While the recycling rates for copper, steel, building materials, glass and paper are high in Germany, technology elements such as the high-tech metal tantalum used in smartphones are only partially reused today. In the "Engineered Artificial Minerals" priority program funded by the German Research Foundation (DFG), scientists in a network coordinated from Freiberg are working on a new solution for the processing and reuse of waste and recycling products from metallurgy using artificial ore minerals.
To implement the innovative idea, the interdisciplinary team first looked far back into the Earth's history: "We want to take the genesis of raw material deposits as an example, when our current ores crystallized from magma a long time ago," explains Prof. Dr. Urs Peuker from the Institute of Mechanical Process Engineering and Mineral Processing at TU Bergakademie Freiberg, who is coordinating the priority programme. "We can use this principle of crystallization to produce artificial ore minerals from metallurgical slags, which we can then make fit for reuse."
The hot slags are produced during the extraction of metals or the melting down of electronic scrap and contain the technology elements in dissolved form. When the slag is cooled, crystals are formed that can be modified in their structure and type by changing the cooling rate.
By combining the target elements with other substances, such as sulphur or phosphorus, new ore minerals can be created. These can then be fed back into the material cycle as artificial ores.
