Carbothermic Reduction and Kinetics of a Lean Grade Multimetallic Magnetite Ore

Reducibility and reduction kinetics of hardened pellets prepared from a novel, lean-grade multimetallic magnetite ore (MMO) was investigated in the present study. This lean-grade ore contains a significant amount of chromium and nickel, which can lead to a reduction in the cost of steelmaking. The hardened pellets were reduced at 950–1150 ℃ for 30–120 min in a bed of high ash coke. The optimum reducibility and metallisation of 76% and 85% were obtained at 1100 ℃ at a holding time of 120 min. The kinetic model “[(1-α)−1/3–1]2 = kt” was found to be the best fit for the reduction of pellets. The activation energy calculated for the pellets was 220.19 kJ/mole. Pellets reduced with high ash coke fines at 1100 ℃ for 120 min and above are thus found necessary to achieve the industrially desired metallization of greater than 85%.