Purification of lanthanum and cerium by plasma arc zone melting
Purification of lanthanum and cerium by plasma arc zone melting
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DOI：
10.1007/s10853-008-2449-9
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发表时间：
2008-02
影响因子：
4.5
通讯作者：
K. Mimura;Takanori Sato;M. Isshiki
中科院分区：
文献类型：
--
作者：
K. Mimura;Takanori Sato;M. Isshiki
研究了在常压下水平等离子体电弧区熔炼（PZM）和氩等离子体电弧加热提纯La和Ce的方法。在水冷铜缸上保持了一个稳定的La和Ce熔带，熔带通过后，杂质沿棒状物偏析。铁、铜、铝、硅等金属杂质沿区向移动，并在区熔棒头侧有效减少。特别是在La上观察到这些杂质的明显分离。此外，挥发性杂质，如Ca， Mg， Zn和Mn通过汽化被降低到更低的水平。对于非金属杂质，Ce中的O、N、C、S和La中的O、N向相反的区带方向移动，La中的C、S向区带方向移动。此外，在PZM过程中，整个棒材的非金属杂质都有所减少。因此，PZM可以充分提高La和Ce棒材头部周围的纯度。
Purification of La and Ce by a horizontal plasma arc-zone melting (PZM) with Ar plasma arc heating under atmospheric pressure was examined. A stable molten zone of La and Ce on the water-cooled copper hearth could be maintained and, after zone passes, the segregation of impurities along the bars was recognized. Metallic impurities such as Fe, Cu, Al, and Si moved in the zone direction and decreased efficiently at the head side of the zone-melted bars. Especially, remarkable segregations of those impurities were observed on La. In addition, volatile impurities such as Ca, Mg, Zn, and Mn were reduced to further low levels by vaporization. For non-metallic impurities, O, N, C, and S in Ce, and O and N in La moved in the opposite direction of zoning, while C and S in La moved in the zone direction. Furthermore, nonmetallic impurities were reduced unexpectedly along the whole bar during PZM. Consequently, the purity around the head side of La and Ce bars could be sufficiently increased with PZM.