Sintered glass–ceramic from municipal solid waste incinerator ashes

In the present study, the sinter-crystallization behavior of a glass from municipal solid waste incineration ashes was investigated. The crystallization kinetics were estimated by DTA at different heating rates and the formed crystalline phases were evaluated by XRD. The sintering was studied at different heating rates and at different holding temperatures by dilatometry, measuring the % of linear shrinkage, while the structure of the sintered samples was observed by SEM. The bending strength and the Young modulus were evaluated after heating at 5 and 20 K/min and 1 h holding at 1123 K. The DTA show two overlapped crystallization peaks, corresponding to 440 and 430 kJ/mol activation energies of crystallization. The XRD highlight that the crystallization starts by pyroxene formation, followed by anorthite and gehlenite. The sintering of the glass particles is inhibited by the crystalline phase formation and stops after the formation of 10% of crystal phase. Higher densification may be obtained by applying fast heating rate (20 K/min), which also improves the mechanical properties.