Author(s)

S. Bethanis & C. R. Cheeseman

Abstract

Waste incineration is increasingly considered a leading alternative to landfill in many countries due to limited availability of landfill sites and potential adverse environmental effects associated with waste disposal. Incinerator bottom ash (IBA) residues are generated at a rate of approximately 800 kilotonnes per year in the UK and the majority is currently landfilled. The production of lightweight aggregate by sintering mixes of municipal solid waste IBA and pulverised fuel ash (PFA) represents a potentially attractive reuse application for these high-volume waste materials. PFA has been added to IBA to control the sintering behaviour. The effect of adding a carbonaceous material that decomposes during firing to produce controlled levels of porosity has been investigated. Waste activated carbon has been used as a pore former in pellets containing significant quantities of IBA. Two lightweight aggregates were manufactured, a carbon-free and a carbon-containing aggregate, and were characterised in terms of physical, mechanical, mineralogical and microstructural properties. The IBA-derived aggregate performance was assessed in comparison with commercial synthetic aggregate (Lytag) and the results confirmed the feasibility of the production of lightweight aggregate using significant concentrations of the high-volume combustion bottom ashes. Keywords: waste reuse, incinerator bottom ash, pulverised fuel ash, resource conservation, aggregate.

Keywords

waste reuse, incinerator bottom ash, pulverised fuel ash, resource conservation, aggregate.