熔体结构对钢包渣脱氧速率的影响

摘要

The effect of silicate melt structure on deoxidization velocity of ladle slag was studied using the lade slag deoxidization experiment. The results show that the initial denxidization rate is affected by the original content and basicity of Al2O3. And the diffusion of iron ions is the controlling factor of deoxidization reaction. With the increase of Al2O3 content, the polymerization degree of molten slag increases, the viscosity increases and the average diffusion diameter of iron ions decreases, thereby the diffusion coefficient of iron ions increases then decreases when exceeding a critical Al2O3 content; with the increase of basicity, the polymerization degree of molten slag decreases, the viscosity decreases and the average diffusion diameter of iron ions increases, so the diffusion coefficient of iron ions increases then decreases when basicity exceeds a critical value. The variation tendencies of initial deoxidization rate is in coincide with diffusion coefficient of iron ions. To enhance the deoxidization rate of ladle slag, the composition of ladle slag should be modified with w(CaO)/w(SiO2)=4-5, w(Al2O3)=1 8％-20％ before LF refining.%采用熔渣脱氧实验、动力学分析和实验渣熔体结构分析,对熔体结构对钢包渣脱氧速率的影响进行研究.研究结果表明:初始Al2O3的质量分数和碱度(二元碱度,w(CaO)/w(SiO2))对熔渣初始脱氧速率具有重要影响:铁离子扩散是熔渣脱氧反应的控制环节;随A1203的质量分数的提高,熔渣聚合程度增强,黏度升高,铁离子平均扩散直径减小,铁离子扩散系数先增大后减小;随着碱度增大,熔渣聚合程度减弱,黏度降低,铁离子平均扩散直径增大,铁离子扩散系数也呈先增大后减小的趋势;铁离子扩散系数变化趋势与熔渣初始脱氧速率变化趋势相一致.为提高LF精炼过程钢包渣脱氧速率,LF(Ladle fumace)精炼前铡包渣改质的成分调整控制目标为:w(CaO)/w(SiO2)=4～5,w(Al2O3)=18%～20%.