拉曼光谱技术用于转炉渣中磷的结构行为的研究

Raman Spectroscopy Analysis for Microstructure Behavior of Phosphorus in Converter Slag

转炉脱磷过程通常被解释为钢水中的磷元素被氧化成五氧化二磷进入熔渣,而后又被氧化钙固定生成磷酸三钙。但对于熔融态转炉渣来说,上述磷酸盐并不真实存在,磷在熔渣会以含有一个PO双键的四面体形式存在。基于此,根据转炉炼钢过程熔渣成分的变化范围,采用拉曼光谱测定了CaO—SiO2—FexO—P2O5系熔渣的熔体结构,解析了磷在熔渣中的存在形式及转变行为,以期从微观角度解析转炉的脱磷机制,为优化脱磷条件提供指导。结果表明,随着渣中CaO和FeO总量的增加,熔渣中聚合程度较低的Q0(P),Q1(P)和Q0(Si),Q1(Si)含量升高,而聚合程度较高的Q2(P)和Q2(Si),Q3(Si)含量降低。另外,Fe—O—P和Si—O—P结构单元的含量也逐渐降低,当碱度为2.83时,Si—O—P和Fe—O—P结构消失。

The dephosphorization process of converter is usually considered that phosphorus in the molten steel is oxidized to P2O5 into the slag,and then fixed by CaO to Ca3(PO4)2.However,for molten converter slag,the above phosphate does not exist and phosphorus can exist as a tetrahedron containing a P≡O bond.Therefore,the structure of CaO—SiO2—FexO—P2O5 molten slag was examined by Raman spectroscopy,and the existence form and transformation behavior of phosphorus were further analyzed in terms of the variation of slag composition during the process of basic oxygen steelmaking.The results show that with the increasing total content of CaO and FeO,the molar fractions of Q0(P),Q1(P),Q0(Si)and Q1(Si)with lower degree of polymerization increase,and the molar fractions of Q2(P),Q2(Si)and Q3(Si)with higher degree of polymerization decrease.In addition,Si—O—P and Fe—O—P units also gradually decrease.The Si—O—P and Fe—O—P units disappear when the basicity of molten slag was 2.83.