Abstract: In order to achieve less slag of “Full-Tri-de” smelting process, new technology which was study on dephosphorization converter using recycling of hot steel slag of decarburization converter was employed to further reduce material consumption of semi steel smelting process  by Shougang Jingtang. The dephosphorizing ability and recyclability of hot steel slag of decarburization converter were analysised. Simultaneously, the effect of hot steel slag on slag forming path and application effects in dephosphorization converter were investigated. The results show that average consumption of 1.6－2.4 t lime was saved through recycling hot steel slag 10－15 t per ladle. If silicon mass fraction in molten iron is lower than 0.15 %, lime could not be added to dephosphorization furnace. The consumption of 2.4 kg/t iron and steel raw material was correspondingly cut. Meanwhile, lightburned dolomite and fluorite as burden materials were eliminated in dephosphorization furnace. The endpoint phosphrous content was almost the same with the normal operation after adopting recycling of hot steel slag of decarburization converter. At the same time, the heat loss could be reduced by using sensible heat of converter hot slag.

Key words: hot metal pretreatment, dephosphorization converter, hot steel slag, resource utilization