low environmental impact pozzolanic cement production plant, obtained from mixed construction and demolition waste (rcd), and resulting products for construction

摘要

low environmental impact pozzolanic cement production plant, obtained by mixed construction and demolition waste (rcd), and resulting construction products, which strategically combines dosing operations, mixing of rcd graded gravel and urban soil, grinding, calcination and lime addition for formation of low environmental impact product, less than 200 kg co2 / t product, formed by pozzolanic cement (150 micrometer) mixed with rcd gravels with a particle size of less than 50 mm. The invention relates to a fixed or mobile recycling plant (Figure 1) of mixed construction and demolition waste (RCD), which combines separate crushing of different nature rcds. Gray (predominantly cementitious), red (predominantly red ceramic), and mixed (composed of a mixture of the above two) residues are stocked in plant storage silos (devices 1, 2, and 3, respectively). after crushing (device 4), graded gravels (50 mm) obtained from each residue are stored in new silos (devices 6, 7, and 8, respectively), together with urban soil residue (device 9) and hydrated lime (device 14) and can be fed separately or together depending on the potential for cement production from mixed rcd fines. Mixed RCD fines can simply be metered or thermally activated, in which case it is necessary to dryly separate them by pneumatic classification into an aeroclassifier. Depending on the product to be produced, the plant devices can be triggered or not, and combined to obtain the best result for each planned product. in all cases low environmental impact pozzolanic cements (200 kg CO2 / tonne of product) are obtained. The unit generates differentiated products in the field of construction with compressive strengths below 25 mpa, such as ditches, floors, mortars, prefabricated cementitious components and concrete, compatible with the established strength requirements.