氯化物熔体中镱铜中间合金的形成和电解制备

FORMATION OF Yb Cu ALLOY AND ITS PREPARATION BY ELECTROLYSIS IN MOLTEN CHLORIDES

利用线性扫描伏安法研究了Ｙｂ（Ⅲ）在等摩尔ＮａＣｌＫＣｌ熔体中Ｃｕ电极上还原的电化学行为及扩散系数。结果表明：Ｙｂ（Ⅲ）第一步可逆还原为Ｙｂ（Ⅱ），Ｙｂ（Ⅱ）进一步还原并与Ｃｕ形成合金：Ｙｂ３＋＋ｅ＝Ｙｂ２＋，Ｙｂ２＋＋２ｅ＋ｎＣｕ＝ＹｂＣｕｎ。测定了Ｙｂ（Ⅲ）和Ｙｂ（Ⅱ）在９７３ＫＮａＣｌＫＣｌ熔体中的扩散系数分别为１．５×１０－５和１．０×１０－５ｃｍ２·ｓ－１。用自耗阴极法在１１２３Ｋ，阴极电流密度２０Ａ·ｃｍ－２。

Linear sweep voltammetry has been used to study the redox of Yb(Ⅲ) in equimolar NaCl KCl melt on the Cu cathode. It is reasonable to presume that the reduction of Yb(Ⅲ) to Yb(Ⅱ) is reversible on Cu electrode at first step and Yb(Ⅱ) is reduced to form alloy with Cu on Cu electrode surface: Yb 3+ +e=Yb 2+ , Yb 2+ +2e+ n Cu=YbCu n . The diffusion coefficients of Yb(Ⅲ) and Yb(Ⅱ) in NaCl KCl melt at 973 K are 1.5×10 -5 and 1.0×10 -5 cm 2·s -1 , respectively. The Yb Cu alloy was prepared by consumable cathode in molten chlorides. The Yb Cu alloy contains about 15% of Yb.