Metals play a key enabling role as well for climate protection technologies such as electro mobility, the hydrogen economy, solar and wind power plants, and also for digitalization and electronic products. Accordingly, it is necessary to make their use much more resource-efficient than before and to develop advanced circular economy systems and sophisticated recycling technologies. Closed metal cycles contribute to this by securing relevant parts of the raw material supply for high-tech products and by reducing CO2 -emissions in their production at the same time. Interacting steps in multistage treatment processes by mechanical, chemical and thermal unit operations are challenging but will give a competitive advantage for networks of industry and science that are able to handle that. In this context, high-quality recycling means the economically viable recovery of many relevant metals and materials with high yields, in marketable quality and in compliance with high environmental and social standards.