Physical and chemical properties of ash from thermal power station combusting lignite. A case study from central Poland
Czerwiec 28, 2019
Listopad 02, 2019
Hard coal and lignite are the main sources of electricity and heat in many countries. Waste generated during lignite combustion is deposited primarily on disposal sites. In the development of its reclamation technologies, it is crucial to precisely specify the physical and chemical properties of coal ash. The aim of this study was to determine selected physical and chemical parameters of an unreclaimed fragment of the disposal site established for the disused Adamów power plant. These properties were analysed in terms of the potential to support vegetation cover growth and development. It was also undertaken to determine the effect of the distance from the coal ash discharge outlet on these properties. Particle density of that rock was 2.23–2.56 Mg m-3, bulk density ranged from 0.99 to 1.18 Mg m-3. Its reaction was alkaline (pH in 1 M KCl 9.68-12.19). Hydrogen carbonate content amounted to 40.50-76.00 g kg-1. The organic substance found in the rock was identified as residues of unburned coal. Analyses showed no nitrogen and phosphorus content, at excessive amounts of Ca and Na. Cation exchange capacity (CEC) ranged from 57.2 to 128.4 cmol(+) kg-1. It is the so-called “apparent capacity” resulting from the reaction of ammonium acetate with calcium compounds, mainly hydrogen carbonates. The study showed that properties of coal ash deposited in wet surface impoundments (storage lagoons) depended on the distance from the discharge outlet. Greater particles, less abundant in alkali metals, are deposited closer to the discharge outlet. With an increase in the distance from the ash discharge outlet we observe an increase in the share of smallest particles, a more alkaline reaction and greater amounts of calcium, sodium, potassium and magnesium.
Gilewska M., Otremba K., Kozłowski M. 2020. Physical and chemical properties of ash from thermal power station combusting lignite. A case study from central Poland. J. Elem., 25(1): 279 - 295 . DOI: 10.5601/jelem.2019.24.4.1886
ash storage lagoons, ash, physical properties, chemical properties