JP2018070772A - Method for producing molded coke and apparatus for manufacturing molded coke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method for manufacturing the molded coke that can reduce a heating amount by an external heat source, can reduce a manufacturing cost for the molded coke, and can improve strength of the molded coke to be produced.SOLUTION: The method for producing the molded coke of the present invention comprises the steps of: mixing first coal and a solvent; eluting a solvent-soluble component from the first coal in slurry obtained in the mixing step; separating a solution containing the solvent-soluble component obtained in the elution step from the slurry; evaporating the solvent from the solution separated in the separation step; drying second coal; pulverizing a second coal after the drying step; kneading ashless coal obtained in the solvent evaporating step into the second coal after the pulverizing step; molding a kneaded product containing the second coal and the ashless coal after the kneading step; dry-distilling the molded coal obtained in the above molding step, wherein the ashless coal supplied in the kneading step is in a liquid state.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing molded coke and an apparatus for producing molded coke.

  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 coal is used, but such coking coal is relatively expensive. Therefore, it is desired to use inexpensive inferior coal for the purpose of reducing the production cost of coke. 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 a coke production method to obtain high-strength coke while suppressing the use of highly caking coal, mixed coal consisting of ashless and inferior coal is heated above the softening start temperature of ashless coal. There has been proposed a method of dry distillation of blended coal containing pulverized and pulverized coal and strong caking coal (see JP 2009-215421 A). In this method, ashless coal is softened and melted and used as a caking filler (binder), thereby obtaining high-strength coke while reducing the amount of caking coal used.

  However, in the above conventional coke manufacturing method, heating by an external heat source is required in order to bring the mixed coal above the softening start temperature of ashless coal. Moreover, in the above conventional coke production method, the mixture of ashless coal and inferior coal is a solid-to-solid mixture, so that insufficient contact between ashless coal and inferior coal and ashless coal that becomes a binder. Due to the uneven distribution, the strength of the formed coke may not be sufficiently increased.

JP 2009-215421 A

  The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to reduce the heating amount by an external heat source and reduce the manufacturing cost of the formed coke and improve the strength of the manufactured formed coke. A method for producing a formed coke and an apparatus for producing the formed coke are provided.

  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 components soluble in the solvent from the first coal in the slurry obtained in the mixing step, A step of separating the solution containing the solvent-soluble component obtained in the elution step from the slurry, a step of evaporating the solvent from the solution separated in the separation step, a step of drying the second coal, and the drying A step of pulverizing the second coal after the step, a step of kneading the ashless coal obtained in the solvent evaporation step into the second coal after the pulverization step, the second coal after the kneading step, and the above A method for producing molded coke, comprising a step of forming ashless coal and a step of dry distillation of the formed coal obtained in the forming step, wherein the ashless coal supplied in the kneading step is liquid.

  The method for producing the formed coke includes a step of kneading the liquid ashless coal obtained in the solvent evaporation step with the second coal. That is, since the produced ashless coal is kneaded 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 stronger bond and a uniform dispersion of ashless coal can be obtained between the ashless coal and the second coal, and the strength of the formed coke can be improved. Moreover, since the said ashless coal is liquid, it is not necessary to perform the heating for softening the ashless coal. For this reason, the heating amount by an external heat source can be reduced by using the manufacturing method of the said forming coke. Furthermore, since the ashless coal is in a liquid state, it is easily contacted with the second coal and has a high temperature. For this reason, since 2nd coal is heated with the calorie | heat amount which ashless coal has, the shaping | molding in a shaping | molding process can be made into hot forming, and the crushing strength of forming coke increases. Therefore, by using the method for producing molded coke, the amount of heating by the external heat source can be reduced, the production cost of the formed coke can be reduced, and the strength of the produced coke can be improved.

  The second coal may include non-caking coal and strong caking coal. Non-caking coal is less expensive than caking coal. Therefore, the production cost of the formed coke can be further reduced by including the non-caking coal while maintaining the strength of the formed coke by including the strong caking coal in the coal.

  The temperature of the ashless coal supplied in the kneading step is preferably 200 ° C or higher and 300 ° C or lower. By setting the temperature of the ashless coal supplied in the kneading step within the above range, the liquid ashless coal can be kneaded while suppressing the melting of the second coal, so between the ashless coal and the second coal. The bond is further increased.

  The ashless coal may be continuously supplied in the kneading step. In this way, by continuously supplying the ashless coal in the kneading step, the dispersion of the ashless coal into the second coal can be further uniformized.

  A screw pump or a gear pump may be used to supply the ashless coal in the kneading step. Screw pumps and gear pumps are pumps that can stably supply even liquids with high viscosity. For this reason, the supply of the ashless coal can be controlled easily and reliably by using a screw pump or a gear pump for the supply of the ashless coal in the kneading step.

  Another invention made in order to solve the above-mentioned problem is to elute a component soluble in the solvent from the first coal in the slurry obtained in the mixing unit and a mixing unit for mixing the first coal and the solvent. An elution part, a separation part for separating the solution containing the solvent-soluble component obtained in the elution part from the slurry, a solvent evaporation part for evaporating the solvent from the solution separated in the separation part, and a second coal Kneading to knead the drying unit to be dried, the pulverizing unit to pulverize the second coal dried in the drying unit, and the ashless coal obtained in the solvent evaporation unit to the second coal pulverized in the pulverizing unit A kneading part for molding a kneaded product containing the second coal obtained in the kneading part and the ashless coal, and a dry distillation part for carbonizing the coal obtained in the molding part, The coke production equipment in which the ashless coal supplied in the section is liquid That.

  The apparatus for producing the formed coke kneads the liquid ashless coal obtained in the solvent evaporation section with the second coal. That is, since the produced ashless coal is kneaded 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 stronger bond and a uniform dispersion of ashless coal can be obtained between the ashless coal and the second coal, and the strength of the formed coke can be improved. Moreover, since the said ashless coal is liquid, it is not necessary to perform the heating for softening the ashless coal. For this reason, the heating amount by an external heat source can be reduced by using the said forming coke manufacturing apparatus. Furthermore, since the ashless coal is in a liquid state, it is easily contacted with the second coal and has a high temperature. For this reason, since 2nd coal is heated with the calorie | heat_amount which ashless coal has, shaping | molding in a shaping | molding part can be made into hot shaping | molding, and the crushing strength of shaping | molding coke increases. Therefore, by using the molded coke production apparatus, the amount of heating by the external heat source can be reduced, the production cost of the molded coke can be reduced, and the strength of the produced molded coke can be improved.

  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.

  As described above, by using the method for producing the formed coke and the apparatus for producing the formed coke, the amount of heating by the external heat source is reduced, the production cost of the formed coke is reduced, and the strength of the produced coke is increased. Can be improved.

It is the schematic which shows the manufacturing apparatus of the shaping | molding coke of one Embodiment of this invention.

  Hereinafter, an embodiment of a forming coke manufacturing apparatus and a forming coke manufacturing method according to the present invention will be described in detail.

[Molding coke production equipment]
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 first solvent evaporation unit 8, the second solvent evaporation unit 9, the second coal supply unit 10, the drying unit 11, the pulverization unit 12, the kneading unit 13, the molding unit 14, and the dry distillation unit 15 Prepare mainly.

<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. As the solvent supply unit 2, a solvent tank that stores a solvent can be used, and the solvent is supplied 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 produced by carbonization 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.

  As the mixing unit 3, a preparation tank 31 can be used. 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. In the preparation tank 31, the mixed slurry is maintained 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.

  A heating furnace 51 can be used as the heating unit 5. 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 a component soluble in a solvent from the first coal in the slurry obtained by the mixing part 3 and heated by the heating part 5.

  As the elution part 6, an extraction tank 61 can be used, and the heated slurry is supplied to the extraction tank 61. In the extraction tank 61, components soluble in the solvent are 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 the slurry eluted at the elution unit 6 into a solution containing a solvent-soluble component and a solid concentrate containing a solvent-insoluble component. The solvent-insoluble component refers to 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 the separation is performed by the gravity sedimentation method, the solution containing the solvent-soluble component is accumulated in the upper part of the sedimentation tank. 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.

  Moreover, when performing separation by the gravity sedimentation method, the solution and the solid content concentrate can be discharged from the sedimentation tank while continuously supplying the slurry into the separation unit 7. Thereby, continuous solid-liquid separation processing becomes possible.

  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, contains almost no ash, has no moisture, and is, for example, from the second coal which is coke raw material coal. Shows a high calorific value. 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 a caking additive to be 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.

  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. In this manner, the production cost of the formed coke can be reduced by recycling the solvent.

<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, by-product coal B does not inhibit the softening and melting properties of other coals contained in the second coal when used as the second coal. Therefore, this by-product coal B can also be used as a part of the second coal as a coke raw material. Further, the by-product coal B has a calorific value equal to or higher than that of steam coal, and therefore can be used as boiler fuel.

  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. In this manner, the production cost of the formed coke can be reduced by recycling the solvent.

<Second coal supply section>
The second coal supply unit 10 supplies the second coal to the drying 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. Among these, non-caking coal and strong caking coal may be included as the second coal. Since non-caking coal is less expensive than strong caking coal, the cost of forming coke is obtained by including non-caking coal while maintaining the strength of the forming coke by including caking coal in the coal. Can be further reduced.

  As a minimum of content of non-caking coal in the 2nd coal, 50 mass% is preferred and 60 mass% is more preferred. On the other hand, as an upper limit of content of the said non-caking coal, 80 mass% is preferable and 70 mass% is more preferable. If the content of the non-caking coal is less than the lower limit, the effect of reducing the manufacturing cost of the formed coke may be insufficient. Conversely, if the content of the non-caking coal exceeds the upper limit, the strength of the formed coke produced may be insufficient.

  As a minimum of content of strong caking coal in the 2nd coal, 10 mass% is preferred and 20 mass% is more preferred. On the other hand, as an upper limit of content of the said strong caking coal, 40 mass% is preferable and 30 mass% is more preferable. There exists a possibility that the intensity | strength of the formed coke manufactured as the content of the said strong caking coal is less than the said minimum may be insufficient. Conversely, if the content of the strongly caking coal exceeds the upper limit, the effect of reducing the manufacturing cost of the formed coke may be insufficient.

  In addition, when using multiple types of coal as the second coal, such as non-caking coal and strong caking coal, these coals are mixed in advance and stored in one second coal supply unit 10 and supplied to the drying unit 11. Or the 2nd coal supply part 10 may be provided for every kind of coal, and you may mix at the time of supply to the drying part 11. FIG.

<Dry section>
The drying unit 11 dries the second coal supplied from the second coal supply unit 10. As the drying unit 11, a known drying device such as a rotary dryer or a steam tube dryer can be used.

  The moisture content of the second coal after drying in the drying unit 11 is preferably less than 5%, and more preferably less than 3%. There exists a possibility that a 2nd coal may burst (explode) at the time of dry distillation in the dry distillation part 15 mentioned later that the moisture content of the said 2nd coal is more than the said upper limit. On the other hand, the lower limit of the water content of the second coal is not particularly limited, and may be 0% by mass.

  Moreover, it does not specifically limit as temperature and pressure conditions in the said drying part 11, but it can be 100 to 150 degreeC and 0 kPaG (atmospheric pressure) to 10 kPaG.

<Crushing part>
The pulverization unit 12 pulverizes the second coal dried by the drying unit 11. As the pulverization unit 12, a known pulverizer such as an impact pulverizer such as a hammer mill or a hammer crusher can be used.

  The upper limit of the 90% cumulative particle diameter of the second coal after being pulverized by the pulverizing unit 12 is preferably 1 mm, and more preferably 0.7 mm. When the particle diameter of the second coal exceeds the upper limit, ashless coal cannot sufficiently enter between the particles of the second coal, and the strength of the obtained coke may be insufficient. In addition, “particle diameter of 90% cumulative mass” means that when all the particles are sieved with a metal mesh sieve specified in JIS-Z8801-1: 2006, 90% by mass of all the particles are sieved. It means the value of sieve opening that can pass through.

<Kneading part>
The kneading unit 13 kneads the ashless coal A obtained by the first solvent evaporation unit 8 into the second coal pulverized by the pulverization unit 12. The kneading unit 13 includes a kneader 131 and a pump 132 that supplies the ashless coal A to the kneader 131. Moreover, the ashless coal A supplied by the kneading part 13 is liquid.

  As the kneader 131, a known mixer or the like can be used.

  The pump 132 is not particularly limited as long as it can supply the liquid ashless coal A to the kneader 131, but a screw pump or a gear pump such as a single screw pump or a twin screw pump is preferable. Screw pumps and gear pumps are pumps that can stably supply even liquids with high viscosity. For this reason, the supply of the ashless coal A can be easily and reliably controlled by using a screw pump or a gear pump for the supply of the ashless coal A in the kneading unit 13.

  The pump 132 is preferably a double pipe type pipe from the viewpoint of preventing solidification of the liquid ashless coal A. When a double pipe type pipe is used for the pump 132, the ashless coal A can be heated and kept warm by flowing the ashless coal A through the inner pipe and, for example, hot oil through the outer pipe.

  Further, the ashless coal A may be continuously supplied to the kneader 131. In this way, by continuously supplying the ashless coal A to the kneader 131, the dispersion of the ashless coal A into the second coal can be made more uniform. Furthermore, ashless coal A may be supplied to the kneader 131 at a constant flow rate from the viewpoint of uniform dispersion. For example, when using a screw pump, the flow rate of the ashless coal A can be adjusted by the discharge pressure of the pump. The discharge pressure of the screw pump can be about 200 kPa or more and 300 kPa or less, depending on the flow rate.

  As a minimum of temperature of liquid ashless coal A supplied to kneading machine 131, 200 ° C is preferred and 250 ° C is more preferred. 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, if 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 resulting formed coke may be reduced. is there. The temperature of the ashless coal A can be controlled by the solvent separation temperature in the first solvent evaporation section 8.

  The lower limit of the blending amount of the ashless coal A in the total amount of the second coal and the ashless coal A after kneading in the kneading unit 13 is preferably 1% by mass, and more preferably 10% by mass. On the other hand, as an upper limit of the compounding quantity of the said ashless coal A, 40 mass% is preferable and 30 mass% is more preferable. If the blending amount of the ashless coal A is less than the lower limit, the strength of the formed coke produced may be insufficient. On the other hand, when the blending amount of the ashless coal A exceeds the upper limit, the proportion of non-caking coal that is relatively inexpensive is decreased, and the production cost of the formed coke may be increased.

  The kneaded liquid ashless coal A adheres to the surface of the second coal, and part of it impregnates in the coal pores. 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 kneading ashless coal A. Although the temperature of the 2nd coal after the kneading | mixing in the kneading part 13 is decided by the temperature and compounding quantity of the ashless coal A, it can be made into 120 to 200 degreeC. When kneading solid ashless coal with the second coal, it is necessary to heat the ashless coal to a high temperature (for example, 150 ° C. or more and 250 ° C. or less) in order to ensure fluidity of the ashless coal. Since the ashless coal A is liquid and is kneaded using the heat of the liquid ashless coal A, the amount of heating by the external heat source can be reduced.

  In addition to liquid ashless coal A, solid ashless coal may be mixed with the second coal. When kneading solid ashless coal, it is preferable to pulverize and knead so that the particle diameter of 90% of the cumulative mass of solid ashless coal is 1 mm or less, more preferably 300 μm or less.

<Molding part>
The molding unit 14 molds a kneaded product containing the second coal and ashless coal A obtained in the kneading unit 13. As the molding unit 14, a known molding machine, for example, a double roll (double roll) molding machine using a flat roll, a double roll molding machine having an almond pocket, a punching molding machine, an extrusion molding machine, a pelletizer, etc. Can be used. Among them, it is preferable to use a twin roll molding machine with high productivity.

  Molding in the molding unit 14 is performed under pressure. As a pressure in the shaping | molding part 14, it can be 50 MPa or more and 300 MPa or less, for example. Moreover, the shaping | molding in the shaping | molding part 14 is good to be performed maintaining the state with which the 2nd coal and the ashless coal A were heated in the kneading part 13. FIG.

  Although it does not specifically limit as a shape of the forming charcoal shape | molded by the shaping | molding part 14, For example, it can be set as a briquette form or a pellet form. Moreover, as an average volume of the said charcoal, it can be 2 ml or more and 20 ml or less, for example.

<Dry distillation section>
The dry distillation unit 15 performs dry distillation of the coal formed in the molding unit 14 to obtain molded coke C. Although it does not specifically limit as the dry distillation part 15, For example, a well-known solid type dry distillation furnace (shaft furnace) can be used. When the shaft furnace is used, the coal is continuously inserted into the shaft furnace, and carbonization is performed while the coal is moving to the high temperature carbonization zone through the low temperature carbonization zone in the furnace.

  The lower limit of the carbonization temperature in the high temperature carbonization zone is preferably 900 ° C., more preferably 950 ° C. On the other hand, the upper limit of the carbonization temperature is preferably 1100 ° C, and more preferably 1050 ° C. When the dry distillation temperature is less than the lower limit, the second coal is not sufficiently melted, and the strength of the coke may be reduced. On the other hand, when the carbonization temperature exceeds the upper limit, the production cost of coke may increase from the viewpoint of heat resistance of the furnace body and fuel consumption.

  Moreover, as a minimum of dry distillation time, 8 hours are preferable and 10 hours are more preferable. On the other hand, the upper limit of the carbonization time is preferably 24 hours, more preferably 20 hours. When the carbonization time is less than the above lower limit, the second coal is not sufficiently melted and the strength of the coke may be reduced. Conversely, if the carbonization time exceeds the above upper limit, the production cost of coke may increase from the viewpoint of fuel consumption. The dry distillation time refers to the time from when the coal is inserted into the furnace until it is carried out of the furnace.

  In addition to the coal obtained by the molding unit 14, second coal that is not molded may be used as the coal to be carbonized in the carbonization unit 15.

[Method for producing molded coke]
The method for producing the formed coke includes a mixing step, an elution step, a separation step, a first solvent evaporation step, a second solvent evaporation step, a pulverization step, a kneading step, a forming step, and a dry distillation step. Prepare. The method for producing the formed coke can be performed using the formed coke production apparatus of FIG.

<Mixing process>
In the mixing step, the first coal and the solvent are mixed. Specifically, the first coal supplied from the first 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 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, components soluble in the solvent are 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, the slurry after the elution in the elution step is separated into a solution containing a solvent-soluble component and a solid concentrate containing a solvent-insoluble component. 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.

<Drying process>
In the drying step, the second coal is dried. Specifically, the second coal supplied from the second coal supply unit 10 is dried by the drying unit 11.

<Crushing process>
In the pulverization step, the second coal after the drying step is pulverized. Specifically, the coal dried by the drying unit 11 is pulverized by the pulverizing unit 12.

<Kneading process>
In the kneading step, the ashless coal A obtained in the first solvent evaporation step is kneaded with the second coal after the pulverization step. Specifically, the liquid ashless coal A obtained in the first solvent evaporation step in the kneading unit 13 is kneaded by the kneader 131 while being supplied to the second coal after the pulverization step by the pump 132.

<Molding process>
In the forming step, a kneaded product containing the second coal and the ashless coal A after the kneading step is formed. Specifically, a kneaded product containing the second coal and ashless coal A kneaded by the kneading unit 13 is molded by the molding unit 14.

<Dry distillation process>
In the carbonization process, the coal char obtained in the molding process is carbonized. Specifically, the charcoal formed by the forming unit 14 is dry-distilled by the dry distillation unit 15. Thereby, the formed coke C is obtained.

〔advantage〕
The method for producing the formed coke includes a step of kneading the liquid ashless coal obtained in the solvent evaporation step with the second coal. Moreover, the manufacturing apparatus of the said forming coke knead | mixes the liquid ashless coal obtained in the solvent evaporation part with 2nd coal. That is, since the produced ashless coal is kneaded 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 stronger bond and a uniform dispersion of ashless coal can be obtained between the ashless coal and the second coal, and the strength of the formed coke can be improved. Moreover, since the said ashless coal is liquid, it is not necessary to perform the heating for softening the ashless coal. For this reason, the heating amount by an external heat source can be reduced by using the manufacturing method of the said forming coke and the manufacturing apparatus of the said forming coke. Furthermore, since the ashless coal is in a liquid state, it is easily contacted with the second coal and has a high temperature. For this reason, since 2nd coal is heated with the calorie | heat amount which ashless coal has, the shaping | molding of 2nd coal and ashless coal can be made into hot forming, and the crushing strength of a forming coke increases. Therefore, by using the method for manufacturing the formed coke and the apparatus for manufacturing the formed coke, it is possible to reduce the heating amount by the external heat source, reduce the manufacturing cost of the formed coke, and improve the strength of the formed coke.

[Other Embodiments]
In addition, the manufacturing method of the forming coke and the manufacturing apparatus of forming coke of this invention are not limited to the said embodiment.

  In the above embodiment, the case where the second solvent evaporation step is provided as a method for producing the formed coke has been described. However, for example, when the by-product coal is not used, this second solvent evaporation step can be omitted. When the second solvent evaporation step is not performed, the molded coke manufacturing apparatus may not include the second solvent evaporation unit.

  Moreover, although the said embodiment demonstrated the structure which the mixing part of the manufacturing apparatus of a shaping | molding coke has a preparation tank, you may abbreviate | omit not only this structure but a mixing tank with a solvent and coal. 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.

  As described above, by using the method for producing the formed coke and the apparatus for producing the formed coke, the amount of heating by the external heat source is reduced, the production cost of the formed coke is reduced, and the strength of the produced coke is increased. 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 unit 11 Drying unit 12 Crushing unit 13 Kneading unit 131 Kneading machine 132 Pump 14 Molding unit 15 Carbonation unit A Ashless coal B Byproduct coal C Molded coke

Claims (6)

Mixing the first coal and the solvent;
A step of eluting components soluble in the solvent from the first coal in the slurry obtained in the mixing step;
Separating the solution containing the solvent-soluble component obtained in the elution step from the slurry;
Evaporating the solvent from the solution separated in the separation step;
Drying the second coal;
Crushing the second coal after the drying step;
Kneading the ashless coal obtained in the solvent evaporation step into the second coal after the pulverization step;
Forming a kneaded product containing the second coal and the ashless coal after the kneading step;
A step of carbonizing the coal obtained in the molding step,
A method for producing molded coke in which the ashless coal supplied in the kneading step is liquid.   The method for producing formed coke according to claim 1, wherein the second coal includes non-caking coal and strong caking coal.   The method for producing molded coke according to claim 1 or 2, wherein the temperature of the ashless coal supplied in the kneading step is 200 ° C or higher and 300 ° C or lower.   The method for producing a formed coke according to claim 1, wherein the ashless coal is continuously supplied in the kneading step.   The method for producing a formed coke according to any one of claims 1 to 4, wherein a screw pump or a gear pump is used to supply the ashless coal in the kneading step. A mixing section for mixing the first coal and the solvent;
An elution part for eluting components soluble in the solvent from the first coal in the slurry obtained in the mixing part;
A separation unit for separating the solution containing the solvent-soluble component obtained in the elution unit from the slurry;
A solvent evaporating unit for evaporating the solvent from the solution separated by the separating unit;
A drying section for drying the second coal;
A pulverizing unit for pulverizing the second coal dried in the drying unit;
A kneading unit for kneading the ashless coal obtained in the solvent evaporation unit with the second coal pulverized in the pulverization unit;
A molding part for molding a kneaded product containing the second coal and the ashless coal obtained in the kneading part;
A carbonization part for carbonizing the coal obtained in the molding part,
An apparatus for producing molded coke in which the ashless coal supplied in the kneading section is liquid.

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