Improvement in LF Process Through Optimization of Dual Porous Plugs Location in Gas Stirred Ladles

Mathematical and physical simulation of fluid flow had been carried out for a scaled down model of a gas stirred 300 T ladle of Bokaro Steel Plant, Steel Authority of India Ltd. The existing ladle is equipped with two porous plugs located in adjacent quadrant at the bottom of ladle. Comparison of fluid flow and mixing efficiency of the existing arrangement is made with a modified arrangement of porous plugs located diagonally across to each other. Simulation study reveal that the modified arrangement of porous plug leads to improved mixing efficiency in the ladle. Based on the results from the simulations, the operating parameters like argon pressure and flow rate were modified. Plant trials with optimized ladle furnace (LF) operating parameters were carried out in a modified ladle having porous plugs located diagonally across. While the desulphurization efficiency improved, aluminium loss from the melt was reduced by 8.2%. Redistribution of the gas plumes from adjacent quadrant to diagonal quadrant led to uniform wear of refractory walls of the ladle, which led to increase in the lining life of the ladle. Improved mixing of the melt at lower argon pressure and flow rate also led to reduction in hood jamming of the LF.