The synthesis of zeolites from fly ash may be an alternative method of this waste management, which is all the more valuable as zeolites are commonly used in various fields. ![]() In the next years, the methods of synthesis were gradually developed and improved. The first attempts in this area begun already in the 1980s (Holler, Wirsching 1985). ![]() Due to the high content of aluminium and silicon, fly ash can also be a valuable raw material for the synthesis of zeolites. Expansion of the road network and highways created greater opportunities for the use of ashes in engineering and road works (Gawlicki, Wons 2012 Swamy, Das 2012 Wong et al. To a slightly lesser extent, ashes are used in the production of special ceramics or thermal insulation materials (Erol et al. (Galos, Uliasz-Bocheńczyk 2005 Giergiczny 2013 Uliasz-Bocheńczyk et al. One of the most significant recipients of fly ashes is building materials industry, where they are used as mineral additive in the production of cement, multi-component binders or concrete. Attempts of using these side products of burning in diverse ways have been made for years and are ecologically beneficial as well as economically. The separation of all useful components from the tested ashes before their further management will allow the full use of their raw material potential.įly ashes, created as a result of burning coal in power plants, have some specific properties, which that allow their various uses. The main component of irregular particles found in ashes is unburned coal and, to a lesser extent, a mineral substance. One of the valuable components of hard coal ash are microspheres, which are characterized by high variability in chemical composition, so further utilization will require prior refining. Magnetic separation of iron-rich particles may be a way to manage the researched ashes. The amorphic phase of ash from lignite coal has aluminium–silicate-calcium chemical composition, which is what determines pozzolanic and hydraulic properties of these ashes. ![]() This kind of morphology and chemical composition make these ashes a potential material for zeolites synthesis. A high proportion of spherical particles was found in bituminous coal ashes (rich in SiO 2 and Al 2O 3), which gives them high pozzolanic activity. Microscopic observations have shown that fly ashes are a heterogeneous material composed of particles occurring in three basic morphological forms: spherical, irregular and fine-detritic. Innovative research techniques were used, among others: SEM with EDS detector and Image Analysis. The aim of the research presented in this paper was to indicate the possibilities of managing fly ashes from bituminous coal and lignite based on the observation of individual particles of these ashes. The changing properties of energy waste force us to look for alternative directions of their use.
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