Chemistry and mineralogy of municipal solid waste incinerator bottom ash

Abstract

A petrographic study was conducted on a suite of bottom ash samples from 28 municipal solid waste incinerators in Switzerland. Chemical and mineralogical analyses of bottom ash from waste combustors with comparable technology show similar major oxide composition. A significant decrease of SiO2 was observed in comparison to the chemical composition of bottom ash from 10 years ago. In contrast to major oxide contents, heavy metal concentrations vary significantly in the bottom ash samples, but without any correlation to the type of input waste or plant operating conditions. Similar types and contents of crystalline phases were observed in all samples. The content of newly formed melilite increases with decreasing bulk Si/Ca ratio, indicating that the type of Ca-Mg-Al-silicates crystallizing during incineration and cooling follow petrogenetic rules. A considerable recycling potential for ferrous and non-ferrous metals was identified in the bottom ash. Optimized mechanical metal separation technologies could reduce the waste volume, heavy metal content, H2 production, and exothermic reactions of the bottom ash in landfills and might be economically viable.

Use of Burnt Municipal Solid Waste and Lime in Local Subgrade Soil Stabilization for its Use in Low Traffic Volume Roads

“…From the ash collected from different incinerators from developed countries it is noted that the combustion temperature varies from 800 o C to 1200 o C. Loss on Ignition (LOI) varies from 1%-15%. According Eggenberger et al (2004) un burnt carbon in pozzolanic materials can serve as filler in the material being stabilized [21]. Ciara´n J. Lynn (2016) et.al carried study and examined data on MIBA available globally and explored the possibilities of using it in pavement component layers using stabilization technique [22].…”