The deadman coke was sampled by the core probe from Kobe No. 3BF at shutdown. On the basis of the sampling results, the decrease of coke size by solution loss reaction was evaluated from the coke degradation model considering the strength distribution.
The main results obtained are as follows.
1) The coke size decreases by the degradation of reacted layer near the coke surface by solution loss reaction.
2) The accumulation of fine coke in the deadman is derived from the solution loss reaction zone rather than the raceway by evaluating temperature hystory. This affects the permeability in the blast furnace.
3) The decrease in coke size calculated from the coke degradation model, which takes into account the critical strength of 20 × 105 Pa, results in the average of 10 × 10-3 m and is similar to the sampling results in the blast furnace. Consequently, this model is possibly applied to the criterion of estimating coke degradation in the blast furnace.
