Accumulated sludge and acid mine drainage (AMD) in mine water facilities are a major environmental problem because of the constant discharge of potential environmentally harmful substances (e.g.: heavy metals) on the one hand, and on the other hand due to the resulting loss of function, leading to both flooding and discharge of contaminants into the surrounding environment. Even though water and sludge contain economic relevant elements it can be usually only treated as hazardous waste.

Within the project ZauBer a field test laboratory was build up. The constructed multi-stage pilot-scale container plant combines a membrane system with a chamber filter press and a precipitation line for the continuous treatment of mine waters and the recycling of mine sludge which serves as a starting stock for geopolymers and slag as a raw material source. ITUN developed the 3-stage membrane filtration device with the following tasks: the continuous treatment of the mine water and the treatment of sludge press water enabling the safe release of purified water into the receiving water body. 

The overall results showed a consistent performance, based on flow rate, turbidity reduction as well as permeate quality. A turbidity reduction of 99 % to under 0,06 FNU was achieved. The success of nanofiltration process parameter adjustment leads to Zn-retention rates ˗ as an example for polyvalent cations – up to 92 %. RO convinced with a high conductivity reduction above 98 % and further cation retention. 

The BMBF-funded project (03WIR1908A) is part of the rECOmine network and a cooperation between the Institute of Technical Chemistry, the Institute of Thermal-, Environmental- and Resources’ Process Engineering  (TU BAF), terra mineralia (TU BAF) and the regional companies G.E.O.S Ingenieurgesellschaft mbH, INTEC Gesellschaft für Injektionstechnik mbH & Co. KG, SAXONIA Standortentwicklungs- und verwaltungsgesellschaft mbH and Befesa Zinc Freiberg GmbH.