Abstract
From the view point of urban mine, Japan is one of the most abundant countries in resources, especially in scarce metals. In this study, the total materials requirements to recycle metallic materials and mixed-plastics from urban ores (urban ore TMR, UO-TMR) have been estimated and evaluated in comparison with the total materials requirements to smelt them from natural ores (natural ore TMR, NO-TMR). As the urban ores, mobile phone and laptop PC were selected. The estimation were carried out using scenario analyses, in which the number of recycled materials (gold, silver, copper, tantalum, indium, scrap steel, scrap aluminum and mixed-plastics) was changed considering additional energy and material inputs. As for the evaluation of recycled gold, silver, copper, tantalum and indium, which have almost the same qualities as the materials from natural ores, their UO-TMR were lower than respective NO-TMR, except for indium. In the case of scrap steel and scrap aluminum, which qualities are less than pure steel and aluminum from the natual ores, the trade-off between the increase in UO-TMR and the additional materials and energy inputs for increase in quality by dilution process or advanced disassembling-selection process was discussed by comparing with the NO-TMR.
