Environmental Behavior of Power Plants Fly Ash Containing FGD Solids Utilized in Deep Coal Mines
The environmental implications of underground use of fly ash (FA) containing end products from dry flue gas desulfurization (D-FGDS) and semi-dry flue gas desulfurization (FA + SD-FGDS) were exemplified in the evaluation of the respective wastes from 3 power plants (Rybnik, Opole, Laziska) utilized in deep coal mines in the Upper Silesia coal basin (USCB, Poland). Following load-based criteria, environmental behavior of these end products and their mixtures with water used in the deep mines was evaluated and compared with that of “pure” FA without FGDS that might originate from the electric utilities either not using desulfurization process or applying wet flue gas desulfurization technology. The end product properties were shown to highly depend upon the FA rate, which moderated the effect of FGDS. Solids from dry and semi-dry flue-gas desulfurization process exerted a considerable effect on the end product properties and release of constituents from this material due to influence on solidification process, hydraulic conductivity, pH, contents and forms of sulfur and calcium compounds, as well as on concentrations of trace elements. With respect to trace element contents, flue gas desulfurization products were found to cause positive “diluting” effect on the FA. The phase and chemical composition of FGDS in dry (CaSO4, residual CaO), and semi-dry process (CaSO3, CaSO4, Ca(OH)2 CaCO3), besides quantity and quality of mine water, determined properties and the environmental effect of the end product utilization in mine working in the form of mine water: FA + FGDS mixture. The most environmentally beneficial way of utilization either of pure FA, or FA + FGDS was found to be its use in the deep mines as a sealing material in the form of low-ratio mixture with saline mine water placed in dry workings, insulated from recoverable usable water resources.
KeywordsClay Sulfide Geochemistry Acidity Lime
Unable to display preview. Download preview PDF.
- 1.Anon., Methods of flue gas desulfurization in the professional power industry of Katowice district, Proc. Conf under the auspices of The Katowice District Council, Jaworzno Laziska Rybnik, 1995, 21 (in Polish).Google Scholar
- 2.Blaszczak, A., and Buzek, A., Problems of managing waste from desulfurization process in the electric utilities of low and medium power, in Proc. IV Int. Conf. on Economy in Power Industry and Ecological Investments, EUROBUSINESS, Ustron—Zawodzie—Katowice, 1998, 13.Google Scholar
- 3.LIFAC Flue gas desulphurisation process, Tampella Ltd., 12.Google Scholar
- 4.Collins, S., Managing powerplant wastes. Special Report, Power, 8, 15, 1992.Google Scholar
- 5.Tyson, S. S., Overview of coal ash use in the USA, in WASCON’94, Environmental Aspects of Construction with Waste Materials, Goumans, J. J. J. M., van der Sloot, H. A., and Aalbers, Th. G., Elsevier, Amsterdam-London-New York-Tokyo, 1994, 699.Google Scholar
- 6.Garavaglia, R., and Caramuscio, P., Coal fly-ash leaching behaviour and solubility controlling solids, in WASCON’94, Environmental Aspects of Construction with Waste Materials, Goumans, J. J. J. M., van der Sloot, H. A., and Aalbers, Th. G., Elsevier, Amsterdam-London-New York-Tokyo, 1994, 87.Google Scholar
- 7.van der Sloot, H. A., Piepers, O., and Kok, A., A Standard Leaching Test for Combustion Residues, BEOP-31, Bureau for Energy Research Projects. Netherlands Energy Research Foundation, ECN, Petten, the Netherlands, 1984.Google Scholar
- 8.Witczak, S., and Adamczyk, A., Catalogue of Selected Physical and Chemical Parameters of Ground Water Contamination and Methods of their Evaluation, vol. 1, PIGS, Environmental Monitoring Library, Warsaw, 1994, 117 (in Polish).Google Scholar
- 10.de Groot, G. J., Wijkstra, J., Hoede, D., and van der Sloot, H. A., Leaching characteristics of selected elements from coal fly ash as a function of the acidity of the contact solution and the liqiud/solid ratio, Standard Technical Publication 1033, American Soc. for Testing and Materials, Philadelphia, PA, 1989, 170.Google Scholar