A theoretical study of slag-metal reaction kinetics using a numerical technique

Abstract

<p>Currently available theoretical formulation for the kinetics of slag-metal systems have been extended to clarify certain aspects of the system. Coupling factors for electrochemical reactions and for ionic diffusion have been defined to clarify the significance of coupling phenomena in the kinetics of multi-component systems. Theoretical equations for the interfacial reactions and the diffusion processes in both phases, in seven hypothetical pseudo-ternary slag-metal systems have been numerically solved by a finite difference method. Typical features of coupling phenomena, i.e.m acceleration and deceleration of reaction or diffusion, and up hill reaction or diffusion have been clearly demonstrated. Through numerical analysis, a modified form of "Sherwood Number", Shᵢ*≡kᵢL/ρDᵢ for a particular reaction i, is defined and found to be proper to explain the rate controlling steps for the over-all reaction. In the present analysis, the relationships between the modified Sherwood Number and rate controlling steps were found to be as follows: Sh*ᵢ > 360: diffusion control, 0.05 ≲ Sh*ᵢ ≲ 360: mixed control, Sh*ᵢ < 0.05: interfacial reaction control Thus non-trivial numerical solutions for slag-metal systems have been developed for the first time.</p>