Study on the mineral phase characteristics of various Indian biomass and coal fly ash for its use in masonry construction products

The productive utilization of the vast amount of industrial ash generated is of economic and environmental importance. The use of industrial ash in brick manufacturing gives the two-fold advantage of the reduced cost of fly ash bricks as well as efficient disposal of industrial ash. However, due to variations in chemical characteristics in the various types of ashes originated from different sources, and production processes often lead to restricted use in lime based fly ash bricks. To overcome this, comprehensive characterization of different industrial ashes is necessary to clearly define the chemical characteristics that have influencing role on the lime based fly ash bricks. Considering this, XRD patterns, FT-IR spectra, Raman spectra, SEM images, and chemical reactivity method have been collectively used for comprehensive characterization of industrial ashes, including their mineralogy, particle morphology, and lime reactivity. A total of six different ashes have been characterized, including two biomass ash and three coal based ash from local industries, and one coal based ash from thermal power plant. The primary aim of the study is to assess the suitability of the proposed experimental programme to characterize local industrial ashes and to evaluate their potential to use them as raw material in masonry construction products. From the present study, it is revealed that by and large, local coal-based industrial ash can be utilized in lime based fly ash bricks based on their comprehensive characterization. The results obtained by characterization of industrial ash are expected to provide helpful insights to evaluate their potential to manufacture masonry construction products.