Effect of additives on melting temperature and energy consumption of municipal solid waste incineration fly ash

Abstract

This paper presents the melting temperature (MT) and energy consumption (EC) of model municipal solid waste incineration (MSWI) fly ash (FA) under the influence of calcium oxide (CaO), silicon dioxide (SiO₂), aluminium oxide (Al₂O₃) and boron oxide (B₂O₃) based on thermochemistry simulations. Nine different base-to-acid ratios (B/A) of raw FA have been explored. The results show that the effects of CaO, SiO₂ and Al₂O₃ vary for different B/A ranges. SiO₂ and Al₂O₃ play positive roles in decreasing the MT and EC of FA4–FA9 with high B/A (B/A: 2.61, 4.48, 6.43, 6.90, 8.32, 8.82). CaO plays a positive role in decreasing the MT and EC of FA1 and FA2 with low B/A (B/A: 0.22, 0.43). In FA3 (B/A: 1.22), the MT and EC of FA cannot be reduced by adding CaO, SiO₂ and Al₂O₃. The addition of B₂O₃ cannot only further reduce the MT of FA, but also reduce the EC. B₂O₃ and SiO₂ can work together to reduce the MT and EC when B/A is high (2.61–8.82), and SiO₂ and B₂O₃ can be introduced into the FA by adding waste glass and other boron containing waste to realize the coordinated disposal of waste.