高纯铌的制备

Preparation of High-purity Niobium

详细讨论了各种杂质在铌提纯过程中的行为。指出萃取、电解精炼能有效地去除高熔点Ｔａ、Ｗ杂质；电子束精炼是去除一般金属杂质及低熔点杂质的常用手段；而超高真空退火则能使间隙固溶杂质的含量降低到很低的极限。并推荐了一种高纯铌制备工艺：Ｎｂ２Ｏ５萃取→ＮｂＯ５还原→电解精炼→电子束精炼→．电子束悬浮区域熔炼→超高真空退火→高纯铌．最后还介绍了三种新型精炼方法。

The behaviour of various impurity during Nb refiningdiscussed. It is pointed out that liquid/liquid extraction and moltensalt electrolysis refining can effectively remove refractory Ta and Winpurity while electron-beam refining is conventionaly used for ordinarymetal impuri ty and low-melting-point impurity. Ultra-high-vacuum annealing can minimize the content of intetstitial solid-solution impurity,Oneprocess for high-purity Nb preparation is recommended, ie: Nb2O5extracnon→Nb2O5 reduction→electrolytic refining→electron beam refining→zone melting by suspended electron beam→ultra-high vacuum annealing→high-impurity Nb. Three new refining processes are finally described.