Closing the loop for rare metals used in consumer products: Opportunities and challenges

Abstract

Metals are classical examples of non-renewable resources, and their extraction from Earth by mining of ores cannot be seen as sustainable in the strict sense of the word. Mining, by definition, depletes the ore reserves. Through mineral processing and subsequent smelting and refining, ores are disintegrated, and the desired metals are isolated for use in the technosphere. Special and precious metals play a key role in modern societies as they are of specific importance for clean technologies and other high tech equipment. Important applications are information technology (IT), consumer electronics, as well as sustainable energy production such as photovoltaic (PV), wind turbines, fuel cells and batteries for hybrid or electric cars (contributions of Helmers (Part III), Schebek et al. (Part IV), Zepf et al. (Part VI) and Jägermann (Part VI). They are crucial for more efficient energy production (in steam turbines), for lower environmental impact of transport (jet engines, car catalysts, particulate filters, sensors, control electronics), for improved process efficiency (catalysts, heat exchangers), and in medical and pharmaceutical applications (Hagelüken and Meskers 2008; Angerer et al. 2009).