Effect of hot metal utilization on the steelmaking process parameters in the electric arc furnace

The effect on the electric arc furnace steelmaking process parameters by hot metal utilization from 41 to 75% in a 150 ton/ch furnace has been investigated. Process parameters including oxygen lancing, accumulated power consumption, and tap-to-tap times were evaluated. An increase in the HMR (hot metal ratio) can decrease the accumulated power consumption, but to maintain the tap-to-tap times, oxygen injection into the melt must be significantly increased. Utilizing an optimized oxygen injection pattern, scrap-melting rate was increased and the tap-to-tap times as a function of HMR variations from 0.41 to 0.75 at fixed oxygen lancing showed a 0.45 min ton^-1 hot metal decrease in the tap-to-tap time. At HMR of 0.61 the decarburization rate linearly increased with higher oxygen lancing. Visual inspection of the slag foaming with the modified oxygen injection practice showed initial foaming above 6000 Nm³ h^-1 and was fully developed at 10 000 Nm³ h^-1. Hot metal additions into a 150 ton DC-EAF is studied. 1700 kWh of accumulated power consumption is decreased for every ton of hot metal utilized. Oxygen lancing practices is modified with hot metal additions in the EAF without increasing the tap-to-tap times. At hot metal additions of above 0.6, the decarburization rate linearly increases with oxygen lancing.