Leaching characteristics of bottom ash from thermal power plants

The disposal of coal ash from thermal power plants in India is a challenging task. The objective of the present study was to investigate the leaching characteristics of the bottom ash disposed in ash pond of thermal power plants. A series of leaching experiments have been performed to analyze the tracing elements of metal at different liquid-to-solid ratios (L/S). L/S ratio varies from 20:1 to 80:1. From the experiment, it is observed that the elements Mn, Mg, Cr, Zn, and Cu are present in major concentrations while elements viz. Pb, Fe, Zn, and Co are present in minor concentrations. It is also observed that the leaching characteristics of the bottom ash are affected by the pH of extraction solution and L/S ratio. The minimum leachability of the solution was determined using an ASTM method, whereas the maximum leachability was determined using a TCLP method.