REDUCTION OF IRON-ORE IN A FLUIDIZED-BED REACTOR .2. REDUCTION OF IRON-ORE FINES WITH CHARCOAL AND METHANE IN A FLUIDIZED-BED REACTOR

In this second part of the two part paper, the reduction of iron ore fines with charcoal, methane, and charcoal and methane together has been reported. Experiments were carried out in the laboratory scale fluidzed bed reactor (FBR), described in detail in part 1, in the temperature range 850 - 950-degrees-C using nitrogen as the fluidzing medium. The kinetics of reduction was monitored by continuously analysing the flue gas leaving the reactor, using an on-line gas chromatograph. It was observed that the reduction of iron ore with charcoal fines was substantial only above 900-degrees-C. Higher rates of reduction were obtained if either methane or both charcoal and methane were used as reducing agents. The overall activation energy for reduction with charcoal fines ws 56.6 kcal/g mol whereas for reduction with methane it was 18.5 kcal/g mol at higher methane flow rates and 12.8 kcal/g mole at lower flow rates. Characterization of final product, using chemical and x-ray analyses, indicated that the product was a mixture of Fe2O3, FeO, Fe and Fe3C at lower temperatures whereas it predominantly consisted of Fe3C and Fe at higher temperature. Effects of process parameters, e.g., the particle size, temperature, type of reducing agent etc. on rate of reduction have also been discussed.