Project Details
Projekt
Coordination Funds
Applicant
Professor Dr.-Ing. Urs Peuker
Subject Area
Mechanical Process Engineering
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 470477639
Nowadays, recycling technology is at the crossroads. In developed countries, recycling technologies have been implemented to recover those elements and materials, which represent the main mass of waste and have a business model. However, we are lacking technologies to address the essential and often rare elements of a modern society, which still become dissipated in the waste streams. Such rare elements typically provide a special functionality to a product; they are contained in batteries, capacitors, magnets, electronic circuits, sensors and functional composite structures in general. Pyrometallurgical processes for the recovery of metals are a significant sink for a large number of these elements. Since these processes traditionally aim at the quality, yield and economic importance of the main metal phase, all non-functional elements and those which effect the material quality are forced to migrate to the slag phase. The latter consists of oxides, phosphates, carbonates and sulphides of metals and metalloids. Thus, the slag becomes the carrier of a broad number of valuable elements. The concentration of these elements is low and therefore they are dissipated and integrated into the inorganic matrix after solidification. A common application of a slag, which contributes formally to a recycling rate, is as a filler, binder or geopolymer in construction, removing the contained critical elements entirely from any material cycle. SPP 2315 EnAM addresses the slag phase as an important source for critical technology elements. When the slag solidifies, it either forms a homogeneous amorphous structure or generates crystals. These crystals are be seen as artificial minerals (EnAM), ores respectively and their generation is investigated to concentrate diluted elements by orders of magnitude. SPP 2315 looks at Li, Ta or Cr containing slag systems. The formation of EnAM itself depends on the thermodynamics of the complex multi-component slag system and the processing conditions of the melt, e.g., the temperature profile and gradient during solidification. Identifying and characterising an EnAM system is only the first step in the processing route in SPP 2315. The EnAM crystal has to be crystallised to a sufficient size and purity and then mechanically liberated from the remaining, sometimes partially amorphous, solid matrix. Finally, mechanical separation of the EnAM particles results in a new artificial ore concentrate. As slag processing has so far been a waste treatment process, there is a lack of strategies and process laws. SPP 2315 is therefore dedicated to the development of appropriate comminution laws and flotation strategies for EnAM. In summary, the SPP 2315 works on holistic separation and concentration concepts, which will allow to keep more elements in the material circle in the future.
DFG Programme
Priority Programmes
