BaCO_3基熔剂对锰铁熔体脱磷的实验研究

Experimental Study on Dephosphorization of Ferromanganese Melt by BaCO_3-based Flux

1 30 0℃时 ,在硅钼棒炉中采用BaCO3 BaF2 MnO2 系熔剂对 [Si]i=0 .0 84 %～ 0 .2 4 5 %的锰铁合金进行脱磷实验。结果表明 ,只要改变渣系组成和脱磷处理时间适当 ,对不同硅质量分数的锰铁合金均可获得 5 0 %以上的脱磷率。采用BaCO3 (6 0 %～ 70 % ) BaF2 (10 % ) MnO2 (2 0 %～ 30 % )渣系脱磷时 ,锰的氧化损失为负值。脱磷保锰的最佳处理时间为 10～ 15min ,脱磷过程中熔体氧位在5min内迅速上升到一定值 ,5min后氧位在很窄的范围内波动。改变渣系组成 :MnO2 从 30 %降至10 % ,BaCO3 从 6 0 %增至 80 % ,对熔剂的最大脱磷率和其对应的氧位影响不大 ,最大脱磷率为4 9.1%～ 5 6 .2 % ,对应氧位在 0 .35× 10 -6～ 0 .5 0× 10 -6之间变化。

Experiments are performed on dephosphorization of the ferromanganese melt containing 0.084% ～ 0.245% i with BaCO 3-BaF 2-MnO 2 flux in a MoSi 2 furnace at 1300℃. The results show that more than 50% dephosphorization rate can be achieved for the ferromanganese with various Si content provided that the dephosphorization time is properly governed and the flux composition rationally readjusted. No manganese is found to have been lost during dephosphorization with BaCO 3(60%～70%)-BaF 2(10%)-MnO 2(20%～30%) flux. The optimum time for dephosphorization without any Mn loss is assumed to be about 10 to 15 minutes. In the process of dephosporization the oxygen potential in the ferromanganese melt with swiftly rise to a certain level in 5 minutes and then fluctuate within a narrow range. Readjustment of the flux constituents i.e. decrease of MnO 2 content to 10% from 30% and increase in BaCO 3 content to 80% from 60% shows little influence on the maximum dephosphorization rate of the flux as well as on the oxygen potential. The oxygen potential relative to the maximum dephosphorization rate will change within the range of 0.35 ×10~ -6 to 0.50 ×10~ -6 .