Coal coking issues

Reply to 1# Shiyi Di: The quality referred to by the original poster is probably the strength of coke, right? Cohesiveness: The cohesiveness of the coal used as a blending material is a fundamental requirement for coking; therefore, whether it possesses cohesiveness is also a key indicator for distinguishing coking coal from thermal coal and other types of coal. Generally speaking, by examining the relationship between the strength of coke and the caking property of the coaling coal under constant coking conditions (such as turnaround time) and other parameters (such as the volatility of the coaling coal), it can be found that the higher the caking property of the coaling coal, the better the quality of the resulting coke. However, once a certain peak is reached, the particle size of the coke decreases; at this point, by adding an appropriate amount of diluents (such as lean coal), even though the caking property is reduced to some extent, the strength of the resulting coke remains high. Fineness: The study on the effect of fineness on coke strength is divided into two aspects. Firstly, as fineness increases, the bulk density rises, and the expansion pressure during the coking process increases as well; consequently, the quality of the coke improves. However, research has also shown that when the fineness reaches a certain peak value, the bulk density actually decreases. Second is the impact of the fineness of different coal types on coke quality. Generally, coals with low caking properties act as inert substances in blended coals; for example, lean coals. The smaller the particles of such coals, the more evenly they can be distributed in the blended coal, resulting in better crack distribution and microstructure in the coke. Therefore, the finer the grind size of coals with weak caking properties, the better. However, for primary coking coal and fat coal, the finer the particle size, the better it is not always the case.