Article ID Journal Published Year Pages File Type
1624775 Journal of Alloys and Compounds 2008 9 Pages PDF
Abstract

A new niobium (Nb) powder production process based on the reduction of electrochemically dissolved niobium ions (Nbn+) by dysprosium divalent ions (Dy2+) in the NaCl–KCl–MgCl2–DyCl2 molten salt was investigated. Nbn+ ions – feed material – were continuously supplied into the molten salt by the anodic dissolution of a Nb rod. They were subsequently reduced in situ by Dy2+ ions – reductant – in the salt to produce Nb powder. The Dy3+ ions generated were reduced to Dy2+ ions by electrochemical or magnesiothermic reduction at the cathode (liquid Mg–Ag alloy). Fine and uniform Nb powder with a purity of around 99 mass% was successfully obtained under a specific condition. Further, it was found that the reaction time had a small influence on the particle size of the powder. A possible reaction pathway of the reduction of Nbn+ ions by Dy2+ ions in the molten salt was discussed with the aid of an isothermal chemical potential diagram of the Nb–Dy–Cl system at 1000 K.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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