300 ° C and more preferably 280 ° C. If the boiling point of the solvent is less than the lower limit, the solvent is likely to volatilize, and it may be difficult to prepare and maintain the mixing ratio between the first coal and the solvent in the slurry. Conversely, if the boiling point of the solvent exceeds the upper limit, separation of the solvent-soluble component from the solvent becomes difficult, and the solvent recovery rate may be reduced.

<Mixing section>
The mixing unit 3 mixes the first coal supplied from the first coal supply unit 1 and the solvent supplied from the solvent supply unit 2.

  The mixing unit 3 has a preparation tank 31. The solvent and the first coal are supplied to the preparation tank 31 through a supply pipe. The preparation tank 31 stores a slurry in which the supplied solvent and the first coal are mixed. Moreover, the said preparation tank 31 has the stirrer 31a. The preparation tank 31 maintains the mixed state of the slurry by holding the mixed slurry while stirring with the stirrer 31a.

  As a minimum of coal concentration on the basis of anhydrous coal in the slurry in preparation tank 31, 10 mass% is preferred and 13 mass% is more preferred. On the other hand, the upper limit of the coal concentration is preferably 25% by mass, and more preferably 20% by mass. If the coal concentration is less than the above lower limit, the elution amount of solvent-soluble components eluted in the heating unit 5 described later decreases with respect to the slurry processing amount, which may reduce the production efficiency of ashless coal. . Conversely, if the coal concentration exceeds the upper limit, the solvent-soluble component is saturated in the solvent, and the elution rate of the solvent-soluble component may be reduced.

  The slurry prepared in the preparation tank 31 of the mixing unit 3 is sent to the heating unit 5 through a supply pipe.

<Pump>
The pump 4 is disposed in a supply pipe that supplies slurry from the mixing unit 3 to the heating unit 5. The pump 4 pumps the slurry stored in the preparation tank 31 of the mixing unit 3 to the heating unit 5 through a supply pipe.

  The type of the pump 4 is not particularly limited as long as the slurry can be pumped to the heating unit 5 through a supply pipe. For example, a positive displacement pump or a non-positive displacement pump can be used. More specifically, a diaphragm pump, a tube diaphragm pump, or the like can be used as the positive displacement pump, and a spiral pump or the like can be used as the non-positive displacement pump.

<Heating section>
The heating unit 5 heats the slurry obtained in the mixing unit 3.

  Although the heating furnace 51 will not be specifically limited if the slurry which passes the inside of the heating furnace 51 can be heated, For example, a resistance heating type heater and an induction heating coil are mentioned. Moreover, you may heat using a heat medium. For example, the slurry passing through the heating furnace 51 can be heated by arranging a heating pipe around the flow path of the slurry passing through the heating furnace 51 and supplying a heating medium such as steam or oil to the heating pipe. .

  As a minimum of the temperature of the slurry after the heating with the heating furnace 51, 300 degreeC is preferable and 360 degreeC is more preferable. On the other hand, the upper limit of the temperature of the slurry is not particularly limited as long as it is a temperature at which elution is possible, but 420 ° C. is preferable, and 400 ° C. is more preferable. If the temperature of the slurry is less than the lower limit, the bonds between the molecules constituting the first coal cannot be sufficiently weakened, and the elution rate may decrease. On the other hand, when the temperature of the slurry exceeds the upper limit, the amount of heat for maintaining the temperature of the slurry becomes unnecessarily large, which may increase the manufacturing cost.

<Elution part>
The elution part 6 elutes the coal component soluble in the solvent from the first coal in the slurry obtained by the mixing part 3 and heated by the heating part 5.

  The elution part 6 has an extraction tank 61, and the slurry after the heating is supplied to the extraction tank 61. In the extraction tank 61, a coal component soluble in the solvent is eluted from the first coal while maintaining the temperature of the slurry. The extraction tank 61 has a stirrer 61a. The elution can be promoted by stirring the slurry with the stirrer 61a.

  In addition, although it does not specifically limit as elution time in the elution part 6, From the viewpoint of the extraction amount and extraction efficiency of a solvent soluble component, 10 minutes or more and 70 minutes or less are preferable.

<Separation part>
The separation unit 7 separates, from the slurry, a solution in which the coal component obtained in the elution unit 6 is dissolved in a solvent and a solid concentrate containing a solvent-insoluble component. The solvent-insoluble component is an extraction residue that is mainly composed of ash and insoluble coal that are insoluble in the extraction solvent, and also includes the extraction solvent.

  Specifically, the separation in the separation unit 7 can be performed by a gravity sedimentation method. Here, the gravity sedimentation method is a separation method in which a solid content is settled by using gravity in a sedimentation tank to perform solid-liquid separation.

  When performing separation by the gravity sedimentation method, the slurry containing the solvent-soluble component is discharged from the upper part of the settling tank while the slurry is continuously supplied into the separation unit 7, and the solid concentrate containing the solvent-insoluble component is settled. It can be discharged from the bottom of the tank. Thereby, continuous solid-liquid separation processing becomes possible.

  Further, in the gravity sedimentation method, the solution containing the solvent-soluble component is accumulated at the upper part of the separation unit 7. This solution is filtered using a filter unit as necessary, and then discharged to the first solvent evaporation section 8. On the other hand, the solid concentrate containing the solvent-insoluble component is collected at the lower part of the separation unit 7 and discharged to the second solvent evaporation unit 9.

  Although the time which maintains a slurry in the separation part 7 is not specifically limited, For example, it is 30 minutes or more and 120 minutes or less, and sedimentation separation in the separation part 7 is performed within this time. In addition, when using lump coal as 1st coal, since sedimentation separation is made efficient, the time which maintains a slurry in the separation part 7 can be shortened.

  The inside of the separation unit 7 is preferably heated and pressurized. As a minimum of heating temperature in separation part 7, 300 ° C is preferred and 350 ° C is more preferred. On the other hand, as an upper limit of the heating temperature in the separation part 7, 420 degreeC is preferable and 400 degreeC is more preferable. If the heating temperature is less than the lower limit, the solvent-soluble component may reprecipitate and the separation efficiency may be reduced. Conversely, if the heating temperature exceeds the upper limit, the operating cost for heating may increase.

  Moreover, as a minimum of the pressure in the separation part 7, 1 MPa is preferable and 1.4 MPa is more preferable. On the other hand, the upper limit of the pressure is preferably 3 MPa, more preferably 2 MPa. If the pressure is less than the lower limit, the solvent-soluble component may reprecipitate and the separation efficiency may be reduced. Conversely, when the pressure exceeds the upper limit, the operating cost for pressurization may increase.

  In addition, as a method of isolate | separating the said solution and solid content concentrate, it is not restricted to a gravity sedimentation method, For example, you may use the filtration method and the centrifugation method. When a filtration method or a centrifugal method is used as the solid-liquid separation method, a filter, a centrifugal separator, or the like is used as the separation unit 7.

<First solvent evaporation section>
The first solvent evaporating unit 8 evaporates the solvent from the solution separated by the separating unit 7. Ashless coal A is obtained by evaporating and separating the solvent.

  The ashless coal A thus obtained has an ash content of 5% by mass or less or 3% by mass or less, hardly contains ash, has no moisture, and has a higher calorific value than, for example, coke raw material coal. Show. Furthermore, ashless coal has a significantly improved softening and melting property, which is a particularly important quality as a raw material for iron-making coke, and exhibits fluidity far superior to, for example, raw material coal. Therefore, ashless coal can be used as coal blended with coke raw materials.

  As a method for evaporating and separating the solvent, a separation method including a general distillation method using an evaporative separator or an evaporation method (spray drying method or the like) can be used. By separating the solvent from the solution, ashless coal A substantially free of ash can be obtained from the solution.

  In addition, the ashless coal A obtained in the 1st solvent evaporation part 8 is a liquid state. As a minimum of the temperature of the said liquid ashless coal A, 200 degreeC is preferable and 250 degreeC is more preferable. On the other hand, as an upper limit of the temperature of the said liquid ashless coal A, 300 degreeC is preferable and 290 degreeC is more preferable. When the temperature of the liquid ashless coal A is less than the above lower limit, the fluidity of the ashless coal A is lowered, and the effect of improving the bonding strength between the ashless coal A and the second coal is sufficiently obtained. There is a risk of not. Conversely, when the temperature of the liquid ashless coal A exceeds the upper limit, the second coal melts when the ashless coal A is blended with the second coal, and the strength of the coke obtained from the raw coal for producing coke. May decrease. The temperature of the ashless coal A can be controlled by the solvent separation temperature in the first solvent evaporation section 8.

  The solvent evaporated in the first solvent evaporation unit 8 may be liquefied by, for example, a heat exchanger, supplied to the mixing unit 3, and used as a solvent to be mixed with the first coal supply unit 1. By recycling the solvent in this way, it is possible to reduce the production cost of coking coal raw coal.

<Second solvent evaporation section>
The second solvent evaporating unit 9 evaporates and separates the solvent from the solid concentration liquid separated by the separating unit 7 to obtain by-product coal B.

  By-product charcoal B does not exhibit softening and melting properties, but the oxygen-containing functional group is eliminated. Therefore, byproduct coal does not inhibit the softening and melting properties of other coal contained in the second coal when used as the second coal. Therefore, this byproduct coal B can also be used as a part of the second coal as a coke raw material. The by-product coal B may be discarded without being collected.

  As a method for separating the solvent from the solid concentrate, a general distillation method or evaporation method (e.g., spray drying method) using an evaporation separator is used, as in the separation method of the first solvent evaporation unit 8. it can. By separation and recovery of the solvent, by-product coal B in which solvent-insoluble components including ash and the like are concentrated from the solid concentrate can be obtained.

  The solvent evaporated in the second solvent evaporation unit 9 may be liquefied by, for example, a heat exchanger, supplied to the mixing unit 3, and used as a solvent to be mixed with the first coal supply unit 1. By recycling the solvent in this way, it is possible to reduce the production cost of coking coal raw coal.

<Second coal supply section>
The second coal supply unit 10 supplies the second coal to the blending unit 11. As the 2nd coal supply part 10, well-known coal hoppers, such as a normal pressure hopper used in a normal pressure state, a pressure hopper used in a normal pressure state and a pressurization state, can be used.

  The 2nd coal supplied from the 2nd coal supply part 10 is coal used as the raw material of coke. The second coal is not particularly limited, and a moderate ratio that enables fusion of the whole coal by dry distillation of strong caking coal, semi-caking coal, weak caking coal, slightly caking coal, non-caking coal, etc. Can be used in combination.

  In addition, by using the apparatus for producing coking coal for coke production, liquid ashless coal A is blended so that a strong bond and uniform dispersion of ashless coal A can be achieved between the ashless coal A and the second coal. Since it is obtained, inferior coal with a low total expansion rate can be used as the second coal. The upper limit of the total expansion rate of the second coal is preferably 10%, more preferably 7%. If the total expansion rate of the second coal exceeds the above upper limit, the content of relatively expensive coal in the second coal increases, which may increase the production cost of coke. On the other hand, the lower limit of the total expansion rate of the second coal is 0%.

  The second coal is preferably in the form of finely pulverized particles. When making 2nd coal into a particulate form, 3 mm or less is preferable as 80% particle size of 2nd coal. If the 80% particle size exceeds the above upper limit, the strength of the obtained coke may be insufficient. Note that “80% particle size” means the cumulative mass of particles that have passed through the sieve when all the particles are sieved in order from the smallest sieve with a metal mesh sieve defined in JIS-Z8801-1: 2006. Means the size of the sieve mesh when 80% of the total particle mass is reached.

  In addition, although 2nd coal is good also as dry coal by air drying etc., the thing containing a water | moisture content may be used. When the second coal contains moisture, the moisture content of the second coal is preferably 20% by mass or less from the viewpoint of the preheating effect of the second coal by the ashless coal A described later.

<Combination part>
The blending unit 11 blends the liquid ashless coal A obtained in the first solvent evaporation unit 8 with the second coal. As the blending unit 11, for example, a mixing tank is provided, and a configuration in which the ashless coal A is applied to the second coal by immersing the second coal in the liquid ashless coal A stored in the mixed layer, or a known sprayer The structure etc. which sprinkle liquid ashless coal A to the 2nd coal can be mentioned.

  Further, as the blending unit 11, an evaporating separator used in the first solvent evaporating unit 8 can be used. That is, the blending unit 11 can be configured to blend the liquid ashless coal A with the second coal while the first solvent evaporating unit 8 evaporates the solvent from the solution separated by the separating unit 7. Specifically, the first solvent evaporating unit 8 sprays the solution at a high temperature from the upper part of the evaporating separator so that the solvent is evaporated and separated, and the mistless ashless coal A falls to the lower part. Since the solvent is separated, by placing the second coal in the lower part of the evaporative separator, the mistless ashless coal A is poured from above, and the ashless coal A can be blended with the second coal. it can. Thus, by using the evaporative separator used in the first solvent evaporating unit 8 as the blending unit 11, the equipment cost of the coke producing raw coal production apparatus can be reduced.

  As a minimum of the compounding quantity of the above-mentioned ashless coal A to the total amount of ashless coal A and the 2nd coal, 3 mass% is preferred and 4 mass% is more preferred. On the other hand, the upper limit of the amount of the ashless coal A is preferably 40% by mass, and more preferably 35% by mass. If the blending amount of the ashless coal A is less than the lower limit, the bonding strength between the ashless coal A and the second coal may be insufficient, and the coke strength improvement effect may be insufficient. The heat exchange efficiency between A and the second coal may be insufficient. On the other hand, when the blending amount of the ashless coal A exceeds the upper limit, the proportion of relatively cheap inferior coal may decrease, and the production cost of coke may increase.

  The blended liquid ashless coal A adheres to the surface of the second coal, and part of it impregnates in the pores of the coal. Moreover, since the said ashless coal A is liquid, it is easy to contact with 2nd coal, and is high temperature. For this reason, the heat exchange efficiency of ashless coal A and the 2nd coal is high, and the temperature of the 2nd coal rises by blending ashless coal A. Although the temperature of the 2nd coal after the mixing | blending of ashless coal A is decided by the temperature and compounding quantity of ashless coal A, it can be 40 degreeC or more and 150 degrees C or less. On the other hand, the ashless coal A is deprived of heat by the second coal, and its temperature becomes the melting point or lower, so that it is solidified in the second coal and the coal pores, and the raw coal C for producing coke is obtained. In addition, the temperature of the raw coke C for producing coke is approximately the same as the temperature of the second coal after blending the ashless coal A as a result of heat exchange between the ashless coal A and the second coal. That is, the preheated coking coal C is obtained.

  In addition, liquid ashless coal A can also be mix | blended with a part of 2nd coal. For example, when the second coal includes raw coal having a high total expansion rate and inferior coal having a low total expansion rate, liquid ashless coal A may be blended only with the inferior coal having a low total expansion rate. Moreover, when 2nd coal contains multiple types of coal, you may change the compounding quantity of liquid ashless coal A for every classification of coal. In this way, by changing the blending amount of liquid ashless coal A according to the type of coal, the difference in binding strength due to the difference in the type of coal is adjusted, and the binding strength between ashless coal and coal is uniform. Can be

  Moreover, in addition to liquid ashless coal A, you may mix | blend solid ashless coal with 2nd coal.

[Production method of coking coal for coke production]
The method for producing coking coal for coke production includes a mixing step, a heating step, a separation step, a first solvent evaporation step, a second solvent evaporation step, a recovery step, and a blending step. The coke production raw coal production method can be performed using the coke production raw coal production apparatus shown in FIG.

<Mixing process>
In the mixing step, the first coal and the solvent are mixed. Specifically, the first coal supplied from the coal supply unit 1 and the solvent supplied from the solvent supply unit 2 are mixed in the preparation tank 31 of the mixing unit 3 to form a slurry.

<Heating process>
In the heating step, the slurry obtained in the mixing step is heated. Specifically, the following procedure is performed. First, the slurry prepared in the mixing step is supplied to the heating furnace 51 of the heating unit 5 by the pump 4 and heated to a predetermined temperature.

<Elution process>
In the elution step, a coal component soluble in the solvent is eluted from the first coal in the slurry obtained in the mixing step. Specifically, the slurry after heating is supplied to the extraction tank 61, and extraction is performed while being held at a predetermined temperature while being stirred by the stirrer 61a.

<Separation process>
In the separation step, a solution in which the coal component obtained in the elution step is dissolved in a solvent and a solid concentration liquid containing a solvent-insoluble component are separated from the slurry. Specifically, the slurry discharged from the extraction tank 61 is supplied to the separation unit 7, and the slurry supplied in the separation unit 7 is separated into the solution and the solid content concentrate by, for example, gravity sedimentation.

<First solvent evaporation step>
In the first solvent evaporation step, the solvent is evaporated from the solution separated in the separation step. Specifically, the solution separated by the separation unit 7 is supplied to the first solvent evaporation unit 8, and the solvent is evaporated by the first solvent evaporation unit 8. This separates the solution into solvent and ashless coal A. The ashless coal A obtained in the first solvent evaporation step is liquid.

<Second solvent evaporation step>
In the second solvent evaporation step, the solvent is evaporated from the solid content concentrate separated in the separation step. Specifically, the solid concentration liquid separated by the separation unit 7 is supplied to the second solvent evaporation unit 9, and the solvent is evaporated by the second solvent evaporation unit 9 to separate the solvent and the by-product coal B.

<Mixing process>
In the blending step, the liquid ashless coal A obtained in the first solvent evaporation step and the second coal are blended. Specifically, the raw coal C for producing coke is obtained by applying or spraying the liquid ashless coal A obtained in the first solvent evaporation unit 8 to the second coal supplied from the second coal supply unit 10. .

[Method of manufacturing coke for blast furnace]
The method for producing coke for blast furnace includes a step of dry-distilling coke production raw coal C produced by the coke production raw coal production method.

<Dry distillation process>
In the carbonization step, coke is obtained by charging the coking coal C for producing coke into a coke oven and performing carbonization. As this coke oven, for example, one having a furnace body capable of charging about 30 tons per gate can be used.

  The coke production raw coal C is charged into the coke oven continuously after the blending step, that is, in a state where the temperature of the coke production raw coal C obtained in the blending step is high. By using the raw coke C for producing coke that has been preheated in the above blending process, part of the amount of heat necessary for drying the coal during coke production is supplemented, and the production cost of blast furnace coke can be reduced.

The lower limit of the packing density of instrumentation Nyutoki to coke oven coke raw material for producing carbon C, preferably ^{700.0kg / m 3, 730kg / m} 3 and more preferably. On the other hand, the upper limit of the packing density is preferably ^{1050kg / m 3, 1000kg / m} 3 and more preferably. There exists a possibility that the intensity | strength of coke may become inadequate that the said packing density is less than the said minimum. On the other hand, when the packing density exceeds the upper limit, the pressure applied to the furnace body is increased, the furnace body may be damaged, and the production cost of coke increases due to the work of improving the packing density of the raw coal C for producing coke. There is a fear. The “filling density” means a bulk density measured according to JIS-K2151: 2004.

  As a lower limit of the dry distillation temperature of the raw coal C for producing coke, 950 ° C is preferable, and 1000 ° C is more preferable. On the other hand, as an upper limit of dry distillation temperature, 1200 degreeC is preferable and 1150 degreeC is more preferable. If the dry distillation temperature is less than the above lower limit, the second coal is not sufficiently melted, and the strength of the coke may be reduced. On the other hand, if the dry distillation temperature exceeds the upper limit, the production cost may increase from the viewpoint of heat resistance of the furnace body and fuel consumption.

  The lower limit of the carbonization time of the raw coal C for producing coke is preferably 8 hours and more preferably 10 hours. On the other hand, the upper limit of the carbonization time is preferably 24 hours, more preferably 20 hours. If the carbonization time is less than the above lower limit, coal may not be sufficiently melted and coke strength may be reduced. On the other hand, when the carbonization time exceeds the above upper limit, the production cost may increase from the viewpoint of fuel consumption.

〔advantage〕
The coke production raw coal production method includes a step of blending the liquid ashless coal A obtained in the first solvent evaporation step with the second coal. The coke production raw coal production apparatus blends the liquid ashless coal A obtained in the first solvent evaporation unit 8 with the second coal in the blending unit 11. That is, since the manufactured ashless coal A is blended with the second coal in a liquid state without cooling, the ashless coal A adheres to the surface of the second coal, and a part thereof is contained in the coal pores. Invade. For this reason, compared with the case where ashless coal A is mixed with solid, coke which can obtain a strong bond between ashless coal A and the second coal and a uniform dispersion of ashless coal A and can improve the strength of coke. Coking coal C for production is obtained. Moreover, since the said ashless coal A is liquid, it is easy to contact with 2nd coal, and is high temperature. For this reason, the heat exchange efficiency of ashless coal A and the 2nd coal is high, and a part of calorie | heat amount required in order to dry the raw coal C for coke manufacture can be supplemented. Therefore, the coke production cost can be reduced by using the coke production raw coal production method and the coke production raw coal production apparatus.

  Moreover, the manufacturing method of the said blast furnace coke uses the raw coal C for coke manufacture manufactured by the manufacturing method of the said raw coke for coke manufacture. Since the ashless coal A adheres to the surface of the coal as the coking coal, the ashless coal A and the coal can be firmly bonded during dry distillation, and the ashless coal in the coke tank can be obtained. Uneven distribution can be prevented. Furthermore, since the second coal is preheated when ashless coal A adheres to the second coal surface and solidifies, a part of the calorie required for drying the coal at the time of coke production is supplemented, and the production of coke for blast furnace Cost is reduced.

[Other Embodiments]
In addition, the manufacturing method of the raw coal for coke manufacture of this invention, the manufacturing apparatus of the raw coal for coke manufacture, and the manufacturing method of coke for blast furnace are not limited to the said embodiment.

  In the above-described embodiment, the case where the second solvent evaporation step is provided as a method for producing the raw coal for producing coke has been described. However, for example, when the by-product coal is not used, the second solvent evaporation step can be omitted. When not performing the 2nd solvent evaporation process, the manufacturing apparatus of the raw coal for coke manufacture does not need to be provided with the 2nd solvent evaporation part.

  Moreover, in the said embodiment, although the preparation part of the manufacturing apparatus of the raw coal for coke manufacture demonstrated the structure which has a preparation tank, if not only this structure but mixing of a solvent and coal can be performed, a preparation tank will be abbreviate | omitted. Also good. For example, when the above mixing is completed by a line mixer, the preparation tank may be omitted and a line mixer may be provided between the supply pipe and the separation unit.

  Moreover, although the method of performing a separation process by a continuous process was shown in the said embodiment, it is good also as a batch process which repeats not performing a separation process by a continuous process but storing a slurry in a separation part and performing separation, for example.

  In the above embodiment, in the method for producing coke for blast furnace, a case has been described in which the carbonization step is performed continuously to the blending step of the method for producing raw coal for coke production. Coking coking coal produced by the method for producing coking coal can also be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

  Calculate the reduction ratio of the amount of heat required for the production of blast furnace coke for the case where the dry distillation process of the coke production process for the blast furnace is performed continuously with the blending process of the coke production process. did.

  In the calculation of the reduction ratio of the calorific value, the temperature of the liquid ashless coal was 270 ° C., and the temperature of the second coal was 30 ° C. In addition, 270 degreeC liquid ashless coal has a calorie | heat amount of 91 kcal / kg on the basis of a 30 degreeC state. The moisture content of the second coal was 10% by mass.

  Under the above calculation conditions, the temperature of coking coal raw coal produced by blending ashless coal with second coal was simulated. As a result, when the blending amount of ashless coal in the raw coal for coke production is 5% by mass, the temperature of the raw coal for coke production is 41 ° C., and when the blending amount of ashless coal is 30% by mass, coke is obtained. The temperature of the raw coal for production was 100 ° C.

  The amount of heat required for the production of blast furnace coke is 550 kcal / kg (see coke note 2015 edition of the Japan Institute of Energy). When the ratio of the amount of heat reduced in the production of blast furnace coke was calculated based on this numerical value, 0.9% was obtained when the blending amount of ashless coal was 5 mass%, and the blending amount of ashless coal was 30 mass%. %, It was 5%.

  From this result, by using the coke production raw coal produced by the coke production raw coal production method, a part of the calorie required for coal drying during coke production is compensated, and the production cost of coke for blast furnace Can be reduced.

  As described above, by using the coke production raw coal production method, the coke production raw coal production apparatus, and the blast furnace coke production method, while reducing the coke production cost, Strength can be improved.

DESCRIPTION OF SYMBOLS 1 1st coal supply part 2 Solvent supply part 3 Mixing part 31 Preparation tank 31a Stirrer 4 Pump 5 Heating part 51 Heating furnace 6 Elution part 61 Extraction tank 61a Stirrer 7 Separation part 8 1st solvent evaporation part 9 2nd solvent evaporation part 10 Second coal supply section 11 Blending section A Ashless coal B By-product coal C Coking coking coal

Claims (5)

Mixing the first coal and the solvent;
A step of eluting coal components soluble in a solvent from the first coal in the slurry obtained in the mixing step;
Separating the solution in which the coal component obtained in the elution step is dissolved in a solvent from the slurry;
Evaporating the solvent from the solution separated in the separation step;
A method for producing coking coal for coke production, comprising the step of blending liquid ashless coal obtained in the solvent evaporation step with second coal.   The method for producing raw coal for coke production according to claim 1, wherein the temperature of the liquid ashless coal in the blending step is 200 ° C or higher and 300 ° C or lower.   The method for producing coking coal for coke production according to claim 1 or 2, wherein a total expansion rate of the second coal is 0% or more and 10% or less. A mixing section for mixing the first coal and the solvent;
An elution part for eluting a coal component soluble in a solvent from the first coal in the slurry obtained in the mixing part;
A separation part for separating the solution in which the coal component obtained in the elution part is dissolved in a solvent from the slurry;
A solvent evaporating unit for evaporating the solvent from the solution separated by the separating unit;
An apparatus for producing raw coal for coke production, comprising: a blending unit that blends liquid ashless coal obtained in the solvent evaporation unit with second coal. A method for producing coke for blast furnace, comprising a step of carbonizing the coking coal for producing coke produced by the method for producing coking coal for producing coke according to claim 1, claim 2 or claim 3.

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