Naslov
Optimisation of environmentally friendly tool for geopolymer and zeolite preparation from kaolin

Autori
Bafti, Arijeta ; Rukavina, Marko ; Janković-Miloš, Lucija ; Ljubičić, Ines ; Tomić, Andrea ; Mandić, Vilko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstracts / - , 2023, 1-1

Skup
3rd YCN Workshop

Mjesto i datum
Aveiro, Portugal, 19.04.2023. - 21.04.2023

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
zeolite ; kaolin ; mechanochemical synthesis

Sažetak
Metakaolin is one of the most commonly used precursors for the geopolymer and zeolite preparation due to its high aluminosilicate content, and chemical purity. Generally, metakaolin is obtained by dehydroxylation of kaolinite structure by thermal activation. In this work, we prepared metakaolin through different activation routes, thermal and mechanochemical, respectively. Mechanochemically activated kaolinite (metakaolin) was chosen because it tends to follow the rules of green chemistry, by avoiding energy dissipation when high-temperatures are used. Geopolymers were additionally prepared using the conventional method of alkaline activation of metakaolin with sodium silicate solution. Zeolites were also prepared according to green chemistry rules and by mechanochemical activation instead of the commonly used, hydrothermal one. During the synthesis, both the water amount, and curing temperature were varied. First, the activation reactions were optimized, by monitoring the process and obtaining perfect values for most efficient parameters in terms of time, and other parameters such as temperature and milling speed. Furthermore, the correlation and difference between metakaolin prepared by two different methods were monitored. All prepared samples were thoroughly characterised. For the precursor, we monitored the degree of dihydroxylation, i.e., the degree of activation of the kaolin, or metakaolin preparation. For this purpose, we used the X-ray diffraction method (XRD) as a function of reaction time (milling or thermal activation). Following characterisation was performed using Fourier Transformed Infrared Spectroscopy (FTIR), which again allowed us to gain insight into the dihydroxylation rate and, to confirm characteristic aluminosillicate bonds present in our samples. Finally, we used Scanning Electron Microscopy to monitor microstructure of our samples, precursors and prepared geopolymes/zeolites.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Interdisciplinarne prirodne znanosti, Kemijsko inženjerstvo, Temeljne tehničke znanosti, Interdisciplinarne tehničke znanosti

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