| Autor: |
Längauer D; Department of Environmental Engineering, Faculty of Mining and Geology, VŠB-Technical University of Ostrava, 17 listopadu 15, 708 33 Ostrava-Poruba, Czech Republic., Čablík V; Department of Environmental Engineering, Faculty of Mining and Geology, VŠB-Technical University of Ostrava, 17 listopadu 15, 708 33 Ostrava-Poruba, Czech Republic., Hredzák S; Institute of Geotechnics of Slovak Academy of Sciences, Watsonova 45, 040 01 Košice, Slovakia., Zubrik A; Institute of Geotechnics of Slovak Academy of Sciences, Watsonova 45, 040 01 Košice, Slovakia., Matik M; Institute of Geotechnics of Slovak Academy of Sciences, Watsonova 45, 040 01 Košice, Slovakia., Danková Z; State Geological Institute of Dionýz Štúr Bratislava, Regional Centre Košice, Jesenského 8, 040 01 Košice, Slovakia. |
| Jazyk: |
angličtina |
| Zdroj: |
Materials (Basel, Switzerland) [Materials (Basel)] 2021 Mar 07; Vol. 14 (5). Date of Electronic Publication: 2021 Mar 07. |
| DOI: |
10.3390/ma14051267 |
| Abstrakt: |
Large amounts of coal combustion products (as solid products of thermal power plants) with different chemical and physical properties cause serious environmental problems. Even though coal fly ash is a coal combustion product, it has a wide range of applications (e.g., in construction, metallurgy, chemical production, reclamation etc.). One of its potential uses is in zeolitization to obtain a higher added value of the product. The aim of this paper is to produce a material with sufficient textural properties used, for example, for environmental purposes (an adsorbent) and/or storage material. In practice, the coal fly ash (No. 1 and No. 2) from Czech power plants was firstly characterized in detail (X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), particle size measurement, and textural analysis), and then it was hydrothermally treated to synthetize zeolites. Different concentrations of NaOH, LiCl, Al 2 O 3 , and aqueous glass; different temperature effects (90-120 °C); and different process lengths (6-48 h) were studied. Furthermore, most of the experiments were supplemented with a crystallization phase that was run for 16 h at 50 °C. After qualitative product analysis (SEM-EDX, XRD, and textural analytics), quantitative XRD evaluation with an internal standard was used for zeolitization process evaluation. Sodalite (SOD), phillipsite (PHI), chabazite (CHA), faujasite-Na (FAU-Na), and faujasite-Ca (FAU-Ca) were obtained as the zeolite phases. The content of these zeolite phases ranged from 2.09 to 43.79%. The best conditions for the zeolite phase formation were as follows: 4 M NaOH, 4 mL 10% LiCl, liquid/solid ratio of 30:1, silica/alumina ratio change from 2:1 to 1:1, temperature of 120 °C, process time of 24 h, and a crystallization phase for 16 h at 50 °C. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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