EMSARZEM: Use of MV slag as raw material for cement production

Funding: Federal Ministry of Education and Research (BMBF), funding code: 033R265H

Project Duration: 02/2021 bis 01/2024

Coordination: GKS- Gemeinschaftskraftwerk Schweinfurt GmbH

Project partner:


Description:

In Germany, approx. 26 million t of waste are thermally treated in waste incineration plants for energy recovery and volume reduction. Approx. 5 million t of slag from incineration are produced from the recycling process, from which approx. 0.5 million t of iron and non-ferrous metals are recovered according to the state of the art. Due to problems with the installation of the remaining MV slag (finished slag) as a mineral substitute building material in technical structures, it is mainly used in landfill construction. In the medium term, this should be questioned, as it is foreseeable that the possibility of utilization as a landfill construction material will decrease due to a decreasing number of new landfills to be built. In addition, it must be taken into account that especially the fine fraction of MV slag (< 3mm), which corresponds to an annually accruing quantity of approx. 1.5 million t, contains further metals that can currently only be recovered to a limited extent. Among the economically interesting metals is copper, which is contained in the fine fraction in the order of 0.3 - 0.4% in the MV slag, based on a conservative view. Poor copper ores with copper contents in this order of magnitude are mined from natural deposits worldwide.

The aim of EMSARZEM (Use of MV slag as a raw material for cement production) is to process the fine fraction of MV slag in order to make the metals and minerals it contains available as high-quality secondary raw materials. The recovered minerals calcium oxide and silicon dioxide from finished slag can be used as raw materials in the cement industry, so that natural resources such as sand and limestone can be conserved in certain proportions. Process-related CO2 savings result from the replacement of raw material by MV slag, which does not have to be deacidified and thus does not release CO2.

The Chair of ABWL and Production Management applies the methods of life cycle assessment and techno-economic evaluation of the processing alternatives to be developed by the scientific and industrial project partners. In a life cycle assessment, the potential environmental impacts of the complex system of slag reprocessing, along the entire life cycle, from raw material extraction, through the use phase of the products, to their disposal, are evaluated. Based on the results of the life cycle assessment, well-founded statements can be made as to whether the additional effort in slag reprocessing is ecologically overcompensated by the advantage of secondary use. For future implementation on an industrial scale, it is also important that the increased effort for processing is economically viable through savings in disposal costs, the sale of the metallic fraction and the recycling of the mineral fraction.

The EMSARZEM project is funded by the initiative "Resource Efficient Circular Economy - Construction and Mineral Material Cycles (ReMin)" from 2021 - 2024. The initiative is part of the framework program "Research for Sustainable Development - FONA³" of the Federal Ministry of Education and Research with the aim of enabling future generations to have a future worth living through research and innovation.

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