PROCESS FOR PRODUCING CONSTRUCTION MATERIALS FROM COMBUSTION RESIDUES

摘要

1. Two step process for manufacturing isolated workpieces having a dry bulk density of between 500 and 800 kg/m**3 from combustion residues, preferably fly ash, whereby during the first step 96 to 80% by weight of said combustion residues are mixed with 4 to 20% by weight of a CaO containing binder, water and an agent producing gas or foam, the mixture being then formed and hardened in an autoclave while during the second step the ingot taken off the autoclave is crushed to chips and mixed with 3 to 10% by weight of a CaO containing binder and water, then stored at increased temperature, pressed in moulds and hardened in an autoclave, the treatment in said autoclave being carried out under 0,8 to 1,6 MPa (8 to 16 bar) for 2 to 20 hours.