Kinetic Study on Reduction of FeO in a Molten HIsarna Slag by Various Solid Carbon Sources

Abstract

To investigate the reduction behaviour of different reductants such as charcoal (CC), thermal coal (TC), and carbon black (CB) with HIsarna slag, a series of isothermal reduction experiments were performed in a vertical tube resistance furnace (VTF), coupled with a Quadrupole mass spectrometer (QMS) at 1450 °C, 1475 °C and 1500 °C. The results confirm that the highest overall reduction rate was achieved by CC, followed by TC and CB. The reduction mechanism between FeO containing molten slag and the selected carbonaceous materials is determined by studying the morphology of the water quenched samples at the intervals of 1.5, 3 and 5 minutes, using optical and scanning electron microscopes. The results reveal that the overall reaction is controlled by two main mechanisms: (1) nucleation and growth of CO bubbles, proceeded by the gaseous intermediates CO and CO2; and (2) diffusion of FeO in the molten slag. The initial reduction period in which chemical reaction control is dominant, can be described by the Avrami–Erofeev model, whereas the final period is described by the three-dimensional diffusion model.

Study on hydrogen smelting reduction behaviour in synthetic molten HIsarna slag

“…As a continuous study on the role of individual reductants (e.g. different carbons [18,19], hydrogen), this work studies the reduction behaviour of hydrogen with FeO in molten synthetic HIsarna slag. In the present research, to determine the reduction behaviour of iron oxide in molten HIsarna slag by hydrogen-containing gas, two types of experiments were carried out: (1) blowing H 2 -Ar onto the FeO-containing liquid HIsarna slag at 1450°C, 1475°C and 1550°C respectively, (2) injecting H 2 -Ar into the liquid slag at 1550°C .…”