The dissolution of alumina-based refractory ceramics in CaO-Al2O3-SiO_(2)slag melts was performed based on the in-situ observation system of an ultra-high-temperature laser confocal microscope,and the effect of the Ca...The dissolution of alumina-based refractory ceramics in CaO-Al2O3-SiO_(2)slag melts was performed based on the in-situ observation system of an ultra-high-temperature laser confocal microscope,and the effect of the CaO/SiO_(2)slag mass ratio(C/S ratio)on the dissolution rate of alumina-based refractory ceramics was investigated.The results indicate that the dissolution rate increases with an increase of the C/S ratio and is mainly controlled by diffusion.During the early stage of dissolution,for all C/S ratios,the dissolution process conforms to the classical invariant interface approximation model.During the later stage of dissolution,when the C/S ratio is≥6,the dissolution process is significantly different from the model above because of the formation of a thick interfacial layer,which can be explained by dissolution kinetics.展开更多
基金supported by the National Natural Science Foundation of China(52272022)the Special Project of Central Government for Local Science and Technology Development of Hubei Province(2019ZYYD076)the Innovation and Entrepreneurship Fund of Wuhan University of Science and Technology(D202202171045002669).
文摘The dissolution of alumina-based refractory ceramics in CaO-Al2O3-SiO_(2)slag melts was performed based on the in-situ observation system of an ultra-high-temperature laser confocal microscope,and the effect of the CaO/SiO_(2)slag mass ratio(C/S ratio)on the dissolution rate of alumina-based refractory ceramics was investigated.The results indicate that the dissolution rate increases with an increase of the C/S ratio and is mainly controlled by diffusion.During the early stage of dissolution,for all C/S ratios,the dissolution process conforms to the classical invariant interface approximation model.During the later stage of dissolution,when the C/S ratio is≥6,the dissolution process is significantly different from the model above because of the formation of a thick interfacial layer,which can be explained by dissolution kinetics.
文摘为了控制低碳铝镇静钢中Al_(2)O_(3)夹杂物,并提升渣系对Al_(2)O_(3)夹杂物吸附能力,采用FactSage 8.1模拟计算CaO-SiO_(2)-Al_(2)O_(3)-5%MgO-5%FeO渣系的等黏度图和等ΔC/η(ΔC=C_(Al_(2)O_(3))^(s)-C_(Al_(2)O_(3))^(b),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Al_(2)O_(3)的吸附试验,试验研究了Al_(2)O_(3)在CaO-SiO_(2)-Al_(2)O_(3)-5%MgO-5%FeO渣系中的溶解速率,讨论了Al_(2)O_(3)棒浸入深度、直径、转速、渣成分以及温度对Al_(2)O_(3)溶解速率的影响,求解了Al_(2)O_(3)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,Al_(2)O_(3)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,Al_(2)O_(3)和SiO_(2)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Al_(2)O_(3)的溶解速率呈负相关,Al_(2)O_(3)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·2Al_(2)O_(3)和CaO·6Al_(2)O_(3),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ΔC/η值线图进行对比,验证了Al_(2)O_(3)在渣中的溶解速率受渣物性的影响。
