含Ce_2O_3渣系作用浓度的计算模型

Calculating model of action concentration of slag systems containing Ce_2O_3

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。

In order to investigate the effect of addition of Ce203 to refining slag on the activity of Al2O3, thermodynamic model for the evaluation of mass action concentrations for Ce203-Al2O3 and CaO-Al2O3-Ce203 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 Ce203 on the action concentration of Al：O3 was investigated. The results show that, for Ce203-Al2O3 slag system, when the mole fraction of Ce203 is 0.49, the mass action concentration （Ni） of Ce2Oa＇Al2O3 achieves its maximum value 0.90, and both the mass action concentrations of Ce^O3 and Al2O3 maintain at very low levels. For CaO-Al2O3-Ce203 slag system, the change trends of calculated NAl2O3 are in good agreement with reported measured trends of aAl2O2 which are that Nal203 decreases with the increase of w（CaO）/w（Al2O3） at a certain content of Ce203 and with the increase of Ce203 content at a certain value of w（CaO）/w（Al2O3）. Moreover, the iso-curves Nce2% and Nca0 are also drawn from the calculated results. Above all, adding certain content of Ce203 to refining slag can effectively reduce NA[203 , which can improve the Al203 inclusions removal efficiency of high grade clean steel and refining efficiency of refining slag.