Treatment of residues from combustion of shredder mill waste - by treating sludge with Portland cement and other additives to give harmless or reusable material to reduce phosphate content

摘要

To treat residues from the combustion of shredder mill waste and sludge with Portland cement or ground Portland cement clinker and other additives plus water, the shredder mill waste and sludge is fed into a circulating fluidised bed combustor in a ratio such that the phosphate content of the ash, which arises from the sludge, does not exceed 3.5 wt.% The obtd. mixt. is further treated with cement and water. A device for carrying out the process comprises a first mixer unit (5) attached to hoppers (1,2,3,4) for the individual components, moisturising device (7) associated with a conveyor belt (6) connecting the first mixer to a second mixer (8). The second mixer assists the de-gassing of the material being treated. The dampened material is fed, further degassed and homogenised to a briquetting unit (10) by a vacuum screw feeder (9). Pref. aluminium contg. waste is treated with up to 30 wt.% of inorganic silicate materials, 20 wt.% Portland cement or Portland cement clinker is added, and the materials are further mixed, homogenised dry, and further processed. Material aggregates are additionally broken down by means of pore formation the reaction of Al with the (alkaline) material to form hydrogen and hydrated calcium aluminate. USE/ADVANTAGE - Produces re-usable materials, or materials which are harmless and can be dumped without environmental risk, from non-ferrous components of waste such as sludge, scrap motor vehicles, refrigerators, etc. The final (hydrated) material is of dense structure.