Abstract:
Combustion performance of pulverized coal (PC) in blast furnace (BF) process is regarded as a criteria parameter to assess the proper injection dosage of PC. In this paper, effects of two kinds of additives, Fe
2O
3 and CaO, on PC combustion were studied using the thermo-gravimetric method. The results demonstrate that both the Fe
2O
3 and CaO can promote combustion performance index of PC including ignition index (
Ci), burnout index (
Db), as well as comprehensive combustibility index (
Sn). The
Sn increases from 1.37 × 10
−6 to 2.16 × 10
−6 %
2·min
−2·°C
−3 as the Fe
2O
3 proportion increases from 0 to 5.0wt%. Additionally, the combustion kinetics of PC was clarified using the Coats-Redfern method. The results show that the activation energy (
E) of PC combustion decreases after adding the above additives. For instance, the
E decreases from 56.54 to 35.75 kJ/mol when the Fe
2O
3 proportion increases from 0 to 5.0wt%, which supports the improved combustion performance. Moreover, it is uneconomic to utilize pure Fe
2O
3 and CaO in production. Based on economy analysis, we selected the iron-bearing dust (IBD) which contains much Fe
2O
3 and CaO component to investigate, and got the same effects. Therefore, the IBD is a potential option for catalytic PC combustion in BF process.