ESTUDO DO COMPORTAMENTO DA CUBA DO FORNO DE AUTO-REDUÇÃO UTILIZANDO CARVÃO GRANULADO ATRAVÉS DO MODELO MULTIFASICO

DRI demand continues increasing due to shortage of high quality scrap iron for the steel production through electric arc furnace. In this context, the shaft furnace based on self-reducing process becomes an alternative route to supply the demand of metallic. It is possible to recycle the fines of iron and steelmaking industries since the self‑reducing agglomerate are mixtures of fine ore/residues and reducing agent. The principal characteristic is the "internal environment of the agglomerate", this results in high rates of reduction (extraction of the oxygen from the ore) due to the kinetic conditions. The present paper aims to develop a mathematical model capable of simulating the operating conditions of the shaft furnace with self-reducing agglomerate, lump coal and secondary gas injection. The model used the technique of finite volume to solve the transport equations of momentum, energy and chemical species of both, solid and gas phases considered in this model. The main finds of this paper are: a) the self-reducing furnace can operates with a mixture of self‑reducing briquettes and anthracite; b) the productivity of the process can achieve 35.5 t/m3/day; and c) the process produces outlet gas with high calorific value.