Numerical simulation of slag entrainment and carryover during ladle teeming process

A three-dimensional numerical model was established based on a 210 t industrial ladle to simulate the multiphase fiow behavior during the entire teeming process. The volume of fiuid method was used to capture the gas-slag-steel interface, and large eddy simulation was employed to resolve the turbulent fiow. A discrete phase model was applied to simulate the entrainment of dispersed inclusions, and the simulation results were validated by industrial sampling under different retained steel conditions. In addition, a user-defined function was developed to calculate the slag detection system, and the predicted critical slag carryover moments matched well with online recorded results. Parametric studies showed that with the increase of the interfacial tension from 0.4 to 1.8 N/m the critical steel mass was decreased by 3.53 t, while increasing the slag viscosity from 0.1 to 0.6 Pa s resulted in a gain of 0.57 t. The clogging layer around the ladle nozzle significantly advanced the slag carryover. A 100 mm clogging layer increased the retained steel by 3.89 t. Relative infiuence weights of the interfacial tension, slag viscosity, and clogging layer height were calculated to be 44.2%, 7.1%, and 48.7%, respec-tively. Industrial trials confirmed that retaining 25 t of steel reduced 40% of the slag-type inclusions, comparing to the condition without the retained steel.