Recycling of Solid Urban Waste
COMPLEX PROCESSING OF SOLID URBAN WASTE
Basic obstacles for economically effective processing of SUW on the urban dumps are: the mixed morphological and chemical composition, high humidity (to 70%), low bulk density (0.01-0.2 t/m3), the admixture of food and construction wastes, and tendency for spontaneous combustion.
Therefore, for the profitable utilisation of SUW to be promising, the use of the mechanised complex line of multistage processing, obtaining of secondary raw material and energy is proposed. Line must include: magnetic separation of ferrous metal, induction separation of nonferrous metal, air separation of paper- plastic fraction, wet separation of paper from plastic, and pyrolysis of plastic. The wastes of soft roofing and tires are to be utilised as well.
As a result SUW is separated into the following forms of secondary raw material: ferrous metal (5th class, 5-8%), nonferrous metal (aluminum 1-2%), paper- cardboard is wet (30-40%), plastic the mixed dirty (10-15%), and heavy fraction (food waste + construction rubbish -50%).
Scrap metal, paper is realised, heavy fraction goes to burial (density 1,0-1,5 t//м3), plastic, rubber, wastes of soft roofing are processed in the pyrolytic apparatus, obtaining bitumen, asphalt, coke, scrap metal, artificial oil, liquid boiler propellant, diesel fuel, gasoline, combustible gas, electric power, thermal energy. Thus, the volume of burial SUW decreases 20 fold, the possibility of the combustion at a dump is excluded, removal and utilisation of SUW becomes profitable.