Numerical simulation of multiphase flow in oxygen bottom-blowing copper melting furnance

During the oxygen-enriched bottom blown copper smelting process, multiphase flow in the molten pool determines the particle feeding, heat transfer, mass transfer, and chemical reaction rate. In this paper, a three-phases mathematical model including air bubble, copper matte and slag was established. The model was further verified through a hydraulic model experiment. Numerical simulations under different airflow rates, copper matte depths and slag layer thicknesses were conducted to investigate the size of the plume eye, swirl intensity and position of the vortex. The results show that as the air flow velocity increases, the stirring from bubble flow to the bath is enhanced and bubble dispersion is decreased, but excessive airflow speed is easy to cause melt splash. The stirring area of the vortex and the swirl intensity increase with copper matte depth. The slag layer becomes shorter and thicker, which is beneficial for slag-off. However, the diameter of the plume eye decreases sharply, and the degree of copper matte slag increases when the depth of molten poll increase to a certain extent. With the increase of the slag layer thickness, the bubble size in the copper matte layer increases, while the plume eye size decreases sharply or even disappears. Vortexes appeare in both the copper matte and slag layers, resulting in serious slag entrapment.