Study On The Electro-Refining Of Tin In Acid Solution From Electronic Waste

• Main Authors: Son Seong Ho, Park Sung Cheol, Kim Jin Hwa, Kim Yong Hwan, Lee Man Seung, Ahn Jae-Woo
• Format: Article
• Language: English
• Published: Polish Academy of Sciences 2015-06-01
• Series: Archives of Metallurgy and Materials
• Subjects: Electro-refining; Tin; Electronic waste; Recycling; High purity
• Online Access: http://www.degruyter.com/view/j/amm.2015.60.issue-2/amm-2015-0101/amm-2015-0101.xml?format=INT

The tin metal could be retractable from wasted tin scrap, sludge, and wasted electroplated solution hydrometallurgical treatment, and purification process. In order to be used as resource of electronic devices, the retracted crude metal should be purified to the extent of higher than 99.9%. In this study, tin electro-refining process was performed to purify the casted tin crude metal at various experimental conditions: at the current density of 3, 5A/dm2, and in various electrolytes such as hydrochloric acid, sulfuric acid and methansulfonic acid. Additional experiment was conducted using Rotating Disk Electrode (RDE) in order to investigate the rate determining step of tin electro-refining process. The current efficiency, 65.6%, was achievable at the condition of current density, 5A/dm2, and in the electrolyte of Hydrochloric acid. During tin electro-refining process, impurity dissolved from tin crude metal into the electrolyte was analyzed using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), and the result showed the concentration of impurity metal gradually increased. Quantitative analysis on casted tin crude metal showed that it consists of tin with 93.9 wt.% and several impurity metals of Ag, Bi, Pb, Cu, and etc. After tin electro-refining process, the purity of tin increased up to 99.985 wt.%.