Production of Fine Tantalum Powder by Electronically Mediated Reaction (EMR)

Abstract

Production of fine tantalum powder by calciothermic reduction of tantalum oxides (<TEX>$Ta_{2}O_5$</TEX>) pellet through an electronically mediated reaction (EMR) has been investigated. <TEX>$Ta_{2}O_5$</TEX> pellet feed and reductant calcium-nickel (Ca-Ni) alloy were charged into electronically isolated locations in a molten <TEX>$CaCl_2$</TEX> bath. The current flow through an external path between the feed (cathode) and reductant (anode) locations was monitored. The current approximately 4.7A was measured during the reaction in the external circuit connecting cathode and anode location. Tantalum powder with approximately 99 <TEX>$mass\%$</TEX> purity was readily obtained after each experiment. Tantalum powder by EMR using <TEX>$Ta_{2}O_5$</TEX> pellet feed was fine compared with that of metal powder by metallothermic reduction and EMR using <TEX>$Ta_{2}O_5$</TEX> powder feed.