Study of the operative conditions and the optimum amount of municipal incinerator bottom ash for the obtainment of ceramic floor tiles.

Abstract

The idea of reusing municipal incinerator bottom ash (MIBA), the residue from incinerating municipal solid wastes, fits nicely in a circular economy scheme, which leads to an avoided impact of landfill disposal, and at the same time reduces the demand of natural resources. Past studies have attempted to add 20 to 60% MIBA for ceramic production, and resulted in some inspiring success. Focused on delivering quality interior and exterior floor tiles meeting industrial standards, this study investigated the operative conditions and the optimum amount of MIBA in the mix. In this study, only the kaolinite clay and MIBA were used. Before making specimens, raw materials of clay and MIBA underwent SEM, EDS, and TCLP tests to determine their chemical contents. Six sets of specimens with different replacement levels of MIBA (0%, 5%, 10%, 15%, 20%, and 30%) were then prepared. These specimens were fired at 1000°C, 1050°C,1100°C, and 1150°C and the products underwent a series of mechanical tests to verify their performance. NMR (nuclear magnetic resonance spectroscopy) were also used to determining the organic compound structure after each specimens' crystallization. Research results showed that proper mix of MIBA up to 20% could result in quality tiles complying with specifications for interior and exterior flooring applications at certain kiln temperatures, while the specimens with 30% MIBA failed to meet either bending strength or size shrinkage requirement at all four kiln temperatures, and could not deliver a satisfactory result.