ResuS

The mining facilities used today as water reservoirs contain sediments with elevated metal contents, most of which were brought in from the surrounding catchment areas influenced by mining. Due to the significant material contamination, these sediments deposited in standing waters, the so-called subhydric sediments, are not directly usable, e.g. as raw material for the building materials industry and/or agriculture and forestry.

The aim of ResuS - Recycling of Subhydric Sediments is to process the sediments according to different technologies and a holistic concept in such a way that a diverse utilization is ensured for the largest possible sediment quantities. Target elements include semimetals (arsenic), metals (lead), and transition metals (cadmium, zinc). Innovatively, the type and extent of treatment technologies are aligned with potential recovery options depending on the spatial chemical nature of the sediments. ResuS - Recycling of Subhydric Sediments pursues the approach of utilizing the entire sediment and thus not only potential value elements as raw materials. Possible recycling options for the sediment can be found as a soil substrate in agriculture and forestry as well as on contaminated sites and/or as an alternative building material in old mining and in the ceramics industry. The water should also be available for further use and the minimal amount of residual material that cannot be recycled should be enriched.

The technologies and the concepts for this are to be tested at the development site of the Freiberg Watercourse Institute (Ore Mountains), specifically at the smelter pond near Berthelsdorf. For this purpose, the sediment quantities of the dams will first be quantified. In addition, the sediments will be spatially sampled with high resolution and analyzed with respect to material and geotechnical properties. In addition, investigations of the chemical-physical water quality will be carried out. After obtaining these data according to a concept for monitoring and representative subaquatic sampling, they will be presented in geographic information systems (GIS), among other things, for more efficient processing of similar questions in the future. On the basis of the analytical findings, possible utilization options will be determined, the utilization-specific and legal framework conditions will be clarified, and the parameters for a utilization concept will be defined. Against this background, treatment concepts will be developed and subsequently treatment processes will be tested and scaled up. In the process, the recyclability of a recycling option up to TRL 6 is to be demonstrated as an example.

The results of the preliminary investigations and the three-year project phase will be used to test innovative and economical processing technologies and combinations for the extraction of raw materials from subhydric sediments. The results of the development of the processing methods will be used in a complementary manner to develop a marketable and adaptive utilization concept. By integrating local competencies during the development phase and marketing the results, ResuS - Recycling of Subhydric Sediments provides important impulses for strengthening the economic power of the Ore Mountains.

Development site: Freiberg Watercourse Institute (Main focus: smelter pond near Berthelsdorf).