(北京科技大学 冶金与生态工程学院 钢铁冶金新技术国家重点实验室,北京 100083)
摘 要: 为研究精炼渣中Ce2O3的加入对渣中Al2O3活度的影响,根据炉渣结构离子与分子共存理论和相关相图,建立1 500 ℃下Ce2O3-Al2O3和CaO-Al2O3-Ce2O3渣系作用浓度的计算模型,考察Ce2O3对Al2O3作用浓度的影响。结果表明:对于Ce2O3-Al2O3渣系,当Ce2O3的摩尔分数在0.49左右时,Ce2O3·Al2O3的作用浓度达到最大值0.90,使得Al2O3和Ce2O3的作用浓度均达到较低水平;对于CaO-Al2O3-Ce2O3渣系,模型所计算的Al2O3作用浓度与实测Al2O3活度的变化趋势一致,即Ce2O3含量一定时,随着w(CaO)/w(Al2O3)的增加,Al2O3的作用浓度降低;保持w(CaO)/w(Al2O3)不变,随着Ce2O3含量的增加,Al2O3的作用浓度降低。同时,由计算结果绘出CaO和Ce2O3的等作用浓度线。总之,精炼渣中添加一定量的Ce2O3能够有效地降低Al2O3的作用浓度,这能提高精炼过程中高质量洁净钢中Al2O3的去除速率和精炼渣的精炼效率。
关键字: Ce2O3-Al2O3;CaO-Al2O3-Ce2O3;共存理论;作用浓度;活度;计算模型
(State Key Laboratory of Advanced Metallurgy, School of Metallurgical and Ecological Engineering,
University of Science and Technology Beijing, Beijing 100083, China)
Abstract:In order to investigate the effect of addition of Ce2O3 to refining slag on the activity of Al2O3, thermodynamic model for the evaluation of mass action concentrations for Ce2O3-Al2O3 and CaO-Al2O3-Ce2O3 slag systems was formulated at 1 500 ℃ according to the ion and molecule coexistence theory (IMCT) for molten slags and corresponding phase diagrams, and the effect of Ce2O3 on the action concentration of Al2O3 was investigated. The results show that, for Ce2O3-Al2O3 slag system, when the mole fraction of Ce2O3 is 0.49, the mass action concentration (Ni) of Ce2O3?Al2O3 achieves its maximum value 0.90, and both the mass action concentrations of Ce2O3 and Al2O3 maintain at very low levels. For CaO-Al2O3-Ce2O3 slag system, the change trends of calculated are in good agreement with reported measured trends of ,which are that decreases with the increase of w(CaO)/w(Al2O3) at a certain content of Ce2O3 and with the increase of Ce2O3 content at a certain value of w(CaO)/w(Al2O3)。Moreover, the iso-curves and are also drawn from the calculated results. Above all, adding certain content of Ce2O3 to refining slag can effectively reduce , which can improve the Al2O3 inclusions removal efficiency of high grade clean steel and refining efficiency of refining slag.
Key words: Ce2O3-Al2O3; CaO-Al2O3-Ce2O3; coexistence theory; action concentration; activity; calculating model