Effect of Coarser Fraction on Coke Strength After Reaction (CSR) of Coke Plant Blend at Tata Steel

Metallurgical coke plays three primary roles in blast furnaces. It acts as a source for supplying reducing gases for reduction of metal oxide; it acts as a support to the raw material burden while descending through blast furnace and lastly it acts as a porous medium through which reactive gases can pass through the blast furnace. These roles are significant in blast furnace operation. Coke strength after reaction (CSR), coke reactivity index (CRI) along with parameters like Micum indices (M40/M10) assess the suitability of coke for blast-furnace operation. With the installation of larger blast furnaces, the need of coke with high CSR is more than ever. There are already many established methods to improve coke CSR through blend design, process optimization, additives, etc. But these works somewhat overlook the effect of particle size on coke CSR. The current work presents the impact of coal granulometry on coke CSR. It was observed in laboratory-scale carbonization of a commercial blend that the elimination of the > 5 mm fraction from the blend improves coke CSR by 2 points.