A speckle photographic method and a turbulence two-equation model are proposed for the performance evaluation of melt- particle mixing in gas-stirred ladles with throughflow. Laminar and turbulent flow studies will be performed on a simplified water mode. The flow pattern will be determined by a laser light-sheet flow visualization technique and will be analyzed with automated image processing. The results can be used for the performance optimization of melt-particle mixing in gas-stirred tanks with throughflow. Applications of the study include ladle metallurgy, such as desulfurization of molten iron and steel, and nonferrous industries, such as copper and aluminum processing.