GAS FLUXING OF ALUMINUM: COMPARISON OF COMPUTATIONAL FLUID DYNAMICS MODELS AND EXPERIMENTS

摘要

Chlorine fluxing is an essential purification step in aluminum refining in which impurities such as Ca, Na, Li, and Mg are removed by bubbling a mixture of chlorine and argon gas through molten aluminum. The efficiency of impurity removal and control of toxic chlorine and chloride emissions are dependent upon the extent of gas dispersion or mixing, residence time of the bubbles, and surface area of the bubbles. Clearly, these gas phase parameters cannot be directly observed in molten aluminum, thus there are details of the fluxing process which are not fully understood. To gain further insight, two computational models have been developed to simulate the complex two-phase fluid dynamics of a rotary gas injection system. The results of these two modeling approaches are presented and analyzed and compared to experimental bubble measurements gathered using a capacitance probe, which detects bubbles in molten aluminum.