Novel Evaluation Method of Elemental Recyclability from Urban Mine

Abstract

In this study, the total materials requirement (TMR) to recycle chemical elements from the urban ore by recycling (urban ore TMR, UO TMR) has been compared with the TMR to extract the element from the natural ore by smelting (natural ore TMR, NO TMR) in order to evaluate the urban ore grade on an equal footing with the natural ore. A framework of UO TMR based on the NO TMR framework is developed. To validate the developed framework, the UO TMR of a laptop PC is estimated assuming gold, silver, copper, iron, aluminum, tantalum and indium are recycled. It is found that the UO TMRs for gold, silver, copper, iron, aluminum and tantalum are lower than NO TMR, but that for indium is higher. The ratio of``urban tailings'' is at most 60 of the total, which is smaller than that of NO TMR``tailings''. In contrast to the contributions of energy and material inputs for the recycling process, the contribution of transportation is not very large. For the UO TMR of indium, the contribution of materials for recycling process is extremely large. The availability and scalability of UO TMR are also discussed.