Utilization of fly ash as an alternative to silica sand for green sand mould casting process

Abstract

The availability of silica sand for Indian foundry industries has been decreasing day by day. The present investigation evaluates the power plant fly ash (F-type) suitability as an alternative material to silica sand for Indian foundry industries. The sand mould properties such as permeability, hardness, compressive and shear strength, and compactibility are evaluated as per the standard (American Foundry Society (AFS)). The fly ash is added to silica sand at a different weight percentage (5 wt%, 10 wt%, 15 wt% and 20 wt%) and made the sand mould specimen. The physical and mechanical properties of fly ash blended silica sand mould is evaluated and compared with plain silica sand mould. The results revealed that up to 15 wt% of fly ash can be added to silica sand mould to meet the desired physical and mechanical properties of green sand mould castings. It is observed that the fusion point of fly ash is below 1350 °C and suitable for nonferrous sand casting. The utilization of power plant fly ash in green sand mould casting reduces environmental pollution and minimizes the scarcity of silica sand in Indian foundry industries.