Kazue Ichino Takahashi1,3, Jiro Nakamura1, Kazumi Otabe2, Masaaki Tsuruoka2, Yasunari Matsuno3 and Yoshihiro Adachi3
1NTT Energy and Environment Systems Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi 243-0198
Mobile phones contain many useful metals, such as gold, silver, copper and tungsten, etc. The contained metals in each mobile phone are relatively little, however, the total number of mobile phones used in Japan has become very large. Therefore, mobile phones are paid attention as a stock-in-use of various metals. In contrast, these metals have not been well recycled because of low collecting rate of end-of-life mobile phones. Moreover, the lifecycle of the mobile phone is very short because they have been changed many times for offering new functions, such as cameras, electronic organizers, music players, and televisions. So many materials are considered to be added to obtain these multi functions, and the compositions of materials in mobile phones have changed. In this paper, we collected more than two hundred used mobile phones made between 1996 and 2008 and dismantled them to analyze their metal content. Concentrations of more than 20 metals in mobile phones were measured. It was found that their net amounts of these metals increased year by year. However, the tendency was different for each element. For example, the copper content increases as the number of the functions of a mobile phone was increased. Lead was mostly used as solder and its content decreased. This can be explained with the influence of the environmental regulations. To improve the recycling of mobile phones, the useful data base that including environmental and economic information is essential. Therefore, we also investigated CO2 emissions and the economic effects of mobile phones based on the results of elemental analyses. CO2 emissions generated by the incineration of plastics were estimated to be nearly equal to the avoided CO2 emissions by recovering the metals. The economic impact assessment result showed that the manpower cost exceeds the recovered cost of metals. Therefore it is suggested that the eco-design for recycling is needed.
resource recovery, mobile phone, environmental impact, economic impact
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