Combustion performance of pulverized coal and corresponding kinetics study after adding the additives of Fe2O3 and CaO

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 2 O 3 and CaO, on PC combustion were studied using the thermogravimetric method. The results demonstrate that both the Fe 2 O 3 and CaO can promote combustion performance index of PC including ignition index ( C i ), burnout index ( D b ), as well as comprehensive combustibility index ( S n ). The S n increases from 1.37 × 10 −6 to 2.16 × 10 −6 % 2 ·min −2 ·°C −3 as the Fe 2 O 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 2 O 3 proportion increases from 0 to 5.0wt%, which supports the improved combustion performance. Moreover, it is uneconomic to utilize pure Fe 2 O 3 and CaO in production. Based on economy analysis, we selected the iron-bearing dust (IBD) which contains much Fe 2 O 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.