Thermodynamics of the Vitrified Bottom Ash Slag from Municipal Solid Waste Incinerators-Phase Relations of CaO-SiO2-Na2O Oxide System

Abstract

Vitrification is considered to be an attractive technology for municipal solid waste incineration. The main components of the vitrified bottom ash slag are SiO2, CaO, Al2O3, Fe2O3, Na2O and MgO, accounting for more than 90% of the total mass. The phase relations and thermodynamic properties of the CaO-Al2O3-SiO2-FeOx-MgO-Na2O oxide system is highly required, and is of great significance for optimization of vitrification processing and sustainable resource utilization of melting slag. Thermodynamic properties of the vitrified bottom ash slag were investigated in the present work. A study on the phase equilibria of CaO-SiO2-Na2O system was carried out with modelling method.