JP-2026075886-A - Coke manufacturing method

Abstract

[Problem] To provide a method for producing coke that can produce coke with little variation in strength between manufacturing lots. [Solution] The manufacturing method comprises a preparation step (S10), a loading step (S20), a cutting step (S30), a monitoring step (S40), and a coke manufacturing step (S50). In the preparation step (S10), raw coal is prepared. In the loading step (S20), the raw coal is loaded into a coal bin (11). In the cutting step (S30), the raw coal in the coal bin (11) is cut from the bottom end of the coal bin (11) to the charging car (30). In the monitoring step (S40), the amount of raw coal remaining in the coal bin (11) is monitored. In the coke manufacturing step (S50), the raw coal on the charging car (30) is charged into a carbonization chamber (41), and the raw coal in the carbonization chamber (41) is carbonized to produce coke. Then, in the input process (S20), raw coal is fed into the coal bin (11) so that the inventory amount monitored in the monitoring process (S40) is maintained at or above a predetermined amount. [Selection Diagram] Figure 2

Inventors

• 小山 雄也
• 片桐 将達
• 今野 沙緒梨

Assignees

• 日本製鉄株式会社

Dates

Publication Date

20260511

Application Date

20241023

Claims (3)

1. A preparation process for preparing raw coal, which is a mixture of molded coal and powdered coal, The preparation step involves feeding the raw coal prepared in the preparation step into the coal tank inside the coal tower, A cutting process in which the raw coal in the coal bunker is cut from the lower end of the coal bunker to the charging car, A monitoring process for monitoring the amount of raw coal remaining in the coal bin, The process includes a coke production step in which the raw coal on the charging vehicle is charged into the carbonization chamber of a coke oven, and the raw coal in the carbonization chamber is carbonized to produce coke, A method for producing coke, comprising adding the raw coal to the coal tank in the input step so that the amount of inventory monitored in the monitoring step is maintained at or above a predetermined amount.
2. A method for producing coke according to claim 1, further, A method for producing coke, comprising a setting step for setting a predetermined amount of inventory, where the mixing ratio of molded coal in the raw coal cut out in the cutting step is defined as the cutting mixing ratio, and the mixing ratio of molded coal in the raw coal prepared in the preparation step is defined as the standard mixing ratio, the setting step for setting the predetermined amount of inventory is such that the difference in mixing ratio, expressed as the absolute value of the difference between the cutting mixing ratio and the standard mixing ratio, is less than or equal to an allowable value.
3. A method for producing coke according to claim 2, A method for producing coke, wherein the setting step involves determining the extraction and mixing ratio according to the inventory amount by DEM analysis.

Description

This disclosure relates to a method for producing coke. In coke production, increasing the strength of the coke produced is crucial. Typically, to produce high-strength coke, powdered coal and molded coal are mixed, and this mixture is used as the raw material. The coking coal is transported by a belt conveyor and loaded into a coal bin within the coal tower. The coal bin stores a stock of coking coal sufficient to produce multiple batches of coke. From the coal bin, the amount of coking coal needed to produce one batch of coke is sequentially cut from the bottom of the bin into a charging car. The cut coking coal is then transported by the charging car from the coal bin to the carbonization chamber of the coke oven and charged into the chamber. The coking coal charged into the carbonization chamber is carbonized, producing coke. The produced coke is then extruded from the carbonization chamber by an extruder. By repeating this procedure, multiple batches of coke are produced in multiple carbonization chambers. The strength of coke produced can vary between production lots. This is due to variations in the mixing ratio of molten coal between different batches of raw coal being charged into the carbonization chamber. For example, when mixed raw coal is introduced into a coal bin, molten coal moves more easily than pulverized coal because its angle of repose is smaller. This can lead to uneven distribution of molten coal within the coal bin. If molten coal is unevenly distributed within the coal bin, the mixing ratio of molten coal in the raw coal cut from that bin and charged into the carbonization chamber will vary between different batches. A technique for suppressing fluctuations in the mixing ratio of mixed powders when the mixed powder is supplied from the top of a tank is disclosed in Japanese Patent Publication No. 2022-150851 (Patent Document 1). In Patent Document 1, the physical properties (particle size, density, etc.) of multiple types of powders constituting the mixed powder are set, and the behavior of the mixed powder supplied from the top of the tank is analyzed using the discrete element method (DEM). Based on the analysis results, the particle size of each powder is determined to minimize uneven distribution of each powder within the mixed powder in the tank. Japanese Patent Publication No. 2022-150851 Figure 1 is a schematic diagram of a coke manufacturing apparatus used in the coke manufacturing method according to the first embodiment.Figure 2 is a flowchart illustrating the method for producing coke according to the first embodiment.Figure 3 is a flowchart illustrating the method for producing coke according to the second embodiment.Figure 4 is an example of a graph showing the relationship between the amount of coking coal stockpiled in the coal bin and the mixing ratio of molded coal in the extracted coking coal (extraction mixing ratio).Figure 5 is a graph showing the relationship between the amount of raw coal stockpiled in the coal bin and the relative ratio of the extracted and mixed coal. To reduce variations in coke strength between production lots, it is necessary to minimize variations in the mixing ratio of molded coal between different batches of coke used in coke production. Therefore, the inventors investigated the properties of coke sequentially cut from a coal tower in order to suppress variations in the mixing ratio of molded coal between different batches of coke. In a coal tower, coking coal is supplied to the coal bunker by dropping it from above. In other words, coking coal is introduced into the coal bunker. The coking coal introduced into the coal bunker usually piles up in a mound shape. The coking coal contained in the coal bunker is sequentially cut from the bottom of the bunker to the charging car and used in coke production. Coking coal is introduced into the coal bunker as needed. However, there are times when the entire amount of coking coal in the coal bunker is removed, for example, during equipment maintenance, leaving the coal bunker empty. In this case, coking coal is introduced into the empty coal bunker. The inventors have discovered that, among the raw coal sequentially cut from a coal tandem, the mixing ratio of molded coal can deviate significantly from the desired ratio in the first few batches of raw coal immediately after the tandem is refilled, and in the first few batches of raw coal immediately before the tandem is emptied. In short, it was found that the mixing ratio of molded coal in raw coal cut from a coal tandem can change significantly before and after the tandem is emptied. Therefore, it can be said that by managing the amount of raw coal stock in the coal tandem and preventing the tandem from becoming empty, the variation in the mixing ratio of molded coal between raw coal cutting batches can be reduced. The coke manufacturing method according to the embodiment of this disclosure was completed based on these findings. The coke manufa