Thermodynamics of Slag Formation in Multi-Component Oxide Systems in Thermal Processing of Incineration Bottom Ash - Equilibrium Phase Relation in CaO-SiO₂-FeO_x-MgO System

Abstract:

Vitrification is considered as an attractive procedure for municipal solid waste incineration ash, which can realize the volume reduction and innocent treatment of incineration ash, as well as reuse of bottom ash. The main oxide components of molten ash slag are CaO, Al₂O₃, SiO₂, Fe₂O₃, MgO, and Na₂O, accounting for more than 90% of the total mass. The phase relations and thermodynamic properties of the CaO-Al₂O₃-SiO₂-FeO_x-MgO-Na₂O oxide system is highly required, and is of great significance for optimization of vitrification processing and sustainable resource utilization of melting slag. A study on the equilibria phase relations of CaO-SiO₂-MgO-FeO_x system was done by applying CALPHAD based on FactSage in this paper. The modeling parameters for the thermodynamic properties of liquid phase in CaO-SiO₂-MgO-FeO_x system were established and the equilibrium phase relations of MgO-SiO₂-FeO_x and CaO-SiO₂-FeO_x-MgO systems were calculated for different temperatures and oxygen partial pressures.

• Periodical: Advanced Materials Research (Volumes 194-196)
• Pages: 2175-2178
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.194-196.2175
• Online since: February 2011
• Authors: Nan Wang, Zong Shu Zou, Zhan Zhang, Yan Ping Xiao, Yong Xiang Yang
• Keywords: Bottom Ash, CALPHAD, CaO-SiO₂-FeO_x-MgO System, Equilibrium Phase Relation, Vitrification

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