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Potential comprehensive solutions in order to protect environment is the synthesis of alternative mineral binders such as belite-sulfoaluminate cement clinkers, which are considered as energy and carbon reducing, allowing the substitution of natural raw materials with secondary ones. In this study, three different samples of fly ash (FA) from "Nikola Tesla" Thermal power plant (Serbia) were used in clinker synthesis with the targeted phase composition of 65 wt.% belite, 20 wt.% calcium sulfoaluminate and 5 wt.% ferrite. Fly ashes and cement clinkers were investigated in terms of physical–chemical, mineralogical and also radiological characterization. Results showed that incorporation of fly ash in raw mixture resulted in achieving the targeted phase composition of cement clinkers with satisfactory radiological properties. [ABSTRACT FROM AUTHOR]

The main goal of this study was the evaluation of physical–chemical, as well as radiological properties of residual materials used for geopolymer synthesis and those final products as a possible application as new materials in a civil engineering industry. Concentration of 40K and radionuclides from the 238U and 232Th decay series in waste precursors, their metaphases and geopolymer samples synthetized by alkali activation were determined together with corresponding absorbed dose rate ( D ˙ ) and the annual effective dose rate. Natural activity concentrations in the alkali-activated material (geopolymer) were found to be lower than that of both residual materials and calcined ones. [ABSTRACT FROM AUTHOR]

In the present work, remediation of lead-containing solution using raw and modified kaolinite has been presented. The micro and nanostructure of samples has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Laser diffraction and scattering (LDS), was analyzed by particle size analyzer based on laser diffraction and particle size distribution (PSD) was done. The degree of metal adsorption was evaluated analyzing the Pb(II) contaminated samples by inductively coupled plasma atomic emission spectrometry (micro- and nanostructure on immobilization efficiency correlCP AES). The results show the impact of immobilization efficiency and ation between micro- and nanostructure. The thermodynamic data (Δ H°, Δ S°, Δ G°) are calculated from the temperature-dependent sorption isotherms. The results suggest sorption process of Pb(II) on kaolinite as spontaneous and endothermic. [ABSTRACT FROM AUTHOR]