Research on Unconsumed Fine Coke and Pulverized Coal of BF Dust under Different PCI Rates in BF at Capital Steel Co.

摘要

The unconsumed fine coke and pulverized coal in BF dust (gravitational dust and bag dust of hop pocket) under different PCI rates in BF at Capital Steel Co. was investigated in this paper. By means of microscopic and chemical analysis the percentage of unconsumed fine coke and pulverized coal were determined. It has been found that with increasing of PCI rate all the amount of BF dust at BF, carbon mass fraction, unconsumed fine coke and pulverized coal in BF dust increase. The amount of unconsumed pulverized coal in BF dust is about 5 to 7 kg/tHM less than that of fine coke at PCI rate between 135 to 200 kg/tHM. Under PCI rate of 200 kg/tHM, utilization factor of pulverized coal could reach over 98.52%. However at PCI rate of 190 kg/tHM the amount of unconsumed fine coke was increased suddenly and has reached about 10 kg/tHM in BF dust. This result indicates that under high PCI rate the worn coke in BF increased quickly, which results in the decreasing the permeability in the cohesive zone and lower part of BF. The quality of coke should be improved for increasing of the PCI rate in BF at Capital Steel Co.