为了控制低碳铝镇静钢中Al2O3夹杂物,并提升渣系对Al2O3夹杂物吸附能力,采用FactSage 8.1模拟计算CaO-SiO2-Al2O3-5％MgO-5％FeO渣系的等黏度图和等△ C/η(△C=CsAl2O3-CbAl2O3.η为渣的黏度)值线图.根据模拟计算图选取合适的五元精炼渣做Al2O3的吸附试验,试验研究了 Al2O3在CaO-SiO2-Al2O3-5％MgO-5％FeO渣系中的溶解速率,讨论了 Al2O3棒浸入深度、直径、转速、渣成分以及温度对Al2O3溶解速率的影响,求解了Al2O3在溶解过程中的活化能.最后,采用场发射扫描电子显微镜(Apreo S HiVac)对氧化铝棒与熔渣接触的界面处进行微区线元素的定性分析.研究结果表明,Al2O3在渣中的溶解速率受诸多因素的影响;溶解速率随氧化铝棒的旋转速度、棒直径、浸入深度和温度的增加而增加;溶解速率也会随着CaO含量的增加而增加,Al2O3和SiO2含量的增加而降低.溶解速率高度依赖于熔渣的黏度,渣的黏度对Al2O3的溶解速率呈负相关,Al2O3的溶解速率与浓度驱动力呈正相关.氧化铝棒溶解于渣系前,会先生成中间相CaO·2Al2O3和CaO·6Al2O3,中间相溶解在熔渣中,溶解于渣A中的表观活化能为410.9 kJ/mol.结合溶解速率图与等△C/η值线图进行对比,验证了Al2O3在渣中的溶解速率受渣物性的影响.
A12O3 dissolution into molten CaO-SiO2-Al2O3-MgO-FeO slags
In order to control the Al2O3 inclusions in low-carbon Al-killed steel and improve the adsorption capacity of the slag system to Al2O3 inclusions,the isoviscosity diagram of CaO-SiO2-Al2O3-5％MgO-5％FeO slag system and the contour map of △C/η(△C=CsAl2O3-CbAl2O3,η is the viscosity of slag)were simulated by FactSage 8.1.The dissolution rate of Al2O3 in CaO-SiO2-Al2O3-5％MgO-5％FeO slag system was studied.The effects of Al2O3 rod immersion depth,diameter,rotation speed,slag composition and temperature on the dissolution rate of Al2O3 were discussed.The activation energy of Al2O3 in the dissolution process was solved.Finally,the qualitative analy-sis of the micro-line elements at the interface between the alumina rod and the slag was carried out by field emission scanning electron microscopy(Apreo S HiVac).The results show that the dissolution rate of Al2O3 in slag is affect-ed by many factors.The dissolution rate increases with the increase of rotation speed,rod diameter,immersion depth and temperature of alumina rod.The dissolution rate also increases with the increase of CaO content,and de-creases with the increase of Al2O3 and SiO2 content.The dissolution rate is highly dependent on the viscosity of the slag.The viscosity of the slag is negatively correlated with the dissolution rate of Al2O3,and the dissolution rate of Al2 O3 is positively correlated with the concentration driving force.Before the alumina rod is dissolved in the slag system,it will be transformed into intermediate phases CaO·2Al2O3 and CaO·6Al2O3,and the intermediate phase is dissolved in the slag.The apparent activation energy of dissolution in slag A is 410.9 kJ/mol.The dissolution rate of Al2O3 in slag was verified by comparing the dissolution rate diagram with the contour diagram of △C/η.
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