Risk and performance assessment of cement made using municipal solid waste incinerator bottom ash as a cement kiln feed

Abstract

To assess the feasibility of incorporating municipal solid waste incineration (MSWI) bottom ash (BA) as a replacement for traditional raw materials in cement kiln feed, an industrial-scale kiln trial was performed. Leach testing and chemical and physical characterization data from a cement product made at a replacement percentage of 2.8% by mass of kiln feed were comparable to results from ordinary portland cement. The concentrations of constituents of concern in leach tests were generally below risk-based screening levels or of similar or lower magnitude than leachate from control products. Ash-amended cement exhibited greater early age reactivity, and this was reflected in initial mortar compressive strength results; ultimate compressive strength results were higher in the control mortar. The ash-amended and control cements were similar in characteristic, but quantitative x-ray diffraction results reveal differences in alite and aluminate formation during the clinker formation process.