HOT METAL PRETREATING METHOD

摘要

PURPOSE: A hot metal pretreating method is provided which obtains superior pretreatment effect of hot metal by injecting ladle slag into hot metal as flux during pretreatment of hot metal and recycles steelmaking byproduct disused by using the ladle slag generated as a byproduct from the steelmaking process. CONSTITUTION: In a method for pretreating hot metal by injecting sintered ore into a reaction container containing hot metal at a time point corresponding to less than 20% of the total pretreatment time and injecting quicklime (CaO) into hot metal during pretreatment, the hot metal pretreating method is characterized in that ladle slag containing 35 to 45 wt.% of CaO, 5 to 15 wt.% of SiO2 and 20 to 35 wt.% of Al2O3 is injected into the reaction container at the time point corresponding to less than 20% of the total pretreatment time so that basicity (CaO/SiO2) of slag produced on the hot metal becomes 1.2 to 1.7, wherein an injection quantity of the ladle slag satisfies a value determined by the following mathematical expression 1: injection quantity of ladle slag(kg)={hot metal quantity(ton)xhot metal£Si|(wt.%)x3-CaO injection quantity(kg)}x4.