From Treatment Plants
Bottom ash is a residue from incineration processes in power stations or waste incineration plants. Slags from incinerations are of major importance for the protection of the environment.
Bottom Ash Treatment.
Waste incineration produces about 250 - 350 kg of slag from every ton of waste. This is - like the waste itself - of extremely different composition as far as the content of minerals, iron scrap, water and heavy metals is concerned.
Prior to a re-use the bottom ash must be prepared and stored such that it complies with the quality requirement for the later use. In most cases the slag is transported from the incineration to the treatment plant via conveying equipment. There, it is pre-stored for an integration of air CO2 for at least one day. Then, the slag is sieved and crushed. Iron scrap and non-ferrous metals such as aluminium, copper and brass are separated from the slag and used as raw materials in metallurgical works. Residues not burned are treated and removed in a classifier.
Physical and chemical processes proceed in bottom ash simultaneously. Therefore, it is important that they be taken into account according to the technical guidelines and stored over a certain period of time. This product cannot be used as a secondary product or building material in road construction unless the specified requirements are complied with. Time and technology work for the bottom ash quality.