关键词: 100t转炉, 提钒半钢, 低磷钢, 炉渣成分, 温度控制, 留渣+双渣法

Abstract: The chemical composition of semi-steel after extracted-vanadium from hot metal with 4. 28% 〜5. 02% C and 0. 19% ~0. 24% V is 3. 30% - 3. 80% C and ≤0. 037% V. The “slag-remaining + double slag” process is remaining the slag of previous heat, charging extracted vanadium semi-steel and 50 ~ 70 kg/t scrap, adding lime and dolomite, blowing for 5 ~6 min, then tapping slag, adding suitable lime and dolomite and continuous blowing to end. Results show that in early blowing period, with increasing slag basicity or liquid temperature, the dephosphorization rate of liquid earlier increases and later decreases, and with increasing (FeO) in slag the dephosphorization rate of liquid earlier increases and later is constant, and the optimal control conditions are slag basicity 3.0 ~3.5 , (FeO) 10.0% ~ 15.0% and liquid temperature at tapping slag 1480 ~ 1 510 ℃； in later blowing period, with increasing slag basicity the dephosphorization rate increases, while with increasing liquid temperature the dephosphorization rate decreases, the effect of (FeO) on dephosphorization is similar to that in the earlier blowing period, it is available to control the slag basicity 3. 5 ~ 4.0, (FeO) 8.0% ~ 10.0% and liquid temperature ≤1 630 °C at BOF blowing end and the dephosphorization rate is more than 90.0% ； and the liquid end [P] shall be controlled less than 0. 015% to meet the requirement for low phosphorus steel steelmaking.