CeO_(2)含量对CaO-Al_(2)O_(3)精炼渣熔化性能的影响  

Effect of CeO_(2) Content on Melting Performance of CaO-Al_(2)O_(3) Refining Slag

作　　者：赵博[1] 吴伟[1] 智建国[2,3] 宿成 武利平 Zhao Bo;Wu Wei;Zhi Jianguo;Su Cheng;Wu liping(Metallurgical Technology Insti-tute,Central Iron and Steel Research Institute Co.Ltd.,Beijing 100081,China;Technical Center of Inner Mongolia Baotou Steel Union Co.,Ltd.,Baotou 014010,China;Inner Mongolia Enter-prise Key Laboratory of Rare Earth Steel Products Research and Development,Baotou 014010,China;State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]钢铁研究总院有限公司冶金工艺研究所,北京100081 [2]内蒙古包钢钢联股份有限公司,内蒙古包头014010 [3]内蒙古自治区稀土钢产品研发企业重点实验室,内蒙古包头014010 [4]北京科技大学钢铁冶金新技术国家重点实验室,北京100083

出　　处：《中国稀土学报》2023年第5期975-985,I0004,共12页Journal of the Chinese Society of Rare Earths

基　　金：中央引导地方科技发展资金项目(2020ZY0034);包头市科技计划资助项目(XM2021CXZX01);北京市自然科学基金面上项目(2222040)资助。

摘　　要：精炼渣中加入稀土氧化物,具有吸附Al_(2)O_(3)夹杂物、提高精炼工艺的脱氧率和减小夹杂物尺寸的作用,但是CeO_(2)含量对炉渣熔化性能的影响机制仍不明确。采用XRD和扫描电镜等分析测试手段对CaO-Al_(2)O_(3)-CeO_(2)炉渣微观结构进行了表征,随着炉渣中Ce O_(2)含量增高,12CaO·7Al_(2)O_(3),CaO·Al_(2)O_(3)以及3Ca O·Al_(2)O_(3)含量减少,2CaO·Ce_(2)O_(3)·Al_(2)O_(3)含量增加。采用热分析仪对炉渣熔化温度进行了测量,发现随着CeO_(2)含量的增加,炉渣熔化温度先下降后增加,吸热峰面积呈现整体减小趋势,由200.65 J·g^(-1)下降到57.36 J·g^(-1),表明炉渣的低熔点矿相结构比例生成趋势降低,生成量减少。采用质量作用浓度模型,研究炉渣中加入CeO_(2)后组元活度的变化规律;结果表明:随着CeO_(2)加入量的增加,CaO活度先增加后减少,Al_(2)O_(3)和铝酸钙类化合物(xCaO·y Al_(2)O_(3))的活度逐渐减少,Ce_(y)O_(x)和稀土复合化合物(xCaO·yCe_(2)O_(3)·z Al_(2)O_(3))活度逐渐增加。采用BP神经网络建立炉渣成分活度与熔化温度之间的回归模型,采用组元活度预测炉渣的熔化温度,模型拟合精度较高,并以MIV算法为基础,评价了各组元对熔化温度的累计贡献率,为炉渣的优化提供了理论基础。Adding rare earth oxides in refining slag can adsorb Al_(2)O_(3) inclusions,improve the deoxidization rate of refining process and reduce the size of inclusions.However,the influence mechanism of CeO 2 content on the melting performance of slag is still unclear.In this paper,the microstructure of CaO-Al_(2)O_(3)-CeO_(2) slag was charac⁃terized by XRD and SEM.With the increase of CeO_(2) content in slag,the contents of 12CaO·7Al_(2)O_(3),CaO·Al_(2)O_(3) and 3CaO·Al_(2)O_(3) decreases,and the content of 2CaO·Ce_(2)O_(3)·Al_(2)O_(3) increases.The melting temperature of the slag was measured by a thermal analyzer.With the increase of CeO_(2) content,the melting temperature of the slag decreases first and then increases,and the heat absorption shows an overall downward trend,from 200.65 to 57.36 J·g^(-1),indicating that the proportion of low melting point mineral phase structure of the slag decreases and the production decreases.The mass concentration model was used to study the change rule of component activity after adding CeO_(2) in slag.The results show that with the increase of CeO_(2) addition,the activity of CaO increases first and then decreases,the activity of Al_(2)O_(3) and calcium aluminate compounds(xCaO·yAl_(2)O_(3))decreases grad⁃ually,and the activity of Ce_(y)O_(x) and rare earth compound(xCaO·yCe_(2)O_(3)·zAl_(2)O_(3))increases gradually.The regres⁃sion model between slag composition activity and melting temperature was established by using BP neural net⁃work.The model has high fitting accuracy and can meet the prediction requirements.Based on the MIV algo⁃rithm,the cumulative contribution rate of each component to the melting temperature was evaluated,which pro⁃vides a theoretical basis for the optimization of slag.

关 键 词：熔化性能 精炼渣 稀土氧化物 共存理论 BP神经网络 MIV算法 

分 类 号：TF769[冶金工程—钢铁冶金]