Mineral matter in municipal solid waste

Municipal solid waste (MSW) contains mineral materials which are seldom considered as a potential resource. Currently, the waste management sector pays attention to recyclable parts, biodegradable material, waste-to-energy fraction, and residues after waste reuse and recycle. In contrast, this study focus as on the mineral matter in MSW. The aim was to analyze and discuss the sources of mineral matter in MSW, the impact which the minerals have on waste management technologies, and finally, the possibility to recycle the mineral matter. The contribution of inorganic matter in the MSW stream is significant (about 20 wt.%). In the years 2012–2015, the average content of mineral matter in mixed MSW in Poland ranged from 16 wt.% to 36 wt.%, and the content of organic in MSW ranged from 20 wt.% to 42 wt.%. Minerals in MSW have rather negative impact on waste management technologies and their final products, and can be sorted out from the MSW stream, either in the households or in a central sorting line. However, in central collection and separation systems it is difficult to obtain a mineral matter fraction in subsequent processing steps due to technological limitations (inefficiency of devices), high degree of waste fragmentation and pollution of mineral matter with other waste. This indicates a hampered ability to separate minerals in a form available for reuse, so an effective system should be based on improved segregation at the source.