The electro-calciothermic reduction of tantalum sulfide (TaS₂) was applied to open a new pathway for producing high-purity Ta powders applicable for tantalum electrolytic capacitors. The supplied electric charge was varied to electrochemically reduce the sulfide at 900 °C using Ca in molten CaCl₂−xCaS (x = 0.1, 0.5 mol%) salts. The cleaner TaS₂ could also be prepared via the highly efficient carbo-sulfidation of Ta₂O₅ using S₂ gas. The plate-like Ta particles with internal voids and coral structures were obtained through the electrochemical reduction of the sulfides. Sulfur removal was achieved rapidly from TaS₂. Ta powder with 0.08 mass% O and 0.01 mass% S was successfully produced from Ta₂O₅ via clean TaS₂. It was obtained by increasing the electric charge to two times higher than that required to generate the stoichiometric amount of Ca in the CaCl₂ melt. Therefore, the electrometallurgical reduction of TaS₂ could be a promising, cost-effective, and sustainable approach for producing high-purity Ta powders.

Graphical Abstract

中文翻译：

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通过高效电化学还原熔融CaCl 2中的TaS 2生产钽金属

硫化钽（TaS ₂）的电热还原法被用于开辟一条新途径，以生产适用于钽电解电容器的高纯度Ta粉。改变所提供的电荷以使用熔融的CaCl ₂ - x CaS（x  = 0.1，0.5 mol％）盐中的Ca在900°C下电化学还原硫化物。还可以通过使用S ₂气体对Ta ₂ O ₅进行高效碳硫化来制备更清洁的TaS ₂。通过硫化物的电化学还原获得具有内部空隙和珊瑚结构的板状Ta颗粒。从TaS ₂迅速实现了脱硫。通过清洁的TaS ₂由Ta ₂ O ₅成功地制造出具有0.08质量％的O和0.01质量％的S的Ta粉末。它是通过将电荷增加到比在CaCl ₂熔体中生成化学计量的Ca所需的电荷高两倍的电荷而获得的。因此，电冶金还原TaS ₂可能是生产高纯度Ta粉的一种有前途的，具有成本效益的和可持续的方法。

图形概要