Effect of Coke Addition on Sintering Kinetics during Induration of a Single Hematite Pellet

Induration is a thermal treatment process wherein the green pellet properties are enhanced for subsequent reduction processes such as blast furnace and DRI production. During induration, the pellet essentially undergoes (i) physical change, that is, particles sinter with each other imparting strength to the pellet and (ii) chemical change by which phase change occurs either due to reduction/oxidation or thermal decomposition. Both these changes are interdependent. In case of induration of magnetite pellet, the exothermic oxidation of magnetite to hematite generates heat within the pellet. However, for the induration of hematite pellets carbon in the form of coke breeze is added in the green pellet mix to aid heat generation by combustion within the pellet.