The aim of this study was to find a new method for usage of the hazardous waste coming from the aluminium scrap recycling factories. It is generally considered that non-metallic residues (NMR) are process waste and subject to disposal after residual metal has been recovered from primary dross. NMR are impurities, which are removed from the molten metal in the process of dross recycling, and it could be defined as a hazardous waste product. Processing of NMR created in the aluminium scrap recycling companies is one of the most challenging tasks due to its toxic nature - in accordance with the Basel Convention, Annex III, marking of this waste is H 4.3 (reaction with water results in highly inflammable substances) and H 10 (reaction with water results in increased concentration of toxic gases, for instance, ammonia). The new alkali activated materials, which could be defined as porous building materials, were created by using calcined illite clay from local site and NMR. Solution of sodium silicate (Na₂SiO₃+nH₂O) modified by commercially available alkali flakes (NaOH) was used as an activating solution. Polymerization mechanism of raw materials in alkaline media was investigated by using FTIR and XRD. Physical and thermal properties of the obtained materials were tested. Density of the obtained materials was in the range 550-675 kg/m³, but the total porosity was from 73 to 78%. The compressive strength of the materials was in range from 1.4 to 2.0 MPa. The thermal conductivity of porous alkali activated building materials was between 0.14 and 0.15 (W/(m·K).