2004 Volume 90 Issue 4 Pages 190-197
The effective calorific value of pulverized coal in a temperature region over 1400°C in the blast furnace was examined, and it was shown that in an operation in which the heat balance in the lower part of the blast furnace was a rate-controlling factor, a pulverized coal having a lower average volatile matter content was effective in lowering the reducing agents rate. However, there is a restriction in the amount of the resource of semi-anthracite coal whose volatile matter is relatively low, we examined a mixed pulverized coal obtained by mixing a high and low volatile matter content coals. The combustion behavior of the mixed pulverized coal was examined by conducting a combustion experiment and a simulation analysis. It was found that when a mixed coal obtained by mixing coals of different volatile matter contents was used, the combustion temperature of the mixed coal deviated toward the high temperature side from a weighted average value of temperatures obtained when each of the coals of different volatile matter contents was burned individually, and that the use of the mixed pulverized coal showed a remarkable effect on the promotion of temperature rise particularly in the initial period. This was because the high volatile matter content coal formed a high-temperature combustion field and promoted the combustion of the low volatile matter content coal.
