Novel technique for assessing the burnout potential of pulverized coals/coal blends for blast furnace injection

It is imperative to achieve high coke replacement rates in blast furnaces which in turn are strongly influenced by the effects of combustibility of pulverized coal/coal blend due to extremely short residence time in the raceway. To overcome this issue, authors have developed a new methodology based on intrinsic properties of coal/coal blend to assess the suitability of pulverized coal injection grade coal for blast furnace application, named as Composite Burnout Potential (CBP). The CBP values evaluate the combustibility of a coal/coal blend in a vertical drop tube furnace at three different oxygen concentrations viz., 21%, 25%, and 31%. The results confirm that CBP and burnout of coal /coal blend are in close proximity. Drop tube furnace data was used for development and validation of the CBP model. The technique was successfully used for predicting the combustibility of coal/coal blend for better application in the blast furnace.