1998 年 38 巻 1 号 p. 28-35
Metallurgical coke was modified by infiltrating carbon within the pores by methane pyrolysis. The rate of oxidation with CO2 was lowered and the mechanical strength after partial oxidation was enhanced. CSR (Coke Strength after CO2 Reaction) of regular coke for a blast furnace increased from about 56 to 77. This enhanced value corresponds to that of the extremely high-grade coke. The mechanism was considered in terms of the pore structure changes and was elucidated as follows:
Original metallurgical coke has a negligibly small volume of micropores but it increases rapidly during oxidation. In the case of infiltration, carbon deposits mainly in the mesopores. This carbon restricts the rapid increase in the volume of the micropores during oxidation, which is attributed to depress the oxidation rate. As it has been realized that generally the coke with the higher resistance to oxidation has the higher CSR, the depression effect onto the oxidation rate is deduced to result in the extreme enhancement of CSR.
