JP2019059880A - Method of producing solidified carbide - Google Patents

Abstract

To produce a solidified carbide at a low cost.SOLUTION: A circular column 4 of a carbide is produced by steps of crushing a carbide 1, mixing the crushed carbide 1 with acetic acid (an aqueous solution of acetic acid) as a coagulant to make the electric potential of the surface of the carbide particles closer to zero to generate a coagulation force on the particles of the carbide 1 to form aggregate 2, and compression molding the aggregate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of producing a solidified carbide by solidifying carbide to produce a solid.

  In recent years, application of carbides of biomass has been considered as a reducing agent (fuel) for furnaces and boilers. Moreover, the coke using the ground material of coal is applied as a reducing agent (fuel), such as a furnace and a boiler. Pulverized material of biomass carbide and coal may be used as a shaped product (pellet-like, granular) to facilitate transportation, handling and storage.

  In order to make biomass carbide or pulverized coal (carbide) of coal into a molded product, various proposals have conventionally been made to form a solidified body using a caking additive (binder) (for example, Patent Document 1). By forming the carbide into a pellet or granular form using a caking material (binder), handling becomes easy, and transportation costs and storage costs can be suppressed.

  However, in the conventionally proposed technology, in order to obtain a molded product (solidified body), a caking material (binder) is used, and in order to obtain a more rigid solidified body, molding is often performed at high temperature and high pressure Had to do. For this reason, the cost of the material, the temperature control at the time of processing, and the time of pressure control are increased, and it has been the case that it is expensive to obtain a solidified body of carbide.

JP, 2015-63581, A

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a method for producing a solidified carbide body which can produce a solidified carbide body at low cost.

  In order to achieve the above object, according to the method for producing a solidified carbide of the present invention according to claim 1, an aggregate is formed by pulverizing a carbide and mixing a flocculating agent with the crushed carbide to aggregate particles. And compacting the aggregates to obtain a solidified carbide body.

  In the first aspect of the present invention, the flocculating agent is mixed to aggregate the particles to form an aggregate, and the aggregate is compacted to obtain a carbide solidified body. Therefore, the aggregate is formed without using a binder. It can be formed to obtain a solidified carbide. As a result, it is possible to produce a solidified carbide body at low cost.

  And in the method for producing a solidified carbide body according to the second aspect of the present invention, in the method for producing a solidified carbide body according to the first aspect, the coagulant is an acid that lowers the potential of the surface of the particles. It is characterized by

  As a part of the effect of enhancing the cohesion of particles, especially in carbides, as the hydrogen concentration index (pH) becomes lower between the potential of the particle surface and the hydrogen concentration index (pH) It is known that there is a relation that the surface charge approaches zero.

  Based on such a finding, in the present invention according to claim 2, the ground carbide is mixed with an acid (the acid is mixed to enhance the cohesiveness). By adding an acid to the crushed carbide, the value of the potential of the surface of the carbide particles approaches zero, and the repulsive force between the particles is reduced, thereby aggregating the particles and improving the cohesion of the particles. Can.

  In addition, as an acid, a by-product generated in a carbide production process such as wood vinegar, formic acid, acetic acid and the like, and an industrial acid (hydrochloric acid, nitric acid, sulfuric acid etc.) can be applied.

  In the method for producing a solidified carbide body according to a third aspect of the present invention, in the method for producing a solidified carbide body according to the second aspect, the acid is mixed with the carbide without being dissolved in a solvent. Do.

  According to the third aspect of the present invention, the pure acid can reduce the surface charge of the particles according to the type of the carbide and can easily aggregate the carbide particles.

  In the method for producing a solidified carbide body according to a fourth aspect of the present invention, in the method for producing a solidified carbide body according to the second aspect, the acid is dissolved in water to form an aqueous solution, and the aqueous solution of the acid is the aqueous solution It is characterized by mixing with carbide.

  According to the fourth aspect of the present invention, the aqueous solution of the acid can be used to reduce the surface charge of the particles according to the type of the carbide and to easily aggregate the carbide particles.

  Further, in the method for producing a solidified carbide according to the present invention according to claim 5, in the method for producing a solidified carbide according to any one of claims 2 to 4, the ratio of the aqueous acid solution to the carbide is 10%. It is characterized in that it is less than%.

  In the present invention according to claim 5, the weight content of the acid (pure acid, acid aqueous solution) to the carbide is 10% or less (preferably 1% to 10%), and therefore, the particles of the carbide are properly aggregated. be able to.

  In the method for producing a solidified carbide according to the present invention according to claim 6, in the method for producing a solidified carbide according to any one of claims 1 to 5, the carbide is a biomass-derived carbide It is characterized by

  In the present invention according to claim 6, a solidified body of biomass-derived carbide can be produced. As biomass, it is preferable to apply woody biomass. As biomass, it is possible to use biomass (grass, sewage sludge, etc.) other than wood, such as biomass derived from plants. Moreover, it is also possible to apply the ground powder of coal as a carbide and to manufacture coke as a solidified body.

  The method for producing a solidified carbide body according to the present invention makes it possible to inexpensively produce a solidified carbide body.

It is a processing flow figure of the manufacturing method of the carbide solidification object concerning one example of the present invention. It is a process conceptual diagram of the manufacturing method of the carbide solidification object concerning one example of the present invention. It is a process conceptual diagram of the manufacturing method of the carbide solidification object concerning one example of the present invention. It is an external view of the cylindrical lump as a carbide solidification object. It is a graph showing the relationship between the surface potential of a carbide, and a hydrogen concentration index (pH). It is a graph explaining the intensity | strength of a cylinder block. It is a schematic block diagram of the other Example (die and rotary roller: FIG. 2) of a compression means.

  It is known that the charge on the surface of the particles influences one of the mechanisms by which the particles aggregate. That is, it is known that when the potential of the surface of the particles is in a neutralized state, the repulsive force between the particles is alleviated and the particles are easily bonded (it is known that they become easily solidified). .

  And, it is known that there is a relation between the electric potential of the surface of the carbide particles and the hydrogen concentration index (pH), for example, the electric potential of the surface approaches zero as the pH becomes lower (as the acid side). ing. The present invention has been made based on such findings.

  That is, in the example shown below, an acid (for example, acetic acid) is mixed as a flocculant with the crushed carbide, the potential of the surface of the carbide particles is brought close to zero, and the potential of the surface is neutralized. The repulsive force of the Thereby, the particles of the carbide are easily aggregated to improve the aggregation of the particles, and the solidified carbide is manufactured without using a binder or the like.

  Hereinafter, the method for producing a solidified carbide body of the present invention will be specifically described with reference to the drawings.

  1 shows the process flow of the method for producing a solidified carbide according to an embodiment of the present invention in the case of mixing acetic acid (acetic acid aqueous solution), FIG. 2 shows the appearance of a state in which carbide is agglomerated, FIG. An outline of the situation where a cylindrical mass is formed by press molding, FIG. 4 shows the appearance of the cylindrical mass, FIG. 5 a graph showing the relationship between the surface potential of the carbide and the hydrogen concentration index (pH), FIG. A graph representing the result of the compressive strength is shown.

  As shown in FIG. 1, the carbide 1 derived from woody biomass is crushed as a carbide, and the crushed carbide 1 is mixed with an acid (for example, acetic acid, an aqueous solution of acetic acid) which is a coagulant to aggregate particles. Aggregate 2 is formed. That is, as shown in FIG. 2, acetic acid or an aqueous acetic acid solution is mixed with the crushed carbide 1 to aggregate the particles to form an aggregate 2.

  As biomass, biomass other than wood such as plant-derived biomass can be used. Moreover, it is also possible to apply the ground powder of coal as a carbide and to manufacture coke as a carbide solidification object. In addition to acetic acid, it is possible to use formic acid, hydrochloric acid, nitric acid, sulfuric acid or the like as the acid.

  When an aqueous acetic acid solution is used (even when pure acetic acid is used), it is preferable that the weight content of the aqueous acetic acid solution (pure acid) in the solidified carbide (relative to the solidified carbide) be small (for example, 1% to 10%). Moreover, it is preferable to make the acetic acid concentration of the acetic acid aqueous solution to be used large. When the acetic acid concentration of the aqueous acetic acid solution is 0% to 100%, and the weight content of the aqueous acetic acid solution in the solidified carbide is 10% or less (for example, 1% to 10%) As a result of mixing, it was confirmed that the aggregates 2 were formed by aggregating the particles of the carbide 1 in the case of the aqueous solution of any concentration.

  As shown in FIG. 5, the surface potential of the woody biomass carbide particles approaches zero as the hydrogen concentration index (pH) decreases (as the acid side is reached). Therefore, by mixing acetic acid (aqueous acetic acid solution) with the crushed carbide 1, the surface potential approaches zero, and the repulsive force between particles decreases. Thereby, the particles of the carbide 1 are easily aggregated, and the aggregation of the particles of the carbide 1 can be improved (the particles of the carbide 1 are easily bonded).

  As shown in FIG. 1, an aggregate 2 obtained by aggregating particles of carbide 1 is molded to obtain a cylindrical block 4 as a carbide solidified body. That is, as shown in FIG. 3, the aggregate 2 is put into a press 5 and the aggregate 2 is press-formed (consolidated) to obtain a cylindrical block 4 which is a carbide solidified body.

  As shown in FIG. 3, the press device 5 includes a bottomed cylindrical lower die 6 and an upper die 7 which is inserted into and fitted in the cylinder of the lower die 6. The aggregate 2 supplied to the lower mold 6 is pressed by pressing the upper mold 7 to the lower mold 6 at a predetermined pressure (for example, 20 MPa) for a predetermined time (for example, 5 minutes) (by applying a load) Then, it is pressurized (consolidated) to a predetermined size, and a cylindrical cylindrical mass 4 (see FIG. 4) is obtained.

  0.2 g of the aggregate 2 was filled in the lower mold 6, a load of 20 MPa was applied to the upper mold 7, and held for 5 minutes after pressing, to obtain a cylindrical block 4 having a diameter of 10 mm and a height of 2 mm. By making the aggregate 2 into a cylindrical block 4, it is possible to suppress the spontaneous ignition property by making the carbide 1 (see FIG. 1) difficult to contact with oxygen, and suppress dust generation and increase in calorific value per volume can be expected. Thus, the handling becomes easier, and in addition to the reduction of the transportation cost, the cost of management such as storage can be suppressed.

  A cylindrical block was formed by the press device 5 using four types of aggregates (A, B, C, D) in the case of using an aqueous solution of acetic acid. A load was applied to a cylindrical block formed of four types of aggregates (A, B, C, D), and the force (N) and the displacement (mm) until breakage were measured. The test speed was 0.3 mm / min. The cylinder block was cracked and the force (N) when broken was evaluated as the maximum load that the cylinder block can withstand.

The aggregates were as follows, and the weight content of the aqueous acetic acid solution in the solidified carbide was 10%.
Aggregate A (Comparative example: Acetic acid concentration 0% of aqueous acetic acid solution)
Water 1 added to carbide 1 (carbide: water: acetic acid = 9: 0)
Aggregate B (Example: Acetic acid concentration 20% of aqueous acetic acid solution)
Water and acetic acid added to carbide 1 (carbide: water: acetic acid = 9: 0.8: 0.2)
Aggregate C (Example: Acetic acid concentration 50% of aqueous acetic acid solution)
Equal amount of water and acetic acid added to carbide 1 (carbide: water: acetic acid = 9: 0.5: 0.5)
Aggregate D (Example: 100% acetic acid concentration of aqueous acetic acid solution)
Carbide 1 with acetic acid only (carbide: water: acetic acid = 9: 0: 1)

  The maximum load of a cylindrical block using four types of aggregates (A, B, C, D) is indicated by a solid line in FIG. 6 (indicated by 印 in the figure).

  As shown in FIG. 6, while the cylindrical block using aggregate B (A) in the figure) has a maximum load of about 40 N, while the cylindrical block using aggregate B (A) in the figure) is about 40 N It was found that the maximum load of the cylinder block using C (C と な り in the figure) is about 45 N, and the maximum load increases as the concentration increases. And the maximum load of the cylinder block (D in the figure) using the aggregate D exceeds 50 (N), and the maximum load of the cylinder block using the cylinder block (A in the figure) using the aggregate A It was found to be much higher than that of Therefore, it was confirmed that the maximum strength of the cylinder block is influenced by the presence or absence of acetic acid and the mixing ratio.

  When the weight content of the aqueous acetic acid solution in the solidified carbide is in the range of 1% to 10% and the acetic acid concentration of the aqueous acetic acid solution is, for example, 20%, 50%, or 100%, acetic acid is the same as above. It has been confirmed that the maximum load increases as the concentration increases, depending on the presence or absence of and the mixing ratio. For example, it has been confirmed that the maximum load is higher when the weight content of the aqueous acetic acid solution in the solidified carbide is low.

  As described above, the particles of the carbide 1 are agglomerated in the presence of acetic acid, and the agglomerates 2 in which the particles are agglomerated are consolidated to obtain a cylinder block 4 having high compressive strength.

  An example where acetic anhydride is used as the acid will be described. With respect to the four types of aggregates (A, B, C, D) described above, the results in the case of using an acetic anhydride aqueous solution instead of the acetic acid aqueous solution are shown by broken lines in FIG. ).

  As shown in FIG. 6, the maximum load of the cylinder block (B in the figure) using the aggregate B with acetic anhydride is about 35 N with respect to the cylinder block (A in the figure) using the aggregate A, The maximum load of the cylinder block (C in the figure) using aggregate C was about 38 N, and it was found that the maximum load increased as the acetic anhydride concentration increased, as in the case of using acetic acid. . And the maximum load of the cylinder block (D in the figure) using the aggregate D with only acetic anhydride exceeds 45 (N), and the cylinder using the cylinder block (A in the figure) using the aggregate A It was found that it was significantly higher than the maximum load of the mass. For this reason, it was confirmed that the maximum strength of the cylinder block is influenced by the presence or absence of acetic anhydride and the mixing ratio, similarly to acetic acid.

  In the case of acetic acid, when the weight content of the aqueous acetic anhydride solution in the solidified carbide is in the range of 1% to 10% and the acetic anhydride concentration in the aqueous acetic anhydride solution is, for example, 20%, 50%, 100%. Similarly to the above, it has been confirmed that the maximum load increases as the concentration increases, depending on the presence or absence of acetic anhydride and the mixing ratio.

  As described above, the particles of the carbide 1 are agglomerated in the presence of acetic anhydride, and the agglomerates 2 in which the particles are agglomerated are consolidated to obtain a cylinder block 4 having a high compressive strength.

  The method for producing a solidified carbide as described above comprises grinding the carbonized biomass 1 of woody biomass and mixing the ground carbide with an aqueous acetic acid solution containing pure acetic acid (pure aqueous acetic anhydride solution containing acetic anhydride) to form aggregates 2 And press molding (consolidation molding) the aggregate 2 with a press device 5 to obtain a cylindrical block 4. For this reason, by using an acid, the aggregate 2 can be formed without using a binder (binder), a cylindrical block 4 can be obtained, and the cylindrical block 4 in which the carbide 1 of woody biomass is solidified is inexpensive. It will be possible to manufacture.

  Then, since the cylinder block 4 is obtained by pressure molding with the press device 5, the cylinder block 4 is less likely to contact with oxygen, and natural heat generation can be suppressed, and dust scattering can be suppressed, so The handling of the biomass carbide 1 becomes easy, the transportation cost can be reduced and the cost of fuel can be reduced, and the cost of management such as storage can be suppressed.

  Another embodiment of the compression means will be described based on FIG. FIG. 7 shows the appearance of a pellet production apparatus using a die and a rotating roller.

  In the pellet production apparatus 11, a large number of die holes 13 are formed in a fixed die (disk) 12, and the rotating roller rotates while rotating on the die 12. The aggregate 2 is introduced from the top, sandwiched between the die (disk) 12 and the die 12 and pressurized (consolidated), extruded through the die hole 13, cut by a cutter, and pelletized 15 (carbide solidified body) It is assumed.

  Therefore, the aggregate 2 is introduced into the pellet production apparatus 11, and the aggregate 2 is compacted to obtain a pellet 15 which is carbide solidified.

  In the method for producing a solidified carbide, the biomass 1 of woody biomass is crushed, acetic acid (acetic acid aqueous solution) is mixed with the crushed carbide to form an aggregate 2, and the aggregate 2 is pelletized by a pelletizing apparatus 11. The pellet 15 is obtained by pressure molding (compact molding). For this reason, the aggregate 2 can be formed without using a binder (binder) to obtain the pellet 15, and it becomes possible to inexpensively manufacture the pellet 15 in which the carbide 1 of woody biomass is solidified. . And, since the carbonized biomass 1 of woody biomass is consolidated to form pellets 15, the calorific value per unit volume can be secured, and the practicability as a fuel can be enhanced.

  The present invention can be used in the industrial field of a method for producing a solidified carbide body.

Reference Signs List 1 carbide 2 aggregate 4 cylinder block 5 pressing device 6 lower die 7 upper die 11 pellet producing device 12 die 13 die hole 14 rotating roller 15 pellet

Claims (6)

The carbide is crushed, and an aggregating agent is mixed with the crushed carbide to coagulate particles to form an aggregate, and the aggregate is compacted to obtain a carbide solidified body. How to make the body. In the method for producing a solidified carbide body according to claim 1,
The method for producing a solidified carbide body, wherein the coagulant is an acid that lowers the potential of the surface of the particles. In the method for producing a solidified carbide body according to claim 2,
A method of producing a solidified carbide body, comprising mixing the acid with the carbide without dissolving the acid in a solvent. In the method for producing a solidified carbide body according to claim 2,
The acid is dissolved in water to form an aqueous solution,
Mixing the aqueous solution of the acid with the carbide; In the method for producing a solidified carbide body according to any one of claims 2 to 4,
The method for producing a solidified carbide body, wherein the ratio of the aqueous acid solution to the carbide is 10% or less. In the method for producing a solidified carbide body according to any one of claims 1 to 5,
The method for producing a solidified carbide body, wherein the carbide is a biomass-derived carbide.

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