Evolution behavior and mechanism of iron carbon agglomerates under simulated blast furnace smelting conditions

Iron carbon agglomerates (ICA) are the composite burden for low-carbon blast furnace (BF) ironmaking. In order to optimize the reactivity of ICA according to the evolution characteristics of ICA in the BF smelting process, the evolution behavior and mechanism of different reactive ICA under simulated BF smelting conditions were studied. The results show that the existence of more sillimanite and aluminosilicate and less active sites of metallic iron will weaken gasification reaction and carburization ability of ICA-1 (containing 10% iron ore). It weakens the promoting effect of ICA-1 on the reduction, softening, and melting of ferrous burdens and the dripping of slag-iron. The aluminosilicate with a high melting point decreases, the low melting point slag phase and Fe–Si alloy increase, and many active sites of metallic iron exist, which strengthen the gasification reaction and carburization ability of ICA-2 (containing 30% iron ore). The promoting effect of ICA-2 on the reduction, softening, and melting of ferrous burdens and the dripping of slag-iron is significantly improved. The gasification reaction capacity of ICA-3 (containing 35% iron ore) is reduced, and the improvement in ICA-3 on the softening–melting performance of mixed burdens is reduced. The appropriate proportion of iron ore in ICA is about 30%.