Impurity distribution in metallic dysprosium during distillation purification
来源期刊：Journal of Rare Earths2016年第9期
论文作者：张小伟 苗睿瑛 李传军 吴道高 闫缓 王志强 陈德宏 颜世宏 李宗安
文章页码：924 - 930
摘 要：The distribution rules of impurities contents in distilled metallic dysprosium were researched,and a theoretical analysis was carried out.The research results indicated that,the content of impurity in distilled metal,such as Al and Fe,was lower in the initial stage,increased slowly in the middle stage,and increased rapidly in the last stage during the process of distillation purification.The calculated method of separation coefficient of impurity in crude metal by content of impurity in distilled metal was not suitable for high pure metals,and the modified separation coefficient was proposed,and it equaled 1/6.1 and 1/16.9 for impurity Al and Fe.The physical process of distillation was coincident with that of solidification essentially,and solute re-distribution theory in solidifying front could be used to describe the impurity distribution near evaporating surface.In the former stage of distillation purification,the diffusion of impurity in liquid metal could reach a quasi-equilibrium state,the calculated result of impurity content in distilled metal agreed well with experiments.In the latter stage of distillation process,the diffusion rate of impurity in liquid metal decreased,and the content in distilled metal was larger than the calculated result.
张小伟1，苗睿瑛1，李传军2，吴道高1，闫缓1，王志强1，陈德宏1，颜世宏1，李宗安1
1. National Engineering Research Center for Rare Earth Materials,General Research Institute for Nonferrous Metals,and Grirem Advanced Materials Co.Ltd.2. Otto Schott Institute of Materials Research,Friedrich Schiller University Jena
摘 要：The distribution rules of impurities contents in distilled metallic dysprosium were researched,and a theoretical analysis was carried out.The research results indicated that,the content of impurity in distilled metal,such as Al and Fe,was lower in the initial stage,increased slowly in the middle stage,and increased rapidly in the last stage during the process of distillation purification.The calculated method of separation coefficient of impurity in crude metal by content of impurity in distilled metal was not suitable for high pure metals,and the modified separation coefficient was proposed,and it equaled 1/6.1 and 1/16.9 for impurity Al and Fe.The physical process of distillation was coincident with that of solidification essentially,and solute re-distribution theory in solidifying front could be used to describe the impurity distribution near evaporating surface.In the former stage of distillation purification,the diffusion of impurity in liquid metal could reach a quasi-equilibrium state,the calculated result of impurity content in distilled metal agreed well with experiments.In the latter stage of distillation process,the diffusion rate of impurity in liquid metal decreased,and the content in distilled metal was larger than the calculated result.
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