Effect of a self-rotating oxygen lance system on mass transfer between slag and molten steel

To improve the efficiency of the steelmaking process, a system of self-rotating lance was designed, and corresponding cold simulation mechanism was developed. The influence of the self-rotating lance on the mass transfer rate between slag and molten steel was investigated by comparing this novel system with the traditional oxygen lance. The results show that the self-rotating lance can stably rotate with a gas jet as the power source. The mass transfer rate increases with an increase in the top and bottom blow flow rates and with a decline in the lance position. Approximately 13.7% of the top blow flow rate is converted to stirring energy, which is approximately twice that of the traditional oxygen lance, and the mass transfer rate can increase by over 30%. Furthermore, the impact energy can be concentrated at different depths of the molten bath by adjusting the rotational speed. With the same energy density, the mass transfer rate produced by the self-rotating lance is higher; however, the influence of the energy density on the mass transfer rate is low when the rotational speed is 30–50 r/min.