A process for the treatment of plastics wastes based on polystyrene and their thermal utilization in cement combustion furnace

摘要

Polystyrene-based residues and/or scrap, and partic. expanded polystyrene from packaging or insulation applications, is recovered and is thermally treated in a cement kiln. The disintegrated material concerned is fed into a separator (cyclone or silo) which is located in the main or subsidiary heating system of a cement kiln, so that any sepd. material is drawn in (but without any additional air) to the current of gases between the main and subsidiary heating system and/or within the latter system itself. A mobile disintegrator reduces the scrap material to pieces less than 30mm wide and these are stored in a silo (2) at a cement works. Suitable quantities are drawn off (3) and blown to the separator (4) where the air stream flows out and is filtered and the solids are moved (6) so as to drop down through a cooling tower (7) between a furnace head (8) and clinker cooler (9). ADVANTAGE - The method makes it possible to provide part of the plant energy required from the plastic scrap, whilst the remaining energy is provided conventionally from the fossil fuel used. The procedure enables large quantities of plastic scrape to be used thermally.