ANALYTICAL CHARACTERIZATION OF BOTTOM ASHES FROM FOUR BULGARIAN COAL-FIRED POWER PLANTS

In the present study raw coal bottom ashes from four Bulgarian coalfired power plants Bobov dor, Maritsa Iztok-3, Republika and Sliven were investigated by a combination of different analytical methods. They were characterized in terms of mineralogical and chemical composition, grain size distribution, conductivity, moisture, slurry pH, ignition losses and texture parameters. Gravimetric chemical analysis was used for silica assessment. The elements Al, Fe, Ca and Mg were determined titrimetrically, and atomic absorption spectrometry was applied for micro- and trace element determination. The data obtained for surface area and pore volume showed that all investigated materials could be used as low-cost adsorbents for different pollutants.