Vitrified materials were made purely using combustion ashes from agricultural based residues (rice husk ash) which subjected for further recycling to construction materials. The optimum heat-treatment schedule was 1400 °C for 2 h for nucleation. The properties of the produced samples were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques and Toxicity characteristics leaching procedures (TCLP). Cristabolite (SiO2) was formed as a major crystalline phase. The glass-ceramics showed good mechanical properties with a compressive strength of 19.96 MPa and lightweight material with 0.61 kg/m3 and porosity with almost 100%. Furthermore, this glass-ceramic material showed an excellent resistant against leaching of heavy metal ions in water. Toxicity characteristic leaching procedures (TCLP) detected that the amount of heavy metals ions leached after 18 h at 23°C was well below international regulations with Cd2+ < 0.082 ppm, Cr3+ < 0.049 ppm, Cu2+ and Pb2+ < 0.281 ppm and < 0.016, respectively.

Keywords : vitrification, rice husk ash, recycling