Multiscale study of reactive gas injection in pyrometallurgical processes.

The goal of this research is to generate fundamental insight into reactive gas-liquid flows for pyrometallurgical gas injection applications through the construction of a multiscale model. The focus will be on the integration of mesoscopic numerical CFD techniques with microscopic thermokinetic models. this will lead to an isothermal mesoscopic model capable of simulating the behavior of one or more gas bubbles, exhibiting the most relevant phenomena in pyrometallurgical processes, namely convection, diffusion, reaction (in the bulk and at the interface) and precipitation. For reasons of feasibility, a model problem is formulated for this research, which contains the most relevant physico-chemical phenomena for a multitude of other pyrometallurgical applications. The process under consideration is the injection of silicon tetraochloride (SiCl4) gas in a batch of liquid zinc (Zn). Both species take part in a reduction raction, leading to the formation of silicon (Si) and gaseous zinc chloride (ZnCl2). This reaction can take place both at he gas-liquid interface and in the bulk of the bubble, since due to its high vapor pressure, zinc will evaporate into the bubble. Solid silicon particles can form through the gas-gas reaction, and silicon can dissolve into the zinc bath at the interface. Additionally, these reaction and diffusion phenomena will be influenced by the convection pattern in and around the rising bubble.

Keywords:Fluid flow, Chemical reaction, Gasinjection, Pyrometallurgy

Disciplines:Ceramic and glass materials, Materials science and engineering, Semiconductor materials, Other materials engineering, Manufacturing engineering, Other mechanical and manufacturing engineering, Product development