Leaching Characteristics of Selected Elements from Indian Coal Ash

Abstract

Long-term leaching experiments have been conducted to determine release of different ions and heavy metals from different coal ashes obtained from Ramagundam Super Thermal Power Plant, Andhra Pradesh and Chandrapura Thermal Power Plant, Jharkhand. Four columns of Ramagundam fly ash, bottom ash, pond ash, and weathered ash and three columns of Chandrapura bottom ash, pond ash, and weathered ash have been prepared. Leaching experiment has been conducted for one year. The leachates obtained have been monitored for levels of dissolved constituents and heavy metals. Results for leachates indicate that initially maximum concentrations of dissolved inorganic constituents, who have been admixed, with the surface of fly ash particles have been leached out. Irregular pattern of heavy metals released have been obtained in leachates. The leaching behaviour indicated slow and long-term leaching of heavy metals, which have been associated with the ash particles.