Method for charging raw materials into a coke oven and method for producing coke

Abstract

To provide a technique capable of suppressing lowering of coke strength when blending synthetic resins.SOLUTION: A method for charging a raw material to a coke oven includes: when charging synthetic resins as a coke raw material to a coke oven together with raw material coal, passing the raw material coal and the synthetic resins conveyed to the upper part of a coal tower through an inclined sieving net; separating the raw material coal and the synthetic resins into an upper sieve and a lower sieve by particle size and charging the separated raw material coal and synthetic resins; and thereby separating fall positions of the synthetic resins and the raw material coal; and charging the synthetic resins so that the synthetic resins are unevenly distributed on a machine side and a coke side in a coal tower. A method for manufacturing a coke includes: when charging a coke raw material in a coal tower to a carbonization chamber through a coal loading vehicle, carbonizing the coke raw material in the carbonization chamber, and manufacturing a coke, charging the coke raw material to the coal tower by the above method; charging the synthetic resins so that the synthetic resins are unevenly distributed on a machine side and a coke side in the coal tower; and charging the synthetic resins so that the synthetic resins are unevenly distributed on the machine side and the coke side in the carbonization chamber.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for charging raw materials into a coke oven and a method for producing coke when recycling synthetic resins typified by waste plastics as iron-making raw materials in a coke oven. In the following description, "t", which is a unit of mass, represents 10 3 kg. In this specification, "synthetic resins" includes, in addition to used plastics, which are general waste called waste plastics, plastic scraps and defective products of synthetic resins generated in the manufacturing process, and plastics that become industrial waste, such as used plastics.

Background Art

[0002] In recent years, marine pollution caused by waste plastics has become a global problem, with an estimated 8 million tons of waste plastics flowing into the ocean worldwide annually. Solving marine pollution is one of the goals outlined in the Sustainable Development Goals (SDGs) adopted at the UN Summit in 2015. To address this, Europe has launched the "EU Plastics Strategy" to strengthen plastic recycling and reduce single-use plastics. In Japan, the Container and Packaging Recycling Law was enacted in 1995, and the recycling of waste plastics has been promoted since early on. In response to the growing momentum for further reduction of waste plastics, the "Law Concerning the Promotion of Resource Recycling Related to Plastics" came into effect in 2022, requiring further strengthening of waste plastic recycling. In the steel industry, a technology has been put into practical use to recycle waste plastics as a raw material for steelmaking by mixing them with coal and charging them into coke ovens. This is implemented as a chemical recycling technology for waste plastics under the Container and Packaging Recycling Law. However, it is known that mixing waste plastics with coal to produce coke reduces coke strength, and the upper limit for the amount of waste plastics that can be mixed without reducing coke strength is considered to be approximately 1% by mass (Non-Patent Literature 1). Therefore, various technological developments have been carried out to suppress the deterioration of coke strength due to the mixing of waste plastics.

[0003] For example, Patent Document 1 discloses a method of pyrolysis recycling in which, after charging raw materials into the carbonization chamber of a coke oven, waste plastics are charged onto the top of the raw materials in the carbonization chamber at least one hour later. This method utilizes the space above the coke oven and allows for the recycling of large quantities of waste plastics without affecting the coke strength.

[0004] Furthermore, Patent Document 2 discloses a technique in which a blended coal A, which contains a small amount of waste plastic, is charged into the carbonization chamber of a coke oven, and a blended coal B, which contains a large amount of waste plastic, is charged on top of blended coal A, and blended coal A and blended coal B are carbonized to produce coke. It is shown that this technique can suppress blockage of the gas recovery and washing line due to thermal decomposition residue while charging a large amount of waste plastic into the top of the coke oven. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-135281 [Patent Document 2] Japanese Patent Publication No. 2001-098276 [Non-patent literature]

[0006] [Non-Patent Document 1] Seiji Nomura, Kenji Kato, Tomoyuki Nakagawa, Ikuo Komaki, Journal of the Japan Energy Society, Vol. 81, No. 8 (2002), pp. 728-737. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, conventional technology had the following problems: The technologies disclosed in Patent Documents 1 and 2 make it possible to minimize the impact on coke strength by separating coal and waste plastic. On the other hand, after coal is charged, the raw material charging lid must be opened and waste plastic must be charged. Therefore, in order to prevent gas leakage, it is necessary to strictly control the amount of gas generated so that it does not exceed the amount of gas sucked in. However, if the amount of gas generated in the carbonization chamber increases or decreases due to fluctuations in coal quality or other reasons, control may become difficult. In that case, the generated gas may leak to the outside and cause abnormal combustion. In addition, a large amount of gas generated is sucked in at the top of the carbonization chamber. Therefore, if waste plastic is carbonized at the top of the carbonization chamber, a large amount of powdered waste plastic char is sucked in. This may cause blockage in the gas recovery and washing line, and these waste plastic char may be mixed into the recovered tar, potentially lowering the quality of the tar recovered as a product. Furthermore, since plastic is charged after the raw material is charged into the coal tower, it is necessary to prepare a dedicated hopper for waste plastic on top of the coal transport vehicle. In addition, the increased number of steps involved in charging the raw materials contributes to a decrease in the productivity of the coke oven.

[0008] Furthermore, in the technology disclosed in Patent Document 2, first, blended coal A for coke production, which is mixed with waste plastic in a range of 0% to 1% by mass, is charged into the carbonization chamber of the coke oven. Next, while blended coal A is being carbonized, blended coal B, which is mixed with waste plastic in a ratio of 1% to 60% by mass, is charged on top of blended coal A. Then, blended coal A and blended coal B are carbonized to produce coke. This allows for the large-scale charging of waste plastic into the upper part of the coke oven while suppressing blockage of the gas recovery and washing line due to thermal decomposition residue. However, it is necessary to charge blended coal B, which has a high waste plastic content, after charging blended coal A first. As a result, productivity is reduced, and it is difficult to implement in a coke oven because a large amount of waste plastic with greatly different densities and particle sizes needs to be mixed as uniformly as possible in the blended coal.

[0009] This invention has been made in view of the above circumstances, and aims to propose a raw material charging method for a coke oven that can easily realize a raw material arrangement that can suppress the decrease in coke strength when compounding synthetic resins. Furthermore, it aims to propose a method for producing coke using this raw material charging method. [Means for solving the problem]

[0010] The present invention provides a method for charging raw materials into a coke oven that advantageously solves the above problems. This method involves charging synthetic resins into the coke oven together with raw coal as coke raw materials, passing the raw coal and synthetic resins, which have been transported to the top of the coal tower, through an inclined sieve screen, separating them into those above and below the sieve based on particle size, thereby isolating the landing positions of the synthetic resins and raw coal, and charging the synthetic resins so that they are unevenly distributed between the machine side and the coke side within the coal tower.

[0011] Furthermore, the method for charging raw materials into a coke oven according to the present invention is as follows: (a) The sieve screen is positioned at an angle greater than the angle of repose of the blended coal with respect to the horizontal plane, and the sieve screen is of the grizzly feeder type. (b) The mesh opening of the sieve shall be 10 mm or more and less than 20 mm. (c) The synthetic resins are granulated or molded in advance so that the smaller of the sphere-equivalent diameter or the cylindrical axial length and circular cross-sectional diameter is 20 mm or more. These could be more preferable solutions.

[0012] The present invention provides a method for producing coke that advantageously solves the above problems, characterized in that, when producing coke by carbonizing the coke raw materials in the coal tower of a coke oven, synthetic resins are charged together with raw coal as coke raw materials, charged into the carbonization chamber via a coal transport car, and coke is produced in the carbonization chamber by carbonizing the coke raw materials, the raw coal and synthetic resins transported to the top of the coal tower are passed through an inclined sieve screen, separated into upper and lower parts according to particle size, and then charged, thereby isolating the dropping positions of the synthetic resins and raw coal, and charging the synthetic resins so that they are unevenly distributed on the machine side and coke side within the coal tower, and charging the synthetic resins so that they are unevenly distributed on the machine side and coke side within the carbonization chamber.

[0013] Furthermore, the method for charging raw materials into a coke oven according to the present invention is as follows: (d) The sieve screen is positioned at an angle greater than the angle of repose of the blended coal with respect to the horizontal plane, and the sieve screen is of the grizzly feeder type. (e) The mesh opening of the sieve shall be 10 mm or more and less than 20 mm. (f) The synthetic resins are granulated or molded in advance so that the smaller of the sphere-equivalent diameter or the cylindrical axial length and circular cross-sectional diameter is 20 mm or more. These could be more preferable solutions. [Effects of the Invention]

[0014] In the present invention, synthetic resins are conveyed to a coal tower together with raw coal, and when charging the raw materials into the coal tower, the synthetic resins and the raw coal are passed through an inclined sieve mesh. Since the separation is carried out by the sieve mesh into above-the-sieve and below-the-sieve according to the particle size and then charged, it has become possible to unevenly distribute synthetic resins in the coal tower without newly preparing dedicated charging equipment. By unevenly distributing the synthetic resins in the coal tower, it becomes possible to unevenly distribute the synthetic resins charged into the coal car directly below, and it becomes possible to unevenly distribute the synthetic resins in the carbonization chamber. At this time, since the synthetic resins are arranged so as to concentrate at both ends in the longitudinal direction of the carbonization chamber, the mixing rate of the synthetic resins in other parts is reduced, and it becomes possible to suppress a decrease in the strength of coke. Therefore, it becomes possible to process a larger amount of synthetic resins. Although the coke strength decreases at the ends where the synthetic resins concentrate, the greatly deteriorated parts are crushed by the impact received in the subsequent coke conveying process and cooling treatment process (coke dry fire extinguishing device, wet fire extinguishing device, etc.) and become pulverized coke. The pulverized coke is recovered and can be utilized as fuel in the sintering process of iron ore, etc.

Brief Description of the Drawings

[0015] [Figure 1] It is a schematic longitudinal sectional view for explaining a raw material charging method in a coke oven according to an embodiment of the present invention. [Figure 2] It is a schematic top view of a coal tower of a coke oven according to the above embodiment. [Figure 3] It is a schematic longitudinal sectional view for explaining a raw material charging method in a coke oven according to another embodiment of the present invention. [Figure 4] It is a schematic longitudinal sectional view for explaining a raw material charging method in a coke oven according to a conventional method. [Figure 5] It is a graph comparing the distribution of synthetic resins between an invention example and a conventional example.

Embodiments for Carrying Out the Invention

[0016] The embodiments of the present invention will be described in detail below. The following embodiments are illustrative of equipment and methods for realizing the technical idea of ​​the present invention, and do not limit the configuration to those described below. In other words, the technical idea of ​​the present invention can be modified in various ways within the technical scope described in the claims.

[0017] (Method of charging raw materials into a coke oven) Figures 1 and 2 are schematic longitudinal and top views, respectively, illustrating the method of charging raw materials into a coke oven. In this embodiment, when supplying coal (raw coal) 3 and synthetic resins 2 as coke raw materials into the coke oven carbonization chamber 7, the coal 3 and synthetic resins 2 are transported together to the top of the coal tower 1. Then, when charging into the coal tower 1 via a belt conveyor and a swivel conveyor 4, they are passed through a sieve screen 5 (inclined screen). The sieve screen 5 primarily separates the coal 3 below the sieve and the synthetic resins 2 above the sieve. This isolates the drop positions of the coal 3 and synthetic resins 2, allowing for the charging of coke raw materials. The position of the sieve screen 5 is adjusted so that the synthetic resins 2 concentrate near the wall on the coke discharge side [hereafter also referred to as the coke side 9 (C / S)] or the coke extrusion side [hereafter also referred to as the machine side 8 (M / S)] within the coal tower 1. It is preferable to set the mesh size of the sieve screen 5 to be larger than the coal particle size and smaller than the synthetic resin particle size. This makes it possible to cause the coal 3 passing through the sieve screen 5 to fall towards the front, and the synthetic resins 2 passing over the sieve to fall farther away. Typically, the average particle size of the coal 3 is less than 10 mm, and the average particle size of the molded synthetic resins 2 is 20 mm or more. Here, the average particle size is defined as the equivalent diameter of a sphere based on 50% cumulative volume. Therefore, it is preferable that the mesh size of the sieve screen 5 be between 10 mm and 20 mm. The falling trajectory of the synthetic resins 2 is determined by the ejection velocity and direction of the falling synthetic resins at the tip of the sieve screen 5, the shape and mass of the synthetic resins 2, etc., and can be estimated using the equation of motion for free fall. It is preferable to adjust the falling trajectory of the synthetic resins 2 so that it does not come into contact with the wall surface of the coal tower 1. This makes it possible to suppress wear on the wall surface of the coal tower 1 and pulverization of the synthetic resins 2. Furthermore, the type of sieve 5 is not limited as long as it allows for sorting by particle size. Various types of separation methods are available, including sieves with a grid-like mesh and grizzly feeders that pass material through a row of comb-like teeth. In particular, grizzly feeders are suitable because they are less prone to clogging of the sieve mesh. In addition, a vibrating device is not strictly necessary, but it is preferable to install one to suppress the accumulation and clogging of raw materials in the sieve 5.Furthermore, it is preferable that the inclination angle of the sieve screen 5 be greater than or equal to the angle of repose of the coal 3, with respect to the horizontal plane. If the inclination angle of the sieve screen is smaller than the angle of repose of the coal 3, there is a risk that the coal 3 will accumulate on the sieve screen when it becomes blocked. In that case, the synthetic resins 2 and the coal 3 will fall to the same location.

[0018] In this embodiment, synthetic resins 2, which are unevenly distributed on the machine side 8 and the coke side within the coal tower 1, are supplied to the coal transport car 6 without being moved horizontally. By doing so, the mixing ratio of synthetic resins 2 in the coke raw material supplied to the coal transport car closest to the machine side 8 and closest to the coke side 9 (= mass of synthetic resins / (mass of coal + mass of synthetic resins) × 100, mass-based percentage) can be made higher than that of the other coal transport cars 6, without the need to provide a hopper dedicated to synthetic resins 2.

[0019] Then, coke raw materials are charged from these coal transport cars 6 into the furnace of the carbonization chamber 7 through multiple charging ports at the top of the carbonization chamber 7. Therefore, the synthetic resins 2 can be unevenly distributed on the machine side 8 and the coke side of the carbonization chamber 7.

[0020] In this embodiment, the preferred arrangement of synthetic resins within the carbonization chamber 7 is as follows. Specifically, it is preferable to divide the carbonization chamber 7 into four or more equal regions along its longitudinal direction, and to charge the synthetic resins 2 in such a way that the mixing ratio of the synthetic resins 2 in the region adjacent to the coke side 8 and the region adjacent to the machine side 9 exceeds the mixing ratio of the synthetic resins 2 in the other inner regions. Furthermore, it is even more preferable that the mixing ratio is three times or more. In this case, it is preferable that the total mass of synthetic resins 2 charged in the region adjacent to the coke side 8 and the region adjacent to the machine side 9 is 75% or more of the total. At this time, the mixing ratio of synthetic resins 2 in the other inner regions will be 50% or less of the overall average mixing ratio of synthetic resins. Therefore, the decrease in strength of the coke after carbonization in that region can also be suppressed to 50% or less of what it would be if the synthetic resins 2 were evenly distributed. Although there is no upper limit to the number of region divisions in the carbonization chamber 7, considering the installation load of the raw material charging equipment, it is preferable to divide the carbonization chamber 7 into 10 divisions or less, and more preferably 6 divisions or less.

[0021] Typically, the carbonization chamber 7 of a coke oven has a long, narrow, roughly rectangular shape (for example, W0.6m × D15m × H7m). To uniformly distribute the raw materials in this carbonization chamber 7, coal is charged in through multiple coal inlets arranged along the longitudinal direction (D direction) of the carbonization chamber 7. At this time, by increasing the mixing ratio of synthetic resins charged from the charging inlet closest to the coke side 8 and machine side 9, it becomes possible to concentrate the synthetic resins 2 near the coke side 8 and machine side 9.

[0022] In this embodiment, there are no particular restrictions on the amount of synthetic resins 2 to be added to the coke oven mixed with coal 3, but from an environmental perspective, it is preferable to have an amount of 0.5% by mass or more relative to the total amount of raw materials charged into the coke oven. It is more preferable to have an amount exceeding 1.0% by mass, and even more preferable to have an amount of 3.0% by mass or more. There are no particular restrictions on the upper limit, but adding more than 5% by mass may reduce the coke strength. In particular, when adding a large amount of synthetic resins 2, it is preferable to concentrate the synthetic resins 2 in the areas near the coke side 8 and machine side 9 so that the amount of synthetic resins 2 per unit of raw materials is 1.0% by mass or less in the inner areas excluding the areas near the coke side 8 and machine side 9.

[0023] The above embodiment shows an example using a rotating conveyor, but this is not limited to that. As shown in Figure 3, instead of a rotating conveyor, for example, multiple weirs 10 can be provided on the conveyor, and a sieve net 5 can be provided to guide the synthetic resins 2 and coal 3 falling from the conveyor toward the corners of the cork side 8 or machine side 9. This makes it possible to concentrate the synthetic resins near the cork side 8 and machine side 9 within the coal tower 1, similar to the above embodiment. In the example in Figure 3, the two weirs are installed to be movable vertically, and are controlled so that one of them blocks the material being conveyed on the conveyor.

[0024] (Molded products made from synthetic resins) When synthetic resins are added by the same mass, the coke strength decreases as the number of added resins increases. When synthetic resins are carbonized in coal, they contain a large amount of volatile matter, which creates voids after evaporation, resulting in voids within the coke after carbonization. Since these voids serve as crack initiation points within the coke, it is believed that the more voids there are, the more cracks will occur, leading to a deterioration in coke strength.

[0025] Synthetic resins are used to produce molded products, for example, by molding them in a twin-screw extruder. The synthetic resins are crushed or pre-granulated before being supplied. In this process, it is preferable to adjust the moisture content of the synthetic resins to 5% by mass or less. Reducing the moisture content of the synthetic resins allows for stable molding and increases the density of the molded products. Various types of dryers, including hot air flow dryers, can be used to evaporate the moisture from the synthetic resins.

[0026] The twin-screw extrusion molding machine capable of molding synthetic resins is suitable for use in this embodiment, but there is no difference in its basic structure. The raw material is mixed by twin screws housed in a casing, and the synthetic resin is extruded through a nozzle installed on a heated plate. The extruded synthetic resin is cut by a rotary cutter and adjusted to a certain length. At this time, the volume per piece of synthetic resin is adjusted by the inner diameter of the nozzle and the cutting speed of the cutter. Typically, nozzles with an inner diameter of 20 to 30 mmφ are often used. By molding with a large-diameter nozzle with an inner diameter of 40 to 60 mmφ, it is possible to manufacture larger molded products. The mass of synthetic resin per piece increases, and the amount that can be loaded with the same number of pieces can be increased.

[0027] The molded synthetic resins are cylindrical in shape with a diameter equal to or slightly larger than the inner diameter of the nozzle, and their length can be adjusted by the rotation speed of the cutter. Since the length of the molded product is affected by the position and condition of the molding nozzle, it is difficult to make them all the same length. This results in a distribution of molded products ranging from short to long. While increasing the maximum length of the molded product can increase its volume, it is preferable that the maximum length within the distribution of molded product lengths be 200 mm or less. This is because the diameter of the charging port at the top of the carbonization chamber of the coke oven is approximately 400-500 mm, and extending the maximum length beyond this could cause clogging. The average volume of the molded product is 90 cm³. 3 The above is preferable, 150cm 3 The above is more preferable, 200cm 3 The above is even more preferable. The upper limit depends on the size of the charging port when charging the coke oven, but is 1000 cm. 3 Preferably, it should be 600cm 3 The following is even more preferable: As described above, in order to separate the coke raw materials in the coal tower 1 using a sieve, it is preferable to granulate or mold the synthetic resins such that the smaller of the sphere-equivalent diameter, or the cylindrical axial length and circular cross-sectional diameter, is 20 mm or more.

[0028] (Method of producing coke) Molded synthetic resin products are fed into a hopper, cut out at a constant speed by a quantitative feeder, and placed on top of the coal on a belt conveyor that supplies blended coal to the coke oven. In this embodiment, a sieve is used to unevenly distribute the synthetic resins 2 on the coke side 8 and machine side 8 within the coal tower 1. This uneven distribution is maintained while supplying to each coal car 6. Then, more synthetic resins 2 are distributed from the charging port closest to the coke side 8 and machine side 8, and less synthetic resins 2 are distributed from the other charging ports. This reduces the mixing ratio of synthetic resins 2 charged from the other charging ports, making it possible to suppress the decrease in coke strength after carbonization in that portion. As an indicator of coke strength, the drum strength can be measured according to the drum strength measurement method shown in the coke testing method of JIS K2151:2004. The mass ratio on the sieve, which is sieved with a 15 mm mesh sieve after being charged into a drum testing machine and rotated 150 times, can be measured as the drum strength index DI150 / 15. When using the drum strength index DI150 / 15, it is preferable to keep the decrease in DI150 / 15 to less than 1 point. This is because the DI150 / 15 index is known to have a measurement error of about 0.5 points, and a decrease in strength of 1 point or more clearly indicates a decrease in coke strength. In coke oven operation, a decrease in coke strength (DI150 / 15) of 1 point or more is recognized as a decrease in coke strength, and operations such as improving the quality of raw coal may be performed.

[0029] Controlling the mixing ratio of synthetic resins basically involves pre-measuring the coal cutting speed and the synthetic resin cutting speed, and adjusting each cutting speed using the supply speed of the quantitative feeder or gate opening to maintain a constant ratio. Furthermore, it is difficult to directly measure the mixing ratio of synthetic resins in the longitudinal direction (direction D) of the coke oven carbonization chamber. Therefore, it can be estimated from the mixing ratio of synthetic resins in each hopper of the coal transport car at the top of the coal supply port of the carbonization chamber. This is because when raw materials are charged into a single furnace from multiple charging ports in a carbonization furnace, they are charged simultaneously from each charging port, so the mixing ratio of synthetic resins directly below each charging port is considered to be the same as the mixing ratio of synthetic resins in each hopper of the coal transport car. The mixing ratio of synthetic resins in each hopper of the coal transport car can be estimated by installing cameras above each hopper, detecting the synthetic resins through image analysis, and calculating the mass of synthetic resins charged.

[0030] The preferred cutting location for molded synthetic resin products is after passing through the coal drying facility (CMC) and at a low point on the conveyor belt. This is because, since coal is heated and dried in the CMC, adding molded synthetic resin products before the CMC could cause them to melt within the CMC. The molded synthetic resin products, along with the blended coal, pass through the coal tower and coal transport cars and are supplied to the carbonization chamber. The synthetic resins are thermally decomposed in the carbonization chamber, with some remaining as charcoal, but most are recycled as gas and tar. [Examples]

[0031] (Example of an invention) A mixture of waste plastics, mainly thermoplastic resin, was crushed, and after confirming that the moisture content was 5% or less, it was extruded from a 40mmφ nozzle while being heated using a twin-screw extruder, and cut into cylindrical shapes with a shaft length of 20mm or more. After being charged into a hopper, it was cut out at a fixed rate onto a coal conveyor. At this time, the mixing ratio of the molded waste plastic was adjusted to 1.5% by mass. The equipment configuration of the coke oven was the same as in Figure 1. After the coal and molded waste plastic were transported together to the top of the coal tower, the charging direction was adjusted by a swivel conveyor and charged towards the machine side. At this time, a grizzly feeder with a mesh opening of 20mm to 30mm was installed at the tip of the swivel conveyor so that only the coal passed directly below, and only the molded waste plastic passed over the sieve and fell near the machine side. The angle of the grizzly feeder was set to 35 degrees with respect to the horizontal plane to prevent coal from accumulating on the feeder. After loading for a certain period of time, the direction of the rotating conveyor was adjusted, and raw materials were loaded in the same manner towards the coke side. As a result, molded waste plastics fell in a concentrated manner near the coke side inside the coal tower. These operations were repeated several times to load raw materials up to the top of the coal tower. Next, the coal transport car was moved to the bottom of the coal tower, and the raw materials were cut out from the coal tower. When cutting out the raw materials, the inside of each hopper of the coal transport car was filmed from the top with a video camera, and the amount of molded waste plastics loaded was estimated from the video footage. As shown in Figure 5, it became clear that the mixing rate of waste plastics was high in the hoppers near the machine side (M / S) or near the coke side (C / S), and very low in the other hoppers. Since the raw materials from each hopper were loaded simultaneously into the carbonization chamber directly below, the mixing rate of waste plastics was also very high near the machine side and near the coke side inside the carbonization chamber. The drum strength index DI150 / 15 of the coke produced in this example was 85.6.

[0032] (Comparative example) As in the example of the invention, waste plastic molded material was loaded into a hopper and cut out at a fixed rate onto a coal blending conveyor, as shown in Figure 4. Next, the coal blending and waste plastic molded material were transported together to the top of the coal tower, and the loading direction was adjusted using a swivel conveyor to load the material towards the machine side. At this time, the coal blending and waste plastic were cut out together from the swivel conveyor. After loading for a certain period of time, the direction of the swivel conveyor was adjusted, and the raw materials were loaded in the same way towards the coke side. These operations were repeated several times to load the raw materials up to the top of the coal tower. Next, the coal transport car was moved to the bottom of the coal tower, and the raw materials were cut out from the coal tower. When cutting out the raw materials, the inside of each hopper of the coal transport car was filmed from the top with a video camera, and the amount of waste plastic molded material loaded was estimated from the video footage. As shown in Figure 5, the mixing rate of waste plastic tended to be high in hoppers near the machine side or near the coke side, but it became clear that waste plastic was also loaded into other hoppers. Since the raw materials from each hopper are simultaneously charged into the carbonization chamber directly below, the proportion of waste plastics mixed within the carbonization chamber was high near the machine side and near the coke side, but the difference was not as significant as in the inventive example. The drum strength index DI150 / 15 of the coke produced in this comparative example was 84.6, which was inferior to that of the inventive example. [Explanation of Symbols]

[0033] 1 coal tower 2. (Waste Plastics) Synthetic Resins 3 (Blend coal, coal) coking coal 4. Swivel conveyor 5 (Inclined screen) sieve net 6 Coal transport cars 7 Carbonization chamber 8. Machine side 9 Corkside 10 Weir

Claims

1. When synthetic resins are used as coke raw materials and charged into a coke oven along with raw coal, The raw coal and synthetic resins transported to the top of the coal tower are passed through an inclined sieve screen, and separated into upper and lower sections based on particle size before being charged. This isolates the drop locations of the synthetic resins and raw coal. Synthetic resins are charged into the coal tower so that they are unevenly distributed between the machine side and the coke side. Method for charging raw materials into a coke oven.

2. The method for charging raw materials into a coke oven according to claim 1, wherein the sieve screen is set at an angle greater than the angle of repose of the blended coal with respect to the horizontal plane, and the type of sieve screen is a grizzly feeder.

3. The method for charging raw materials into a coke oven according to claim 1 or 2, wherein the mesh opening of the sieve is 10 mm or more and less than 20 mm.

4. The method for charging raw materials into a coke oven according to claim 3, wherein the synthetic resins are granulated or molded in advance so that the smaller of the diameter equivalent to a sphere, or the axial length and circular cross-sectional diameter equivalent to a cylinder, is 20 mm or more.

5. When synthetic resins are used as coke raw materials and charged together with raw coal into the coal tower of a coke oven, then transported via a coal transport car to the carbonization chamber, and the coke raw materials are carbonized in the carbonization chamber to produce coke, The raw coal and synthetic resins transported to the top of the coal tower are passed through an inclined sieve screen, and separated into upper and lower sections based on particle size before being charged. This isolates the drop locations of the synthetic resins and raw coal. Synthetic resins are charged into the coal tower so that they are unevenly distributed between the machine side and the coke side. In the carbonization chamber, synthetic resins are charged in such a way that they are unevenly distributed between the machine side and the coke side. A method for producing coke.

6. The method for producing coke according to claim 5, wherein the sieve screen is set at an angle greater than the angle of repose of the blended coal with respect to the horizontal plane, and the type of sieve screen is a grizzly feeder.

7. The method for producing coke according to claim 5 or 6, wherein the mesh opening of the sieve is 10 mm or more and less than 20 mm.

8. The method for producing coke according to claim 7, wherein the synthetic resins are granulated or molded in advance such that the smaller of the diameter equivalent to a sphere, or the axial length and circular cross-sectional diameter equivalent to a cylinder, is 20 mm or more.

Images