Research on the carbonaceous substance of dust and sludge in BF at large pulverized coal injection rate

The components and microstructure of BF dust (dust and sludge) in Baosteel BF at large pulverized coal injection (PCI) rate were investigated by microscopic analysis. The area percentages of unconsumed pulverized coal and coke particles were obtained at different PCI rates. The effect of large PCI rate on the mass fraction of carbon and the unconsumed pulverized coal ratio in BF dust was analyzed. The amounts of unconsumed pulverized coal and coke particles as well as the utilization rate of pulverized coal were tested in BF at large PCI rate. The experimental results showed that with increasing PCI rate the amount of BF dust increased, but at large PCI rate it fluctuated. With the increase in coal injection rate the amounts of carbon and unconsumed pulverized coal in BF dust increased, but the amount of unconsumed coke particles in BF dust hardly changed and kept at about 3 kg·t^-1. It is indicated that the quality of coke in Baosteel BF is very good.