The change of coke properties in the blast furnace was investigated using samples from Higashida No. 5, Hirohata No. 1 and Kukioka No. 4 blast furnaces, which were dissected after being quenched with water in normal operating state.
The results of the research are summarized as follows:
1) The change of coke properties becomes remarkable below the lower shaft level.
2) According to the microscopic observation, this change of coke properties seems to be due to the selective carbon solution-loss reaction at specified textures of coke, resulting in the weakening of strength and the generation of fine particles.
3) This phenomenon is particularly remarkable around the race-way of blast furnace.
