Crystalline phase evolution behavior and physicochemical properties of glass–ceramics from municipal solid waste incineration fly ash

Abstract

Appropriate management and treatment of fly ash from municipal solid waste (MSW) incineration plant have become an urgent environmental protection problem. In this study, glass–ceramics have been prepared from MSW incineration fly ash and the SiO₂ with different blending ratios (${\text{BR}}_{{{\text{SiO}}_{ 2} }}$). With the increase in ${\text{BR}}_{{{\text{SiO}}_{ 2} }}$, the main crystalline phase of glass–ceramics was converted from gehlenite and pseudowollastonite into wollastonite. The texture was gradually formed in the surface of glass–ceramics due to the mutual arrangement of crystal particles and the decrease in the number and size of the gaps. Because of the mineral evolution and the microstructure change, the compressive strength and water absorption were significantly improved from 8.40 to 18.82 MPa and from 6.83 to 0.44 wt%, respectively, when ${\text{BR}}_{{{\text{SiO}}_{ 2} }}$ was in the range from 19 to 44 wt%. If ${\text{BR}}_{{{\text{SiO}}_{ 2} }}$ >29 wt%, the prepared glass–ceramics had good corrosion resistance in 10 % H₂SO₄ solution and 10 % NaOH solution, respectively. Therefore, glass–ceramics prepared from MSW incineration fly ash can be used as ceramic tile for building and decoration.