摘要
铝提纯过程中高效去除Fe杂质存在困难,影响高纯度铝的进一步提纯。本试验研究了稀土元素La、Ce、Y和Yb添加对工业纯铝熔体中Fe杂质的影响,并综合分析其影响因素和机制。结果表明,稀土合金化可促进纯铝中杂质Fe的沉降以降低其含量,其中,Y和Yb效果更优,使Fe杂质最高降低接近40%。稀土可与Fe反应生成Al-Fe-RE化合物,结合RE/Fe原子比结果,利用第一性原理构建Al-Fe-RE化合物的稳定结构,分别为Al_(16)Fe_(2)La_(2)、Al_(17)FeCe_(2)、Al_(17)FeY_(2)和Al_(16)Fe_(2)Yb_(2),其密度大于铝熔体会沉淀在熔体的底部,有利于Fe杂质的去除。Al_(17)FeY_(2)和Al_(16)Fe_(2)Yb_(2)化合物的形成能更负,更易稳定生成,对Fe杂质的去除效果更佳。
The effective removal of Fe impurities during aluminum purification remains significant challenges,as it adversely affecting the further refinement of high-purity aluminum.This study systematically investigated the effects of rare earth elements(La,Ce,Y,and Yb)addition on Fe impurities in industrial pure aluminum melt,while comprehensively analyzing the influencing factors and underlying mechanisms.The results demonstrated that rare earth alloying promotes the sedimentation of Fe impurities in pure aluminum,thereby reducing their content.Notably,Y and Yb exhibited superior performance,achieving a maximum reduction in Fe impurities of nearly 40%.The rare earth elements reacted with Fe to form Al-Fe-RE intermetallic compounds.Based on the RE/Fe atomic ratio results,first-principles calculations were employed to determine the stable structures of these compounds,identified as Al_(16)Fe_(2)La_(2),Al_(17)FeCe_(2),Al_(17)FeY_(2),and Al_(16)Fe_(2)Yb_(2).Owing to their higher density than the aluminum melt,these compounds precipitate at the bottom of the melt,effectively facilitating the removal of Fe impurities.Among these compounds,Al_(17)FeY_(2) and Al_(16)Fe_(2)Yb_(2) exhibited more negative formation energies,indicating greater thermodynamic stability and easier formation,which contributed to their enhanced efficiency in Fe impurity removal.
作者
窦志昂
楼岳
吴剑
胡传彬
李永春
杜军
DOU Zhi-ang;LOU Yue;WU Jian;HU Chuan-bin;LI Yong-chun;DU Jun(School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China;Guangxi Guangtou High-Purity Aluminum Technology Co.,Ltd.,Hezhou 542899,Guangxi,China)
出处
《铸造》
2025年第11期1518-1523,共6页
Foundry
基金
广西重大科技专项(AA23023025)。
