低碳铝镇静钢转炉炼钢低温脱磷工艺

Low temperature dephosphorization process of low carbon aluminum killed steel in converter

对转炉脱磷进行热力学与动力学分析,介绍了低碳铝镇静钢转炉低温脱磷生产工艺,对该生产工艺过程参数进行了统计分析,并对过程炉渣进行了SEM、EDS、XRD分析。结果表明:通过降低平均出钢温度至1617℃,碱度控制在2.4~3.0,TFe质量分数控制在12%~15%,转炉后期脱磷效率大大加强,冶炼后期调渣后TSC阶段渣钢磷分配比在50~120之间,TSO阶段磷分配比在100~300之间。转炉终点炉渣中固磷矿相主要是15CaO·6SiO_(2)·P_(2)O_(5),其中P_(2)O_(5)主要集中在块状2CaO·SiO_(2)~3CaO·SiO_(2)相中,而针状Fe-Mg-Mn的氧化物相中基本没有P_(2)O_(5),冶炼后期通过适当延长低枪位-大氧气流量冶炼时间来回收渣中部分铁,对脱磷影响不大。

The low temperature dephosphorization process to produce low carbon aluminum killed steel in converter was introduced based on thermodynamic and kinetic analysis of dephosphorization.The process parameters were statistically analyzed,and the slag was analyzed by SEM,EDS and XRD.The results show that the efficiency of dephosphorization is enhanced in the late stage of converter by reducing the tapping temperature to 1617℃,and controlling basicity in 2.4-3.0 and TFe in 12 mass%-15 mass%.The phosphorus distribution ratio of slag and steel in TSC stage is 50-120,and that in TSO stage is 100-300.The solid phosphate phase in converter terminal slag is mainly 15CaO·6SiO_(2)·P_(2)O_(5),and P_(2)O_(5) is mainly concentrated in 2CaO·SiO_(2)-3CaO·SiO_(2) block phase,However,there is no P_(2)O_(5) in the oxide phase of Fe-Mg-Mn with acicular sharp,which means prolong the smelting time by lower lance position and larger oxygen flow to recover some of the ferrous from the slag has little effect on dephosphorization in the late of converter.