A review on nut coke utilisation in the ironmaking blast furnaces

In the ironmaking blast furnaces, nut coke (10-40 mm; 2-23 wt-%) is charged together with the ferrous burden. A systematic review is performed to understand the effects of nut coke use on the permeability, thermal reserve zone (TRZ), reduction kinetics and softening & melting behaviour. State of the art techniques for enhancing reactivity and to lower TRZ temperature are discussed. To utilise nut coke effectively, need of correlational research is expressed on its behaviour with different burden chemistry, carbon ordering, ash content and distribution style. Challenges for higher nut coke utilisation like decrease in regular coke layer thickness and unconsumed fines in lower part of the furnace are pointed out. The scope of further research is marked via this review.