No rubbish is good rubbish
The amount of household waste per capita in Germany in 2019 was 457 kilograms. The total volume of waste in Germany in 2018 was over 417 million tonnes (source: destatis). Waste disposal companies and the circular economy are working on concepts and technologies for the best possible recovery of these quantities. In terms of a cascade of waste, the best garbage would of course be the one that does not arise in the first place. Thus, waste avoidance is actually the top priority. Then comes reuse and recycling. In fourth place is e.g. energy recovery in waste incinerators (especially EfW plants). And the final solution is disposal, which is more like disappearing into landfills. Landfilling of untreated waste has been banned in Germany since 2005.
Burn, Baby, Burn: Energy recovery in incinerators
In a certain way, incinerators provide recycling material after processing municipal waste. Valuable metals can be found in the residues, incinerator bottom ash (IBA). With todays raw material prices for copper, brass & Co., they are worthwhile to recover. In addition to iron, ash from incinerators contains non-ferrous metals such as copper, zinc, lead and brass but also stainless steel and light metals such as aluminum. The 68 German waste incinerators use their annual capacity of over 20 million tonnes. Around a quarter of the input is left over as IBA, which contains 7 to 10 % metals.
Ash as a base
What happens to ash from waste incinerators? First of all, for the above-mentioned reason, it should be ensured that everything valuable is efficiently extracted from the ash. This is done by crushing, screening and separating the ash. Systems from TRENNSO-TECHNIK are recommended for the optimal classification of non-ferrous metal slag. The slag enters the sorting process as dry bulk material. IBA can be used in various construction applications e.g. in road construction as a so-called secondary aggregate. IBA can also be found as a secondary aggregate in the substructure of buildings.