Poster (EARTH)

[PE1-010] Concentration of precious metal from waste printed circuit board

○Hideaki Hara¹, Hitoshi ooya¹, Nobuhiro Inoue², Yuji Komori², Masakazu Konishi², Mizuki Fukuda² (1. The university of kitakyusyu, 2. Astec-irie Company Limited)

Keywords:urban mines, precious metals, waste electronic circuit board, superheated steam

Precious metals are decided in various electric appliances as urban mines in Japan, it is very useful to recycle precious metals. Therefore, it is important to establish the components necessary for recycling in order to increase the efficiency of recycling.
The distribution of electronic components and Au in the waste electronic circuit board must be investigated. Therefore, it becomes clear for optimal processing of each electronic component and highly efficient sorting method is examined.
Electronic component was removed from waste electronic circuit boards. Each sample was prepared by sieving and hand sorting for electronic components. It was treated by superheated steam to deteriorate the epoxy resin which consisted of electronic component. Au in the sample was solved in aqua regia and analyzed by ICP-AES.
Electronic components with high Au concentration were found such as IC chips and connectors in the waste electronic circuit boards. On the other hand, capacitors and resistors contended almost nothing for precious materials. Au concentration was depended on the kinds of electronic component. It had the feature for the electric appliance as well as the electronic component. Communication appliances which as much Au must be separately treated from the television, desk top computers, note computers and copying machines. It is an efficient method to recover precious metals like Au. The electronic components depended on Au concentration must be also separately treated, for instance, size separation as sieving would be efficient to recover Au. We hope to develop an efficient recycling process for precious metals such as Au from many kinds of electric appliances.