Abstract: Aiming at the low dephosphorization rate caused by insufficient heat and slag-forming difficulty in low silicon molten iron steel-making of converter, through industrial trials, the relationships among the temperature at end point of different hot metal silicon content in the smelting process, the amount of thermal agent-ferrosilicon, the amount of scrap and ore were studied, and the KR silicon increasing technology and converter slagmaking technology of adding silica were combined. The results show that the chemical heat of hot metal is less when ferrosilicon is added into converter, and the furnace temperature rises slowly in the early stage. The addition amount of lime is less, and it is difficult to melt, which is bad for the formation of slag and dephosphorization process. However, ferrosilicon is well melted in KR device, and the absorption rate is close to 100 %. The dephosphorization rate of the hot metal with low Si mass fraction (≤0.3 %) increases from 82.3 % to 87.7 %. This can provide a theoretical guidance and technical reference for the dephosphorization process of hot metal with low Si content.

Key words: low silicon hot metal, KR silicon increasing, slagging, dephosphorization effect