ir. Inge Bellemansa, ir. Vincent Cnockaerta, dr. Evelien De Wildea,b, prof. dr. ir. Nele Moelansc, prof. dr. ir. Kim Verbekena
Various pyrometallurgical industries (both primary and recycling) encounter production losses due
to the mechanical entrainment of metallic droplets, i.e. the droplets are attached to solid particles in
liquid slags. The attached metal cannot settle, decreasing the yield of the phase separation. This results
in inadequate sedimentation and eventually production losses in e.g. industrial Cu smelters and Pb
reduction melting furnaces.
Experimental work on this topic remains challenging, but phase field simulations can circumvent this
lack of experimental data and allow a more systematic evaluation on the role of different parameters
on the observed phenomenon. However, simulations are best interpreted in combination with experiments.
The performed experiments are used both for the input microstructure of the solid particles
and to validate the simulation results.
In the present work, a recently developed phase-field model to simulate the attachment of liquid metal
droplets to solid particles in slags considering real microstructures of solid particles in liquid slags is
extended to consider movement of the solid particles in the liquid slag. Furthermore, it is investigated
which initialization method for the liquid metal droplets corresponds best to the experimental
conditions. One of the initialization methods used spinodal decomposition of a supersaturated slag to introduce
the metallic droplets, whereas the other initialization consists of positioning metallic droplets
in the slag in a random way. The simulations showed that both initialization methods result in microstructures
that correspond with experimental observations, which points to the existence of several
origins for the attachment of metal droplets to solid particles in slags.