METHOD FOR DESILICONIZING PIG IRON BEFORE REFINING IT TO STEEL

摘要

The invention relates to a method for desiliconizing pig iron before subsequent refining to steel. According to said method liquid steel slag is deposited onto the tapped molten pig iron slag and possibly the molten blastfurnace slag at a quantity corresponding to the silicon content of the pig iron and the iron and/or chromium oxide content of the slag after blast furnace tapping. The quantity of steel slag is chosen such that the silicon content of the pig iron is reduced to less than 0.5 weight % with a simultaneous increase in the SiO2 content of the slag and a reduction in the iron and/or chromium oxides of the liquid metal slag. The temperature of the slag iron bath is maintained at below 1,500 ~C.