Microstructure and leaching characteristics of fly ash-mine overburden-lime mixtures

Abstract

Fly ash is a major problem for disposal. Its gainful application is being tested at many places. An experimental investigation has been carried out to convert fly ash in combination with another waste material for mining applications. This paper highlights microstructure and leaching characteristics of the developed fly ash, mine overburden and lime mixtures. Fly ash from a local unit and mine overburden from an Opencast coal mine, India were collected, characterized, mixed with lime in different ratios and compacted to different values. The compacted specimens for California bearing ratio tests were cured for 7 and 28 days. The bearing ratio values and microstructural analysis were determined to know the effect of curing. The compacted specimens in the permeability mould were cured for 7 days to carry out the leaching test. The leachate effluents collected from leaching study were analyzed for the metals, Ni, Cr and Pb by a flame atomic absorption spectrophotometer.