Location of micro-pore and the ratio of open/closed pore in the cokes

According to the pulverized coal injection (PCI) to blast furnace (BF), the fine generation of coke in the lower part of BF especially around raceway has come to an important problem for stable operation. To clarify the mechanism of the fine generation from coke, the pore structure change before and after the gasification experiment has been investigated in previous study. In this study, the open and the closed pore were identified using SEM and the optical microscope observation. In the case of one directional penetration of fluorescent resin, the closed pore was about 5%, however, the actually existing closed pore would be less value, when the resin penetrated from many directions. The graphitized region in the coke was defined, where it was a dense and rectangle area and it included an anisotropic texture such as Mosaic, Fibrous and Leaflet texture. The micro-pore less than 10 pm mainly existed in the graphitized structure. The graphitized structure has low reactivity and remains until high temperature region more than 1500 degreesC. From these results, it was found that the micro-pore less than 10 mum does not relate to the gasification reaction.