SMELTING OF IRON OXYSULFIDE MELTS USING SOLID CARBON

Several properties of liquid Fe-S-O at 1 473 K provided the motivation for using iron-oxysulfide melts as smelting medium for iron oxides. E xperiments were carried out to determine rates of smelting of Fe-S-O m elts by solid carbon at temperatures in the range 1 361-1 525 K. Effec t of oxygen concentration, bath agitation rates, and carbon reactivity on the smelting rates were examined. The smelting rates increased wit h increasing oxygen concentration, bath temperature, and carbon reacti vity, but with decreasing bath agitation rates. Microscopic observatio ns and chemical analysis of the melt samples collected after the exper iments revealed that sulfur content of the product metal was around th e thermodynamic equilibrium value and the metal was not saturated with carbon. It was proved based on a micro-mixing model that the transpor t of oxygen within the liquid boundary layer adjacent to carbon sample was not a rate limiting process. The reactivity of carbon or carbon g asification reaction at the liquid-solid interface was found to be the most likely rate limiting step.