转炉渣中磷的微观结构行为

Microstructure Behaviors of Phosphorus in Converter Slag

为了设计合理的转炉渣成分以达到满意的脱磷效果,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-SiO 2-Fe x O-P 2O 5系熔渣的熔体结构,并解析了磷在熔渣中的存在形式及转变行为.结果表明,熔渣中磷主要以桥氧数为0,1,2的磷氧四面体结构单元存在,并可进入硅氧四面体和铁氧四面体形成Si—O—P和Fe—O—P键.随着渣中CaO和FeO总量的增加,熔渣中聚合程度较低的Q 0(P),Q 1(P)和Q 0(Si),Q 1(Si)摩尔分数升高,而聚合程度较高的Q 2(P)和Q 2(Si),Q 3(Si)摩尔分数降低.另外,Fe—O—P和Si—O—P键的含量也逐渐降低,当碱度为2.83时,Si—O—P和Fe—O—P键消失.

To design a reasonal composition of converter slag and achieve a satisfactory dephosphorization ratio,the structures of CaO-SiO 2-Fe x O-P 2O 5 molten slags were 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 phosphorus in molten slags mainly exists in the forms of Q 0(P),Q 1(P)and Q 2(P).Meanwhile,phosphorus can enter the silica tetrahedron and ferrite tetrahedron,and occupy the locations of silicon and iron to form the Si—O—P and Fe—O—P bonds,respectively.With the increasing total content of CaO and FeO,the molar fractions of the Q 0(P),Q 1(P),Q 0(Si)and Q 1(Si)with lower-degree polymerization increase,while the molar fractions of Q 2(P),Q 2(Si)and Q 3(Si)with higher-degree one decrease.In addition,Si—O—P and Fe—O—P bonds also gradually decrease.The Si—O—P and Fe—O—P bonds disappear,when the basicity of molten slag was 2.83.