INFILTRATION OF METALLURGICAL COKE BY PYROLYSIS OF CH4 AND ITS EFFECTON ENHANCEMENT OF CSR

Metallurgical coke was modified by infiltrating carbon within the pore s by methane pyrolysis. The rate of oxidation with CO2 was lowered and the mechanical strength after partial oxidation was enhanced. CSR (Co ke Strength after CO2 Reaction) of regular coke for a blast furnace in creased from about 56 to 77. This enhanced value corresponds to that o f 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, carb on deposits mainly in the mesopores. This carbon restricts the rapid i ncrease in the volume of the micropores during oxidation, which is att ributed to depress the oxidation rate. As it has been realized that ge nerally the coke with the higher resistance to oxidation has the highe r CSR, the depression effect onto the oxidation rate is deduced to res ult in the extreme enhancement of CSR.