Calcined Mullite Powder Produced from Waste Clay-Diatomite

Authors

  • Aleksandra Šaponjić ˮVinča” Institute of Nuclear Sciences National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
  • Jelena Maletaškić ˮVinča” Institute of Nuclear Sciences National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
  • Snežana Zildžović Central Laboratory for testing, Laboratory for chemical testing, Institute for Technology of Nuclear and Other Mineral Raw Materials, Franshe D’Epere 86, 11000 Belgrade, Serbia
  • Željko Radovanović Innovation Centre of the Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia
  • Maja Kuzmanović Group for biomedical engineering and nanobiotechnology, Institute of technical sciences of SASA, Knez Mihailova 35/IV, Belgrade, Serbia
  • Slađana Maslovara Institute of General and Physical Chemistry, Studentski trg 12/V, Belgrade, Serbia
  • Svetlana Ilić ˮVinča” Institute of Nuclear Sciences National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia

Abstract

Mullite powders have been fabricated using diatomite powder as Si and Al-nitrate as Al precursors, without using any additives. Samples were calcined at three temperatures (1300, 1400 and 1500 ºC) for a period of 1, 2 and 4 h. The obtained powders were analyzed using X-ray powder diffraction analysis (XRPD) PSA (Particle Size Analysis), FESEM (Field emission scanning electron microscopy) and EDXS (Energy-dispersive X-ray spectroscopy). Content of the crystalline phases with calcination temperature and dwell time was computed by X-ray powder diffraction analysis (XRPD), using POWDER CELL software. Field emission scanning electron microscopy (FESEM) images confirmed that the rod shape morphology of mullite particles, with the diameters around 500 nm, and lengths, 5 µm embedded in an amorphous matrix. XRPD of the sintered samples at 1300 ºC showed formation of thermally stabile phases (mullite, cristobalite and corundum) that makes the analyzed diatomaceous earth suitable for production of various types of construction and thermal insulating ceramic materials.

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Published

2025-12-05

Issue

Vol. 57 No. 4 (2025)

Section

Articles