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KlaRo: Research Project on Improvement in Efficiency regarding Metal Recycling



On 1st August, 2015 the collaborative project KlaRo (Development of efficient bottom ash classification for recovery of metals) is launched. Within the program KMU-innovativ this research is funded by the Federal Ministry of Education and Research.

Coordinator of the collaborative Project is pbo Ingenieurgesellschaft mbH. Further partners are RWTH Aachen University, represented by the Department of Processing and Recycling (I.A.R.), Wertstoffverwertung Wuppertal GmbH (subsidiary of AWG Abfallwirtschaftsgesellschaft mbH Wuppertal) and Hein, Lehmann GmbH. The funding period is scheduled to 24 months.

Each year, approximately 5 million tons of bottom ash arise from waste incineration processes. The state of the art processing leaves about 65.000 tons of valuable non-ferrous metals (e.g. aluminium and copper) unused. Processing of bottom ash with a grain size of < 10 mm is particularly challenging because of the water content. Therefore, the recovery of metals from this grain range is currently insufficient. This project aims to condition these materials to the optimum to be able to recover more valuable metals. Furthermore, the efficiency of processing plants in Germany and the recycling of wastes are to be improved. One main aspect of bottom ash treatment is classification (=sieving), which prepares the ash for the following metal sorting. The high water content in the ash leads to capillary binding forces, which are the reason for low efficiency in most processing plants. In a pilot installation the moisture will be actively and energy optimized adjusted. Thanks to an improved metal sorting possible revenues can be determined.


The project upon which this publication is based is funded by the German Federal Ministry of Education and Research (BMBF) under Project Number 033RK028A to C within the project “KMU-innovativ”. Responsibility for the content of this publication lies with the author.