Characterisation of Dendromass Ash Fractions Captured in Power Plant with a View to their Further Utilization

management of the ash waste to companies which guarantee its
ecological disposal. In order to specify the correct disposal or further
utilization of the dendromass ash, the various slag and fly ash
fractions from a power plant combusting waste wood were analyzed
and compared in this work. The plant produces approximately 660 t
of ash waste/year. The efficiency of combustion depends on the
season, dendromass quality and plant operating conditions. The
proportion of carbon residue (incomplete burntwood-chips) in slag
and ash fractions increases in the winter months. Except for the
seasonal carbon residue, the crumble slag and fine ashes captured in
the flue channel and cyclone are similar in chemical composition and
phase (28 – 44 wt.% CaO; 25 – 35 % SiO2; ~7 % Al2O3; ~5 % K2O;
~4.5 %MgO). The finest ashcapturedin the fabricfilter containsless
silicon and alumina compounds (<7 % SiO2; ~2 % Al2O3) and a
significantly higher portion of potassium and sulphur, and chlorine
compounds (approx. 13 % K2O; 3.5 % S; <1.5 % Cl) which are well
soluble in water. All ash fractions produce strongly alkaline leaches
in first contact with water. The differences in the chemical
composition of captured ashes providean impulse for consideringthe
possibility of effective re-utilization of individual fractions.