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The disposal of the fly ash generated in coal based power-plants may pose a significant risk to the environment due to the possible leaching of hazardous pollutants, such as toxic metals. Also, there is a risk of leaching even when fly ash is built-in the construction composites. Fly ashes from various landfills were applied in several composite samples (mortar, concrete and brick) without any physical or thermal pre-treatment. The leachability of the potentially toxic pollutants from the fly ash based products was investigated. The leaching behavior and potential environmental impact of the 11 potentially hazardous elements was tracked: Pb, Cd, Zn, Cu, Ni, Cr, Hg, As, Ba, Sb and Se. A detailed study of physico-chemical characteristics of the fly ash, with accent on trace elements and the chemical composition investigation is included. Physico/chemical properties of fly ash were investigated by means of X-ray fluorescence, differential thermal analysis and X-ray diffraction methods. Scanning electron microscope was used in microstructural analysis. The results show that most of the elements are more easily leachable from the fly ash in comparison with the fly ash based composites. The leaching of investigated pollutants is within allowed range thus investigated fly ashes can be reused in construction materials production

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The investigation results of gas removal from smelted metal and the effect on performances of aluminium-magnesium alloy cast elements are presented in this paper. The investigated alloy is based on recycled material. The obtained results define the specific procedure which is used for removal and reduction the presence of inclusions of various types in the cast elements, which is the basic step in achieving the designed quality of cast material and quality final products. Kinetics and mechanisms of degasification process were investigated, parameters of degasification procedures were defined, and the new agents for degasification of alloy cast were implemented. The results of this investigation are significant from the aspect of sustainable development the production of cast elements of aluminium alloys.