Interaction of inclusions in flotation processes

© ISM

So-called inclusions in liquid metal are impurities, particles or drops of material other than the surrounding metal, which need to be removed to warrant high quality of the products.

Flotation procedures in steel making or mineral processing use adhesion forces at the surface of gas bubbles to collect and float particles from a liquid medium. The interaction of inclusion particles among each other and with the bubbles in liquid steel are almost unexplored. Different from mineral flotation in watery solutions, the experimental access in steel is difficult, so that the numerical modelling of this process is of high relevance.

In the research project FLOTINC, funded by DFG, four groups from Germany and France collaborate to elucidate the interaction os inclusions removed from the bubbles. At ISM in Dresden, direct numerical simulations are performed with the in-house code PRIME to quantify particle-particle interactions due to enhanced turbulent fluctuations generated by the rising gas bubbles. This leads to enhanced agglomeration which in turn influences the transport of particles to the surface of the molten metal. The main research question is which effects occur and how they compete and influence each other. The ultimate goal of this project is to determine closure models for population balance equations.