Study On Analyses And Callback Of The Metals In Waste Computer With ICP

The topic of this paper is to research, analyze and callback the metals in computer through ICP method. An economic and efficient way to dispose and recycle the metals should be figured out in order to reduce the pollution to the environment.The composition of the computer is very complicated, it consists of more than 700 chemical materials, and many of them are hazardous. If we do not dispose the waste computer properly, it will cause heavy contamination to air, water and soil, and do great harm to human health, the results will be unaffordable for the human being.The computer consists of many high concentration components; therefore proper separation of the waste computer according to classification of the shell, printed wiring board, display screen and other auxiliary parts is quite necessary. With this way, the easy treated parts such as the metal shell and the plastic parts will not mix with the complicated printed wiring board and display. It can lower the technical difficulty and the possibility of inter-pollution.The PWBs (printed wiring boards) occupy a big proportion in the computer. Moreover the composition of PWB is very complex; it contains lead, cadmium, mercury etc., which may bring serious hazard to human being and the environment without proper disposal. So the key technology to recycle and reuse the waste computer is to solve the problem of reusing the PWB innocuously and changing it into new resource.In order to analyze the metallic elements in the PWB in computers (video card, audio card, network card and main board) quantitatively, which is a necessary step before the recycling of the metals, the first step is to dissolve the metallic elements contained in the PWB by using hydrometallurgy, and then do the quantitative analysis with ICP. Treat the PWB with sodium hydroxide at the proper temperature first, and dissolve the metallic elements using nitric acid. After the optimal conditional experiment, the cost-effective ICP metallic element analyzing method could be found. As shown by the experiments, the best temperature is 60 centigrade, the best concentration for the sodium hydroxide is 10%, and the optimal effects comes when treat the samples with nitric acid solution with a concentration of 20%.After comparing with the current metal recycle methods and making some experiments, an effective, environmental method is found. The purity of Au reclaimed by multi-complex electrolyte can be 99.5%, and it either will not pollute the environment.