| Popis: |
Waste mobile phone has become the largest number of electronic waste, and recycling of metals from mobile phone would ensure resource recycling and reduce environmental degradation. Based on the contents of metals analyzed by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), containing copper and precious metals such as gold, the paper compared the extraction processes of gold, copper from waste mobile phone printed circuit board (PCB). In this study, two processes, nitric acid and thiourea (NT), sulfuric acid-hydrogen peroxide and iodine (SAHPI) were used to leach copper and gold, respectively. The recovery rate of copper was found to be 96.42%, and 94.3% of the gold was leached in the former process. Similar trends were obtained for the leaching of copper and gold in the latter process, but it was lower that about 95.27% of copper was recycled, while 93.4% of gold were leached. Both the two processes were nontoxic and non-cyanide system. However, thiourea is not stable and easy to decompose in alkaline solution, and the technology has disadvantage of instability. Iodine leaching on the other hand is comparatively a environmental process. Therefore, the optimal choice is the combined process of SAHPI method, while further research is required to develop cost effective and environmentally friendly processes. |
