In waste combustion, various different quantities of slag and ash arise for each tonne of waste, with different quantities of minerals, scrap iron, water, and heavy metals.
SLAG AND ASHES are residues from combustion processes in power plants or waste-to-power plants. Slag from waste-to-power plants is particularly important for environmental protection.
After pre-storage of the slag to incorporate air (CO2), it is sieved and crushed. Ferrous scrap and non-ferrous metals (aluminium, copper and brass) are separated, and unburnt residues are removed. Physical and chemical processes take place in conjunction, for which reason the slag must be stored for a set period after processing as per the technical guidelines.
The secondary product can be used as a construction material for roads.