Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 9 No. 2 June 1999|
———Electrochemical Study on Au-Fe Mix Anode in Alkaline Thiourea Solution Containing Na2SO3
（1 Department ofNonferrous Metallurgy,Central South University of Technology, Changsha 410083, P. R. China
2 Center for Integrated Research in Science and Engineering,Nagoya University, Nagoya 464, Japan）
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.
Key words: alkaline thiourea sodium sulfite mix anode of gold and iron