基于高FeO转炉渣的钢液脱磷行为

 为了研究在转炉冶炼中高FeO转炉渣条件下钢液的脱磷行为,采用双联法在某钢厂300 t脱磷转炉上展开高氧化性转炉渣脱磷工业试验。通过理论分析并结合XRD、拉曼光谱分析等手段,研究了脱磷温度、转炉渣矿相结构以及终渣成分等因素对高FeO转炉渣条件下钢液的脱磷的影响。通过热力学公式计算发现,脱磷转炉最佳理论脱磷温度约为1 675 K。对比分析了不同脱磷效果的转炉渣的矿相结构,结果表明,2CaO·SiO₂和3CaO·P₂O₅矿相结构有利于脱磷反应的进行,3CaO·SiO₂对脱磷效果的影响不明显;Si—O—Si键和FeO₄]键特征峰面积越大,Q0和Q2单元特征峰面积越小,脱磷效果越好。最后研究了脱磷炉钢液脱磷率≥60%时终渣成分的最佳控制工艺参数,碱度R为1.05～1.30,w(FeO])为33%～37%,w(MgO])≤3.0%,w(MnO])为4.3%～5.4%。本研究可以为钢铁企业采用双联法开发超低磷钢提供理论依据和技术指导。

Dephosphorization behavior of molten steel based on high FeO converter slag

In order to study the dephosphorization behavior of molten steel under the condition of high FeO converter slag, the industrial test of dephosphorization with high oxidizing converter slag was carried out on a 300 t dephosphorization converter of a steel plant by the duplex method. The influence of dephosphorization temperature, phase structure of converter slag and final slag composition on the dephosphorization of molten steel under high FeO converter slag was studied by means of theoretical analysis and XRD and Raman spectrum analysis. Through thermodynamic formula calculation, it is found that the optimal theoretical dephosphorization temperature of the converter is about 1 675 K. The mineral phase structures of the converter slag with different dephosphorization effects were compared and analyzed. The results showed that the mineral phase structures of 2CaO·SiO₂ and 3CaO·P₂O₅ were conducive to the dephosphorization reaction, while the influence of 3CaO·SiO₂ on the dephosphorization effect was not obvious. The larger the characteristic peak area of Si—O—Si and FeO₄], the smaller the characteristic peak area of Q0 and Q2 units, the better the dephosphorization effect. Finally, the optimum process parameters for controlling the final slag composition when the dephosphorization rate of molten steel in dephosphorization furnace is ≥60% are as follows, basicity R=1.05-1.30, w(FeO])=33%-37%, w(MgO])≤3.0%, w(MnO]) =4.3%-5.4%. This study can provide a theoretical basis and technical guidance for iron and steel enterprises to develop ultra-low phosphorus steel by the double method.