For certain applications, steels have to feature a very distinct and well-defined level of cleanness in
terms of the number and composition of non-metallic inclusions. Therefore, one crucial aspect of
steelmaking is removing and controlling said non-metallic inclusions during the process. Particle
removal during ladle refining comprises three stages, namely:
1. Flotation
2. Transport through the steel/slag interface
3. Dissolution of the particle in the slag.
Only if all three stages are completed the particle can be considered as fully removed from the steel
melt which, in turn, leads to the slag being one of the most influential parameters for inclusion
removal and control. Depending on the composition of the particles and the slag, the dissolution can
be controlled by different mechanisms. This study focuses on the diffusion-controlled dissolution of
solid oxidic particles in slags. For this, a model of particle dissolution has been developed. For
modelling diffusion, either the differential equation following Fick’s second law can be solved, or an
analytical solution to this equation valid for stationary interfaces can be used. Both approaches allow
for calculations of concentration profiles of the dissolving species in surrounding slag. From this, the
mass flux can be derived, which finally leads to calculating the boundary layer velocity due to
considerations of mass balance. In this work, both methods as well as results of dissolution
experiments using High Temperature Confocal Scanning Laser Microscopy are compared. This
research aims to provide a framework for diffusion-based dissolution modelling in further expanding
the understanding of particle dissolution in secondary metallurgy.