DISSOLUTION THEORY OF GOLD IN ALKALINE THIOUREA SOLUTION (Ⅱ)———Electrochemical Study on Au-Fe Mix Anode in Alkaline Thiourea Solution Containing Na₂SO₃

来源期刊：中国有色金属学报(英文版)1999年第2期

论文作者：Chai Liyuan Masazumi Okido

文章页码：393 - 398

Key words：alkaline thiourea,　sodium sulfite,　mix anode of gold and iron

Abstract: Anodic polarization behavior of Au-Fe mix electrode has been examined in the thiourea solution containing Na₂SO₃. It was shown that the polarization characteristics of gold is incarnated in the alkaline thiourea solution and the polarization characteristics of iron is reflected in the acidic thiourea solution. Also iron decreases the apparent activation energy of gold dissolution and accelerates the dissolution of gold in the alkaline thiourea solution containing Na₂SO₃ because of galvanic electrode couple effect between gold and iron. The factors affecting selective dissolution of gold of Au-Fe mix anode in the thiourea solution containing Na₂SO₃ were also investigated by electrolysis, and the optimum condition was obtained. The dissolved mass of gold with the exposed area of 1.0 cm² reached 350g/m³ within 30min, and that of iron was zero, in 0.1mol/L thiourea solution containing 0.5 mol/L Na₂SO₃, at potential 0.34 V, pH 12.5 and temperature 323 K.