Degradation behavior of coke at high-temperature zone in blast furnace.

Coke properties at high temperature zones in a blast furnace play an important role for blast furnace operation. Therefore, with the advance of manufacturing technology on high strength of coke and its stability in the cold state, the interest for coke quality has been turned to that at high temperatures.This report mainly describes the behavior of coke under high temperature conditions in a lower part of blast furnace.In order to clarify the degradation behavior of coke in the blast furnace, a series of fundamental studies on the degradation of coke due to chemical, mechanical and thermal effects were carried out. At Kashima No. 1 BF the sampling of coke has been done during the scheduled time of shutdown at three levels-lower shaft, bosh, and tuyere. The movement and accumulation of fine coke and the mutual relation between coke properties and the furnace performance were examined.Based on the results of these studies and investigations, the mechanisms of degradation and disintegration of coke were discussed.