Quality characteristics of Greek fly ashes and potential uses

Properties and microstructure of lightweight aggregate produced from lignite coal fly ash and recycled glass

“…Coal fired power stations in Greece produce approximately 10,000 kilo tonnes of fly ash (FA) per annum (Skodras et al 2007). The highest level of production is in West Macedonia in northern Greece, where approximately 7,600 kilo tonnes is produced each year.…”

“…This work has characterized FA (Filippidis and Georgakopoulos 1992;Georgakopoulos et al 1994;Sakorafa et al 1996;Fytianos et al 1998;Georgakopoulos et al 2002;Arditsoglou et al 2004;Karangelos et al 2004;Koukouzas et al 2006;Skodras et al 2007) and assessed potential applications including use in cement and concrete (Papayianni and Valiasis 1991;Kouloumbi and Batis 1992;Papayianni 1993;Kouloumbi et al 1994;Malami et al 1994 There is a limit to the amount of glass cullet that can be re-used in glass production due to contamination by impurities, and therefore there is a surplus of green cullet in Greece ( 1993;Swan et al 2001;Huang et al 2007) and glass (Ducman et al 2002). Pumice is quarried primarily from the island of Gialli and this is currently the major type of lightweight aggregate used in Greece, with an annual production of ~800,000 tonnes.…”

“…This work has characterized FA (Filippidis and Georgakopoulos 1992;Georgakopoulos et al 1994;Sakorafa et al 1996;Fytianos et al 1998;Georgakopoulos et al 2002;Arditsoglou et al 2004;Karangelos et al 2004;Koukouzas et al 2006;Skodras et al 2007) and assessed potential applications including use in cement and concrete (Papayianni and Valiasis 1991;Kouloumbi and Batis 1992;Papayianni 1993;Kouloumbi et al 1994;Malami et al 1994 FA in zeolite production (Mouhtaris et al 2003;Moutsatsou et al 2006) and road construction (TEE 1988;AUTH 1994;Mouratidis 2001;Kehagia and Tsoxos 2005) have been reported. The potential for using FA in cement production, brick manufacture and construction of road embankments in Greece has also recently been investigated (Skodras et al 2007). It was concluded that total FA utilisation in these applications would be less than 40% of the total assuming optimistic reuse levels.…”

Development of soil chemical and biological properties in the initial stages of post-mining deposition sites

“…This intensive exploitation of lignite requires the excavation of about 250 million m 3 of overlying coal layers which is deposited on spoil heaps creating a mosaic of soils structurally different due to the excavation depth layer they come from. Moreover, the total annual fly ash production, the principal by-product of the burnt lignite, is about 7.6×10 6 tones most of which (85-90 %) is being dumped to nearby areas as fly ash deposition heaps (Skodras et al 2007). …”

Assessment of the radiological impacts of utilizing coal combustion fly ash as main constituent in the production of cement

“…Potential applications for PFA are grouped into the following main categories: production of construction materials (cement production, concrete, ceramics, glass, and glass ceramics), geotechnical applications (roadbeds, road pavement, structural fill, and embankments), agriculture and miscellaneous (sorbent and sludge conditioning ;Ural 2005;Skodras et al 2007). Approximately 33% of the total PFA produced in Europe is used as cement raw materials, as main constituent in blended cements, and as addition for the production of concrete (Feuerborn 2005), while roughly 1% of the total FA produced in Turkey is being used in a variety of products such as cement, concrete, aggregate in stabilizing roadways, etc.…”