Generation estimation and critical metals quantity assessment of retired mobile phones in Japan

The sustainable management of WEEE (Waste Electrical and Electronic Equipment) can contribute to the defense of the ESBs (Earth System Boundaries) and achievement of the UN SDGs (United Nations Sustainable Development Goals). This work conducted reasonable generation estimation and critical metals quantity assessment of retired mobile phones in Japan with the sales &new method. The generation estimation is based on the statistical data including sales and quantity of the subscribers. The result shows that there are 31.20 million of mobile phones retired in 2021, comparing 32.83 million in 2008. The calculated lifetime have minimum and maximum value in 2008 and 2019, which is 3.36 and 7.58, comparing 6.42 in 2021. 17 metals are selected as critical metals, with which the quantity and dynamic are also calculated. The replacement from feature phones to smart phones demand less of 11 metals, which shows the critical metals savings leading by the technological innovation.