Microwave vitrification for lightweight aggregate manufacture

By-products of aggregate production, such as quarry fines, are a significant burden on the quarrying industry. This paper reports on an experimental study to manufacture lightweight aggregates, suitable for use in lightweight concrete building blocks, from fly ash and mixtures with quarry fines, by microwave heating. Material preparation and processing are described, along with their impact on yields of manufactured lightweight aggregates. Conventional lightweight aggregates include pumice and furnace bottom ash. Compared to these, based upon measurements of density and crushing strength, the manufactured aggregates would be suitable for use as aggregates in lightweight building blocks.